Microstructure and Properties of Mg-Cu Amorphous Powders Fabricated by Mechanical Alloying

High-strength amorphous Mg alloy is becoming more and more important for its potential industrial application prospect since 1990s. In this study, Mg₅₈Cu₄₂ and MgCu₂ amorphous powders, which are expected as thermal spray feedstock powders to deposit amorphous coatings, were prepared by mechanical alloying method. The influence of milling parameters and raw material compositions on the alloy compositions, glass-forming ability and thermal properties were investigated in this study. The results showed that the rotation speed of 300 r/min and the 200:1 of the weight ratio of powder to ball were optimum parameters to get amorphous Mg₅₈Cu₄₂ and MgCu₂ powders. The glass-forming ability of MgCu₂ was better that that of Mg₅₈Cu₄₂. The Mg became the solid solute phase in Cu after 40 hr. ball milling time and 300 r/min rotation speed for MgCu₂ chemical composition and it was 90 hr. for Mg₅₈Cu₄₂ composition. The crystallized temperatures of amorphous MgCu₂ and Mg₅₈Cu₄₂ were approximated to 634 K and 620 K respectively.