Machining characteristics,wear and corrosion behavior of AZ91 magnesium alloy - fly ash composites produced by friction stir processing

In the present work, fine grained AZ91 magnesium alloy – fly ash composite has been successfully fabricated by friction stir processing. Microhardness measurements show marginally higher hardness with uniform distribution compared with the base material. No significant difference in the mean cutting force was observed during drilling of the base metal and the composite. However, lower cutting forces were recorded in the sub-surface region of the composites. Interestingly, decreased corrosion resistance was noticed for the composite compared with the base material. Lower mass loss has been observed for the composite during reciprocating wear experiments. The results strongly suggest that the surface composite of AZ91 magnesium alloy – fly ash exhibits better mechanical and wear properties. However, decreased corrosion resistance is a significant observation that warns the applicability of these composites in corroding environment.