高压烧结TaC陶瓷的致密化机理研究  

Study on Densification Mechanisms of TaC Ceramics by High Pressure Sintering

作　　者：顾俊峰 张帆[1] 张金咏[1] 王皓[1] 王为民[1] 傅正义[1] GU Junfeng;ZHANG Fan;ZHANG Jinyong;WANG Hao;WANG Weimin;FU Zhengyi(State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学材料复合新技术国家重点实验室,武汉430070

出　　处：《载人航天》2023年第4期442-448,共7页Manned Spaceflight

基　　金：中央高校基本科研业务费专项资金资助(2020IVA096)。

摘　　要：针对过渡金属碳化物陶瓷难以烧结致密化的问题,选取TaC陶瓷为对象,对比研究了不同烧结条件下晶界、缺陷等微观结构的形成特点以及动力学差异,探讨了高压烧结过程的特殊传质机理。研究表明,低温/高压的烧结条件有利于获得致密、细晶的结构;随着压力的增加,在烧结初期,致密化机制从晶格扩散/晶界滑移逐渐转变为晶界扩散/晶界滑移;在烧结末期,致密化的控制机制从晶格扩散逐渐转变为晶界扩散。Transition metal carbide is one of the most hard-to-densify ceramics.In this paper,the microstructural features and kinetics of TaC ceramics by different sintering schedules were investiga-ted.The distinguished mass transfer mechanisms in high pressure sintering were studied.It was sug-gested that low temperature and high pressure favored the acquisition of fined-grained structure.With the increase of pressure,the densification mechanisms at initial sintering stage changed from lattice diffusion/GB sliding to GB diffusion/GB sliding/plastic flow.The controlling densification mechanisms at final sintering stage changed from lattice diffusion to GB diffusion.In this paper,the densification mechanisms of TaC ceramics at low temperature/high pressure was illustrated.It pro-vides a useful insight to understand the sintering mechanisms of ultra-high melting point ceramics.

关 键 词：高压烧结 高熔点陶瓷 致密化机理 细晶陶瓷 

分 类 号：TB321[一般工业技术—材料科学与工程]