液相烧结法制备大尺寸双层梯度结构硬质合金的研究  

Fabrication of Functionally Graded Cemented Carbide Components with Large Dimension by Liquid Phase Sintering

作　　者：王晓灵[1] 陈勇[1] 曾守富 Wang Xiaoling;Chen Yong;Zeng Shoufu(Zigong Cemented Carbide Corp. Ltd., Chengdu branch, Chengdu Sichuan 610100, China)

机构地区：[1]自贡硬质合金有限责任公司成都分公司,四川成都610100

出　　处：《硬质合金》2018年第1期15-21,共7页Cemented Carbides

摘　　要：常规均质结构硬质合金的硬度与韧性是一对矛盾特性,需要根据实际使用条件,在硬度和韧性之间进行妥协取舍。功能梯度结构材料是解决这个难题的可行办法。本文采用液相烧结的方法,制备了具有双层梯度结构的大尺寸硬质合金制品。通过测试横向断裂强度(TRS)和室温冲击韧性(ak)研究了结合部位的强度。采用金相显微镜观察了结合部位的显微组织,并通过测试维氏硬度、密度和磁性能的方法分析了结合部位组织的梯度变化情况。实验结果表明:液相烧结扩散法可以实现不同硬质合金之间的冶金结合,结合强度可达2 000 MPa以上,结合部位的显微组织存在明显界面和显著梯度结构。The wear resistance of the conventional homogeneous cemented carbides is inversely proportional to their fracture toughness. Thus, there is always a trade-off between hardness and toughness according to the practical applications.Functionally gradient material may be a feasible method to solve this problem. In this study, an experiment was conducted on adhering two different cemented carbides by diffusion via liquid phase sintering to fabricate large dimension cemented carbide articles with dual-layer structure. The coalescent strength was measured by transverse rupture strength（TRS） and impact toughness（ak） testing. The microstructure of the combination position was observed by optical microscope. The gradient zone was detected by testing the hardness, density and magnetism properties. Results show that metallurgical adhesion between couples of different cemented carbides is possible by this process. The coalescent strength can be higher than 2 000 MPa. Obvious interface and remarkable gradient structure are detected in the combination area.

关 键 词：硬质合金 冶金结合 连接 双层结构 界面 结合强度 

分 类 号：TG135.5[一般工业技术—材料科学与工程]