Dry Sliding Wear Behavior of Cast A7075 and A7075/SAF 2205 Composite Material

2016 ◽  
Vol 35 (5) ◽  
pp. 487-492
Author(s):  
Ahmet Karaaslan ◽  
Alptekin Kısasöz ◽  
Ş. Hakan Atapek ◽  
Kerem Altuğ Güler

AbstractThe wear behavior of cast A7075 and A7075/SAF 2205 composite material fabricated by vacuum-assisted investment flask casting was investigated under dry sliding condition. The wear tests were carried out using a “ball-on-disc” type tribometer. In the wear tests, 100Cr6 and ZrO2 balls were used as counterparts and the load, total distance and rotating speed were selected as 10 N, 100 m and 100 rpm, respectively. The results were evaluated using the friction coefficient–distance diagram, weight loss and wear rate. All worn surfaces were examined by scanning electron microscope and wear characteristics of the materials were discussed as a function of the microstructural features. It was concluded that composite material had lower friction coefficient, less weight loss and slower wear rate than that of cast material.


2015 ◽  
Vol 817 ◽  
pp. 661-666 ◽  
Author(s):  
Yuan Gao ◽  
Jin Chuan Jie ◽  
Peng Chao Zhang ◽  
Jian Zhang ◽  
Tong Min Wang ◽  
...  

The dry sliding wear behavior of Cu-Cr-Zr alloy prepared by electromagnetic horizontal continuous casting was investigated. The wear behavior of the studied alloy was discussed in terms of friction coefficient, mass loss/sliding, specific wear rate and wear mechanism. The results indicate that with the increasing normal load and sliding velocity, the friction coefficient of Cu-Cr-Zr alloy decreased monotonically, the mass loss/sliding and specific wear rate increased. By wear surface morphology and composition analysis, the wear mechanisms were discussed preliminary. Oxidation and abrasion mechanisms dominated at the lower sliding velocities and loads. Increasing loads and velocities led to a combination of oxidation and adhesion. Plastic deformation was dominant for the higher applied load and sliding velocities.



Author(s):  
Rajnesh Tyagi

The Al-TiC composites containing three different volume fractions 0.07, 0.12 and 0.18 of TiC have been fabricated and wear characteristics of Al-TiC composites have been investigated under dry sliding. Dry sliding wear tests have been carried out using a pin-on-disk wear tester at normal loads of 9.8, 14.7, 19.6 and 24.5 N and at a constant sliding velocity of 1.0 m/s. The wear rate has been found to vary linearly following Archard’s law. The wear rate is significantly lower in composites as compared to that in base material. The wear mechanism appears to be primarily oxidative under the test conditions taken in the present investigation. Average coefficient of friction also decreases linearly with increasing normal load and volume fraction of TiC.



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.



2018 ◽  
Vol 55 (1) ◽  
pp. 102-110 ◽  
Author(s):  
Marian Bastiurea ◽  
Dumitru Dima ◽  
Gabriel Andrei

Graphene oxide and graphite filled polyester composites were prepared by using conventional melt-mixing methods in order to improve tribological performance of polyester. It was investigated friction stability, microhardness, friction coefficient, and specific wear rate of the composites in details. It was found that the presence of graphite and graphene oxide influenced friction coefficient and wear rate of the composites. Graphene oxide decreased wear rate with increasing of test speed and graphite decreased wear rate for composite for all speeds. Tribological performance of the polyester/graphene composites is mainly attributed to bigger thermal conductivity for graphene, which can easily dissipate the heat which appears during the friction process at bigger forces. The positive influence of graphite on coefficient of friction (COF) of the composites is the result of the clivage of graphite layers during the loadings due to van der Waals weak bonds between the graphite layers.



2020 ◽  
Vol 1002 ◽  
pp. 151-160 ◽  
Author(s):  
Anmar D. Mahdi ◽  
Saif S. Irhayyim ◽  
Salah F. Abduljabbar

Al7075 hybrid nanocomposites considered one of the most material utilized in modern engineering applications that required a combination of superior properties such as lightweight, high strength, excellent corrosion resistance, and high thermal conductivity. In the current study, Al7075 – 5 vol % graphite self-lubricating composite was reinforced by 0, 1.5, 2.5, 3.5, and 4.5 vol % WO3 nanoparticles in order to study the microstructural, mechanical, and wear characteristics. The classical powder metallurgy route was employed to fabricate the hybrid nanocomposites specimens. The microstructural analysis of the nanocomposites was characterized by utilizing a Field Emission Scanning Electron Microscope (FESEM) and Energy-Dispersive X-ray (EDX) analyses. Mechanical properties such as micro-hardness and diametral compressive strength were studied. Dry sliding wear test was performed under the various loads of 10, 15, 20, and 25 N at a sliding distance and sliding speed of 1810 m and 1.5 m/s, respectively. Results have revealed that the microhardness and diametral compressive strength considerably improved by increasing the WO3 content until 3.5 vol % and then slightly decreased. Besides, both the values of the wear rate and friction coefficient gradually reduced by increment the reinforcement content up to 3.5 vol % and then suddenly increases for all the applied loads. Nevertheless, the wear rate and friction coefficient were correlated positively with the applied loads. From the results obtained, graphite as solid lubricating material with WO3 nanoparticles was successfully combined into the Al7075 alloy matrix. The optimum mechanical and wear performance of the hybrid nanocomposite were revealed at 3.5 vol % content of WO3 nanoparticles.



Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 207
Author(s):  
Eleonora Santecchia ◽  
Marcello Cabibbo ◽  
Abdel Magid Salem Hamouda ◽  
Farayi Musharavati ◽  
Anton Popelka ◽  
...  

The applications of aluminum and its alloys are still limited by low hardness and low wear resistance properties. Surface modifications, such anodizing and plasma electrolytic oxidation, represent a feasible way to overcome these drawbacks. In this study, discs of AA6082 were subjected to the so-called G.H.A. hard anodizing process leading to an anodized layer having a honeycomb-like structure. Samples having alumina layer thicknesses of 10, 50 and 100 μm were subjected to unidirectional dry sliding wear tests, using bearing steel and silicon nitride as counterbody materials. Surface and structure characterization of the samples were performed before and after the tribological tests, using a wide range of techniques; atomic force microscopy and scanning electron microscopy techniques were used before the wear tests. The wear scars were characterized by scanning electron microscopy, energy dispersive spectroscopy and Fourier transform infrared spectroscopy techniques. Results show that the different thickness of the anodized layer does not affect the pores dimensions but has an influence on the micrometric domains in which the pores are divided. These features coupled with the wear test conditions, show to have a strong influence on the wear behavior. The thinnest sample showed also the best performance against the ceramic counterbody.



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.



2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
M. Sudheer ◽  
Ravikantha Prabhu ◽  
K. Raju ◽  
Thirumaleshwara Bhat

The dry sliding friction and wear behavior of epoxy hybrid composites reinforced with glass fibers and a varying amount of potassium titanate whiskers (PTWs) fabricated by vacuum hand layup method were studied. The influence of normal load, sliding velocity, and whisker content on both friction coefficient and specific wear rate was investigated on a pin-on-disc machine. The tests were conducted at ambient conditions based on the 3 × 3 (3 factors at 3 levels) full factorial design. Analysis of variance (ANOVA) was performed to obtain the contribution of control parameters on friction coefficient and wear rate. The density and hardness of the composites were found to be enhanced with the PTW loading. The friction coefficient and wear resistance of the hybrid composites were found to be improved with the whisker content and were also greatly influenced by normal load and sliding velocity. A correlation between dry sliding wear behaviors of composites with wear parameters was obtained by multiple regressions. The worn out surface of selected samples was observed under scanning electron microscope (SEM) to identify wear mechanisms. This study revealed that the addition of the ceramic microfillers such as PTW improves the wear performance of the epoxy/glass polymer composites significantly.



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