Abstract
The grain growth kinetics and densification mechanism of(TiZrHfVNbTa)C high-entropy carbide ceramic are investigated in this work.A single phase carbide with a rock-salt structure is formed until 2300℃,below which an apparent aggregation of V,Zr and Hf exists.It is associated with the slow diffusion rate of V element as well as the relatively poor solubility of VC in HfC(as well as ZrC).The grain growth mechanism gradually changes from surface diffusion to volume diffusion and then grain boundary dif-fusion with increasing sintering temperature.This is attributed to the variation of activation energy of grain growth.The densification mechanism is principally dominated by the mass transport through lat-tice diffusion with the activation energy of 839±53 kJ/mol.Through the design of two-step sintering,it is verified that the solid solution formation can effectively promote the densification process.
基金项目
国家自然科学基金(51972081)
国家自然科学基金(52032002)
国家自然科学基金(51872061)
Heilongjiang Touyan Team Program()
Founda-tion of Science and Technology on Particle Transport and Separa-tion Laboratory()
维普
万方数据