The influence of starting powder characteristics, involving purity and particle size, on the properties and performance of MoSi2-based heating elements was investigated in this study. Compared to a fine powder, densification of the green rods with a coarse powder should be carried out at a higher temperature. This creates a Mo5Si3 layer with a poor capability of a protective SiO2 film formation on the surface. Another negative impact of the high densification temperature is that the rods cannot be bent to a U-shape due to the coarse crystal size. The critical damage temperature of a heating element is significantly influenced by the purity of the starting powder. Impurities will deteriorate the performance of a heating element by decreasing the critical damage temperature.

Keywords: Purity, Particle size, Film formation, Hot bending, Performance