TiN和TiN/Cr_3C_2抑制剂对WC-Co硬质合金组织和性能的影响  

Effect of TiN and TiN/Cr_3C_2 Inhibitors on Microstructure and Properties of WC-Co Cemented Carbide

作　　者：孔德方[1,2] 金鹏[1,2] 

机构地区：[1]硬质合金国家重点实验室,湖南株洲412000 [2]株洲硬质合金集团有限公司,湖南株洲412000

出　　处：《硬质合金》2017年第4期254-262,共9页Cemented Carbides

摘　　要：采用粉末冶金法制备WC-Co硬质合金,研究了单一添加0%~1.2%(文中含量无特殊说明的均为质量分数)TiN和复合添加不同比例TiN/Cr_3C_2晶粒长大抑制剂对WC-Co硬质合金组织和性能的影响。结果表明:添加TiN后,WC晶粒明显细化且晶粒尺寸分布集中,合金硬度上升。TiN与粘结相中的W和C形成(Ti,W)(C,N)固溶体,起到了细化了WC晶粒的作用,但是由于固溶体本身的脆性和粘结相对其润湿性较差,使合金的强度和韧性下降。TiN单一添加量为0.4%时,合金综合性能最佳,硬度值可达到1 770 HV3,强度值为2 870 MPa,韧性达到10.37 MPa·m^(1/2);复合添加w(TiN)∶w(Cr_3C_2)为1∶3时,合金综合性能最佳,硬度值可达到1 770 HV3,强度值为2 860 MPa,韧性达到10.23 MPa·m^(1/2)。WC-Co based cemented carbide was fabricated by powder metallurgic method, and the effects of 0~1.2 %（if no specific description, all the contents in this paper are mass fraction） TiN and different proportions of Ti N/Cr3C2 inhibitors on microstructure and properties of the alloys were studied. The results show that alloy with homogeneous microstructure and finer gains is obtained when TiN is added,and the hardness of the alloy is increased. The mechanism of TiN inhibitor is that the reaction between W, C and TiN leads to the presence of（Ti,W）（C,N） precipitates in the binder phase. However, the brittleness of（Ti,W）（C,N） and the poor wettability between binder phase and（Ti,W）（C,N） lower the strength and toughness of the alloy. When 0.4% TiN is added separately, the material shows the best properties with hardness of 1 770 HV3, bending strength of 2 870 MPa and fracture toughness of 10.37 MPa·m^（1/2）. When the compound additions of TiN and Cr3C2 with the proportion of 1∶3, the material shows the best properties with hardness of 1 770 HV3, bending strength of 2 860 MPa and fracture toughness of 10.23 MPa·m^（1/2）.

关 键 词：硬质合金 晶粒长大抑制剂 TIN CR3C2 组织和性能 

分 类 号：TG135.5[一般工业技术—材料科学与工程]