Influence of Oxygen Content of Silicon Nitride upon Its Sinterability in HIPing without Additives

Abstract

Two kinds of Si₃N₄ powders, of which characteristics were similar to each other in morphology, crystallographic phases and chemical contents except for oxygen content, were sintered by HIP using a glass capsule without additives. The amount of oxygen content in Si₃N₄ powder had influence upon its sinterability without additives. After HIPing, the increase in oxygen content in samples was detected though no penetration of glass through a BN inner capsule into Si₃N₄ was observed. But the oxygen content in well densified bodies was relatively small.