In Situ Synthesis of MOSi2-Al2O3 Composite by Mechanical Milling and Subsequent Heat Treatment

Abstract

In situ MoSi2–Al2O3 composites have been successfully synthesized by mechanical milling (MM) and subsequent heat treatment of pure molybdenum, silicone and Aluminum elemental powders. The powders were mixed and subjected to MM in an attritor ball mill for 20 h under argon (Ar) atmosphere. Mechanically milling powders consolidated and then heat-treated under Ar atmosphere in a tube furnace for 7 h at 1100˚C. The phase transformation, microstructure and morphology of mechanical milling powder particles and consolidated samples were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results did not confirm the presence of any related intermetallics after MM. However, MoSi2 and Al2O3 were successfully in situ formed during heat treatment at 1100˚C. It was also found that after heat-treating, the phase composition Mo(Si,Al)2 was formed.