The automotive technology is growing rapidly, so that there must be the available materialwith high hardness, light in weight, and low cast. Piston is one of engine component for vihecle machine power transformed to move crank shaft and other component of carriage wheel.
The aim of the research was to analyze the chemical composition, micro structure and mechanical properties of piston. So material examinations have been done include is spectrometric test to know about composition, rockwell hardness test to measure hardness, micrographic test for observing microstructure, and tensile test for tensile strength analysis.
The result of research showed that material according to JIS ADC 12, aluminum alloy material with the main elements Si, Cu, Zn, Fe. Maximum hardness was measured at the head of material of 62 HRB and it’s still in range of acceptance criteria. The ultimate tensile strength and still in range of JIS ADC 12 criteria, which is 177,53 Mpa. Test results show that with the higher austempering temperature range has resulted in the higher hardness value
