Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Mechanical properties

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

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.

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

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.

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

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.

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

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 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 7, Pages 1667-1679

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.

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

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.

A Study of Mechanical Properties of Polymethl Methacrylate Polymer Reinforced by Silica Particles (Sio2)

Jawad Kadhim Oleiwi; Farhad Mohammad O.Kushnaw; Israa Faisal qhaze

Engineering and Technology Journal, 2013, Volume 31, Issue 15, Pages 2925-2940

In this research the mechanical properties of PMMA polymer reinforced by
ceramic particles (silica) has been investigated. Many tests are performed on these
composites. The effects of the particles size and volume fraction on the mechanical
properties which include: ultimate tensile strength, elongation percentage, modulus
of elasticity, bending modulus, flexural strength, max. shear stress, impact strength
and fracture toughness were studied.
Statistical and mathematical analyses were used to the processing of the
experimental data. Mathematical models were done which show the mechanical
properties of composite materials as a function of particles size and volume
The results had revealed that the values of modulus of elasticity, elongation
percentage, tensile strength, bending modulus and max. shear stress increase with
the addition of SiO2 particles and with the increase of the volume fraction of them
and its reach the maximum value at (12% vol.) and (25 mm) particles size. The
values of fracture toughness and impact energy decrease with increase of volume
fraction. Silica particles with small particles size improved these properties more
than that of large particles size.

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

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.

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

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.

Creep Behavior in Fiber-Reinforced Epoxy (DGEBA) Composites

Lubna Ghalib

Engineering and Technology Journal, 2013, Volume 31, Issue Issue1A [Engineering], Pages 12-25
DOI: 10.30684/etj.2013.71192

The composite material was prepared by reinforcing the epoxy with E-glass fiber. The creep and flextural test were measured in this work for one and two layer of E-glass fiber with volume fraction rate of (10%, 20%, 30%, and 40%) in orientation of (0-90o) immersed in epoxy (DGEBA) resin with total thickness of 4mm. The tests were done at different temperature levels from (25 to 55)Co for creep test. The results had revaluated showing that the creeping properties of this composite materials will be improved with increasing the volume fraction layer of fiber at different temperature levels with constant stress. Creeping increases when the temperature increases and decreases with increasing of the number of layers and volume fraction of fiber. The creep constant increases with increasing the temperature up to 45Co then the creep constant down. The creeping energy of epoxy E-glass (epoxy composite) increases with increasing the volume fraction rate of E-glass fiber.

Mechanical, Electrical and Thermal Properties of Polypropylene and Polycarbonate Blend Filled with Carbon Black

Fadhil Abbas Hummdai

Engineering and Technology Journal, 2012, Volume 30, Issue 12, Pages 2076-2086

In this work a composite materials were prepared containing matrix of polymer blend (polypropylene 80% + polycarbonate 20%) reinforced by (carbon black) with different of weight fraction %. The specimen sheet, were obtained by hotcompression from extruded material, using single extruder operated at a temperature between (190-200)Co. The extrusion processes give homogeneous mixer through a regular selection of machine screw revolution per minute and temperature used in extrusion process. The weight fraction of the carbon blacks ranged from 0.0 up to 20 wt % with the polypropylene and polycarbonate blend. All samples related to, mechanical, thermal and electrical tests were prepared by single –extruder. By discharging a high voltage through the composite it was found that the resistivity of the composite decreased from (1.00E+09)-(1.00E+028). Carbon black–polypropylene and polycarbonate composites show significant differences from the neat blends measured in the frequency range. The study of physical test show that the thermal conductivity decreases with the increase of weight fraction
from (0.157-0.23).

Mechanical Properties of Polymer-, Pozzolanic Cement- Based Repairing Materials

Qais J. Frayyeh; Maan S. Hassan; Tahseen D. Saadoon

Engineering and Technology Journal, 2012, Volume 30, Issue 7, Pages 1211-1221

In this study, the mechanical properties of five different cement based repairing materials were evaluated. These materials were classified into two groups: laboratory made materials with or without admixtures (3 types), and other two types of commercial proprietary pre-packaged with additives. Mechanical properties, such as compressive strength, modulus of rupture and drying shrinkage were studied. Results show that these mechanical properties were varying significantly from each other. The drying shrinkage of the commercial proprietary repair materials
was less than that of the conventional mortar. This will lead to a reduced cracking risk in the former repair materials compared to the latter. Through the regression analysis on the experimental data collected, power relation with coefficient of determination of 0.766 is obtained between compressive and modulus of rupture.

Analysis the Effects of Shot Peening Upon the Mechanical and Fatigue Properties of 2024-T351 Al-Alloy

Alalkawi H. J. M; Talal Abed-Aljabar; Safaa H. Alokaidi

Engineering and Technology Journal, 2012, Volume 30, Issue 1, Pages 1-12

This paper presents an experimental study on the effect of shot peening on
mechanical properties and residual stresses of 2024-T351 Aluminum alloy. Under the
effects of shot peening time SPT the results show that the existence of SPT can
improve the mechanical properties and fatigue life up to a limit value of SPT. The 15
minutes SPT gave the highest value of (σu, σy) which is about 6.7 % for (σu) and 11.7
% for (σy). Empirical equations were proposed to evaluate the SPT with the
endurance limit stress and the residual stresses.

Effect of Laser Surface Treatment on Mechanical Properties of CK45 Steel

Sabah N. mahmood; Khansaa Dawood Selman

Engineering and Technology Journal, 2011, Volume 29, Issue 8, Pages 1610-1618

The research aims to study the effect of laser surface treatment on mechanical properties of CK45 steel which is widely used in Bolts, Axles Various,Connecting Rods and Hydraulic clamps. Trails of laser hardening were carried out by using CW Nd: YAG laser with different powers 2.7, 3.3, and 4.3 Watt. Mechanical tests were done for the specimens who were used in the research before and after treated by laser such as: Tensile test, Micro hardness. Also grain size measurement and microstructural evaluation were done by using
computerized optical microscope. The results show that improvement in
mechanical properties at laser power 4.3 watt obviously when compared with other laser powers. From tensile test we show that increasing in yield strength, ultimate tensile strength Poisson's ratio and plasticity constant (k). Also decreasing in Young modulus, Rigidity of modulus and strain hardening coefficient (n). While microhardness results show that the highest value was obtained at laser with 4.3
watt power and decreased far from the surface. Metallographic of the specimen show that refining in grains size after the treatment with laser.

One Parameter Composite Semigroups of Linear Bounded Operators in Strong Operator Topology of Schatten Class Cp

Samir Kasim Hassan; Al-Taie M; Al-Malki Anam; Al-Attar Abeer; Mustafa Khaleel Ismael; Fatema Ahmed Sadeq; Radhi A .Zboon; Jehad R.Kider; Samir K .Hassan; Hussain J. M. Alalkawi; Raad H. Majid; Rawaa A. Alomairy; Luma Abdul Ghani Zghair; Hadia Kadhim J.Al-Ogili; Assifa M. Mohamad; Abbas Sheyaa Alwan; Haider L. Aneed; Assim H Yousif; Salema Sultan Salman; Abbas Hussien Miry; Abduladhem A.Ali; Mohammed Zeki Al-Faiz; Sabah N. mahmood; Khansaa Dawood Selman; Shaymaa Tareq Kadhim

Engineering and Technology Journal, 2011, Volume 29, Issue 8, Pages 1463-1470

For semigroups of linear bounded operators on Hilbert spaces, the problem of
being in Cp , 0 Keywords

Effect of Addition Of Copper and Copper –Nickel Elements on Structure and Properties of Low Carbon Steels

Munthir Mohammed Radhy

Engineering and Technology Journal, 2010, Volume 28, Issue 23, Pages 6688-6702

The purpose of this study is to investigate the effect of adding different amounts
(2, 4, 6% of Cu) on properties and microstructure of low carbon steel .Also study
the effect of the same amounts of Cu with half amount of Ni(1,2,3%Ni) are added
on properties of low carbon steels. All these alloys(Fe-Cu,Fe-Cu-Ni) appear an
increase of hardness and strength with increase of the amount of Cu or Cu-Ni. The
microstructure obtained after heat treated(quenched and aging) of Fe-Cu and Fe-
Cu-Ni alloys has been studied by optical microscopy, investigated by X-ray
diffraction and hardness measurement. The microstructures obtained after
quenching depending on composition and cooling rate, the massive ferrite and
massive martensite appears on most of structures in above alloys. The
microstructure after aging of above alloys shown some of precipitates appear as
dash plates, rod and spheres in ferrite or martensite structure and this precipitates
appear as X-ray diffraction were identified the copper rich phase €.