Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Wear


Study of Wear Behavior of Aluminum Alloy Matrix Nanocomposites Fabricated by Powder Technology

Muna Khethier Abbass; Mohammed Jabber Fouad

Engineering and Technology Journal, 2014, Volume 32, Issue 7, Pages 1720-1732

In the present work, the dry sliding wear behavior of Al-12wt%Si matrix nanocomposites reinforced with single addition of 4wt.% Al2O3 or 4wt.%TiO2 nanoparticles, and with hybrid addition of 4wt% (Al2O3 +TiO2) nano particles is investigated. All nanocomposites samples were fabricated by powder technology by mechanical milling of the base alloy (Al-12wt%Si) powder and nanopowders of Al2O3 and TiO2, followed by cold pressing at 100bar and sintering at 520 oC for 90min. Vickers hardness test was done by using Vickers hardness tester. Archimedes technique was used to measure the density of sintered samples and porosity calculated as physical tests of sintered samples. Also AFM, SEM were used to investigate the morphology of mixed powders and nanocomposites samples.
Pin – on Disc wear tests were carried out at room temperature under dry sliding conditions with using different normal loads and sliding times. Worn surface micrographs were investigated based on the optical and scanning electron microscopy observations of wear tracks and wear debris morphology. It has been found that nanocomposite with 4wt% Al2O3 nanoparticles shows the highest hardness than other nanocomposites. It was observed that the wear rate or weight loss of the base alloy and nanocomposite samples increases with the increase in applied load and sliding time. But the nanocomposites samples showed lower wear rate than the base alloy within the same conditions.

Studying the Dry Sliding Wear for Composite Material of Base (Al-4%Cu) Reinforcement by Silicon Carbide Particles

Ahmad Ali Akbar Akbar; Hijran Zinalabiden; Waleed T. Rashid

Engineering and Technology Journal, 2014, Volume 32, Issue 6, Pages 186-195

This work is concerned with a study of dry sliding wear of Aluminum bace alloy of (Al-4%Cu) reinforcement by silicon carbide particles with different percentage (3, 6,9,12 wt %SiC). Composite materials prepared by stir casting method using vortex technique. The base alloy and composite materials samples were tested to investigate wear behavior, using Pin -on-Disc technique, by examining some variables of wear such as applied load, sliding speed, and sliding time. The results showed that wear rate increases with applied load and sliding time, while increasing the sliding speed and the percentage of SiC decreases the wear rate, as well as the alloy containing (12wt% SiC) showed better wear resistance compared with other alloys .

Wear Performance of a Laser Surface Hardened ASTM 4118 Steel

Assifa M. Mohamad

Engineering and Technology Journal, 2013, Volume 31, Issue 17, Pages 3235-3244

In this investigation ASTM 4118 steel was treated by using pulse Nd: YAG
laser with wave length 1064nm and pulse duration 100ns. In order to assess the
new tribological properties of laser surface hardened ASTM 4118 steel, the wear
resistance between specimens treated with laser and those of conventionally
hardened under dry sliding conditions was compared. The change of wear
mechanisms in laser hardened 4118 steel resulted in distinct difference in wear
rates.
The results showed that quenched zones not only had sufficient depth of
hardening and higher hardness, but had more retained austenite and finer carbides
because of a higher degree of carbide dissolution. Laser surface hardened ASTM
4118 steel specimens exhibited superior wear resistance to their conventionally
hardened specimens due to the change in the microstructure hardening, high
hardness. The wear mechanism for both the laser quenched layer and
conventionally hardened layer was highly similar, generally involving adhesive
wear mechanism , material transfer, wear induced oxidation and plowing. Also the
results of hardness show that increases with increasing of laser energy by 70%.

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 .