Mechanical properties of magnesium based amorphous alloys produced by powder metallurgy

Abstract

The newly developed "clean process" enabled safe atomization and consolidation of fine Mg base alloy powders. Amorphous Mg75Cu5Y75 and Mg, ,Ca ..Al.„. powders (smaller than 25 ¡1 mj were extruded at 673 K above Tx. They showed a mixed structure consisting of Mg24Y5+Mg2Cu and ALCa respectively dispersed in a hcp-Mg matrix. The tensile strengths for the bulk MgS75Cu5Y75 and Mg70Ca10AI0 alloys are 740 MPa and 600 MPa at 298 K respectively which are about twice as high as the highest value for conventional Mg alloys. The high strengths are presumably due to the formation of the fine microstructure consisting of nanoscale intermetallic compound particulates homogeneously embedded in the Mg matrix with a fine grain size. These data allow us to expect that the newly developed Mg-based alloys will proceed hereafter as a new type of high specific strength material.