摘要：用球磨的方式将平均粒径为6.46μm的β-氮化硅原料粉细化为不同粒度的亚微米级起始粉料,加入适宜的添加剂,以无压液相烧结的方法研究起始粉料粒度对氮化硅陶瓷的强度、硬度等机械性能的影响。用扫描电镜、X射线衍射等方法测试分析试样的显微结构、相组成等。结果表明,试样密度、强度、硬度等均随起始粉料粒度的减小而增大;试样显微结构显示了烧结体晶粒尺寸随起始粉料粒度的减小而减小,且粒度小的试样烧结的晶粒均匀、致密;烧结后试样的物相主要是β-氮化硅和少量黄长石,粉料的粒度对烧结后样品的物相没有影响。

关键词：粒度；氮化硅陶瓷；机械性能；显微结构

Abstract：The effect of starting particle size on the mechanical properties of liquid-phase sintered Si₃N₄ ceramics was investigated using mill-refined Si₃N₄ powders and the appropriate additives.The microstructure and phase composition were determined by using SEM and XRD.The results indicate that the density,strength and hardness of all of Si₃N₄ ceramic are improved with decrease of Si3N4 particle size.The size of Si₃N₄ crystals grains is uniform and compact with the smaller size of starting particles.The phase composition of resultant Si₃N₄ ceramics is not changed with the particle size and only contains β-Si₃N₄ and a little of melilite.

Keywords：particle size；Si₃N₄ ceramic；mechanical property；microstructure