Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Aluminum

Modification of Prepared (Al 2024/Alumina/Mn) Composite by Laser Surface SiC Clad Layer

Marwa H. Juber; Amer H. Majeed; Mohammed S. Hamza; Thair A. Tawfiq

Engineering and Technology Journal, 2019, Volume 37, Issue 6A, Pages 201-206
DOI: 10.30684/etj.37.6A.3

The present work shows the cladding process of silicon carbide on the substrate of prepared composite (Al 2024/Alumina/Mn) by using a laser beam (pulsed Nd-YAG). To obtain the desired results, the best laser parameters were chosen. The parameters of the laser beam that have chief affected during the experiments in this work are peak power (1.9)kW, work frequency (8)Hz and pulse duration (5.3)ms, the preplaced powder technique favorite during a cladding process and the results in this work were proved by SEM, micro-hardness, EDS, and chemical corrosion tests. The results of the experimental work have shown that a micro-hardness increased about (28%) times for Aluminum/Alumina composite by silicon carbide cladding compared with the original value of micro-hardness, and thickness of the cladding layer was about (34μm). The resistance of corrosion was enhanced with about (35%) for the Aluminum/Alumina composite with SiC cladding.

Effect of Accelerated Weathering on the Compressive Strength for PMMA Nano Composites and PMMA Hybrids Nano Composites Used in Dental Applications

S.I. Salih; J.K. Oleiwi; A.M. Talia

Engineering and Technology Journal, 2017, Volume 35, Issue 3, Pages 204-215

In the present research, efforts are made to develop the properties of PMMA resin that used for upper and lower prosthesis complete denture, by addition four different types of nanoparticles powders, which are fly ash, fly dust, zirconia and aluminum that added with different ratios of volume fractions of (0.01, 0.02 and 0.03) to poly methyl methacrylate (PMMA), cold cured resin (castavaria) is the new fluid resin (pour type) as a matrix. The nano composite and hybrid nano composite for prosthetic dentures specimens, preparation was done by using (Hand Lay-Up) method as six groups which includes: the first three groups consists of PMMA resin reinforced by fly ash , fly dust and ZrO2 nanoparticles respectively, the second three groups consists of three types of hybrid nano composites, which includes ((PMMA:X% fly ash) - (1%Al + 3%ZrO2)), ((PMMA:X% fly dust) - (1% Al + 3%ZrO2)) and ((PMMA:nZrO2) - (1% fly ash+ 3% fly dust)) respectively. As well as, the effect of moisture and UV was taking into consideration in this study. The compression test results shows that the values of compressive strength, compressive elastic modulus, and compressive strength under the effect of accelerated weathering (moisture and UV radiation) increased with the addition of nano powders (fly ash, fly dust, zirconia and aluminum). As well as, the results showed that the maximum values of compressive strength reach to (286.25MPa) for (PMMA + 2%nZrO2) nano composite. In addition, the results showed that the compressive elastic modulus reach to the maximum value (25.4166GPa) in the nano composite material (PMMA + 2%nZrO2). Moreover, the results showed that the compressive strength under the effect of accelerated weathering (moisture and UV radiation) reach to the maximum value to (315MPa) for the nano composite material (PMMA + 3%nZrO2).

Mechanical Properties of Friction Stir Welded Aluminum Alloy with Butt and Lap Cases

Nadhim M.Faleh

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2030-2038

Mechanical properties were investigated in base and friction stir linear welds of 7075 aluminum alloy. Welding tools consist of a shoulder with a pin and with-out pin. This work addresses the effects of tool geometry on tensile stress and shear strength of butt and lap welds, and comparing with base material. Also, the effects of process condition on the strength of friction stir processed material are quantitatively characterized. Compared to the butt case, the friction stir lap linear welds, with pin, leads to a 20% increase in optimized weld strength with 1000 rpm of tool revolutions and 200 mm/min of tool speed. The optimizing of operating conditions primarily leads to a 15% increase in optimized weld shear strength, with 1000 rpm of tool revolutions and 200 mm/min of tool speed.

Study the Optimization Parameters for Spring Back Phenomena in U-Die Bending

Khalida K.Mansor; Aseel Hamad; Karem M.Younis

Engineering and Technology Journal, 2013, Volume 31, Issue 9, Pages 1705-1718

The main objective of the research is to find the optimum parameters that reduce the springback by using the commercially [SPSS] program to analysis data and find the best parameters which given lowest springback in the U-die bending. A commercial aluminum alloy [AL-1050] sheet (0.9 mm) thickness that founded when punch speed increase the springback increase, when rolling direction angle is 90 Lower springback, and when increase the dwell time decrease the springback, and the value of parameters predicted from [SPSS] have lower springback and obtain a goal dimension for the products. And predict the springback value by especial equations which given correlation coefficient 95.4% between the observed value of the dependent variable and the predicted value.

Study of the influence of surface roughness, Sample heat and Sample shape on Wear rate measurements

Abdulhadi k.Judran; Najim Abd-Alkadhim; Haithim T.Hussein

Engineering and Technology Journal, 2013, Volume 31, Issue 2, Pages 252-260

Metal samples such as Copper and Aluminum and alloy as Brass were prepared and machined as discs (plane sample) and as a half rings (curvature sample). The samples were polished by using metallographic paper with different grades. The micro roughness and the initial weight were measured for all samples before wear tests, and then the samples were subjected to wear testing system under lubricated condition, fixed normal load of 15N, sliding time 30 min and sliding speed of 750 rpm. During the running of wear testing system the temperature of the samples were measured .The wear rate was calculated by employing the weighing method. It is clear from the results that micro roughness values increasing leads to increase in weight loss , wear rate and the temperature of samples .The effect of sample shape on weight loss , wear rate and sample heat is also obvious when noticing that the different measurements of weight loss, wear rate and sample heat of curvature samples are higher than that of plane samples .

The Effect of (á-Al2O3) Volume Fraction on The Mechanical Properties of (Al-Alumina) Metal Matrix Composite

Fawziea M. Hussien; Baydaa Abdul-Hassan Khalaf

Engineering and Technology Journal, 2011, Volume 29, Issue 13, Pages 2765-2772

This research tends to study the effect of change in volume fraction of alpha phase alumina on mechanical properties of a metal matrix composite specimens contain (Al- áAl2O3). Specimens were prepared with the following volume fractions (10, 15, 20, 25, 30, 35, 40, and 45). Then effectof this change on hardness, maximum stress and strain,
Young’s modulus, impactand wear resistance has been studied. Results of testing showed that while hardness, maximum stress, Young’s modulus, and impact strength increased markedly with volume fraction of alumina, wear rate, and maximum strain decreased with increasing of volume fraction.

Effect of Heat Treatment on Fatigue Life of Aluminum Alloys 2024 And 7075

Ahmed. N. Al-Khazraji

Engineering and Technology Journal, 2010, Volume 28, Issue 22, Pages 6469-6481

This research studies the effect of heat treatment (precipitation hardening) on fatigue life of two aluminum alloys (2024) and (7075). The alloy (2024) is hardening by natural aging, while the artificial aging is used to hardening the alloy (7075). Mechanical tests are performed to determine the mechanical properties such as yield stress, ultimate tensile strength, hardness and endurance limit of the
alloys. The specimens which used in the tests are divided into eight groups according to the type of alloy, type of heat treatment, and shape. Notched and un-notched specimens are used to perform the tests. The fatigue tests are performed for different type of specimens.
The equations of fatigue life estimation are determined according to data which is obtained from the fatigue tests and endurance limit is calculated by using these equations for each type of specimens.

Effect of Heat Treatment on Notch Sensitivity Factor for Aluminum Alloys

Ahmed. N. Al-Khazraji; Emad Abdul Hussein Al-mudhafar

Engineering and Technology Journal, 2010, Volume 28, Issue 3, Pages 509-519

This study is concerned with the effect of heat treatment (precipitation
hardening) on notch sensitivity factor for aluminum alloy (7075). Tests were
conducted on four configurations of specimens, three of them which had external
circumferential notches with notch radii of 0.5 mm, 0.7 mm, and 1 mm. The
fourth configuration is un-notched specimens. The alloy samples which were used
in fatigue test were subjected to cold working before heat treatment. Dimensions
and roughness of the specimens were measured. The fatigue tests were performed
for different types of specimens. The (S-N) equation was derived for each group to
estimate the fatigue life under any applied stress amplitude. In addition, the
strength reduction factor (kf )and notch sensitivity factor (q) were calculated.
The results showed that the fatigue strength reduction factor were
increased after heat treatment and with decreasing notch radius. Also the notch
sensitivity factor increased with increasing notch radius and after heat treatment.
The enhancement percentage in notch sensitivity factor after the heat treatment for
1 mm radius notch was (22.616%).