Microstructure and mechanical property of A356 based composite by friction stir processing
(1. School of Advanced Materials Science and Engineering, Sungkyunkwan University,
300 Cheoncheon-dong, Jangan-gu, Suwon, Gyeonggi-do 440-746, Korea;
2. MEPL, Sungkyunkwan University, 300 Che)
300 Cheoncheon-dong, Jangan-gu, Suwon, Gyeonggi-do 440-746, Korea;
2. MEPL, Sungkyunkwan University, 300 Che)
Abstract: Friction stir processing (FSP) was used to incorporate SiC particles into the matrix of A356 Al alloy to form composite material. Constant tool rotation speed of 1800 r/min and travel speed of 127 mm/min were used in this study. The base metal (BM) shows the hypoeutectic Al-Si dendrite structure. The microstructure of the stir zone (SZ) is very different from that of the BM. The eutectic Si and SiC particles are dispersed homogeneously in primary Al solid solution. The thermo-mechanically affected zone (TMAZ), where the original microstructure is greatly deformed, is characterized by dispersed eutectic Si and SiC particles aligned along the rotational direction of the tool. The hardness of the SZ shows higher value than that of the BM because some defects are remarkably reduced and the eutectic Si and SiC particles are dispersed over the SZ.
Key words: friction stir processing; A356 alloy; SiC powder; eutectic Si