【摘要】 采用部分热压法,以Y₂O₃,MgO和CaO为添加剂,制备了气孔率在0.009～0.236的氮化硅多孔陶瓷。结果表明:制备的氮化硅多孔陶瓷是由众多长柱状的β-Si₃N₄晶粒及部分残余的α-Si₃N₄构成,气孔由长柱状的β-Si₃N₄搭接形成,其形状不规则。同时分析了氮化硅多孔陶瓷的力学性能与气孔率的关系,得出了气孔率与抗弯强度及断裂韧性的关系。更多还原

【Abstract】 Porous Si₃N₄ ceramics with porosity from 0.009 to 0.236 were synthesized by partial hot pressing of Si₃N₄ powders with Y₂O₃, MgO and CaO as additives.The resultant porous ceramics consisted of the rod-shapedβ-Si₃N₄ grains and a small amount of residualα-Si₃N₄.The pores were formed in the voids of the overlapped rod-shapedβ-Si₃N₄ grains,and the shapes of pores were irregular.The relationship between mechanical properties and the porosity of the Si₃N₄ ceramics were investigated and the relationships of flexural strength-porosity and fracture toughness-porosity were found.更多还原