Prediction of hardness of stir cast LM13 aluminum alloy - copper coated short steel fiber reinforced composites using response surface methodology

Copper coated steel fibers reinforced LM13 aluminum alloy composites have been prepared using stir casting process. Experiments have been designed using response surface methodology (RSM) by varying wt % of reinforcement (0–10), stirrer speed (350 min^?1–800 min^?1) and pouring temperature (700 °C–800 °C). Microstructure and hardness of composites have been investigated. Analysis of variance, significance test and confirmation tests have been performed and regressions model has been developed to predict the hardness of composites. Response surface plots reveal that hardness of composites increases with increasing wt % of reinforcement and stirrer speed. The optimum stir cast process parameters for obtaining higher hardness are found to be the wt % of reinforcement of 8.2, pouring temperature of 748 °C and stirrer speed of 708 min^?1.