Nb_(2)O_(5)含量对原位碳热还原法制备的Ti(C,N)基金属陶瓷显微组织和力学性能的影响  

Effects of Nb_(2)O_(5)Content on Microstructures and Mechanical Properties of Ti(C,N)-Based Cermets Fabricated by In-Situ Carbothermal Reduction Method

作　　者：王旺旺 杨政凯 梁海峰 姜智艺 郑勇[1] Wang Wangwang;Yang Zhengkai;Liang Haifeng;Jiang Zhiyi;Zheng Yong(College of Material Science&Technology,Nanjing University of Aeronautics and Astronautics,Nanjing Jiangsu 210016,China)

机构地区：[1]南京航空航天大学材料科学与技术学院,江苏南京210016

出　　处：《硬质合金》2024年第3期171-178,共8页Cemented Carbides

基　　金：国家自然科学基金(51674148);国家重点实验室基金(JCKY61420052023)。

摘　　要：以原位碳热还原法制备了Ti(C,N)基金属陶瓷,研究了Nb_(2)O_(5)添加量对金属陶瓷显微组织和力学性能的影响规律。结果显示:当添加Nb_(2)O_(5)的质量分数由0增加至2.80%时,金属陶瓷硬质相晶粒明显细化,显微组织中“白芯-灰环”晶粒数量增多;室温抗弯强度、硬度、临界热震温差和高温抗弯强度有所增加,但断裂韧性略微降低。随着Nb_(2)O_(5)的添加量继续增加,金属陶瓷显微组织中出现孔洞,室温抗弯强度、硬度、临界热震温差、高温抗弯强度和断裂韧性均不断下降。当Nb_(2)O_(5)的添加量为2.80%时,金属陶瓷表现出最佳的综合力学性能,其室温抗弯强度、硬度、断裂韧性、临界热震温差和高温抗弯强度分别为:2439MPa、90.6HRA、12.8MPa•m^(1/2)、360℃、1519MPa。The in-situ carbothermal reduction method was used to fabricate Ti(C,N)-based cermets,and the effects of Nb_(2)O_(5)on microstructures and mechanical properties of Ti(C,N)-based cermets were studied.The results indicate that when the content of Nb_(2)O_(5)increases from 0%to 2.80%,the hard phase grains of the cermets are significantly refined,and the number of“white core/gray rim”grains increases.Moreover,room-temperature transverse rupture strength(TRS),hardness,critical thermal shock temperature difference,and high-temperature TRS increase,while the fracture toughness decreases.As Nb_(2)O_(5)content rises,there are holes in the microstructure of the cermets,and room-temperature TRS,hardness,critical thermal shock temperature difference,high-temperature TRS,and fracture toughness gradually decrease.The cermets with Nb_(2)O_(5)content of 2.80%exhibit the best comprehensive mechanical properties,with a room-temperature TRS of 2439 MPa,a hardness of 90.6HRA,a fracture toughness of 12.8 MPa·m^(1/2),a critical thermal shock temperature difference of 360℃,and a high-temperature TRS of 1519 MPa,respectively.

关 键 词：TI(C N)基金属陶瓷 Nb_(2)O_(5) 原位碳热还原 显微组织 力学性能 

分 类 号：TG148[一般工业技术—材料科学与工程]