(西安科技大学 材料学院，西安 710054)
摘 要: 以TiC、TiN、Ni、Co等粉末为主要原料，以稀土Y2O3为添加剂，采用无压烧结技术制备Ti(C,N)基金属陶瓷，研究烧结工艺和稀土Y2O3添加量对Ti(C,N)基金属陶瓷显微组织和力学性能的影响。结果表明：随着温度的升高，TiC、TiN、WC、Cr3C2、Mo等相逐渐消失，向硬质芯相扩散发生固溶，经溶解-析出过程，最终形成新的Ti(C,N)硬质相和(Cr,W,Mo,Ti)(C,N)固溶体环形相，黏结金属Ni和Co主要以Ni相、TiCo和Co3W3C中间相的形式存在；稀土Y2O3的添加未改变Ti(C,N)基金属陶瓷烧结过程中的相结构演变过程，材料的显微硬度、抗弯强度和断裂韧性均随Y2O3添加量的增加呈先增加后降低的趋势，当Y2O3的加入量为0.8%(质量分数)时，Ti(C,N)基金属陶瓷的力学性能最佳，样品的显微硬度、抗弯强度和断裂韧性相比1450 ℃烧结50 min样品的分别提高了7.9%、45.8%和6.1%。
关键字: Ti(C,N)基金属陶瓷；Y2O3；烧结工艺；力学性能
（College of Materials Science and Engineering, Xi’an University of Science and Technology, Xi’an 710054, China）
Abstract:Ti(C,N)-based cermets were prepared by pressureless sintering method using TiC, TiN, Ni and Co powders as main raw materials and Y2O3 as additive. The effects of sintering process and Y2O3 content on the microstructure and mechanical properties of Ti(C,N)-based cermet were investigated. The results show that TiC, TiN, WC, Cr3C2 and Mo phases disappear gradually and diffuse into hard and rim phases by dissolution-precipitation process with increasing the sintering temperature, finally, new Ti(C,N) hard phases and (Cr,W,Mo,Ti)(C,N) rim phases are formed, while the bonding metals Ni and Co exist mainly in the form of Ni phases and the intermediate phases of TiCo and Co3W3C. The phase structure evolution of Ti(C,N)-based cermet almost has no change with adding Y2O3 during sintering process. The micro-hardness, bending strength and fracture toughness of Ti(C,N)-based cermet increase first, and then decrease with the increase of Y2O3 content. Ti(C,N)-based cermet achieves the best mechanical properties with 0.8% Y2O3 (mass fraction) addition, the micro-hardness, flexural strength and fracture toughness are increased by 7.9%, 45.8% and 6.1%, respectively, when compared to those of the sample sintered at 1450 ℃ for 50 min.
Key words: Ti(C,N)-based cermet; Y2O3; sintering process; mechanical property
