The Effect of Y on Microstructure and Properties of Al-5wt.%Cu Based Alloy

There is a great attention to the usage rate of Al-Cu alloys due to the largely use of Al-5%Cu based alloys in the aerospace industry in the past decades. The improvement of microstructure and properties of Al-5%Cu based alloy by refinement and modification. Specially, the refinement and modification of Al-Cu alloy can be achieved by addition of rare earth. In this paper, the effect of Y on the microstructure and properties of Al-5%Cu based alloy was investigated. The results show that θ (Al 2 Cu) phases change from mesh structure into fish-bone shape and grains are refined. Y additions promoted the end-solidification temperature and decreased the quantity of eutectic in grain boundaries, and narrowed the crystallization range and increased the hot-tearing resistance and decreased the hot-tearing susceptibility significantly.