Microstructure of Rapidly Solidified Al-3.8Li-0.8Mg-0.4Cu-0.13Zr Alloy by Spray Deposition Processing

Microstructure of rapidly solidified Al-3.8Li-0.8Mg-0.4Cu-0.13Zr alloy prepared by spray deposition has been investigated. The grains are 5~ 20μm in size, and the microstructure exhibits the rapid solidification merits. Shrinkage porosities have been avoided, and the formation of prior particle boundary (PPB) has been prevented to a large extent. But there still exist some micropores with various shapes. The relative density of the as-deposited material is 94% on average.The main precipitates in the tested alloy are δ(AlLi), S(Al2CuMg) and δ'(Al3Li) phases.