Spider web approach hardness validation of peak aged Al6061/SiC/h-BN composite and related mechanical characterization

Current work focusses on stir cast Al6061 based composites with SiC (3, 6, 9 wt.%) and h-BN (1, 2, 3 wt.%) as reinforcements and subjected to heat treatments followed by mechanical characterization. Quality level of composites is confirmed from reinforcement distribution and hardness uniformity in castings after homogenization. The castings were further subjected to peak aging and hardness data is refined for accuracy using Spider web approach. Due to lack in the reinforcement spreadout, especially higher volume quantity of h-BN, the peak hardness of Al6061/9 wt.% SiC/3 wt.% h-BN as estimated by Spider web approach is less than the recorded value. The Minitab result is in line with that of experimentally supported Spider web approach. Due to the result of nonuniform dispersivity, beyond the optimum quantity of reinforcement content, fracture surface resulted coarse mirror facets with lower tensile and wear properties. 2 wt.% h-BN quantity with 6 wt.% SiC in the composite is regarded as the optimum quantity of reinforcement, resulted excellent tensile strength with least ductility among the family and is at par with hardness variation trend. It is found that optimum quantity of solid lubricant h-BN in the composite resulted excellent wear resistance even at higher normal loads.