Si3N4晶须对原位形成Mo2NiB2金属陶瓷组织与性能的影响  

Effect of SiN whiskers on microstructure and properties of in situ prepared MoNiB cermet

作　　者：潘颖慧 潘应君[1] 柯德庆[1] 甘章华[1] 徐鑫 PAN Ying-hui;PAN Ying-jun;KE De-qing;GAN Zhang-hua;XU Xin(College of Materials Science and Metallurgical Engineering,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学材料与冶金学院,湖北武汉430081

出　　处：《材料热处理学报》2020年第10期111-116,共6页Transactions of Materials and Heat Treatment

基　　金：省部共建耐火材料与冶金国家重点实验室青年基金项目(2018QN04)。

摘　　要：采用化学镀方法在Si3N4晶须表面镀覆了一层均匀的镍镀层,利用真空液相烧结法制备了不同镀镍Si3N4晶须含量的Mo2NiB2基金属陶瓷,采用扫描电镜、显微硬度仪和三点弯曲试验等研究了不同镀镍Si3N4晶须的添加量对Mo2NiB2基金属陶瓷组织与性能的影响。结果表明:添加了适量镀镍晶须的金属陶瓷的组织细化,分布更均匀,抗弯强度和断裂韧性均有显著提高;当镀镍Si3N4晶须添加量为0.6 mass%时,金属陶瓷的力学性能最佳,其抗弯强度和断裂韧性分别达到了1887.4 MPa和19.24 MPa·m1/2。Si3N4晶须对Mo2NiB2基金属陶瓷的增韧是裂纹偏转、晶须桥联、微裂纹增韧以及细小硬质相颗粒对裂纹的阻碍等机制共同作用的结果。A uniform nickel coating was prepared on the surface of Si3N4 whisker by electroless plating, and Mo2NiB2 cermet with different content of Ni-coated Si3N4 whisker was prepared by vacuum liquid sintering method. The effect of different Ni-coated Si3N4whisker addition amount on microstructure and properties of the Mo2NiB2 cermet were studied by means of scanning electron microscopy, microhardness tester and three-point bending test. The results show that the microstructure of the Mo2NiB2 cermet with proper amount of Ni-coated Si3N4 whisker is refined, the distribution is more uniform, and the flexural strength and fracture toughness are significantly improved. When the addition of Ni-coated Si3N4whisker is 0.6 mass%, the mechanical properties of the cermet are the best, and the flexural strength and fracture toughness reach 1887.4 MPa and 19.24 MPa·m1/2, respectively. The toughening of Si3N4 whisker on Mo2NiB2 cermet is the result of crack deflection, whisker bridging, micro-crack toughening and the resistance of fine hard phase particles to cracks.

关 键 词：Si3N4晶须 Mo2NiB2金属陶瓷 微观组织 力学性能 

分 类 号：TG174.44[金属学及工艺—金属表面处理]