Hardness Property Measurement, Grain Size Reduction and Heat Treatment of AA6061+CuO Composite with and without TiB2 Addition

Abstract

Aluminum composites are widely used in the aerospace applications for their outstanding properties. Through this study, Aluminum alumina composite was fabricated by in-situ process by adding 2 %, 4 % CuO (Cupric Oxide) powder with the AA6061 matrix alloy. The synthesized in-situ composites were evaluated using optical metallography, Image Analysis, and micro hardness testing. The phases produced in the in-situ process are like α-Al2O3, Mg2Si, Cu, CuAl3. For improving the hardness, the samples were solution heat treated at 535 °C for 4 hours and then aged at 175 °C for 8 hours. From the result, the heat treated samples had much more hardness compared with the as cast samples. In addition to that, the grain refinement study was also done on AA6061 matrix composite reinforced with in-situ alumina particle with TiB2. Al-5%Ti -1%B master alloy was proved to be a good grain refiner.