中國有色金屬學(xué)報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 19 No. 5 October 2009 |
（College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China）
Abstract:The Al2O3-SiO2(sf) (volume fraction, 20%)/Al-12.6Si metal matrix composites(MMCs) with or without rare earth Pr addition were fabricated by infiltration squeeze method. Effect of Pr addition on microstructures and fractographs of Al-Si MMCs was investigated by SEM and TEM. Tensile properties at room temperature and 200 ℃ were tested. It is shown that the addition of Pr is favorable to produce uniform microstructures and modify the eutectic Si crystal effectively. Compounds/intermetallics with high content of Pr are formed at the interface between short fiber and matrix. Yield strength(s0.2), ultimate tensile strength(sb) and fracture elongation of Al-Si MMCs are improved by adding suitable amount of Pr. Compared with those values of Al-Si based MMC at 200 ℃, s0.2 and sb of MMC with 0.29% Pr are increased by 33% and 55%, respectively. The tensile fracture surface of Al-Si MMCs with Pr addition presents ductile fracture features.
Key words: Al-Si alloy; rare earth; metal matrix composites; microstructure; tensile properties
