Solid State Reaction in Mechanical Alloyed Materials of the Mg-SiO₂ System

Abstract

Pure magnesium powder was mechanically alloyed with SiO₂ powder by using a planetary ball mill under an Ar atmosphere. After mechanical alloying, the powder was consolidated to the P/M material by vacuum hot pressing. Solid state reaction in the mechanically alloyed powder and the P/M material of the Mg-SiO₂ system was studied by XRD, DSC and TEM. In this system, the solid state reaction started to occur during MA processing between Mg and SiO₂ and in-situ formation of MgO and Mg₂Si was attained in the Mg matrix. Such solid state reaction progressed further during hot-pressing and heating of the P/M material. The hardness increase was observed during heating of the P/M material at 773 K, and thus the Mg-SiO₂ P/M material can be strengthened by in-situ formation of MgO and Mg₂Si.