Dry Sliding Wear Behavior of Al₂O₃/SiC Particle Reinforced Aluminium Based MMCs Fabricated by Stir Casting Method

Abstract

Al2O3/SiC particulate reinforced metal matrix composites were produced by a stir casting process. The Al2O3/SiC powder mix was prepared by reaction of aqueous solution of aluminium sulphate, ammonium sulphate and water containing SiC particles at 1200• C. 10 wt% of this hybrid ceramic powder with dierent sized SiC particles was added to a liquid matrix alloy during a mechanical stirring between solidus and liquidus under inert conditions. Dry sliding wear tests were conducted with a pin-on-disk friction and wear tester. The morphologies of the worn surfaces were examined using a scanning electron microscope to observe the wear characteristics and investigate the wear mechanism. An optical microscope was used to examine the precipitations of the hybrid ceramic reinforced metal matrix composites after wear tests at room temperature under dry conditions. It was found that hybrid and bimodal particle reinforcement decreased weight loss especially when SiC powder with larger grain size was used. Microstructural examination showed that besides occurring coarse SiC particle reinforcement, a ne alumina particle reinforcement phase was observed within the aluminium matrix (A332). The improvement in wear resistance of the hybrid ceramic reinforced metal matrix composites could be attributed to the ability of the larger SiC particles to carry a greater portion of the applied load, as well as to the function of the larger SiC particles in protecting the smaller alumina particles from being gouged out during the wear process. Furthermore, the incorporation of hybrid and bimodal particles increased hardness of the composites with respect to the composite with fully small sized particles.

The Effect of SiCp Addition on Corrosion and Wear Behavior of Conventionally and Microwave Sintered PM 316L

“…The positive effects of these coarse SiC particles are also seen in the study of Altinkok et al, [1] in which coarse SiC particles (>10 mm) have also improved wear resistance in Al/SiC composite system. The positive effects of these coarse SiC particles are also seen in the study of Altinkok et al, [1] in which coarse SiC particles (>10 mm) have also improved wear resistance in Al/SiC composite system.…”

“…The wear test results confirm that SiC particles can carry load efficiently. The positive effects of these coarse SiC particles are also seen in the study of Altinkok et al, [1] in which coarse SiC particles (>10 mm) have also improved wear resistance in Al/SiC composite system. Another reason of this high wear resistance for SS/SiC composites would probably be the filling of the porosities by glassy phase as it was investigated in our previous study in the same system.…”

“…[1] Another reason is that ceramic particulate composites tend to retain their mechanical properties at elevated temperatures for long times. MMCs are being used to replace conventional materials in many applications such as automotive, aviation, transportation, etc.…”

“…The most favourable reinforcements are hard ceramic particles, which are expected to improve wear resistence by carrying a great amount of applied load. [1] Another reason is that ceramic particulate composites tend to retain their mechanical properties at elevated temperatures for long times. [2] In case of austenitic stainless steels, an additional major drawback for use in certain tribological environments has to be taken into account: They have relatively poor wear resistance owing to their low hardness.…”

Investigation on the Wear Behaviour of Eutectic Al-Si Alloy- Al2O3 - Graphite Composites Fabricated Through Squeeze Casting

“…They reported that the incorporation of graphite particles enhanced the wear resistance. Altinkok et al 11 analyzed the dry sliding wear behaviour of Al 2 O 3 /SiC particle reinforced aluminium based metal matrix composites fabricated by stir casting method. Mohan et al 12 investigated the dry sliding wear of Al -Gr composites and showed that graphite particles smears at the sliding interface and reduces wear, but inclusion of graphite beyond 1.5 % reduces the mechanical properties of the composite drastically.…”