Aging response of aluminium alloy 2024/silicon carbide particles (SiC_p) composites

摘要

The aging behaviour of AA2024/0, 8, 14, 19, and 24 vol. pencent SiC_p composites was studied using the hardness Rockwell B and X-ray diffraction techniques. The composites were manufactured by stir-casting in the semi-solid state of the alloy AA2024 (compocasting). Aging of the composites and unreinforced alloy took place at 177 deg C for a period of 2-200 h. Precipitation phases present were Al_2CuMg for the unreinforced alloy 2024, and CuAl_2, Mg2Si for the composites. Peak hardness increased as the SiC_p volume fraction increased and appeared almost at the same time after about 14 h aging in all the materials. The hardness reduction rate in the overaged condition decreased with increasing SiC_p content.