Abstract
In this study, Mo-Si and Mo-Si-Nb system were fabricated by the pulse discharge pressure-combustion synthesis method (Nb was added into Mo-Si, in order to improve ductility at room temperature and high temperature strength). During the synthesis of Mo-Si and Mo-Si-Nb mixed powders, samples abruptly shrunk at 1323K. It is clear that combustion reaction occurred at this temperature and compounds were formed by combustion reaction. The relative density of fabricated samples was 96 to 98% and no internal defects were foundby ultrasound images in the samples. The formed phases of the fabricated samples were as follows;only MoSi2 phases were formed for Mo:Si=1:2 mixed powders, and, for the Nb added samples, MoSi2, Nb5Si3 and Mo5Si3 phases were formed and unreacted Nb remained. Young's modulus and the bending strength of fabricated samples showed similar results. Monolithic MoSi2 sample had the highest value of Young's modulus and bending strength, and for Nb added samples, Young's modulus and bending strength decreased with the increase in Nb content.
