Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : mechanical properties


Microstructure and Mechanical Properties of ZK60 Mg Alloy Processed by Cyclic Expansion-Extrusion (CEE) at Different Temperatures

Ahmed M. Marheb; Akeel D. Subhi

Engineering and Technology Journal, 2022, Volume 40, Issue 12, Pages 1614-1620
DOI: 10.30684/etj.2022.133572.1194

In this work, the cyclic expansion extrusion (CEE) process was applied to ZK60 Mg alloy. The correlation between the evolved microstructure and mechanical properties was investigated. The CEE process was performed at a constant ram speed (15 mm/min) and at different processing temperatures (190, 270, and 350 °C). Optical and scanning electron microscopes, X-ray diffraction instruments, Vickers hardness tester, and tensile testing machine were utilized to examine the influence of CEE processing temperature on the characteristics of ZK60 Mg alloy. The XRD analysis showed that two phases were presented in the matrix of ZK60 Mg alloy, namely α-Mg and MgZn2, in small amounts. The CEE process reduced the size of α-Mg grains due to dynamic recrystallization, especially at the processing temperature of 190 °C. A slight coarsening of the α-Mg grains was observed with increasing processing temperature to 270 and 350 °C. The hardness value ​​of ZK60 Mg alloy was enhanced by about 11 to 19% using the CEE process compared to the as-extruded sample. The processing temperature greatly affected the mechanical properties, where a significant improvement of about 24% yield strength, 9% ultimate tensile strength, and 38% elongation was observed using a processing temperature of 190 °C. The characterization of the tensile fracture surface of the tested samples indicated that the ductile-brittle fracture mode was responsible for the failure.

Elevated Temperature Corrosion of Mechanical Properties and Fatigue Life of 7025 Aluminum Alloy

Mohammed H. Alwan; Hussain J. Al-Alkawi; Ghada A. Aziz

Engineering and Technology Journal, 2022, Volume 40, Issue 1, Pages 1-7
DOI: 10.30684/etj.v40i1.1587

Aluminum alloys are widely used in aircraft industry where good corrosion resistance, light weight and high strength are the primary requirements.
In the present study, attempts have been made to extend the application of mechanical and fatigue properties of AA7025 in laboratory with corrosive environment of media and combined corrosive at elevated temperature (ET) 150⁰C. The experimental results and analysis of corrosion and corrosion - elevated temperature mechanical and fatigue behavior of the samples showed that the 3.5%NaCl corrosive media and corrosion - elevated temperature (ET) greatly decrease the properties mentioned. The Ultimate Tensile Strength (UTS) and Yield stress YS of AA 7025 reduced by 5.3% and 14.83% respectively due to combine corrosion and elevated temperature but these properties reduce by 8.7% and 19.35% respectively due to combined actions corrosion (ET). The Brinell hardness also reduced by 4.2% and 11.26% due to corrosion only and corrosion and (ET). Ductility was increased by 10.5% and 16.25% for corrosion and corrosion (ET). The environment and elevated temperature – corrosion have significant effect on reduction the fatigue life and strength of AA 7025. It’s clear that the combine corrosion and (ET) combination reduce safely of the mechanical properties compared with the corrosion only and room temperature conditions.

Evaluation of the Microstructure and Mechanical Properties of Al / Fe3O4 Nanocomposites

Suaad M. Jiaad; Khansaa Salman; Ahmed A. Hussein

Engineering and Technology Journal, 2021, Volume 39, Issue 11, Pages 1632-1638
DOI: 10.30684/etj.v39i11.2080

The goal of this research is to study the microstructural analysis and mechanical properties of an aluminum matrix reinforced with different amounts of nano Fe3O4 at (2, 4, 6, 8, and 10wt. %). Al/ Fe3O4 nanocomposites specimens were prepared using the powder metallurgy route. Many examinations, including Field Emission Scanning Electron Microscopy (FESEM) and X-Ray Diffraction (XRD) analysis, were performed on the specimens in this study to determine the microstructure and phases of the nanocomposites. Mechanical tests, such as compressive, microhardness, and wear tests, were also performed to assess the mechanical properties of the nanocomposites. The results of this study show that Fe3O4 nanoparticles have been homogeneously dispersed in the Al matrix by FESEM and XRD examination. While the mechanical tests show improving the compressive strength at 6 wt.% by 5.36%, the highest microhardness was at 10% by 101.6% compared with the pure Al, and improving the wear rate.

The Influence of Ultrasonic Impact Peening on the Mechanical Properties of Similar Friction Stir Welded Joints of AA 7075-T73

Abdul Ameer H. Jebur; Samir A. Amin; Ibtihal A. Mahmood

Engineering and Technology Journal, 2021, Volume 39, Issue 9, Pages 1345-1351
DOI: 10.30684/etj.v39i9.1725

The purpose of this study is to study the ultrasonic peening influence upon the mechanical properties of the welded joints of 3 mm AA 7075-T73. Friction stir welding (FSW) was carried out by using milling machine and cylindrical tool with tapered pin. The used welding parameters were 710 rpm , 35 mm min for rotational and travel speed , respectively .Tensile tests results showed that the welding efficiency was about 60% for welded samples , and this value increased by using one and two lines ultrasonic peening treatment to 74% , and 71% , respectively , this improvement is due to generating compressive stresses along the surface of welded joints. The microhardness of the welded samples showed that there were fluctuations across the welded centerline and minimum hardness occur in the heat affected zone (HAZ).

Investigating The Effect of Magnetite (Fe3O4) Nanoparticles on Mechanical Properties of Epoxy Resin

Ehab Kaadhm; Khansaa D. Salman; Ahameed Hameed Raja

Engineering and Technology Journal, 2021, Volume 39, Issue 6, Pages 986-995
DOI: 10.30684/etj.v39i6.2063

In this paper, study the effects of magnetite nanomaterial Fe3O4 on the mechanical properties of epoxy. Dispersion of Fe3O4 nanoparticles in the epoxy resin was performed by ultrasonication. The samples of the nanocomposites were prepared using the casting method. The nanocomposites contain epoxy resins as a matrix material incorporated by different weight percentages of magnetite Fe3O4 that varies from 0wt.% to 15wt.% as a reinforcing material. The epoxy with the additive reinforcement materials Fe3O4 was slowly mixed in a sonication bath for 15 minutes, then the mixture poured into silicon molds. Field Emission Scanning Electron Microscopy FESEM and X-ray diffraction spectra XRD were used to characterize the morphological and structural properties of preparing samples and the distribution of Fe3O4 nanoparticles to the epoxy resin. Mechanical testing consists of tensile, hardness shore, and three-point flexural tests were performed on the samples at room temperature according to ASTM standards. The results showed that reinforcement by 15wt.% of Fe3O4 nanoparticles maximizes these mechanical properties of nanocomposites compared with pure epoxy except for the young modulus's preferred weight at 9 wt.%, this is due to aggregation of the additives nanomaterials in epoxy resin above 9 wt.%.

Effect of Adding TiO2on Some Mechanical Properties of Galloy

Osamah A. Khadhair; Rana A. Anaee; Kadhum M. Shabeeb

Engineering and Technology Journal, 2021, Volume 39, Issue 5A, Pages 695-702
DOI: 10.30684/etj.v39i5A.1395

Because of importance the Ga alloys in dental applications, many attempts were  done  to  improve  the  properties  of  this  alloy. The  currentwork involves  addition  of  TiO2nanotube  powder  to  Galloy  to  improve  somemechanical  properties.  These  properties  included  hardness,  compression, and creep. The characterization of prepared TiO2/Galloys with five wt% of TiO2(1, 2, 3, 4, and 5 wt%) was done by XRD and SEM/EDS. The results showed  that  the  hardness,  compression, were  increased  with  increasing percentage  of  added  TiO2,  while  creep  decrease.Some phases  such as β-Sn,  Ag2Ga  and  Ag9In4were  contributed  to  improve  the  properties  of  new TiO2/Galloycomposites.

Effect of Oil – Corrosion on Tensile and Fatigue S-N Curve Properties of AA6061-T6

Hussain J.M. Al-Alkawi; Ghgada A. Aziz; Shmoos R. Mazel

Engineering and Technology Journal, 2021, Volume 39, Issue 3A, Pages 407-414
DOI: 10.30684/etj.v39i3A.298

The present study described the effect of shot peening on mechanical properties and rotating corrosion –fatigue behavior (strength and life) of AA6061-T6. Ultimate tensile strength (UTS) and yield stress (YS) were reduced by 4.6% and 1.24% when immersing the tensile samples in crude oil for 60 days. The values of (UTS) and (YS) were raised from 307 to 316 MPa and from 248 to 254 MPa respectively when treated for 10 min. shot peening (SP). Hardness of oil corrosion samples dropped due to pitting corrosion and slightly raised for SP prior to corrosion samples. Oil corrosion reduced the fatigue strength by (-1.25%). This percentage was enhanced due to SP to 2.377%. SP significantly increased the rotating fatigue life by a factor of 1.19 and 1.3 at (UTS) and (Ys) loads respectively. (SP) technique improved corrosion-fatigue resistance due to producing compressive residual stresses at surface layers.

Influence of Microfibers Additive on the Self-healing Performance of Mass Concrete

Alaa Z. Dahesh; Farhad M. Othman; Alaa A. Abdul-hamead

Engineering and Technology Journal, 2021, Volume 39, Issue 1A, Pages 104-115
DOI: 10.30684/etj.v39i1A.1581

Because cracks are the main problem of mass concrete, this paper investigates an experimental study on the effect of polypropylene microfiber (PPMFs) on self -repair behavior of mass concrete, through study the microstructure, workability, physical, and mechanical properties of mass concrete. PPMFs with a diameter of 18 μm add in different percentages (0, 0.5, 1 and 1.5) % of cement weight. Where the prepared mixture ratio was (1:2:4.8) and the water-cement ratio (W/C) was 0.4. Also, 0.6% of Superplasticizer (SP) % of cement weight to all concrete mixtures was added. In this study, an SEM analysis used to observe the effect of PPMFs on the microstructure of mass concrete, and compressive and flexural strength tests for study the mechanical properties of this. And referring to the analysis and discussion of the results, PPMFs used have changed the microstructure of mass concrete, and have an effective effect on improving compressive strength and flexural strength, and mechanism of sealing the cracks of concrete autogenously. Also, 1% PPMFs (% of cement weight) recorded as the highest addition, which has a positive effect on mass concrete properties to apply it in the construction field.

Effect of ZrO2 Addition on Microstructure and Mechanical Properties of Al-Zn-Mg Alloy Matrix Composite

Israa A. Aziz; Russul S. Bedien

Engineering and Technology Journal, 2020, Volume 38, Issue 12, Pages 1751-1757
DOI: 10.30684/etj.v38i12A.336

Aluminum – based metal matrix composite are widely used in industrial applications compared with conventional and unreinforced alloy. The composite materials usually exhibit a higher strength both at elevated and ambient temperature, as well as wear resistance. The production of composite materials which contain different weight percentage of ZrO2 (0.5, 1.5 and 2.5wt %) by stir casting process. The mechanical properties of the base alloy and composite were evaluated by using tensile and hardness tests. The microstructure inspection by optical microscopy, scanning electron microscope and energy dispersive spectroscopy (EDS) were utilized to study the fracture surface topography. The results represent that the hardness, strength of yield and tensile strength increased with increasing the weight % of ZrO2 to 2.5 % while the elongation decreased. The microstructure inspection by optical microscope shows that the dendrites structure and the particles distribution in matrix without any voids. Furthermore, the grain size refining with the weight percentage of weight reinforcement elevated.

Effect of Filler Metals on Microstructure and Mechanical Properties of GTAW Welded Joints of Aluminum Alloy (AA2024-T3)

Muna K. Abbass; Jihad G. Abd Ul-Qader

Engineering and Technology Journal, 2020, Volume 38, Issue 8, Pages 1236-1245
DOI: 10.30684/etj.v38i8A.1277

This study presents an appropriate filler metal or welding electrode to join aluminum alloy (AA2024-T3) sheet of 3.2 mm thickness with a square butt joint using Gas Tungsten Arc Welding (GTAW) process. This process was carried out at three different welding currents with three various filler metals: ER4047 (12% Si), ER4043 (5% Si), and ER5356 (5% Mg). Experiments were conducted to investigate the microstructure and the mechanical properties. The effect of various filler metals upon the weld joints quality were analyzed via an X-ray radiographic and tensile test. Hardness test, microstructures, SEM, and XRD also conducted to the welded specimens. It was found that the best result was at 100 Ampere with using filler metal (ER5356) which produced the highest strength of 240 MPa in comparison with welded joints with utilizing fillers (ER4043) and (ER4047) having values of 235 MPa and 225 MPa, correspondingly. The hardness results showed that the highest hardness values were at the weld metal for ER4047 and ER4043, then decreased to HAZ and increased in the base metal. While in the case of ER5356, the highest hardness was in HAZ and decreased in the weld metal. The fractography of the fracture surface of the welded joints after the tensile test was analyzed using SEM

Evaluation of Mechanical Properties and Finite Element Modeling in Friction Stir Welding of C12200 Copper Alloy to C36000 High-Leaded Brass Pipe

Ahmed A. Akber; Ali A. Khleif; Abbas N. Hasein

Engineering and Technology Journal, 2020, Volume 38, Issue 8, Pages 1106-1116
DOI: 10.30684/etj.v38i8A.602

In systems transporting fluids like petrol, water, or any fluids. Copper and brass pipes are used because of the capability to resist corrosion. The copper alloys can be welded by several methods like arc, resistance, friction welding, and gas methods and they can be readily soldered and brazed. In the present study, mechanical properties and finite element modeling evaluation for friction stir welding of two dissimilar pipes (C12200 copper alloy pipe with C36000 copper alloy pipe). During this study six parameters were used where rotation speed of (775,1000,1300 and1525rpm), welding speed of 1.7 mm/min, axial force of 8.5KN, with a CW direction of rotation, and zero degree of tilt angle, using a threaded cone geometry of the tool. The results showed that the best weld quality was in case when the speed of rotation was 1525 rpm

Effect of Tin Addition on Shape Memory Effect and Mechanical Properties of Cu-Al-Ni Shape Memory Alloy

Raad S. Ahmed Adnan

Engineering and Technology Journal, 2020, Volume 38, Issue 8, Pages 1178-1186
DOI: 10.30684/etj.v38i8A.440

This study examines the effect of Sn additions on Cu-14%Al-4.5%Ni shape memory alloy. Sn was added in three different percentages (0.3,1,3) %. The alloys were mechanically tested both in compression test and micro hardness test. Also, a thermo-mechanical test was performed on the alloys. Results showed an increase in the transformation temperature outside the domain and also a better recovery strain with the increase of Sn percentage of 3% Sn addition showed the best results in mechanical properties while the 3% Sn showed a better Shape Memory Properties near to super elastic.

Study of Mechanical Properties of Carbon Steel Plate SA-516 Gr. 70 Welded by SAW Using V-Shape Joint Design

Samir A. Amin; Mohannad Y. Hanna; Abdulaziz S. Khider

Engineering and Technology Journal, 2020, Volume 38, Issue 2, Pages 152-165
DOI: 10.30684/etj.v38i2A.269

Submerged arc welding (SAW) is a fusion type welding and it is considered one of the most important welding types due to its inherent capabilities of high welding speed, high deposition rate, welding large thickness plates owing to its deep penetration characteristic and many other advantages. In this study, the goal was to investigate the effect of welding parameters, namely (welding current and welding speed) as well as the joint design on the mechanical properties (yield stress, bending force on the face of the weldment and hardness of the weld metal. Experiments were conducted employing Design of Expert (DOE) software and Response Surface Methodology (RSM) technique. The experiments were conducted by welding ASME SA-516 Gr. 70 steel plate with dimension (300 mm × 150 mm × 10 mm) depending upon the design matrix developed via the DOE. Results manifested that the optimum process parameters for maximum yield stress, maximum bending force and minimum hardness were at (425 amps) welding current and (35 cm/min) welding speed, where the arc voltage was held constant at (37 volts). The optimum values for the yield stress, bending force and hardness were (474.447 MPa, 36.997 kN and 150 HV), respectively. Finally, it was found that the predicted and experimental results of yield stress, bending force and hardness agree very well according to the ultimate error (1.05%, 1.92%, and 4.25 %), respectively.

The Effects of Anodizing Process on the Corrosion rate and Fatigue Life of Aluminum Alloy 7075-T73

Ibrahim M. AL-Sudani; Samir A. Al-Rabii; Dhafir S. Al-Fattal

Engineering and Technology Journal, 2020, Volume 38, Issue 1, Pages 34-42
DOI: 10.30684/etj.v38i1A.1594

This research aims to study the effect of using the anodizing process on the corrosion rate, mechanical properties as well as the fatigue life for aluminum alloy (7075-T73), which is one of the most commonly used aluminum alloy in production of aircrafts, vehicles and ships structures. The anodizing process was employed through using sulfuric acid for time (20) min in a salty atmosphere. The mechanical properties and fatigue life of the AA7075-T73 were obtained before and after the anodizing process. All the results were listed in detailed tables and figures for comparison purpose. Generally, these results showed a decrease in corrosion rate by (155.06%) in comparison with untreated, an increase in hardness by (21.54%) and a slight decrease in fatigue life by (7.7%) due to anodizing for a time of 20 min at the stress level of (σa = 491.10 MPa). It was concluded that this technique could be applied on other aluminum alloys in order to know the magnitude of change in the mechanical characteristics and their fatigue life.

Recycling of Sewage Sludge Ash in Polymer Structures

Mohamad Alsaadi; Aseel B. Al-Zubaidi; Mukhallad Haider; Hasanain Hashim

Engineering and Technology Journal, 2019, Volume 37, Issue 3C, Pages 311-318
DOI: 10.30684/etj.37.3C.2

In this study sewage sludge ash (SSA) particles were used as filler in the polyester resin to fabricate particulate composites with various filler contents of 0, 1, 2, 3, 4, 5, 6 and 7 wt%. The tensile, flexural, impact, hardness, chemical composition and scanning electron microscope tests wear done on the samples in accordance with ASTM standards. The results were improved at the particle content of 5 wt% for the tensile and flexural strength and then showed reducing trend with extra particle addition. Tensile and flexural modulus values of the particulate polyester composites significantly enhanced compared with the unfilled polyester composite. Energy Dispersion Spectrometry (EDS) results showed that the SSA contains elements and oxides which may increase adhesion force with polymer. In spite of the particle content of SSA that used with polymer to produce various structures for different applications was low, this study approved that using of SSA can protect the environment due to increasing the amount of SSA can affect the environment badly in addition to produce cheaper polymer composite for industrial applications.

Optimization Using Taguchi Method for Physical and Mechanical Properties of Bio Mimicking Polymeric Matrix Composite for Orthodontic Application

Jenan S. Kashan

Engineering and Technology Journal, 2019, Volume 37, Issue 5A, Pages 181-187
DOI: 10.30684/etj.37.5A.5

This work take in consideration the application of Taguchi optimization methodology in optimizing the parameters for processing (composition, compounding pressure) and their effects on the output physical (Density and true porosity) properties and mechanical(fracture strength and microhardness) properties for the Nano HA,Al2O3 fillers reinforced HDPE hybrid composite material for orthodontic application. An orthogonal array of the Taguchi approach was used to analyses the effect of the processing parameters on the physical and mechanical properties. On the other hand, the surface roughness and particle size distribution were also calculated to study their effect on the output properties. The result shows that the Taguchi approach can determine the best combination of processing parameters that can provide the optimal physical and mechanical conditions, which are the optimum values (the optimum composition was15HA/ 5Al2O3/80HDPE, and optimum compounding pressure was102 MPa.

Mechanical Properties Modeling and Optimization for Polymeric Matrix Hybrid Bio Composite for Scaffolds Application

Jenan S. Kashan; Marwan N. Arbilei

Engineering and Technology Journal, 2018, Volume 36, Issue 12A, Pages 1226-1235
DOI: 10.30684/etj.36.12A.3

TiO2 / Polypropylene composite considers very promising biomaterials in bone replacement and repair application, but mechanical properties still out of load bearing scaffolds application. In this work, two approaches were suggested to produce enhanced polymeric matrix bio composite for scaffolds application, 1st one was by using Nano TiO2 particles to produce bio composite with good mechanical properties. while the 2nd approach applied by the addition of Al2O3 Nano particles. Different processing conditions have been used like different compounding pressures, compounding temperatures, and chemical composition. This work aimed to investigate the effect of these additions and processing factors on mechanical and physical properties for the proposed composite. Linear and multiple regression modeling techniques approached, and the mathematical models have been concluded and evaluated. The optimum preparation factors have been reduced and analyzed with Taguchi method to find the best preparation criteria to prepare the best mechanical properties product. Using Nano scale TiO2 powder enhanced mechanical and physical properties, moreover the addition of Nano Al2O3 powder maximize the mechanical properties to very similar values to natural bone.

Effect of Natural Fibers on Mechanical Properties of Polymer Composites

Ruaa H. AbdulRaheem

Engineering and Technology Journal, 2018, Volume 36, Issue 10A, Pages 1059-1067
DOI: 10.30684/etj.36.10A.6

The mechanical behavior of coconut shell (CS) particulate epoxy composites was concentrated on keeping in mind the end goal to create designing materials for modern application. Minute of the support with various weight portions (5, 10, 15, 20 and 25) wt%. Epoxy and composite materials were prepared by hand lay-up molding. The physical properties are thermal conductivity while the mechanical properties were hardness, tensile properties, impact properties, and flexural strength. The resulting composites of thermal conductivity 0.1005 W∕ m.c° that is lower than pure epoxy and commonplace materials utilized for home-structures. As for the mechanical properties, composite materials with (Epoxy+25%CS) has the maximum hardness of (76.6) shore D, The ultimate tensile strength of 33.42MPa was obtained from (Epoxy+25%CS), while the elongation at fracture with addition in filler concentration of 1.50 % was obtained from (Epoxy+25%CS) is lower than other composites. The highest impact strength, fracture toughness was 80J∕m2, 12.87 MPa.m-1/2 respectively. Flexural strength & shear stress of the composite materials with addition in reinforcement content at 5wt % &10wt% (39, 40.5)Mpa & (1.95,2.03)Mpa respectively while is other composites.

Effect of High Temperature on Mechanical Properties of Rubberized Concrete Using Recycled Tire Rubber as Fine Aggregate Replacement

Wrya A. Abdullah; Mohamed R. AbdulKadir; Muhammad A. Muhammad

Engineering and Technology Journal, 2018, Volume 36, Issue 8A, Pages 906-913
DOI: 10.30684/etj.36.8A.10

Effects of various elevated heating temperatures on mechanical properties of normal concrete containing recycled tire rubber as a fine aggregate (RTRFA) has been investigated in this paper. Five different concrete mixes were prepared in the laboratory. In each mix Ordinary Portland Cement, natural coarse and fine aggregate, water and RTRFA are used with fine aggregate replacement ratios (0%, 6%, 12%, 18% and 24%) by weight. In the laboratory, 60 cylindrical specimens (100mm diameter × 200mm high) and 60 cubic specimens (150×150×150mm3) were prepared. The concrete specimens were exposed to four different heating temperatures: Control (Not heated), 200, 400, and 600°C, and tested according to British standards to observe the post-heating mechanical properties. These properties included density and mass loss, split tensile strength and compressive strength. The results showed a linear decrease in compressive strength with higher temperature degrees and percent replacement of fine aggregate by RTRFA. Moreover, the concrete’s tensile strength fluctuated as it increased at 6% of rubber replacement then linearly declined at further replacement rates. Finally, some crucial conclusions of heating rubberized concrete have been drawn.

Characterization of AA 6061–Alloy Composites Reinforced by Al2O3 Nano Particles Obtained by Stir Casting

Hussain J. AL Alkawi; Abdul J. Owaid; Batool Kadhim H.

Engineering and Technology Journal, 2018, Volume 36, Issue 7A, Pages 792-797
DOI: 10.30684/etj.36.7A.12

The aim of this work is generated a Nano materials having good mechanical properties for 6061AA-alloy.Fivewt% of Nano particles (Al2O3) (20-30nm grain size) were adoptees (1, 1.5, 2, 2.5 and 3wt% AL2O3).The Nano composites were manufactured by stir casting technique. The mechanical properties of Nano composites were obtained at room temperature and was found that the matrix hardness is improved by 35.36%, matrix ultimate by107%, yield by36.84% and ductility by 12% at 1.5wt% AL2O3.Also it was obtained that all the mechanical properties of the Nano composites are higher than that of metal matrix. The above improvements are due to less porosity, high uniform distribution and good bounding between metal matrix and Al2O3.

Investigate the Effect of Different Kinds of Discontinuous Fibers on the Mechanical Properties of Epoxy Matrix Composite Materials

Ahmed Muhammad; Ibrahim A. Atiyah; Hamza M. Kamal; Ahmed M. Al-Mukhtar

Engineering and Technology Journal, 2018, Volume 36, Issue 5A, Pages 520-522
DOI: 10.30684/etj.36.5A.7

The composite manufacturing has been a wide variety of applications. The low density, stiffness, and weight to strength ratio giving these materials significant mechanical properties in aerospace, and automotive industries. In this work, the specimens of fiber reinforced composites have been prepared by adding different percentage of two types of fibers in epoxy resins matrix. So, the aim of this study is to evaluate the effect of additives on the mechanical properties according to Standard Test Method for Tensile Properties ASTM D3039. The tensile and hardness testing show that the carbon fibers improve the hardness and tensile strength due to their higher mechanical properties. In addition, they have high strength to weight ratio as compare with polypropylene fibers.

Mechanical Properties of Al 6061/Al2O3 Nanocomposite by Stir Casting

Hussain J. Al-Alkawi; Huda A. Al-Salihi

Engineering and Technology Journal, 2018, Volume 36, Issue 3A, Pages 328-332
DOI: 10.30684/etj.36.3A.12

Present work deals with the examination of the mechanical properties of Al 6061 composites, which were successfully fabricated by stir casting technique and then reinforced by using different percentages of Al2O3 nanoparticles up to 10 wt%. The required samples were carefully prepared. Evaluation of the mechanical properties such as hardness, yield tensile stress and ultimate tensile stress were effectively obtained at various percentages of Al2O3 nanoparticles .It was found that the mechanical properties of 6061 /Al2O3 nanoparticles are critically influenced by the concentrations of the reinforced Al2O3 nanoparticle, since there was a substantial enhancement in the mechanical properties, as the fractions of Al2O3 nanoparticles increased. This improvement in the mechanical properties was attributed to the uniform distribution of reinforcement nanoparticles as well as the grain refinement of aluminum matrix with minimal porosity.

Mechanical Properties of Unsaturated Polyester Filled With Silica Fume, Glass Powder and Carbon Black

A.H. Majeed; S.Q. Ibrahim

Engineering and Technology Journal, 2017, Volume 35, Issue 6, Pages 640-647
DOI: 10.30684/etj.35.6A.12

In this study a polymer matrix composites (PMCs) have been prepared with the aid of ultrasonic wave dispersion method for mixing , using of unsaturated polyester resin with Silica Fume(SF), Glass Powder (GP)and Carbon Black (CB). Moulds were prepared by hand-made from silicon rubber according to the ASTM standard table (4). The fillers added separately with different ratios as (0%,0.5%, 1%, 1.5 %, 2%,2.5% and 3%).The results show increase the hardness and impact strength when added GP, SF, and CB to polymer matrix. Flexural strength and maximum shear stress decrease when added silica fume , but when added glass powder and carbon black led to increase flexural strength and maximum shear stress to certain percent at ( 2%, 1.5% for GP and CB respectively) then dropped when increase weight fraction of GP, CB . Compressive strength decrease when added glass powder and carbon black, while it is increase when added silica fume to polymer matrix. Wear rate decrease when increase weight fraction of carbon black but it increases when added GP and SF.

Mechanical and Physical Properties of Nano Carbon Tube with Carbon Fiber Reinforced with Polyester Resin

M. Subhi; E. S. AL-Hassani; A.B. Abdul-Hussein

Engineering and Technology Journal, 2017, Volume 35, Issue 5, Pages 465-472
DOI: 10.30684/etj.35.5A.5

In this research, study some physical and mechanical properties of polymernano composites. The polymernano composites based on unsaturated polyester resin reinforced with carbon fibers (C.F). The samples are attended by hand lay – up method. The samples constituent were polyester resin as matrix with 3% volume fraction from carbon fiber and (0.5%, 1%, 1.5%, 2 %( volume fractions of carbon nanotube. The water absorption, hardness (shore D), flexural test, impact test and toughness fracture properties are studied. Results showed that water absorption increase with addition 3% volume fraction of carbon fiber and Carbon Nanotube, the sample (polyester+3%C.F+0.5% CNTs) has lower water absorption than other samples. The hardness (shore D), flexural test, impact testand toughness fracture for the sample (polyester+3%C.F+0.5% CNTs) has higher value for Nano- composites.

Effect of B4C/Fly Ash Addition on Wear and Mechanical Properties of Al-Cu-Mg Alloy

I.A. Alkadir; L.S. Salim

Engineering and Technology Journal, 2017, Volume 35, Issue 4, Pages 301-310
DOI: 10.30684/etj.35.4A.1

This research studied the effect of adding fly ash and boron carbide (B4C) particulates reinforcement on the mechanical properties and wear resistance of Al- 4.5% Cu- 1.18% Mg matrix alloy. Stir casting method has been used to fabricate the alloy and hybrid composite samples containing 2wt% of B4C and 5, 10, 15،20 wt % fly ash. The x-ray inspection revealed the dispersion of intermetallic compounds (Al2Cu,MgO and SiO2) Also, the mechanical properties have been evaluated, the results showed an increase in the tensile and yield properties with the increase of weight percentage of fly ash content up to 15 wt%, but the elongation decreased, while the hardness increased. Wear rate examination has been concluded by using pin on disc apparatus under different loads of (5, 10, 15) N, sliding velocities (1.413, 2.827, 4.241) mm/sec, and different times of (5, 10, 15) min. The results showed decrease in wear rate at 20% fly ash composite sample when compared with other composites samples and base alloy.

Improvement the Mechanical and Physical Properties of Epoxy–Polyurethane Matrix Resin by Using Kevlar Fiber and ZnO Particles

M.R. Gharkan

Engineering and Technology Journal, 2017, Volume 35, Issue 3, Pages 261-266
DOI: 10.30684/etj.35.3A.11

This work focuses on the synthesis of hybrid polymer composite matrix materials prepared from the epoxy–Polyurethane resin (Polyprime EP) as matrix reinforced phase by using (5%, 10%, 15% and 20%) Zinc oxide particles and 5% woven roving Kevlar fiber (00-900) kind (49). Mechanical and physical tests such as tensile strength, impact strength, hardness, density, thermal conductivity, and water absorption were done. The results showed increased hardness with increasing volume fraction of ZnO for the ratios (5%, 10%, 15% and 20%). The impact strength was increased for volume fraction of zinc oxide at 15%, modulus of elasticity at 5%, thermal conductivity at 20% and density test at 10%. The stress increased at volume fraction of zinc oxide at 10% and 15%. The water absorption decreased with increasing volume fraction of ZnO additives.

Titanium-Base Nanostructure Coatings for AISI M52 Tool Steel by Gas-Phase Mix Process

F.Q. Mohammed; A. J. Haider; A.D. Thamir

Engineering and Technology Journal, 2017, Volume 35, Issue 3, Pages 182-189
DOI: 10.30684/etj.35.3A.1

Deposition of Multicomponent hard coatings (Ti-B-N-C) on the molybdenum high-speed tool steel (AISI M52) has been achieved by mixed vapor deposition technique to improve the mechanical properties of the surface. In this technique the coating materials that were supplied in the gas phase were produced from powders that vaporized by thermal energy (that is, PVD- Reactive Evaporation Process), while the reactor that used to deposit Ti-Base coatings is hot-wall chemical vapor deposition (HWCVD) system equipment. This combination results in technical and financial advantages. The structure of deposited Ti-Base hard film was characterized by XRD technique, Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray spectroscopy (EDX). Mechanical characterization of the hard films has been performed by using Vickers micro hardness tester and The Ball-on-disk wear tests. With different reactive gas flow rates that ranged from 500 to 3000Sccm(standard Cubic Centimeter per Minute), the film showed amorphous matrix with crystalline Nano fibers of Ti-B phase which led to achieve higher hardness of 2051HV and better wear resistance with relatively good COF values of 0.61 than the uncoated tools.

Effect of laser surface treatment on the some of mechanical properties of AISI 4130 steel

J.M. Taha

Engineering and Technology Journal, 2017, Volume 35, Issue 2B, Pages 85-90
DOI: 10.30684/etj.35.2B.1

In this work the surface of an alloy of AISI 4130 steel is hardened by using CW Nd:YAG laser and then study the effect of laser surface hardening on mechanical properties such as yield strength (σy), ultimate tensile strength (σu.T.S), plasticity constant (k),strain hardening coefficient (n) , also evaluate the microstructure and microhardness during the hardening of the alloy. CW Nd:YAG laser was used to scan on the surface of samples by varying the laser beam energies (500,750,1000 mj) with travel speed 500 mm/min of the work table. There are many examinations were done for laser hardened of AISI 4130 steel such as an analysis of microstructure features by using an optical microscopy and microhardness. Also tensile test is carried out for the specimens before and after laser surface treatment. The results of this investigation showed that an improvement in mechanical properties after laser surface hardening, also microhardness decreases faraway the hardened surface toward the center of the specimen. While the microstructure examination showed that the laser energy 1000 mj lead to form fine plate martensite structure more than another energies 500 and 750 mj.

Effect of SiC Particulate on Glass Fibers Reinforced Polymer Composites in Erosive Wear Environment

R.H. Abdel-Rahim; Z.F. Atya

Engineering and Technology Journal, 2017, Volume 35, Issue 2A, Pages 118-123
DOI: 10.30684/etj.2017.127321

In this study the physical property, mechanical properties and erosion wear of pure epoxy and hybrid composites were studied. Composites were prepared and investigated by Hand lay-up molding. Pure epoxy and hybrid compositions were prepared, 4% and 8% volume fractions of glass fibers as reinforcement and 4% and 8% of SiC as filler particles. The investigated physical property is density while the mechanical property was hardness. Solid particles erosion wear tests are also carried out. The experimental results showed that increased volume fraction of glass fibers to (8%) led to increase the (density). The maximum density is equal (1.661gm/cm3). Hybrid composite with (Epoxy +8%GF+8%SiC) has the maximum hardness of (82) shore D. The particle-contained water jet type experimental erosion test results that the reinforcement volume fraction as well as particles distribution and bonding has considerable effect on the wear of epoxy composites. It was found that the better resistance was for hybrid composites (Epoxy+8%GF+4%SiC) at angle 30°, erodent size 800 μm, and time 10 hour.

Study the Effect of adding Natural Rubber and Polymethyl Methacrylate to the Epoxy Resin on the Quantitative Analysis and its Mechanical Properties

S.E. Salih; W.M. Salih; M.A. Abdul hameed

Engineering and Technology Journal, 2017, Volume 35, Issue 2A, Pages 163-171
DOI: 10.30684/etj.2017.127328

From polymer blends can be obtained more useful properties compared with single polymer. In this work, polymer blend (Epoxy (EP): Natural Rubber (NR)) with different ratios of NR (0, 2, 3.5 and 5%wt) and ternary polymer blend with ratio of (Epoxy: 2%NR: 5% wt. PMMA) were prepared. The Mechanical properties were included (tensile, flexural, impact, compression) tests and analytical physical properties (FTIR, SEM) were investigated, and the results show that the elongation values, impact strength and fracture toughness for polymer blend system (Epoxy: NR) were increment with increase natural rubber ratio in the polymer blend system. Whereas fracture strength, young’s modulus, flexural strength, flexural modulus and maximum shear stress decreased. The highest values of impact strength and fracture toughness were (0.041KJ/m2) and (0.321 MPa √m) respectively for polymers blend (95% Epoxy: 5% NR). Ductile fracture in rubber modified epoxy may be produce from the elastomeric nature of rubber which is represents an energy dissipating center.

High Performance Concrete Improvement by Styrene-Butadiene Rubber Addition

Alaa Abdulhasan Atiyah; Saad B. H. Farid; Ahmed Saad Kadhim

Engineering and Technology Journal, 2016, Volume 34, Issue 12, Pages 2296-2309
DOI: 10.30684/etj.34.12A.12

In this paper, the properties of high performance concretes modified by polymer were studied. Liquid synthetic styrene-butadiene rubber (SBR) was added (5%, 10% and 15%) by weight of cement to high performance concrete (HPC) to elucidate the effect of the polymer additive to their properties.The compressive strength, splitting tensile strength, flexural strength, porosity, dry density and total water absorption were measured.Thermal conductivity, thermal diffusivity and specific heat of HPC isalso measured. In addition, SEM micrographs are compared reference and polymer modified HPC.The results show that there is an improvement in the workability for HPC after the addition of the polymer. Furthermore, the density of the set concrete was increased and both the porosity, total water absorption was decreased. Thermal conductivity, thermal diffusivity, and specific heat show improvement after polymer addition, which indicate better endurance.The SBR modified HPC, exhibits a significant improvement in splitting tensile strength and flexural strength, although it was at the expense of the compressive strength to some extent.The HPC has shown balanced microstructure before and after the addition of polymer, although they noticed improved on the ductile properties.

The Effect of Thermo-Mechanical Treatment on Mechanical Properties & Microstructure for (Cu-Al-Ni )Shape Memory Alloy

Muna Khethier Abbass; Munther Mohamed Al-Kubaisy; Raad Suhail Ahmed Adnan

Engineering and Technology Journal, 2016, Volume 34, Issue 13, Pages 2518-2526
DOI: 10.30684/etj.34.13A.14

This paper aims to study the effect of thermo mechanical treatment in different temperatures of (260 ,280& 300) ◦C on the microstructure and mechanical properties of Cu-14wt%Al-4.5wt%Ni shape memory alloy which prepared by casting method in induction furnace under argon atmosphere. Then thermo –mechanical treatment was performed upon the alloy by applying stress of 190MPa with heating upto 260◦C,280◦C,300◦C, then cooled to room temperature performingstrain recovery measurement. Many tests and inspections such as optical and SEM examinations , DSC Measurement ,XRD inspection , compression and Vickers hardness tests were investigated. The results showed that there is an increase in the transformation temperatures, shape memory limits at 300◦C .It was found that hardness increases and Young modulus decreases Also It was found that the thermo-mechanical treatment at 260 ◦C gave better properties , 2%in recovery strain , increase hardness due to the formation of martensitic phase and austenite phase in structure.

Mechanical Performance of CO2 and Autoclave Cured Date Palm Fiber Reinforced eco-mortar Composites

Maan Salman Hassan; Wahad Marwan Salih

Engineering and Technology Journal, 2016, Volume 34, Issue 14, Pages 2754-2765
DOI: 10.30684/etj.34.14A.18

Using nature waste fibers in construction industries had shown important character "environmental friendly" which paid a great interest around the world. The aim of this paper was to investigate the suitability of agriculture waste date palm fibers as lignocellulosic materials for the production of wood-cement composite, in addition to enhance their compatibility with cement using accelerated curing like carbonation or autoclave.
Three percentages of date palm fibers were used (2, 6, and 10)% by weight of cement in cement composites specimens. Compressive, flexural and direct tension strengths were examined as strength properties and X-ray diffraction (XRD) as microstructure properties. The results show that carbonation curing was the most effective curing for compressive strength property while autoclave curing leads to better performance in flexural strengths. Curing type effects on direct tension property were fluctuated. This could be attributed to the variation in cellulose fiber roles with respect to each property evaluated. X-ray diffraction confirmed that CO2-curing led to increased CaCO3 content compared with autoclaved composites.

Fine Aggregate Ratios Effect on Mechanical and Physical Properties of Pervious Concrete

Muyasser Mohammed Jomaa; Mohammed Sabah Irhayyim

Engineering and Technology Journal, 2016, Volume 34, Issue 9, Pages 246-260
DOI: 10.30684/etj.34.9A.18

The porous concrete applications and the process of production in different ways depending on the replacement of fine or coarse aggregate components of research important topics, The study dealt with production pervious concrete by depending on normal concrete by removing fine aggregate by four percentage by weight (25%, 50%, 75%, 100%), as was the work of trail mixtures of concrete for a reference mix of were depended mixture the weight [1:1.5:3] with a ratio (W/C) is equal to (0.40), which recorded the highest compressive strength of age (7) days, by the results tests show that the increased rate of removal of fine aggregate contributed to reduce the strength and density with the increase in porosity and permeability and absorption, as less density obtained is (1756.2)kg/m3 remove the fine aggregate by (100%), which gives less strength to compressive (14.28)MPa and the highest value for porosity (24.81%), as were better strength to compressive, splitting tensile, and bending are (36.77MPa, 4.28MPa, 4.4MPa), respectively to the proportion of removing fine aggregate (25%) compared to the reference mixture.

Comparative Study of Influence Post weld Aging on the Mechanical Properties of Similar Friction Stir Welded Joints for Al 2024-T3 and Al 7075-T73

Muna K. Abbass; Munthir M. radhy; Ruqaya Abdulkadhim Abbas

Engineering and Technology Journal, 2016, Volume 34, Issue 3, Pages 588-599
DOI: 10.30684/etj.34.3A.13

The aim of present study is to investigate the effect of precipitation hardening heat treatment at different aging conditions on the mechanical properties and microstructure of similar friction stir welding (FSW) joints ofAA 2024-T3 and AA 7075-T73 aluminum alloys. Friction stir welding was carried out using milling machine with best welding parameters (tool rotation speed 898 rpm, welding speed 45 mm ̸ min and threaded cylindrical pin geometry). Tensile test, microhardness test,microstructure examination,and X-ray radiographic inspection of FSW joints were made.The results indicated that the best aging conditions for similar welded joints of Al2024 and Al 7075 were in sample (natural aging for two week) and sample
(artificial ageing at 120°C for 24 h) respectively. ‏Microhardness in the as-welded samples showed fluctuations across the weld zone and minimum hardnessoccurs in the heat affected zone(HAZ) in both alloys while the hardness after heat treatment at best aging conditions was improved across the whole weldment and increased in stir zone,

Effect of Applied of Pre-Stresses on Corrosion Behavior of 304 Stainless Steel in 1N H2SO4

Sami Ibrahim Jafar; Israa Abud Alkadir; Samah Abdul Kareem Khashin

Engineering and Technology Journal, 2016, Volume 34, Issue 3, Pages 600-612
DOI: 10.30684/etj.34.3A.14

This research is devoted to study the effect of applying different pre-tensile stresses (255,305,355,405,455,505 555 and 605) MPa on the microstructure, hardness and corrosion behavior of 304 stainless steel in 1N H2SO4. The stress-strain curve was drawn for standard (304) stainless steel in laboratory environment. The curve was divided into three zones. At zone one the values of elastic pre-stresses vary between (σ0 - σpro.) MPa. The results showed; that the corrosion rate was very little increased compared with that of as received (304) stainless steel. The microstructure presented undeformed austenitic grains and the hardness value was (157.433) Hv. At zone two the value of plastic pre-stress varies between (σpro.- σ U.T.S) MPa. The corrosion rate increases after applying pre-stress between (σ255 - σ 455) MPa. The microstructure showed that the austenitic grains begin to deform in the direction of applied pre-stresses. The maximum hardness at this region was (229.2) Hv, but at higher pre-stress (σ455 – σ 605) MPa, the corrosion rate decreases. The microstructure inspection shows the deformed austenitic grain and ά-martensitic phase needle are appeared inside austenitic grains and the hardness reached the maximum value (332.433) Hv. At zone three the values of pre-stresses are between (σ605 - σf) MPa. The results showed that the corrosion rate increases. The investigation of microstructure showed that there are distortion in austenitic grains and ά- martensite phase observed inside austenitic grains. The hardness reached the maximum value at (354.3) Hv. The necking of gauge length of specimens occurs in specimens and this leads to deterioration in original properties

Effect of Hydrocarbon Solutions on Polymer Concrete

Sanaa Abdul Hadi; Mustafa Hassan Omar

Engineering and Technology Journal, 2016, Volume 34, Issue 2, Pages 234-242
DOI: 10.30684/etj.34.2B.6

The damaging effect of oil products on concrete besides the high permeability of concretehave made researchers try to improve the properties of concrete exposed to oil products, hence improving the durability and serviceability of oil concrete structures.
Polymer concrete exposed to oil products is one of a new field that deals with the enhancement of concrete durability. In the present work polyester resin concrete was used and then immersed in different types of oil exposure liquids (gasoline, gas oil and kerosene) compared with reference concrete which left in the air.
Polyester resin concrete is used as a new type in this field, it is noteworthy that the use of this concrete gives good test results that raise the values of the mechanical properties, so we did the SEM test in an attempt to study the microstructure of this concrete after soaking for 90 days in oil products.

The Effect of Ferrite Content on the Thermomechanical and Dielectric Strength Properties of Epoxy Composite

Lamees S. Faiq; Zahraa F. Attiyah

Engineering and Technology Journal, 2016, Volume 34, Issue 1, Pages 186-192
DOI: 10.30684/etj.34.1A.16

Different concentrations of cadmium ferrite (2%, 5%, 8%, 10% and 15%) were incorporated into epoxy resin. Cadmium ferrite was prepared by conventional ceramic technique. Composites are prepared by mixing the ferrite with epoxy by hand lay - up method at different percentages. The effect of ferrite content on tensile strength, hardness, thermal properties such thermal conductivity, thermal diffusivity and specific heat beside the dielectric strength were investigated. Using ferrite powders as filler to form particulate composite could lead to composite properties improvement. All the measured properties were improved with the increasing of the filler content. The results showed the important role of perfect adhesion between the filler and the polymer on the composite properties. It is found that the uniform distribution of filler particles in all directions of composite leads to the improved properties.

Effect of Plasma Peening on Mechanical Properties and Fatigue life of AL-Alloys 6061-T6

Hussain J.M AL-Alkawi; Dhafir Sadik Al-Fattal; Ahmed Adnan AL-Qaisy

Engineering and Technology Journal, 2015, Volume 33, Issue 7A, Pages 1667-1679
DOI: 10.30684/etj.33.7A.9

An Investigation of estimated Mechanical Properties of AL-Alloys 6061-T6, which is one of the most commonly used in industrial applications, has been established experimentally. A new novel Plasma Peening techniques had been applied to the whole surfaces of the material by CNC-Plasma machine for 48 specimens, and then a new investigation were takeover to figure the amount of change in mechanical properties and estimated fatigue life. It was found that the improvement was showing a nonlinear behavior, according to peening duration time, speed, peening distance, peening number, and amount of effected power on the depth of the material thickness. The major improvement was at medium speed long duration time normal peening distance. Which shows up to 4 times improvements than the other cases. It was found that reducing in elongation of about 25% from references for 1x plasma peening for the most techniques used while a reduction in elongation of 31% for the two time plasma peening, on the other hand increment of 10% in elongation for 2x plasma peening and 5% of the increment for peening with 5kW of plasma power. These results illustrated in both tables and figures. Further study may established for other AL-Alloys to study the effects of plasma peening on it and to find the most effected one of them for the completely nine AL family.

The Effect of Rolling and Heat Treatment on Mechanical Behavior of 6061 Aluminum Alloy

Ruaaabd al Kaream Salman

Engineering and Technology Journal, 2015, Volume 33, Issue A6, Pages 1389-1398
DOI: 10.30684/etj.33.6A.9

In this study, the influence of bothheat treatment and cold working (rolling) on the tensile properties andhardness of6061 aluminum alloy sheets was investigated. The solution heat treatment is first performed at about 520°C 1 hr followed by rolling to(40% and 60%). Artificial aging is obtained by heating to about 180 °C for 1/2hr and 2 hr.Theexperimental work has revealed that when two strengthening mechanism(cold work and aging)are combined, the values of the mechanical properties are come up.Increasing the aging time from ½ hrto 2hr with redaction in area was causing increase in the values of the strength and hardness and dropping the elongation. In the other hand, increasing the redaction in area from (40%) to (60%) with aging was rising the value of the strength and hardness and dropping the elongation. The changes in mechanical properties were discussed as a result of increasing the dislocation density(result of rolling) and formation of precipitation(effect of aging) which are interface with the motion of dislocation and causes hindering of dislocation.

Investigation of Tensile and Impact of Composite Materials Reinforced with Natural Materials

Alaa Abd Mohammed

Engineering and Technology Journal, 2015, Volume 33, Issue A4, Pages 919-933
DOI: 10.30684/etj.33.4A.14

This work focuses on studying the effect of Data Seeds (DS) and Olive Seeds (OS) particles on tensile and impact properties of epoxy resin. Olive and dates seeds powder were added to epoxy matrix at weight fraction (0, 8, 13, &18 wt %) with grain size (300, 450 & 600µm). The composite specimens were prepared by Hand-Lay-up technique and cut according to standard test. It's found the higher value of modulus of elasticity and tensile strength happened at (=18 wt %) and grain size (300µm) for specimens reinforced with olive seeds powder, but obtained the lower percentage of elongation at break, impact strength and fracture toughness at this value. Also the mathematical model results show that the weight fraction of powder have higher effect than grain size on properties.

Effect of Plastic Optical Fiber on Some Properties of Translucent Concrete

Shakir Ahmed Salih; Hasan Hamodi Joni; Safaa Adnan Mohamed

Engineering and Technology Journal, 2014, Volume 32, Issue 12, Pages 2846-2861
DOI: 10.30684/etj.32.12A.1

Translucent concrete is a building material with light-transmitting properties, due to embedded light optical elements in its mixture; and has the advantage of energy saving in addition to providing nice view to a building. The present study investigated the use and properties of translucent concrete mixture as a construction material with light admittance. The work includes two parts: in the first part many trail mixes are designed and tested to produce self-compact mortar (SCM).Then the obtained mixture is used to prepare a new type of translucent composites with plastic optical fibers POF embedded in the SCM mixture. The second part investigates some of the mechanical properties of translucent concrete by using three concentration of (POF) and three different diameters. The tested results indicate that it is possible to use SCM to produce translucent concrete contain plastic optical fiber (POF) with compressive strength between 31.1 to 40.4 MPa and flexural strength between 5.89 to 8.12MPa for different POF volume fraction content and diameter size at 28 days age.

Effect of Surface Roughness and Shot Peening Treatments on The Mechanical Properties of Aluminum Alloy 2024 – T4

Alalkawi H. J. M; Ameer Tofan Shafiq; Mohammed khalouk al-azzawi

Engineering and Technology Journal, 2014, Volume 32, Issue 10, Pages 2386-2393
DOI: 10.30684/etj.32.10A.6

The objective of the present paper is to investigate the effect of surface roughness on mechanical properties of aluminum alloy 2024-T4. This paper describes the effect of surface roughness at values of ( 0.1 , 3.5 , 8 ) μm on hardness and yield strength and also estimate the effect of shot peening on the yield strength at period time of ( 5 , 10 , 15 , 20 , 25 ) min. The obtained results show that the low roughness improved the mechanical properties by 15.7% and also the low roughness is better than the shot peening treatments by 5.3% because the low roughness make surface more coherent. Empirical equations are formulated based on the experimental results to evaluate the yield strength with the surface roughness and the hardness.

Sy= 394.3 ( Ra + 1.35 ) -0.1356
Sy = 1 / 2.2227(10)-2 - 1.32(10)-4 HV

Study the Effect of Surface and Internal Heat Treatment on Mechanical Properties of C40 Steel Alloy

lamyaa kalel; Ahlam Abd Alamer Al khafaji; Sabah N. Mahmood

Engineering and Technology Journal, 2014, Volume 32, Issue 4, Pages 922-931
DOI: 10.30684/etj.32.4A.9

The research aims to study the effect of quenching, tempering and laser surface treatment on the mechanical properties of C40 steel. The steel specimens were heated to a temperature of 860°C, soaked for 60 minutes and quenched in oil and then tempered at different temperatures (100,200,300,400,500,600,700) °C.
Laser hardening were carried out by using Nd: YAG laser with different pulses up to 5 pulses, the applied laser energy was 500 mJ.
The mechanical tests such as: impact test and microhardness, were carried out for the specimens before and after heat treatment. Microstructure evaluation was carried out using computerized optical microscope. The results showed an improvement in the internal and surface properties of the metal.

A modeling comparison studies for thermo-mechanical and other Properties of RHDPE and RLDPE Wastes

Falak O. Abas; Raghad U.Abass; Mohammed O.Abass

Engineering and Technology Journal, 2014, Volume 32, Issue 3, Pages 681-701
DOI: 10.30684/etj.32.3A.10

A recycled waste plastic (recycled high density poly ethylene RHDPE and recycled low density poly ethylene RLDPE) are exposed to environmental conditions during the usage for many years ago. Also the chemical contaminants in the internal composition had effects on the thermo-mechanical and other properties for these wastes.
Then weathering effect data are examine for both locally and international wastes on their thermo-mechanical and chemical properties such as (Tensile strength, modulus, elongation, impact and permeability) respectively.
Afterward different mathematical software models are applied to analysis these weathering – properties data in order to estimate the more effective properties that changed by these weathering conditions such as (concentration of contaminant, time, temperature, thickness of specimen, length of spectra, basic property).
The results shows that a multi-polynomial model has a best fit for most or several of properties to active weathering variables, also gave a vary residual and deviation than experimental analyzed data for both sources of wastes local and international RHDPE and RLDPE. Also results of thermo-mechanical and chemical properties prove that both tensile strength and modulus of elasticity thermo-mechanical properties and permeability / length of spectra chemical property were given a high quality of correction and fitting factor from 93-99 %, with less deviation and residual function was produced. And analyzed weathering properties of RHDPE gave a best fit than RLDPE; all of them fitted the mathematical software model below:

…(1)

Where:
a, b, c …J = coefficient of the best fit model.
x1 = concentration of contaminants.
x2 = time of aging.

Mechanical, Thermal and Wear Characteristics of Polymer Composite Material Reinforced with Calcium Carbonate Powder

Aseel B. Al-Zubaidi; Ahmed A. Al-Tabbakh; HanaaA. Al-Qaessy; Ragad N. Al-Kaseey

Engineering and Technology Journal, 2014, Volume 32, Issue 3, Pages 519-532
DOI: 10.30684/etj.32.3B.13

Quick mast–105 is a well-known epoxy-based adhesive used in fabric reinforcement, bonding of wooden parts and variety of metals. Its mechanical and thermal properties are still limiting factors for extended technological and industrial applications. Enhancement of mechanical, wear and thermal characteristics of this epoxy resin using a cheap filler of CaCO3powder is the focus of the present study. The mechanical properties are demonstrated in terms of the flexural modulus, hardness and impact strength of the reinforced cured compound while thermal properties are presented through thermo gravimetric analysis and thermal conductivity coefficient. Results show that addition of 15% by weight of CaCO3 to the epoxy resin improves the mechanical properties and the thermal resistance of the end product paving the way for wider applications in industry and technology. Wear characteristics show that the reinforced product is suitable for high-speed applications.

Study Fatigue Behavior of Friction Stir Welded Joints for Dissimilar Aluminum Alloys (2024 -T3 and 7020 -T6)

Muna K. Abbass; Ali H. Ataiwi; Ahmed Ameed

Engineering and Technology Journal, 2014, Volume 32, Issue 2, Pages 439-452
DOI: 10.30684/etj.32.2A.11

The aim of the present work is to investigate the fatigue behavior of friction stir welded joints for dissimilar aluminum alloys (2024 -T3 and 7020-T6). Friction stir welding (FSW) had been done for 6.6 mm thick plate by using NC milling machine with R18 tool steel of 18mm with shoulder diameter and 6mm pin diameter with different tool designs; threaded cone with double bevel, threaded cylinder with concave shoulder of 4°, and beveled cone with concave shoulder of 4°. FSW were carried out under various welding parameters, travel speed of 40, 50, 75 mm/min, rotation speed range (275-1250) rpm and tilt angle of (Ɵ = 3°) with counterclockwise revolution.
Many non- destructive inspections and mechanical tests were performed to evaluate welded joints to determine the best welding parameters. Fatigue test has been done at constant stress amplitude cantilever with stress ratio of (R= -1). The results showed that maximum tensile strength and joint efficiency were 360MPa and 86% respectively for dissimilar joints which were welded at 40mm/min travel speed and 550 rpm rotation speed by using threaded cone with double bevels.

Effect of Particle Size on the Physical and Mechanical Properties of Nano HA/HDPE Bio-Composite for Synthetic Bone Substitute

Jenan Sattar Kashan; Jafar.T.Al-Haidary; Amin D.Thamir

Engineering and Technology Journal, 2014, Volume 32, Issue 2, Pages 286-297
DOI: 10.30684/etj.32.2A.1

The effect of using nano particle size of Hydroxyabatite to produce HA/HDPE biocomposite
by Hot Pressing technique was studied by investigating the effect of particle
size and production technique on the physical and mechanical properties of the biocomposite
at different volume fraction of nano HA powder and different compression
pressures.
Nano particle size and Hot Compression technique had great impact on the properties
by reversing the behavior of the bio composite comparing with that using micro scale
particle size in some of previous studies .The fracture strength and hardness increased
with increasing the filler content by more than 200% for strength and 300-400% for
micro hardness values , the densities increased with increasing filler content
compressing pressure where as the porosity decreased.
The modification in mechanical properties due to filler particle size and production
process enhanced the osteo- conductivity of biomaterial to use in different bone substitute
applications.

To Study the Effect of Fillers on the Glass Fiber Reinforced Composites

Rafah A.Nasif

Engineering and Technology Journal, 2014, Volume 32, Issue 1, Pages 47-53
DOI: 10.30684/etj.32.1B.7

This study was carried out to investigated the effect of ceramic fillers (aluminum oxide Al2O3 and titania TiO2 ) and industrial wastes (red mud and copper slag) with weight fraction (10% wt)on the mechanical properties of composite material consist of epoxy reinforced with glass fiber with weight fraction (40/50)%wt .Some tests are carried out like: impact strength, tensile strength and harness and results have been compared with composite material reinforced only with glass fiber (50/50)%wt . The results show that the composite reinforced with TiO2 had higher value of impact strength and lowest value of tensile strength compared with other composites, while composite material reinforced only with glass fiber had higher value of tensile strength. Also, it can be seen that all hybrid composites have hardness values higher than that of composite material reinforced only with glass fiber and the highest hardness value was for the composites material reinforced with Al2O3.

Influence of Ceramic Particles Reinforcement on some Mechanical Properties of AA 6061 Aluminium Alloy

Jameel Habeeb Ghazi

Engineering and Technology Journal, 2013, Volume 31, Issue 14, Pages 2611-2618
DOI: 10.30684/etj.31.14A.2

This paper is to investigate the influence of adding 5,10 and 15 weight percentage
silicon carbide particles on some mechanical properties of 6061 Aluminium alloy.
The composites Al6061/SiC were prepared by stir casting technique.
The results revealed that as the reinforcement content was increased, there were
significant increases in the ultimate tensile strength, yield strength and hardness of
composites accompanied by a reduction in its percentage of elongation.
Microstructural studies have been carried out to understand the nature of structure.

A Comparison Study of Mechanical Properties between Friction StirWelding and TIG Welded Joints of Aluminum Alloy (Al 6061-T6)

Muna Khethier Abbass; Hassan Hady Abd

Engineering and Technology Journal, 2013, Volume 31, Issue 14, Pages 2701-2715
DOI: 10.30684/etj.31.14A.9

In this study two different welding processes have been considered, a
conventional tungsten inert gas (TIG) and a relatively new solid state welding
known as friction stir welding (FSW). TIG welding process has been performed on
Al 6061-T6 of thickness 4mm by using filler metal of Al-Mg alloy type (ER5356)
according to AWS classification metal with tungsten electrode (EWth-2) and arc
voltage of (12V). Various welding currents of (125, 160, 200, 225) Amp were used
under argon as shielding gas of flow rate of (15-20 cf / hour) and welding speed of
280 mm/min.
Friction stir welding is carried out using automatic milling machine with five
different welding or bed speeds of (25-50-80-100-125 mm/min) and five different
tool rotation speeds of (630-800-1000-1250-1600 rpm). Tool steel of type R18
consists of a shoulder with diameter of (20 mm) and pin of diameter (5.5 mm). Xray
radiographic inspection, tensile test and microhardness test of FSW and TIG
joints at optimum welding conditions were made.
The results indicate that the best tensile strength of FSW joints is 289 MPa and
joint efficiency is 79% which were welded with welding parameters of (1250 rpm,
800 rpm and 50 mm/min, 125 mm/min) respectively. While in case of TIG joint the
best tensile strength is 210 MPa and joint efficiency is 57%.
It was found that the microhardness hardness values in the TIG welded joints
are lower than that of the FSW joints. The formation of fine equiaxed grains and
very fine strengthening precipitates (Mg₂Si) in the stir or weld region are the
reasons for higher tensile strength and hardness of FSW joints compared to TIG
joints.

Mechanical and Morphological Properties of HDPE: PP and LDPE: PP Polymer Blend Composites Reinforced with TiO2 particles

Sihama I. Salih; Abdullkhaliq F.hamood; Alyaa H. Abdalsalam

Engineering and Technology Journal, 2013, Volume 31, Issue 12, Pages 2211-2227
DOI: 10.30684/etj.31.12A.1

In this research two groups of polymer blends have been prepared First group included (High density polyethylene (HDPE): Polypropylene (PP))While the Second group(included Low density polyethylene (LDPE): Polypropylene (PP)) both groups prepared withpolypropylene of (20% and 80%). From the results of tensile test for the prepared blends it has been showed that the optimum blending ratio was (20%LDPE:80%PP and 20%HDPE:80%PP) which thenreinforced with (2, 5 and 8wt%) oftitanium dioxide (TiO2), particle size (0.421μm). Titaniaparticles were
mechanically mixed with the polymers prior tomelt mixing for better dispersion.
Polymerblend composites were obtained by using single screw extruder. Results showed that mechanical properties increased as titania content increased except elongation.Furthermore the result recorded highest values ofimpact strength and fracture toughness at2%wt TiO2which is 312 Mpa and 572.8Mparespectively,for the polymer blend (20%HDPE: 80%PP) composite and for the polymer blend (20%LDPE: 80%PP) composites the impact strength and fracture toughness are 262.5Mpa and 468 Mpa respectively.The mechanical properties values of 20%HDPE: 80%PP is higher than 20%LDPE: 80%PP polymer blendcomposites. Scanning
electron microscopy (SEM) imagesshowed that there isbonding developed between TiO2 and polymer blends in some regions.

Study the Effect of Glass Fibers on Mechanical Properties of Epoxy Composites

Raghad Hussein Mohammed

Engineering and Technology Journal, 2013, Volume 31, Issue 5, Pages 653-659
DOI: 10.30684/etj.31.5B.9

The tensile behavior, flexural strength and impact strength were studied in this research for some epoxy composites. First, epoxy composite reinforced with carbon fibers (chopped), secondly,hybrid epoxy composite reinforced with carbon fibers (chopped) and glass fibers (woven roven) with volumefraction(30) % for each type.The tests were done at room temperature (34±2 ºC). In this work the hybrid composite (C+G/Epoxy) have the higher mechanical properties than that composite (C/Epoxy).The results shown that the exists of woven glass fiber increasing the tensile behavior, flexural strength and impact strength of hybrid composite in comparison with the composite reinforced with randomly chopped carbon fibers.

Influence of Gamma Radiation at Low Dose on some of Mechanical Properties of (HDPE/HIPS) Blends

Liqaa A.Ameer Hameed; Bushra Hosni Musa

Engineering and Technology Journal, 2013, Volume 31, Issue 5, Pages 621-632
DOI: 10.30684/etj.31.5B.6

To solve different problems related to the radiation stability of polymeric articles and purposeful radiation-induced modifications of polymeric materials, the effect of low dose of gamma irradiation on some mechanical properties, at room temperature and in the presence of oxygen, on blends of high density polyethylene (HDPE) and high impact polystyrene (HIPS) has been studied.
Thermal – mechanical mixing was used to prepare binary polymeric blends from (HDPE / HIPS) with different compositional ratios, i.e. (100/0, 90/10, 80/20) using single screw extruder. The exposure of these blends to dose of Cs-137 gamma radiation at 0.2 kGy improves the mechanical properties. Scanning electron microscopy (SEM) has been used to investigate the effect of gamma irradiation on the surface morphology of the polymer material. It is noticed that after the radiation treatment; tensile strength, modulus of elasticity and hardness of used (HDPE/HIPS) at all blends ratio have been increased due to partial cross linking.