Non-equilibrium microstructure of hyper-eutectic Al-Si alloy solidified under superhigh pressure

摘要

The non-equilibrium microstructures of hyper-eutectic Al-26.6wt%Si solidified under superhigh pressure(5.5GPa)have been investigated. The results show that there existsa great deal of primary αphase in hyper-eutectic Al-Si alloy. Thenon-equilibrium microstructure for hyper-eutectic Al-Si alloy iscomposed of primaryαphase,βphase and (α+β)eutectic phase.The solid solubility of Si in αphase and the solid solubility of Alin βphase increase significantly. The effects of high pressure onthe solidification structures of Al-Si alloy are discussed.