摘要：采用热压烧结制备了不同亚微米级cBN含量的(Ti，W)C基复合金属陶瓷刀具材料，用热场发射扫描电子显微镜及能谱仪、透射电子显微镜和X射线衍射仪对材料的微观组织结构和力学性能进行了研究。结果表明：添加cBN可改善材料的力学性能，当cBN含量为1.5wt%时，(Ti，W)C基复合金属陶瓷刀具的性能最优，其抗弯强度达到917MPa，断裂韧性为9.27MPa·m1/2，维氏硬度为20.64GPa；适量cBN可起到细化晶粒、减少气孔缺陷和提高致密度的作用，复合材料由沿晶断裂为主转变为穿晶断裂为主；在cBN复合(W，Ti)C基金属陶瓷刀具材料中，主要的增韧补强机理有晶粒细化、颗粒桥联、裂纹偏转和裂纹分叉。

关键词：cBN；(Ti，W)C；热压烧结；金属陶瓷；增韧补强

中图分类号：TG711；TH140.7；TB331文献标志码：A

Study on Cubic Boron Nitride Reinforced (W，Ti)CBased

Composite Metal Ceramic Tool Material

Li Xianglong，Fang Bin，Pai Junjun，Xu Ming，Ma Xiao

Abstract:(Ti，W)C based composite cermet tool materials with different cBN contents are prepared by hot-pressing sintering.The microstructures and mechanical properties of the composites are studied by using field emission scanning electron microscope and energy dispersive Xray spectrometer，transmission electron microscope and Xray diffractometer.The results show that the addition of cBN can improve the mechanical properties of the composites. When the content of cBN is 1.5wt%，the mechanical properties of (W，Ti) Cbased composite cermets are the best.Its flexural strength reaches 917MPa，fracture toughness 9.27MPa·m1/2 and Vickers hardness 20.64GPa.It is found that the proper content of cBN can refine the grain effectively，improve the density and reduce the defects such as cavities. With the addition of cBN，the fracture form of composite can change from intergranular fracture to transgranular fracture，the fracture mode changes can effectively improve the mechanical properties of composite materials.In cBN composite(W，Ti) C matrix cermet tool materials，the main toughening mechanism is grain refinement，particle bridging，crack deflection and crack bifurcation.

Keywords:cubic boron nitride；titanium tungsten carbides；hot pressing sintering；cermet；toughening and reinforcing