摘要
本文提出了两种制备氮化硅陶瓷自生复合材料的方法：以氟化钙为添加剂，对硅坯体直接进行氮化；经预氮化后的反应烧结氮化硅多孔体，在含酚醛树脂和硅酸乙酯的无水乙醇溶液中浸渍处理后，再经过高温热处理，分别可得到以β－Ｓｉ＿３Ｎ＿４和β－ＳｉＣ晶须增强的氮化硅陶瓷复合材料。同时，还对生长条件对晶须的形态，以及自生晶须对氮化硅陶瓷力学性能的影响进行了探讨。
Two new methods to prepare in-situ whiskers reinforced Silicon Nitrde matrixcomposites are proposed.When Si powders containing CaF_2 as catalyst are nitrided, in-situβ-Si_3N_4 whiskers grow in the reaction bonded silicon nitride. In-situ β-SiC whiskers grow onthe Si_3N_4 matrix and in the pores,after the porous compacts of Si_3N_4 are infiltrated withphenolic resin and tetraetyl silicate,La_2O_3 as catalyst. There is a droplet on the top of eachβ-SiC whisker,which suggests that it grows by the Vapour-Liquid-Solid mechanism,Whentwo and more such whiskers with different directions occur, the whisker network is formed.The microstructure of in-situ whisker depends on the experimental conditions. With the timeand temperature increased , the in-situ whiskers become wider and longer. The experimentalresults show that in-situ whiskers can increase not only the fracture strength but alsofracture toughness.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
1995年第1期43-49,共7页
Acta Materiae Compositae Sinica
