B_(4)C陶瓷中原位生成TiB_(2)及其对力学性能的强化机制  

In-Situ Formation of TiB_(2)in B_(4)C Ceramics and Its Strengthening Mechanism on Mechanical Properties

作　　者：姚万凯 鄢俊兵 李享成[1] 陈平安[1] 朱颖丽 朱伯铨[1] YAO Wankai;YAN Junbing;LI Xiangcheng;CHEN Pingʹan;ZHU Yingli;ZHU Boquan(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;Wuhan Xinxin Semiconductor Manufacturing Co.,Ltd,Wuhan 430223,China)

机构地区：[1]武汉科技大学,省部共建耐火材料与冶金国家重点实验室,武汉430081 [2]武汉新芯集成电路制造有限公司,武汉430223

出　　处：《硅酸盐学报》2022年第9期2414-2421,共8页Journal of The Chinese Ceramic Society

基　　金：湖北省重点研发计划(2020BAA028);湖北省自然科学基金创新群体项目(2020CFA038);国家自然科学基金(51972242和51774218)。

摘　　要：以TiO_(2)为烧结助剂,采用反应烧结法在B_(4)C陶瓷中原位生成TiB_(2),制备出致密的B_(4)C陶瓷,并对其强化机制进行了分析。结果表明:随着TiO_(2)添加量的增加,B_(4)C陶瓷的致密度和抗弯强度先增大后减小,断裂韧性不断增大。当TiO_(2)添加量为5%(质量分数)、烧结温度为1700℃时,B_(4)C陶瓷致密度达到99.6%;当TiO_(2)加入量为15%时,B_(4)C陶瓷的Vickers硬度为36.0 GPa,断裂韧性为4.38 MPa·m^(1/2),抗弯强度为405 MPa,综合性能最优。原位生成的TiB_(2)抑制了B_(4)C陶瓷晶粒长大,消除了裂纹尖端应力,使裂纹产生偏转和分叉,对B_(4)C陶瓷起到细晶强化和增韧作用。To improve the mechanical properties of B_(4)C ceramics,TiB_(2)was generated in-situ in B_(4)C ceramics by a reaction sintering method with TiO_(2)as a sintering aid to prepare dense B_(4)C ceramics,and the enhancement mechanism of its mechanical properties was analyzed.The results show that the density and flexural strength of B_(4)C firstly increase and then decrease and the fracture toughness increases with the increase of TiO_(2)addition.The density of B_(4)C ceramics reaches 99.6%when the TiO_(2)addition is 5%(in mass fraction)and the sintering temperature is 1700℃.The optimum overall performance of B_(4)C ceramics(i.e.,the Vickers hardness of 36.0 GPa,the fracture toughness of 4.38 MPa·m^(1/2,)the bending strength of 405 MPa)can be obtained when the amount of TiO_(2)added is 15%.The in-situ TiB_(2)inhibits the growth of B_(4)C grains,eliminates the stress at the crack tip,deflects and bifurcates the crack,and plays a role in grain refinement strengthening and toughening of B_(4)C ceramics.

关 键 词：放电等离子体烧结 碳化硼 二硼化钛 力学强度 

分 类 号：TQ174.1[化学工程—陶瓷工业]