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·m^(1/2),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。
（ 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 cBN is 1. 5 wt%,the mechanical properties of（ W,Ti） C-based composite cermets are the best. Its flexural strength reaches917 MPa,fracture toughness 9. 27 MPa·m1/2 and Vickers hardness 20. 64 GPa. 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.
出处
《工具技术》
2018年第1期34-39,共6页
Tool Engineering
基金
山东省自然科学基金(ZR2013EEM021)
关键词
C-BN
(Ti
W)C
热压烧结
金属陶瓷
增韧补强
cubic boron nitride
titanium tungsten carbides
hot pressing sintering
cermet
toughening and reinforcing
