烧结气压对氮化硅陶瓷力学性能的影响  

Effect of Sintering Pressure on Mechanical Properties of Silicon Nitride Ceramics

作　　者：杨元清 周存龙[1] 王强 郝瑞杰 彭沧 王宇琨 YANG Yuanqing;ZHOU Cunlong;WANG Qiang;HAO Ruijie;PENG Cang;WANG Yukun(Shanxi Key Laboratory of Metallurgical Equipment Design Theory and Technology,College of Mechanical Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,Shanxi,China)

机构地区：[1]太原科技大学机械工程学院、山西省冶金设备设计理论与技术重点实验室,山西太原030024

出　　处：《陶瓷学报》2024年第3期532-538,共7页Journal of Ceramics

基　　金：山西省重点研发计划(201903D421046);山西省科技重大专项(20181102015);2021年度太原市科技计划“揭榜挂帅”项目。

摘　　要：在氮化硅陶瓷气压烧结制备过程中,除烧结加热制度外,氮气压力对其性能影响也很大,为了制备出性能更为优异的氮化硅陶瓷,本文采用气压烧结法在不同压力下制备氮化硅陶瓷材料,研究氮气压力对氮化硅陶瓷材料力学性能的影响。结果表明:当氮气压力达到4 MPa左右时,获得的氮化硅陶瓷材料综合性能最佳,α相几乎全部转变为β相,β-Si_(3)N_(4)晶粒长径比约为5.5,相对密度约为97.9%,抗弯强度约为(671.83±30.00)MPa、维氏硬度(HV)约为1670.25±50.00、断裂韧性约为(7.83±0.3.0)MPa·m1/2;通过分析氮化硅陶瓷材料腐蚀面和压痕裂纹的微观结构,发现适当的氮气压力能促使裂纹在扩展路径上更易发生偏转、分叉等增韧机制,消耗裂纹扩散能量,从而提高氮化硅陶瓷材料的断裂韧性,本研究对氮化硅陶瓷材料的增韧具有一定的指导意义。In pressure sintering of silicon nitride ceramics,nitrogen pressure has a great impact on its properties besides sintering heating system.In order to prepare silicon nitride ceramics with desired properties,this paper was aimed to elucidate the effect of nitrogen pressure on mechanical properties of silicon nitride ceramics.When the nitrogen pressure is about 4 MPa,comprehensive properties of the silicon nitride ceramic materials are the highest,while theα-βphase transition is nearly completed.The aspect ratio ofβ-Si_(3)N_(4) grains is about 5.5 and the relative density is about 97.9%.The bending strength is about(671.83±30.00)MPa,the hardness is about(1670.25±50.00)HV and the fracture toughness is about(7.83±0.3.00)MPa·m1/2.According to the microstructure of corroded surface and indentation cracks,it is found that appropriate nitrogen pressure resulted in crack deflection,bifurcation and other toughening mechanisms on the expansion path,consuming the crack diffusion energy and thus improving fracture toughness of the silicon nitride ceramics.The results could be used as a reference for the toughening of silicon nitride ceramic materials.

关 键 词：氮化硅陶瓷 气压烧结 氮气压力 致密性 抗弯强度 维氏硬度 断裂韧性。 

分 类 号：TQ174.75[化学工程—陶瓷工业]