TaC含量对Ti(C,N)基金属陶瓷及其表面TiAlN涂层组织与性能的影响  

Effects of TaC Content in Ti(C,N)-based Cermet on Its Microstructure,Properties and TiAlN Coating

作　　者：时然 熊计[1,2] 杨天恩 Shi Ran;Xiong Ji;Yang Tian'en(School of Mechanical Engineering,Sichuan University,Chengdu Sichuan 610065,China;Chengdu Mingwu Technology Co.Ltd.,Chengdu Sichuan 610100,China)

机构地区：[1]四川大学机械工程学院,四川成都610065 [2]成都名钨科技有限责任公司,四川成都610100

出　　处：《硬质合金》2019年第5期352-360,共9页Cemented Carbides

基　　金：国家自然科学基金-高性能Ti(C,N)基金属陶瓷材料制备过程中关键冶金科学问题（5163000049）

摘　　要：为增强金属陶瓷涂层刀片的优良切削性能,以Co、Ni为粘结剂,使用Ti(C,N)、Mo2C、WC粉末等制备出不同TaC含量的Ti(C,N)-Mo2C-WC-Co-Ni混合料,以酒精为介质球磨48 h,干燥后经掺胶压制成20 mm×6.5 mm×5.25 mm的试样,然后在低压烧结炉中1440℃烧结进行密度、硬度、抗弯强度、断裂韧性等实验测试,通过SEM、EDS、光学显微镜等观察微观组织形貌并分析了TaC对PVD涂层的影响。结果表明:随TaC添加量增加,金属陶瓷的室温硬度、断裂韧性略微下降,密度略微升高,芯部渐渐变小,环厚度渐渐变厚。当TaC含量为6%时,抗弯强度达到峰值为2550 MPa,同时硬度和断裂韧性分别为91 HRA和8.7 MPa·m1/2。进行PVD处理以后,发现TaC的添加使涂层厚度增加,可以增强基体与涂层之间的结合力。因此当TaC含量是6.0wt%时,材料可以达到一个比较好的综合性能,显微组织晶粒细小,硬度和断裂韧性适中,抗弯强度较高。To enhance the cutting performance of coated cermet,Ti(C,N)-Mo2C-WC-Co-Ni mixture was achieved by mixing TaC,Ti(C,N),Mo2C,WC with binder of Co and Ni,which were planetary-ball milled in alcohol medium for 48 h,and then the slurry was dried and the forming agent was added,finally the resulting mixture was pressed to the samples with 20 mm×6.5 mm×5.25 mm in dimension,followed by sintered at 1440℃in a low-pressure sintering furnace.The tests of density,hardness,bending strength and fracture toughness on the obtained Ti(C,N)-based cermet were conducted.The microstructure of the cermet was observed by using scanning electron microscope(SEM),X-ray diffraction(XRD)and optical microscope.The effects of the TaC content in the cermet on the PVD coating were analyzed.The results show that with the increasing of the TaC content,the room-temperature hardness and fracture toughness of the Ti(C,N)-based cermet slightly decrease,while the density increases.Additionally,the size of the core becomes smaller and the thickness of the rim increases.When 6%TaC is introduced,the Ti(C,N)-based cermet is obtained with a maximum bending strength of 2550 MPa,the hardness of 91 HRA and the fracture toughness of8.7 MPa·m1/2.The thickness and the adhesion of the PVD-TiAlN film both increase with the increasing of the TaC contents in the substrate cermet.Generally,it is considered that when TaC of 6%is added,the optimum comprehensive performance of the Ti(C,N)-based cermet could be achieved,besides small grain size,moderate bending strength and hardness,and high fracture toughness.

关 键 词：TI(C N)基金属陶瓷 TAC 基体 涂层 组织 性能 

分 类 号：TF[冶金工程]