压力和SiC含量对热压烧结hBN陶瓷的致密性及力学性能的影响  

Effects of Pressure and the Content of SiC on Densification and Mechanical Properties of Hot Press Sintered hBN Ceramics

作　　者：苗义民 刘亮光 MIAO Yimin;LIU Liangguang(School of Materials Science and Engineering,Hainan University,Haikou 570228,Hainan,China)

机构地区：[1]海南大学材料科学与工程学院,海南海口570228

出　　处：《陶瓷学报》2022年第4期637-643,共7页Journal of Ceramics

基　　金：国家自然科学基金(51962003);海南省研究生创新科研课题(Hys2020-33)。

摘　　要：六方氮化硼(hBN)陶瓷在化工、冶金、航空航天等领域具有广阔的应用前景,然而,其烧结致密性依然是一个亟待解决的问题。基于恒定的微米级六方氮化硼(hBN)、纳米级立方氮化硼(cBN)粉体的初始晶粒尺寸分布及其体积分数,结合1800℃热压烧结,对比热烧结压力及碳化硅(SiC)粉体的引入量对hBN烧结致密度及其力学性能的影响。结果表明,相比于SiC的引入,提高烧结压力(80 MPa)能够明显提高hBN陶瓷的致密度和机械性能,所制备hBN陶瓷相对密度为93.7%,抗弯强度和抗压强度分别为94.90 MPa和159.32 MPa,而SiC的引入虽然能够在一定程度上提高hBN陶瓷的相对密度和机械性能,但其提升程度远低于烧结压力的作用。另外,当SiC含量为10 wt.%时,其相对密度达到91.1%,抗弯强度和抗压强度达到84.77 MPa和129.16 MPa。结合SEM结果可知,SiC的引入可以明显降低hBN陶瓷晶粒的取向性。Hexagonal boron nitride(hBN)ceramics have broad application prospects in the fields of chemical industry,metallurgy,aerospace and so on,while the densification of hBN ceramics is still an urgent problem to be solved.With fixed initial particle size distribution and volume fraction of microscale hexagonal boron nitride(hBN)and nanoscale cubic boron nitride(cBN)powders,hNB ceramics were prepared with hot pressing sintering at 1800℃,where the effect of the content of SiC on densification and mechanical properties of the ceramics were studied.As compared with the introduction of SiC,an increase in sintering pressure(80 MPa)was more significant in improving the densification and mechanical properties of the hBN ceramics.Specifically,the hBN ceramics had a relative density of 93.7%,with flexural and compressive strengths to be 94.90 MPa and 159.32 MPa,respectively.In addition,when the content SiC was 10 wt.%,the exhibited a relative density of 91.1%,with flexural and compressive strengths to be 84.77 MPa and 129.16 MPa.According to the SEM results,it can be concluded that the introduction of SiC can significantly reduce the anisotropic grain growth of the hBN.

关 键 词：六方氮化硼 立方氮化硼 碳化硅 热压烧结 致密化 

分 类 号：TQ174.75[化学工程—陶瓷工业]