The effect of quenching agents at T6 heat treatment on hardness Al6061-sea sand composite

Aluminum matrix composites (AMCs) are composites made from aluminum reinforced with ceramics. The use of ceramic particles produces high mechanical properties, but the production costs are expensive. In this study, sea sand was used as reinforcement because it contains ceramic compounds that can be used as a substitute for ceramic powder in the manufacture of AMCs and can reduce production costs but still maintain its mechanical properties. T6 heat treatment is used to improve the mechanical properties of the composite which consists of solution heat treatment, quenching, and artificial aging processes. The quenching process affects the mechanical properties of the composite. The higher cooling rate affects the amount of Mg²Si precipitate which affects the hardness of the Al6061-sea sand composite. The purpose of this study was to determine the effect of quenching media on T6 heat treatment on the hardness of the Al6061-sea sand composite. There are 3 variations of quenching media used, namely oil, water, and brine. The hardness test using Brinell method, which is refers to ASTM E10. The results obtained showed that the highest hardness value occurred in brine quenching media with a value of 55.13 HBN, followed by water quenching media with a value of 52.27 HBN, and oil quenching media at 51.60 HBN. Based on the results of this study, it can be concluded that the difference in quenching media affects the hardness of the Al6061 composite reinforced with sea sand.