关键词: 快速淬火, 铝合金, 微观结构

Abstract: Rapidly solidified Al-4.5Cu alloy was studied with the ultrasonic inert gas atomization technique.The solidification cooling rate is 103～105℃/s.The alloy powders have a range of size distribution;the smaller the powders the higher the cooling rate,The relation be-tween cooling rate and microstructure of the alloy was investigated.It is shown that the cooling rate has a strong influence on the solidification process and solute diffusion,With the model of convection heat transfer and microstructure analysis, the critical cooling rate at which the planar solid-liquid interface is destabilized was detennined.The critical cooling rate was compared with microstructural scaling laws.

Key words: rapid quenching(metalurgy), aluminum alloys, microstructure