SiC晶须对超细晶WC-Co硬质合金微观组织和力学性能的影响  

Effect of SiC Whiskers on the Microstructure and Mechanical Properties of Ultrafine-grained WC-Co Cemented Carbides

作　　者：洪梦蝶 吕皓 王海滨[1,2] 刘雪梅 宋晓艳[1,2] HONG Mengdie;LYU Hao;WANG Haibin;LIU Xuemei;SONG Xiaoyan(College of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China;Key Laboratory of Advanced Functional Materials,Ministry of Education of China,Beijing 100124,China)

机构地区：[1]北京工业大学材料科学与工程学院,北京100124 [2]新型功能材料教育部重点实验室,北京100124

出　　处：《中国钨业》2024年第4期20-27,共8页China Tungsten Industry

基　　金：国家自然科学基金(52101003,92163107,52171061,52271085);国家重点研发计划(2022YFB3708800)。

摘　　要：本文利用快速热压烧结的方法制备了含有SiC晶须的超细晶WC-12Co硬质合金,分析了添加不同体积分数的SiC晶须对WC-12Co硬质合金微观组织和力学性能的影响,并研究了SiC晶须增韧超细晶硬质合金的机理。研究结果表明:添加SiC晶须可以细化WC晶粒;随着SiC晶须含量的增加,合金的硬度先下降再上升,断裂韧性先上升再下降。合金受到外力时,SiC晶须从合金基体中拔出,并引起裂纹的偏转和桥接,从而提高合金的断裂韧性。适当延长WC-12Co粉末和SiCw的球磨时间,可以改善合金的微观组织均匀性,避免SiC晶须的团聚,在不降低合金断裂韧性的前提下提高其硬度,获得高的综合力学性能。Ultrafine-grained WC-12Co cemented carbide containing SiC whiskers was prepared using rapid hot-press sintering. The effects of adding different volume fractions of SiC whiskers on the microstructure and mechanical properties of WC-12Co cemented carbide were analyzed, and the toughening mechanism of SiC whiskers in ultrafine-grained cemented carbide was investigated. The research results show that the addition of SiC whiskers can refine the WC grains. As the SiC whisker content increases, the hardness of the alloy first decreases and then increases,while the fracture toughness first increases and then decreases. When the alloy is subjected to external forces, the SiC whiskers are pulled out from the alloy matrix, causing crack deflection and bridging, which enhances the fracture toughness of the alloy. Appropriately extending the ball milling time of WC-12Co powder and SiC whiskers can improve the microstructural uniformity of the alloy, avoid agglomeration of SiC whiskers, and increase its hardness without reducing the fracture toughness of the alloy, thereby achieving high comprehensive mechanical properties.

关 键 词：超细晶硬质合金 SIC晶须 微观组织 力学性能 增韧机理 

分 类 号：TF125.3[冶金工程—粉末冶金] TG135.5[冶金工程—冶金物理化学]