Friction Surfacing: Novel Technique for Metal Matrix Composite on Aluminium-Silicon Alloy
Aluminium alloys are used in applications demanding lightweight and high strength. These applications could be in wrought or cast form. Some of the components need to exhibit wear resistance, which is dedicated by the surface property. For better wear resistance the surface should be hard. The approach to impart hardness is by hardening as well as by some surface treatment involving surface alloying, hard-face coating etc. Aluminium alloys do not exhibit wear resistance, as do not response to surface hardening heat treatments. The general approach to impart wear resistance in such situations is to build a surface layer consisting of metal matrix composites. These MMCs contain ceramic particulates. One such metal matrix that has high wear resistance is MMC with SiC particulate. Deposition of this MMC through fusion route result in the formation of Al4C3 that gets embrittled when exposed to moisture. Keeping the aforementioned in view, studies were carried out to bring the potential usefulness of friction surfacing technique to improve wear and corrosion behavior of A356 Al-Si alloy. The coatings exhibit excellent bonding with the substrate. The coating also has adequate corrosion resistance.