Research on High Strength Hypoeutectic Al-Si Alloy

摘要

In this study, hypoeutectic Al-Si casting alloy was investigated to obtain high strength, according to alloying of Cu Mg, refining of Al-5Ti-B master alloy, modifing of Re and T6 heat treatment. The experimental results show that the mechanical properties of the tested alloy reach peak when addition of Al-5Ti-lB alloy is 1.0% after heat treatment, especially the yield strength, correspondingly, microstructure distribution gets to the best state. When Al-5Ti-lB exceeds 1.0%, the mechanical properties descend gradually. The metallic compounds of Mg_2Si phase, CuAl_2 phase and W phase precipitated along the grain boundary and strengthened- dispersively can improve mechanical properties of the tested alloys. The yield strength of samples added 0.1% Re (La 50%, Ce 40%) increases slightly, simultaneously, the tensile strength and elongation decreases. After 0.1% Re, the mechanical properties get down.