Effect of Bifilm Oxides on the Dry Sliding Wear Behavior of Fe-Rich Al–Si Alloys

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.

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 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.


2017 ◽  
Vol 52 (17) ◽  
pp. 2281-2288 ◽  
Author(s):  
S Sivakumar ◽  
S Senthil Kumaran ◽  
M Uthayakumar ◽  
A Daniel Das

The dry sliding wear behaviour of LM 24 aluminum alloy composites reinforced with garnet particles was evaluated. Stir casting technique was used to fabricate the composites. A pin-on-disc wear-testing machine was used to evaluate the wear rate, in which an EN 24 steel disc was used as the counterface. Results indicated that the wear rates of the composites were lower than that of the matrix alloy and further decreased with the increase in garnet content. However, in both unreinforced and reinforced composites, the wear rate increased with the increase in load and the sliding speed. Increase in the applied load increased the wear severity by changing the wear mechanism from abrasion to particle cracking-induced delamination wear. It was found that with the increase in garnet content, the wear resistance increased monotonically. The observations have been explained using scanning electron microscopy analysis of the worn surfaces and the subsurface of the composites. In this work, the most influencing input and output parameters have been performed and the process parameters have been prioritized using genetic algorithm. Genetic algorithm is used to optimize the most influencing input as well as output process parameters. The practical significance of applying genetic algorithm to dry sliding wear behavior process has been validated by means of computing the deviation between predicted and experimentally obtained wear behavior of metal matrix composite.


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.


2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Roshita David ◽  
Rupa Dasgupta ◽  
B. K. Prasad

The in situ method of making zinc-aluminum composites wherein TiC has been introduced has been investigated in the present paper for its microstructural, physical, and dry sliding wear behavior and compared with the base alloy. In the present study, ZA-27 alloy reinforced with 5 and 10 vol % TiC was taken into consideration. The results indicate that the wear rate and coefficient of friction of composites were lower than that of base alloy. The material loss in terms of both wear volume loss and wear rate increases with increase in load and sliding distance, respectively, while coefficient of friction follows a reverse trend with increase in load. Better performance was obtained for 5% TiC reinforcement than with 10% probably due to agglomeration of particles resulting in nonuniform dispersion. Worn surfaces were analyzed by scanning electron microscopy (SEM) analysis.


2007 ◽  
Vol 534-536 ◽  
pp. 673-676 ◽  
Author(s):  
Ahmet Güral ◽  
Süleyman Tekeli ◽  
Dursun Özyürek ◽  
Metin Gürü

The effect of repeated quenching heat treatment on microstructure and dry sliding wear behavior of low carbon PM steel was investigated. For this purpose, atomized iron powder was mixed with 0.3 % graphite and 1 % Ni powders. The mixed powders were cold pressed and sintered at 1200°C for 30 min under pure Ar gas atmosphere. Some of the sintered specimens were intercritically annealed at 760°C and quenched in water (single quenching). The other sintered specimens were first fully austenized at 890°C and water quenched. These specimens were then intercritically annealed at 760°C and re-quenched in water. The martensite volume fraction in the double quenched specimens was higher than that of the single quenched specimen. Wear tests were carried out on the single and double quenched specimens under dry sliding wear condition using a pin-on-disk type machine at constant load and speed. The experimental results showed that the wear coefficient effectively decreased in the double quenched specimen.


Author(s):  
Akshay Shinde

Abstract: To improve the wear resistance of the hybrid powder coating, TiO2 nanoparticles was hot mixed to form a homogenous mixture with the powder in the range varying wt. dry sliding wear test conducted to determine the wear resistance. The experiments were design according to Taguchi L9 array to find the optimum nanoparticles content required to minimize the wear rate of the coating. ANOVA was used to determine the effect of the parameters on wear rate. It showed that reinforcement has the maximum contribution on the wear rate of the coating as compared to load and frequency. From the graph of means optimum parametric values was obtained at 2 % wt of reinforcement, 2 N load and 2 Hz frequency. The wear rate decrease with the increase in reinforcement. Keywords: Taguchi Method, Tribometer, Hybrid powder, TiO2, Wear Rate.


2013 ◽  
Vol 6 (2) ◽  
pp. 139-153
Author(s):  
Israa .A.K

This research is devoted to study the effect of addition of different weight percent from SiCp ( 2, 4, 6, 8 ) to Al– 4 Cu alloy which have been fabricated by liquid metallurgy method on the dry sliding wear behavior and mechanical properties. Wear characteristics of Al–SiC composites have been investigated under dry sliding conditions and compared with base alloy. Dry sliding wear tests have been carried out using pin-on-disk wear test under normal applied loads 5, 10, 15 and 20 N and at different sliding velocity of (2.7, 3.7, 4.7) m/sec. It was also observed that the wear rate varies linearly with increases normal applied load but lower in composites as compared to the base material. The wear mechanism appears to be oxidative for both Al – Cu alloy and composites under the given conditions of load and sliding velocity as indicated by optical microscopic of the worn surfaces. Further, it was found from the experimentation that the wear rate decreases linearly with increasing weight percent of silicon carbide. The best results have been obtained at 8 % wt SiC . We also observed that the yield strength, tensile strength increases with increasing wt% of SiC , but the ductility decreases.


Sign in / Sign up

Export Citation Format

Share Document