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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(σ 0.2 ),ultimate tensile strength(σ b)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 ℃,σ 0.2 andσ bof 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.
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. Sensory properties at room temperature and 200 ° C 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 (σ 0.2), ultimate tensile strength (σ b) 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 ° C, σ 0.2 and σ bof MMC with 0.29% Pr are increased by 33% and 55% respectively. The tensile fracture surfaces of Al-Si MMCs with Pr addition presents ductile fracture features.