Reactive infiltration of Si-Mo alloyed melt into carbonaceous preforms of silicon carbide

A MoSi2/reaction-bonded SiC composite was prepared from a preform of petroleum coke and commercial SIC powders (in weight ratios of 0.5 and 0,6), following reactive infiltration of a Si-Mo melt (molybdenum concentration of 7-29 wt%) made from elemental powder. The resulting material had a relative density of >90% of the theoretical density and, on a microstructural scale, contained SiC and MoSi2, in addition to unreacted carbon and silicon. The SIC and MoSi2, boundary was smooth and sharp, with no sign of any reaction. The occasional presence of an intermediate zone between SiC and MoSi2, was detected; this zone contained silicon, iron, and aluminum, the formation of which may be related to the presence of impurities in the silicon and SiC.