Effects of Primary Si and Applied Load on the Dry Sliding Wear Behaviors of Hypereutectic Al-20Si Alloy

2014 ◽  
Vol 490-491 ◽  
pp. 83-87
Author(s):  
Qing Lin Li ◽  
Tian Dong Xia ◽  
Ye Feng Lan ◽  
Yi Sheng Jian

The effects of the primary Si phase and applied load on the dry sliding wear behaviors of hypereutectic Al-20Si alloy were investigated. The results show that coarse polygonal and star-like primary Si was refined into fine blocky shape by increasing superheat treatment temperature. The friction coefficient and wear rate significantly decrease after decreasing the size and changing the morphology of primary Si. Moreover, the friction coefficient and wear rate increase with the increase of applied load. Therefore, the wear properties are greatly influenced by the parameters like morphology and size of primary Si as well as applied load.

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
V. C. Uvaraja ◽  
N. Natarajan ◽  
I. Rajendran ◽  
K. Sivakumar

Novel Al-6061 hybrid composite materials with varying range of SiC particulate and constant weight percentage of B4C particulate and 1% of magnesium alloy were fabricated by the stir casting technique (liquid metallurgy route). The mechanical and tribological properties of the hybrid composites and that of Al-6061 unreinforced alloy were examined by a Rockwell hardness test machine, pin-on-disc test machine, and Optical Microscope and Scanning Electron Microscope (SEM). A plan of experiment generated through Taguchi's technique was used to conduct experiments based on the L27 orthogonal array. The developed analysis of variance (ANOVA) and the regression equations were used to investigate the influence of parameters like sliding speed, applied load, sliding time, and percentage of reinforcement and their interactions on the dry sliding wear and friction coefficient of the composites. The motto of the present study is ‘the smaller the better’ to identify the optimum conditions for dry sliding wear and the friction coefficient. The results indicate that wear rate and friction coefficient were highly influenced by applied load, sliding speed, percentage of reinforcement and sliding time whereas the interaction between these parameters show only a minor influence in Hybrid Metal Matrix Composites (HMMCs). The wear surface morphology and wear mechanism of the pins were investigated using SEM and were correlated with wear test results. Finally, confirmation tests were carried out to verify the experimental results. It is concluded that Al-6061 hybrid composite can replace the conventional material used in the brake disc of automobiles owing to improved hardness and strength and reduced wear rate.


2010 ◽  
Vol 7 (1) ◽  
pp. 1 ◽  
Author(s):  
Muna K. Abbass

 The aim of the present research is to study the effect of cadmium addition on microstructure and wear behavior of the alloy (Al-12%Si) under dry sliding conditions. Wear behavior was studied by using the Pin-On- Disc technique under different conditions at applied loads 5-20 N, at constant sliding speed and in constant time. The steel disc hardness was 35HRc. All alloys were prepared with different percentages of cadmium (1.0, 2.0, 3.0) wt%. Also the base alloy was prepared by melting and pouring the molten metal in a metallic mold. It was found that the cadmium addition to Al-Si matrix decreases the wear rate and improves the wear properties for alloys containing -Cd under loads above 10N. It was also found that the alloy Al-12%Si containing 3%Cd is the best alloy in wear resistance and friction coefficient. This is due to presence of the Cd-phase as cuboids or hard particles distributed in a eutectic matrix which reduces the friction coefficient at high loads (20N). 


2021 ◽  
Vol 1021 ◽  
pp. 78-86
Author(s):  
Hussein M. Ali ◽  
Qussay Y. Hamid ◽  
Thaer F.A. Al-Sultan

In the present work, an experimental investigation has been made of a dry sliding wear rate for aluminum, aluminum alloy (Al-Fe-V-Si), bronze, stainless steel 304 and structural steel ASTM A36, using a pin-on-disk apparatus under the effect of sliding speed and time at constant load. The materials were tested on two types of abrasive surfaces with a grit surface of 24 and 36. The applied load was equal to 2500 grams and the same load was used for all of the pins that were tested. The relative wear was indicated by the loss in length and loss in mass. The results show that the wear rate will directly proportional with sliding speed and time, and the stainless steel has less wear rate than the other materials.


2010 ◽  
Vol 45 (6) ◽  
pp. 683-693 ◽  
Author(s):  
Bin Hu ◽  
Liming Peng ◽  
Wenjiang Ding

Dry sliding wear behavior of the creep-resistant magnesium alloy Mg-10Gd-3Y-0.5Zr and its composites have been investigated in this study. Magnesium matrix composites are prepared by squeezing casting infiltration of Mg alloy into Saffil preforms. Wear tests are conducted using ball-on-flat sliding wear set up under a sliding velocity range of 1-15 cm/s and at an applied load range of 1-8 N for a constant sliding distance of 150 m. According to results, mechanical and wear-resistance properties of magnesium alloy improved by introducing Saffil fibers, and the alumina binder composite has a higher strength and lower wear rate than silica binder composite. The wear rates of the matrix alloy, composites and their counter-face balls increase with increasing applied load. The increment of sliding velocities decreases the wear rate of the matrix alloy under the tested sliding velocities. A critical threshold of sliding velocity for the wear rate of both composites and their counter-faces is about 9 cm/s. Abrasion and plastic deformation are considered to be the dominant mechanism for the matrix alloy in tested conditions, and for both composites under low sliding velocity (<10 cm/s) and at low applied loads (1-5 N). Delamination is the wear mechanism of the silica binder composites at a high applied load (8 N). Adhesion and oxidation are the controlling wear mechanism of matrix alloy and composites under a sliding velocity of 15 cm/s.


2017 ◽  
Vol 139 (5) ◽  
Author(s):  
N. Akaberi ◽  
R. Taghiabadi ◽  
A. Razaghian

The effect of bifilm oxides on the dry sliding wear behavior of Fe-rich (1.5 wt.%) F332 Al–Si alloy under as-cast and T6 heat-treated conditions was investigated. Toward this end, the surface oxides were intentionally incorporated into the molten alloy by surface agitation. The results showed that, after sliding under the applied load of 75 N, due to the presence of bifilms, the wear rate of base (0.2 wt.% Fe) and 1.5 wt.% Fe-containing alloys increased by almost 22% and 14%, respectively. The results also indicated that, despite the positive effect on the hardness, T6 heat treatment adversely affected the wear resistance of alloys made under surface turbulence condition. This negative effect can be attributed to the expansion of bifilms which, during heat treatment, are converted to the potential sites for initiation and propagation of subsurface microcracks. However, the strengthening effect exerted by the thermally modified β-Al5FeSi platelets showed that it can compensate the negative effects of bifilm oxides because it improves the wear rate of 1.5 wt.% Fe-containing F332-T6 alloy by about 5% under the applied load of 75 N.


2019 ◽  
Vol 291 ◽  
pp. 1-12
Author(s):  
Arvind Kumar ◽  
Ram Naresh Rai

The present paper discussed the dry sliding wear and friction behavior of flux assisted stir cast AA7050-10% B4C composite. The K2TiF6 flux improves the wettability of B4C in molten aluminium. The casted composite were heat treated as per T-6 standard. The microstructure studies confirm the uniform distribution of B4C with the layers of Ti compound around it. Both As Casted Composite hereafter called as ACC and Heat Treated Composite hereafter called as HTC under gone dry sliding wear test at room temperature. The experiments were designed using Taguchi L18 mixed design. The responses of the experiment were optimized using fuzzy-TOPSIS MCDM method. From the experimental investigation it was concluded that wear rate of the composite material is a function of normal loads and sliding speed. Moreover, wear rate, coefficient of friction and amount of heat generation for HTC is comparatively less than ACC. This may due to the homogeneous distribution of particles and also formation proper interfacial bond between matrix and reinforcements after heat treatment.


2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Vineet Tirth

AA2218–Al2O3(TiO2) composites are synthesized by stirring 2, 5, and 7 wt % of 1:2 mixture of Al2O3:TiO2 powders in molten AA2218 alloy. T61 heat-treated composites characterized for microstructure and hardness. Dry sliding wear tests conducted on pin-on-disk setup at available loads 4.91–13.24 N, sliding speed of 1.26 m/s up to sliding distance of 3770 m. Stir cast AA2218 alloy (unreinforced, 0 wt % composite) wears quickly by adhesion, following Archard's law. Aged alloy exhibits lesser wear rate than unaged (solutionized). Mathematical relationship between wear rate and load proposed for solutionized and peak aged alloy. Volume loss in wear increases linearly with sliding distance but drops with the increase in particle wt % at a given load, attributed to the increase in hardness due to matrix reinforcement. Minimum wear rate is recorded in 5 wt % composite due to increased particles retention, lesser porosity, and uniform particle distribution. In composites, wear phenomenon is complex, combination of adhesive and abrasive wear which includes the effect of shear rate, due to sliding action in composite, and abrasive effect (three body wear) of particles. General mathematical relationship for wear rate of T61 aged composite as a function of particle wt % load is suggested. Fe content on worn surface increases with the increase in particle content and counterface temperature increases with the increase in load. Coefficient of friction decreases with particle addition but increases in 7 wt % composite due to change in microstructure.


2004 ◽  
Vol 25 (2) ◽  
pp. 163-166 ◽  
Author(s):  
Feng Wang ◽  
Huimin Liu ◽  
Yajun Ma ◽  
Yuansheng Jin

2011 ◽  
Vol 314-316 ◽  
pp. 137-142
Author(s):  
Bin Cai ◽  
Ye Fa Tan ◽  
Hui Yong Ji ◽  
Xiao Long Wang ◽  
Long He ◽  
...  

In order to reduce friction coefficient of the Ni-base alloy coating and further improve its wear resistance, the graphite/TiC/Ni-base alloy composite coating was prepared on the surface of 45 carbon steel by plasma spray. Effects of loads, friction counterparts and lubricants on tribological properties of the coating were investigated. The results show that friction coefficient of the composite coating is reduced by 33% than that of the Ni-base alloy coating when worn against GCr15. Wear losses of the composite coating are less than those of the Ni-base alloy coating at all loads of 6N, 8N, 10N and 12N. Worn against Si3N4, friction coefficient of the composite coating is 13% less than that worn against GCr15, but its wear loss is 2.9 times of that worn against GCr15. Wear mechanism of the composite coating is micro cutting and brittle fraction when worn against Si3N4. Under lubrication of NaCl solution, friction coefficient of the composite coating is almost the same as that under dry sliding, wear loss is increased by 1.6 times. Stress corrosion and wedging effects of the NaCl solution are main wear mechanisms of the composite coating.


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