Pengaruh Perlakuan Panas Terhadap Kekerasan Pada Kepala Piston

The piston head, as a key component in internal combustion engines, must possess high hardness to withstand extreme pressure and temperature. Aluminum alloys are commonly used due to their lightweight and corrosion resistance; however, their mechanical properties need to be improved through heat treatment. This study aims to determine the effect of heat treatment on the hardness of piston heads made of aluminum alloy. The heat treatment was carried out at varying temperatures of 200°C, 250°C, 300°C, 350°C, and 450°C, with a holding time of 30 minutes and using oil as the quenching medium. Hardness testing was conducted using the Rockwell method to measure changes in mechanical properties before and after heat treatment. The results showed that heat treatment significantly influenced the increase in piston head hardness. The highest hardness was achieved at 250°C, increasing from 58.6 HRB to 91.06 HRB, or by 32.46 HRB (55.3%). However, at higher temperatures (350°C and 450°C), a decrease in hardness was observed, indicating over-aging or excessive grain growth. Therefore, the optimal heat treatment temperature for improving piston head hardness is around 250°C. This research contributes to the understanding of effective heat treatment in enhancing piston material performance in the automotive industry.