热压烧结制备原位复合(TiB_2+TiC)/Ti_3SiC_2复相陶瓷  

Preparation of In-Situ(TiB_2+TiC)/Ti_3SiC_2 Composite Ceramics by Hot-Pressing

作　　者：杨建[1] 顾巍[1] 潘丽梅[1] 张小敏[1] 丘泰[1] 祝社民[1] 

机构地区：[1]南京工业大学材料科学与工程学院,南京210009

出　　处：《硅酸盐学报》2011年第2期223-227,共5页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(50872052);国家"863"计划(2009AA05Z313);江苏省高校自然科学基础研究面上项目(07KJB430039);江苏省无机及其复合新材料重点实验室资助项目

摘　　要：采用热压烧结法制备了原位复合(TiB2+TiC)/Ti3SiC2复相陶瓷。采用X射线衍射、扫描电镜和透射电镜对材料的物相组成和显微结构进行了表征,研究了烧结温度对材料物相组成、烧结性能、显微结构与力学性能的影响。结果表明:烧结温度在1 350～1 500℃范围内,随着烧结温度的升高,合成反应进行逐渐完全,材料的密度、抗弯强度和断裂韧性显著提高。1 500℃烧结可得到致密的原位复合(TiB2+TiC)/Ti3SiC2复相陶瓷,材料晶粒发育较完善,层片状Ti3SiC2、柱状TiB2与等轴状TiC晶粒清晰可见,增强相晶粒细小,晶界干净,材料的抗弯强度、断裂韧性和Vickers硬度分别达到741 MPa,10.12 MPa.m1/2和9.65 GPa。烧结温度达到1 550℃时Ti3SiC2开始发生分解,材料的密度和力学性能又显著下降。（TiB2＋TiC）/Ti3SiC2 composite ceramics were prepared by in-situ hot-pressing in Ar atmosphere.The phases and micro-structures of the materials were characterized by X-ray diffraction,scanning electron microscopy and transmission electron micros-copy.The effects of sintering temperature on the phases,sintering performance,microstructures and mechanical properties of the ceramics were investigated.The results show that with the increase of sintering temperature,the reaction among raw materials pro-ceeds completely and the density,bending strength and fracture toughness of the ceramics increase significantly.Fully densified in situ（TiB2＋TiC）/Ti3SiC2 composite ceramic with well-developed and optimized microstructure could be obtained when sintered at 1 500 ℃,in which laminated Ti3SiC2 grains,columnar TiB2 grains and equiaxed TiC grains were observed clearly.Moreover,owing to the superiority of in situ reaction,the reinforcing agents of TiB2 and TiC have small grain size and the grain boundaries are clear and clean.The composite ceramic shows the maximum bending strength（741 MPa）,fracture toughness（10.12 MPa？m1/2） and Vickers hardness（9.65 GPa）.When sintering temperature was higher than 1 550 ℃,the density and mechanical properties of the ceramics decrease gradually as a result of the decomposition of Ti3SiC2 matrix.

关 键 词：复相陶瓷 二硼化钛 碳化钛 钛碳化硅 原位合成 热压烧结 力学性能 

分 类 号：TB332[一般工业技术—材料科学与工程]