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.

Keywords:

• MoSi₂-Al₂O₃ composite
• synthesis
• mechanical milling
• heat treatment