Fabrication and Mechanical Properties of Si₃N₄Ceramics with ZrO₂-MgAl₂O₄ Additive System via Reaction Bonding Route

Abstract

Reaction bonded and post-sintered silicon nitride ceramics was fabricated using ZrO₂-MgAl₂O₄ as sintering additives. It was clarified that added ZrO₂ was act as nitridation enhanced effect under MgAl₂O₄ coexistence during reaction bonding process, and nitridation of the silicon was also completed lower temperature than that of Silicon without ZrO₂-MgAl₂O₄. The post-sintered specimen had a four-point bending strength of 850 MPa, which was obtained same fracture strength at same additive system prepared using high purity silicon nitride powder as a starting material.