Fabrication of silicide materials and their composites by reaction sintering

The paper reports on a new powder metallurgical technique applicable for the preparation of refractory silicides, silicide composites, and other poorly sinterable materials. Starting from the fundamentals of sintering a general approach for reaction sintering of elemental powders—termed controlled reaction sintering (CRS)—will be given. The sintering behaviour of pre-alloyed powders, coarse elemental powders, and the mechanically treated elemental powder mixtures are compared. A detailed study of powder preparation, consolidation, CRS, and properties will be pointed out for MoSi2 and MoSi2–SiC composites. Several silicides (MoSi2, MoSi2–SiC, TiSi2, Ti5Si3, FeSi2, ReSi2) were produced by CRS. Properties such as fracture toughness, minimum creep rate, bending strength, and oxidation resistance were determined for MoSi2-based materials. The paper presents an outlook for different fabrication routes for silicides and silicide composites, as pressureless and pressure assisted sintering, metal injection moulding (MIM), and tape casting.