烧结气氛对Ti(C,N)基金属陶瓷刀具微观组织、力学及切削性能的影响  

Effect of Sintering Atmosphere on Microstructure,Mechanical and Cutting Properties of Ti(C,N)-Based Cermets Tools

作　　者：彭欣 高荣根 杨慧 张亮 Peng Xin;Gao RongGeng;Yang Hui;Zhang Liang(Zhu Zhou Hua Rui precision tool incorporated company,Zhuzhou Hunan 412000,China)

机构地区：[1]株洲华锐精密工具股份有限公司,湖南株洲412000

出　　处：《硬质合金》2020年第6期438-445,共8页Cemented Carbides

摘　　要：通过不同烧结气氛制备出Ti(C,N)基金属陶瓷,采用光学金相显微镜、SEM、EDS与标准化仪器研究了Ti(C,N)基金属陶瓷在不同烧结气氛下的微观组织变化与力学性能;制备出金属陶瓷刀具进行切削试验。结果表明:固液阶段为真空烧结所制备出的金属陶瓷微观结构中的黑芯硬质相含量较小而灰色环形相厚度较大。氮气气氛下烧结的环形相厚度减薄,黑芯硬质相数量明显增多且粒度均匀,基体芯部及表层的微观组织存在较大差异。氩气气氛烧结的微观组织与真空条件下相似。氮气气氛烧结的试样的硬度呈现出自芯部至表层连续递增的梯度变化,真空、氩气烧结则无差异;氮气、氩气气氛烧结的抗弯强度高于真空烧结的。氮气气氛烧结的试样力学性能最佳,表层硬度92.5 HRA,抗弯强度为2190 MPa,断裂韧性为9.6 MPa·m^(1/2)。连续干式切削试验表明,氮气气氛烧结的金属陶瓷刀具的前刀面月牙洼磨损及后刀面磨损相对于真空、氩气气氛烧结的有所降低。Ti(C,N)-based cermets were prepared under different sintering atmospheres.The microstructure changes and mechanical properties of Ti(C,N)-based cermets under different sintering atmospheres were studied by optical microscopy,SEM,EDS and standardized instruments.The cermet inserts were prepared for cutting tests.The results show that the microstructure of cermets prepared by vacuum sintering in the solid-liquid phase contains less black hard phase and more gray ring phase.The thickness of the ring phase decreases,the hard phase increases obviously and the particles sizes were uniform in nitrogen atmosphere and the microstructure of the central region and surface layer of the matrix was also different.The microstructure of the cermet under argon sintering is similar to that under vacuum condition.The hardness of samples sintered in nitrogen atmosphere showed a continuous gradient increase from the core to the surface,but no difference was found between vacuum and argon sintering.Compared with vacuum sintering,the bending strength was improved in nitrogen and argon atmosphere.The mechanical properties of the samples sintered in nitrogen atmosphere were best,the surface hardness was 92.5 HRA,the bending strength was 2190 MPa,and the fracture toughness was 9.6 MPa·m^(1/2).The test results also show that the crater wear on the front face and wear on the back face were greatly reduced compared with that under vacuum and argon atmosphere sintering in the continuous dry cutting test.

关 键 词：金属陶瓷 微观组织 力学性能 切削试验 

分 类 号：TG711[金属学及工艺—刀具与模具]