摘要
研究影响气压烧结α/ β sialon复相材料相组成、显微结构及力学性能的基本因素。采用三阶段气压烧结α/ β sialon工艺 ,能有效控制气相分解产物生成 ,消除样品鼓泡现象 ,而有利于致密化。研究了Si3N4 粒度及相组成、AlN粒度对气压烧结α/ β sialon的烧结、相组成、显微结构及力学性能产生的不同程度影响。细Si3N4 原料因氧含量增加 ,使相组成向 β相方向偏移 ;较细的AlN原料有利于烧结致密化和材料性能的提高 ,但要防止样品鼓泡现象 ;较粗的AlN原料因为增加瞬时过饱和度而使材料中出现明显晶粒异常长大现象 ,而使显微结构部分晶粒粗化。埋粉中添加适量AlN可以有效地消除样品鼓泡 ,但埋粉中AlN添加量过多 ,样品失重增大 。
Parameters affecting gas-pressure-sintering(GPS)α/β-sialon ceramics were investigated thoroughly.Preheating stages reduced the gas phases that were produced during reaction sintering process,which were beneficial for α/β-sialon densification.The effects of particle sizes and phase contents of the starting materials Si 3N 4 and AlN on the phase compositions,microstructure and mechanical properties of α/β-sialon ceramics were also investigated.Fine Si 3N 4 made the phase composition shift to the β-phase as it contained more oxygen;Fine AlN could contribute to the densification and the improvement of the mechanical properties if the bloating in the sample was avoided;Coarse AlN increased supersaturation during sintering thus causes abnormal grain growth.AlN in the embedding powder could decrease the bloating in the samples. The excess of content in the embedding powder would increase the weight loss and micro-pores in the samples.
出处
《硅酸盐通报》
CAS
CSCD
2002年第6期3-8,共6页
Bulletin of the Chinese Ceramic Society
