2002 Volume 43 Issue 1 Pages 5-10
In order to improve the mechanical properties of MoSi2 alloys, alloys with Al, B or Nb addition were prepared by an advanced consolidation process that combined mechanical alloying with pulse discharge sintering (MA-PDS). Their microstructure and mechanical properties were investigated. The microstructure of MoSi2 alloys fabricated by the MA-PDS process was much finer than that of the sample sintered from the commercial MoSi2 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, presumably because of the suppression of the oxidation process during milling in Ar gas. Both Vickers hardness and tensile tests indicated that the alloys fabricated by the MA-PDS process showed better performance than the sample sintered from commercial MoSi2 powders because of the finer grain sizes. The Al-added alloy sintered from the powders milled in air gave the best mechanical properties due to the suppression of SiO2 and formation of fine Al2O3 particles.