Enhancing the Mechanical and Reciprocating Wear Behavior of Functionally Graded A359 Aluminium Alloy Through Heat Treatment

This paper discusses on improving the mechanical and tribological characteristics of homogeneous and functionally graded A359 aluminium alloy processed through gravity and centrifugal casting respectively, through T6 heat treatment. Microstructural observation confirmed uniform and gradient structure for homogeneous and functionally graded casts respectively. Maximum micro-hardness values were observed at 10 hours aging time followed by a significant drop due to over aging. After T6 treatment, 38 and 40 % improvement in micro-hardness, 11 and 13.4 % improvement in tensile strength was observed on comparing as-cast homogeneous and functionally graded material respectively. Wear evaluation was performed for all the regions of as-cast and heat treated functionally graded material and homogeneous casts by varying load (15-35 N) and sliding distance (500-1500 m). Maximum wear resistance was observed for heat treated functionally graded material (outer) under the effect of sliding distance. Wear analysis revealed predominant delamination wear mechanism on worn surfaces.