采用SHS/QP技术制备TiC-xNi金属陶瓷——I.燃烧合成过程研究

TiC x Ni CERMETS MADE BY SHS/QP METHOD—? . STUDY ON THE COMBUSTION PROCESS

ＳＨＳ／ＱＰ技术是一种新的材料制备方法。本文分析了组成、稀释剂等对ＴｉＣ－ｘＮｉ体系的ＳＨＳ过程和结构的影响。ＴｉＣ－２０ｍｏｌ％Ｎｉ的ＳＨＳ过程激活能为１６６ｋＪ／ｍｏｌ，预示着其反应过程为溶解－析晶机理控制。采用ＣＦＱ法。

SHS/QP technique as a new method is an easy and economical way, which combines SHS and dynamic consolidation to fabricate full density composites in a single processing operation. So, a thorough understanding of the SHS process and the optimization of the pressing pattern are of the same importance. With the increase of metal contents in TiC x Ni, both the adiabatic and measured combustion temperatures decrease. Because of the heat loss and the industrial raw powders used in the experiment, the measured combustion temperatures are lower than the adiabatic temperatures. Maximum value on the propagating curve is observed at the Ni content about 20mol%, owing to the melting of Ni. Expansion of the sample after SHS is observed. Both combustion temperatures and propagating rates decrease with the add of diluent. By Novozhihov equation, the calculated activation energy for SHS of TiC 20mol%Ni is 166kJ/mol, close to that of the Ti and C reaction in the high temperature region, which indicates a solution and precipitation controlled mechanism. By CFQ method, the structure formation mechanism of SHS TiC 20mol%Ni was proposed.