B_(4)C含量对ZrB_(2)陶瓷微观结构及力学性能的影响  

Effects of B_(4)C content on the microstructure and mechanical properties of ZrB_(2) ceramics

作　　者：杜玉辉 汤振霄 彭可[1] 周远明 易茂中[1] DU Yuhui;TANG Zhenxiao;PENG Ke;ZHOU Yuanming;YI Maozhong(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2021年第1期77-83,共7页Materials Science and Engineering of Powder Metallurgy

基　　金：装备预研相关基础研究项目(4142202XXXX);湖南省自然科学基金资助项目(2017JJ2320)。

摘　　要：针对ZrB_(2)陶瓷粉末在球磨时易掺入ZrO2,影响ZrB_(2)陶瓷烧结致密化的问题,添加B_(4)C作为烧结助剂,采用无压烧结法制备ZrB_(2)陶瓷材料,研究B_(4)C含量(w(B_(4)C),下同)对材料微观形貌、硬度与抗弯强度的影响。结果表明,B_(4)C通过与晶粒表面的ZrO2发生反应,抑制ZrB_(2)晶粒粗化,减小晶粒尺寸,从而提高烧结致密度。随B_(4)C含量增加,ZrB_(2)陶瓷的晶粒尺寸和相对密度逐渐增大,抗弯强度和硬度先升高后降低。当w(B_(4)C)为7%时,ZrB_(2)晶粒细小,材料的抗弯强度和硬度(HV)达到最大,分别为242 MPa和12.65 GPa。w(B_(4)C)增加至9%时,出现晶粒异常长大,材料力学性能下降。Aiming at the problem that ZrB_(2) ceramics powder were easily mixed with ZrO2 during ball milling,which affected the sintering denstification of ZrB_(2) ceramics,B_(4)C was introduced as sintering additive,and ZrB_(2) ceramics were prepared by pressureless sintering.The effects of B_(4)C content on the microstructure and mechanical properties of the materials were investigated.The results show that B_(4)C can inhibit grain coarsening and reduce grain size by reacting with ZrO2 on the grain surface.With the increase of B_(4)C content,the grain size and relative density of the ZrB_(2) ceramics increase gradually,while the flexural strength and hardness first increase and then decrease.When the mass fraction of B_(4)C is 7%,the grain size of ZrB_(2) are fine,and the flexural strength and hardness of the material reach the maximum value,which are 242 MPa and 12.65 GPa respectively.As increasing the content of B_(4)C to 9%,the grains grow abnormally and the mechanical properties decrease.

关 键 词：ZrB_(2)陶瓷 B_(4)C含量 无压烧结 微观结构 抗弯强度 

分 类 号：U465.3[一般工业技术—材料科学与工程]