ZrB2-SiC基超高温陶瓷（UHTCs）的反应烧结及SHS粉体制备

用普通反应热压方法（RHP）和反应放电等离子体方法（R-SPS）原位反应制备了ZrB2-SiC，ZrB2-SiC—ZrC，ZrB2-SiC-ZrN，以及ZrB2-SiC-AIN4种复合材料。从密度，物相以及显微结构等方面比较了两种烧结方式之间的差别，对于升温速度较慢的普通热压方法，反应分步进行，显微结构不均匀；对于升温速度快的放电等离子体烧结，原料间的自蔓延反应被点着，反应速度快，显微结构均匀。同时以红外灯的热量为点火源，引发了Zr，Si及B4C间在空气气氛下的自蔓延反应，制备了较纯及粒径约为1μm的活性粉体。

Reactive Synthesis of ZrB2/SiC Based Ultra High Temperature Ceramics and Powders

Four kinds of ceramics, ZrB2-SiC, ZrB2-SiC-ZrC, ZrB2-SiC-ZrN, ZrB2-SiC-AIN, are in situ prepared by both RHP and R-SPS, using zirconium, silicon, B4C, BN and aluminium as starting powders. The manufacturing process, mechanical properties, and microstructure of the composites prepared by RHP and SPS are reported, and the effect on sintering behavior of ZrC, ZrN and AIN are studied and compared. While HP process tends to form inhomogeneous microstructures due to the low heating rates and longer soaking time for grain growth, SPS process tends to form finer microstructures due to its high heating rates and short soaking time. A kind of powder of ZrB2-SiC-ZrC has been prepared by SHS method in the air, using Zr, Si and B4C as starting powders.