Abstract

[ MoSi_2 ] alloys with Al, B or Nb were prepared by an advanced consolidation process that combined mechanical alloying with pulse discharge sintering (complex forming) to improve the mechanical properties. Their microstructure and mechanical properties were investigated. The MoSi_2 alloys fabricated by complex forming method showed very fine microstructure when compared with the sample sintered from commercial MoSi_2 powders. Alloys made from powders milled in Ar gas had fewer silica or alumina phases as compared to their counterparts sintered from powders milled in air. In densification of the sintered body, addition of B was more effective than Al or Nb. Both Victors hardness and tensile test indicated that the alloy fabricated by the complex forming method showed better properties than the sample sintered from commercial MoSi_2 powders. The Al added alloy sintered from the powders milled in air had the superior mechanical properties due to the suppression of SiO_2 and formation of fine Al_2O_3 particles.

• Keywords: MoSi_2 alloys;Complex forming method;Microstructure;Mechanical property;