High specific strength Mg-based bulk metallic glass matrix composite highly ductilized by Ti dispersoid

Mg-based bulk metallic glass matrix composite with hcp-Ti powders was fabricated by casting the mixtures of Mg65Cu25Gd10 molten alloy and pure Ti powders into a copper mold. Ti powder was spherical and less than 150 mu m in diameter, and its volume fraction was controlled from 5 to 40%. Thermal stability of the glassy matrix was maintanied even in the coexistence with the Ti powders. However, Ti dispersoid caused a significant improvement on compressive ductility from 0% plastic deformation for the monolithic glass to 41% plastic deformation for the composite with 40vol.% Ti powders. This is the first success of synthesizing Mg-based alloys with high ultimate strength of similar to 900 MPa level as well as the large plastic deformation of similar to 40%, and suggests a novel guideline to develop Mg-based alloys having high specific strength with high ductility. (C) 2008 Elsevier B.V. All rights reserved.