Grey relation based optimization of process variables in friction stir process used for fabrication of Al-based surface matrix composite
Abstract
Metal matrix composites play important roles in the field of aerospace, automobiles and other advanced applications. Aluminium based metal matrix composites have specific properties such as high strength to weight ratio, low density, good formability, excellent wear resistance and impact strength. One of the best method of fabricating surface metal matrix composites is friction stir process. A surface metal matrix composites have excellent tribological properties which makes it one of the emerging advanced material to be used in aerospace and automobile parts. Friction stir process provides freedom to metallurgist to fabricate variety of surface composite by varying reinforcement composition and proper controlling of process parameters. Tool rotational speed, tool traverse speed, reinforcement composition percentage, tool tilt angle, etc. are the main process parameters in friction stir process. The present experimental work deals with the effect of various process parameters of friction stir process on mechanical and metallurgical properties of thus fabricated surface FSPed composite. ANOVA has been utilized to study the effect of input parameters on targeted material properties. Reinforcement percentage is more influencing and then RPM speed and Traverse speed for tensile yield strength. Tool rotational speed, reinforcement percentage and traverse speed respectively are more influencing in case of micro hardness of fabricated samples. Similarly, reinforcement percentage is most influencing factor then Traverse speed and then traverse speed in case of average co-efficient of friction. However, GRA analysis reveals that, Reinforcement percentage is most influencing and then rotational speed of tool and least influencing factor is traverse speed when multi-objective optimization is considered. The values of different responses at optimum process parameters are: yield tensile strength (350MPa), microhardness (95HV-101HV) and dry sliding wear rate (0.45mm3/min).
