Tribological Behavior of Novel Hybrid Composite Materials Using Taguchi Technique

Novel Al-6061 hybrid composite materials with varying range of SiC particulate and constant weight percentage of B4C particulate and 1% of magnesium alloy were fabricated by the stir casting technique (liquid metallurgy route). The mechanical and tribological properties of the hybrid composites and that of Al-6061 unreinforced alloy were examined by a Rockwell hardness test machine, pin-on-disc test machine, and Optical Microscope and Scanning Electron Microscope (SEM). A plan of experiment generated through Taguchi's technique was used to conduct experiments based on the L27 orthogonal array. The developed analysis of variance (ANOVA) and the regression equations were used to investigate the influence of parameters like sliding speed, applied load, sliding time, and percentage of reinforcement and their interactions on the dry sliding wear and friction coefficient of the composites. The motto of the present study is ‘the smaller the better’ to identify the optimum conditions for dry sliding wear and the friction coefficient. The results indicate that wear rate and friction coefficient were highly influenced by applied load, sliding speed, percentage of reinforcement and sliding time whereas the interaction between these parameters show only a minor influence in Hybrid Metal Matrix Composites (HMMCs). The wear surface morphology and wear mechanism of the pins were investigated using SEM and were correlated with wear test results. Finally, confirmation tests were carried out to verify the experimental results. It is concluded that Al-6061 hybrid composite can replace the conventional material used in the brake disc of automobiles owing to improved hardness and strength and reduced wear rate.