Effect of α‐Si ₃ N ₄ Particle Size on the Microstructural Evolution of Si ₃ N ₄ Ceramics

Abstract

The effects of initial particle size on the microstructure of silicon nitride ceramics produced by pressureless sintering have been investigated. The microstructures of the silicon nitride ceramics varied considerably with the size of the initial powder. With decreasing powder size, abnormal grain growth was enhanced, which resulted in significant bimodal distribution of grain size. The observed results are discussed in relation to the two‐dimensional nucleation and growth theory for faceted crystals.