High-Strength Reaction-Bonded Silicon Nitride

Abstract

High-purity, small-diameter silicon powders made from laser-heated SiH{sub 4} have been used to fabricate 76% dense reaction-bonded silicon nitride (BSN) samples with a fine, uniform microstructure. Room-temperature strength values were 75% greater than conventionally processed RBSN (83% dense), with toughness and hardness values being {approx}10% greater. These high strengths result from uniformly distributed, small pores (<15 {mu}m in diameter), made possible from the combination of ideal powders and careful post-synthesis processing.