钨添加对Si_(3)N_(4)陶瓷力学性能的影响及强韧化机理研究  

Effect and Toughening Mechanism of Tungsten Addition on Mechanical Properties of Si_(3)N_(4) Ceramics

作　　者：杨超[1] 周存龙[1] 王强 杨元清 郝瑞杰 YANG Chao;ZHOU Cunlong;WANG Qiang;YANG Yuanqing;HAO Ruijie(Shanxi Key Laboratory of Metallurgical Equipment Design Theory and Technology,School of Mechanical Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,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,太原030024

出　　处：《硅酸盐通报》2023年第1期287-294,共8页Bulletin of the Chinese Ceramic Society

基　　金：山西省重点研发计划(201903D421046);山西省科技重大专项(20181102015);太原市2021揭榜项目。

摘　　要：为了增韧Si_(3)N_(4)基陶瓷材料,以钨(W)作为第二相材料,Y_(2)O_(3)-Al_(2)O_(3)作为烧结助剂,采用气压烧结法制备了W/Si_(3)N_(4)复合陶瓷材料。研究了W含量对W/Si_(3)N_(4)复合陶瓷材料致密性、力学性能以及结构的影响。结果表明:在W含量小于5%(质量分数)时,样品致密度均达97%以上;在W含量为5%(质量分数)时,获得的W/Si_(3)N_(4)复合陶瓷材料综合性能最佳,弯曲强度、硬度和断裂韧性分别为(670.28±40.00)MPa、(16.42±0.22)GPa和(8.04±0.16)MPa·m^(1/2),相比于未添加金属W的Si_(3)N_(4)陶瓷材料分别提高了38.08%、13.08%和44.34%;通过分析W/Si_(3)N_(4)复合陶瓷材料样品抛光面和压痕裂纹的微观结构,发现W的引入能促使裂纹在扩展路径上更易发生偏转、分叉等增韧机制,消耗裂纹扩展能量,从而改善Si_(3)N_(4)陶瓷的断裂韧性。To toughen Si_(3)N_(4)-based ceramic materials,W/Si_(3)N_(4)composite ceramic materials were prepared in this article by the pneumatic sintering method with tungsten(W)as the second phase material and Y_(2)O_(3)-Al_(2)O_(3)as sintering additive.Then the effect of W content on the compactness,mechanical properties,and microstructure of W/Si_(3)N_(4)composite ceramic materials was investigated.The results indicate that the densities of samples all reach more than 97%when the W content is less than 5%(mass fraction).The most outstanding overall performance of W/Si_(3)N_(4)composite ceramic materials is obtained when W content is 5%(mass fraction),and the bending strength,hardness,and fracture toughness are(670.28±40.00)MPa,(16.42±0.22)GPa,and(8.04±0.16)MPa·m^(1/2),respectively,which are 38.08%,13.08%,and 44.34%higher than Si_(3)N_(4)ceramic materials without the addition of metal W.By analyzing the microstructure of the polished surface and indentation cracks of W/Si_(3)N_(4)composite ceramic material samples,it is found that the introduction of W can trigger toughening mechanisms such as deflection and bifurcation of cracks in the propagation path,and consume crack expansion energy,thus improving the fracture toughness of Si_(3)N_(4)ceramics.

关 键 词：Si_(3)N_(4)陶瓷 钨 气压烧结 微观结构 致密性 弯曲强度 断裂韧性 

分 类 号：TQ174[化学工程—陶瓷工业]