固相烧结阶段保温参数对Ti(C,N)基金属陶瓷显微组织和力学性能的影响  

Influences of Solid State Sintering Parameters on Microstructure and Mechanical Properties of Ti(C,N)-based Cermet

作　　者：马遗萍 郑勇[1] 周伟[1] 赵毅杰[1] 沈裕峰 

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》2014年第3期141-147,共7页Cemented Carbides

基　　金：国家自然科学基金(编号:51174118)资助项目

摘　　要：采用真空烧结工艺制备了Ti（C,N）基金属陶瓷,液相出现前,在1 220～1 260℃进行了保温。采用扫描电镜、能谱仪等研究了此阶段的保温温度和保温时间对Ti（C,N）基金属陶瓷最终烧结体的显微组织和力学性能的影响。结果表明：在1 220～1 260℃温度区间,随着保温温度的升高,金属陶瓷最终烧结体的组织逐渐变得均匀,环形相包覆变得完整且环形相厚度增加,材料致密度和强度提高;随着保温时间的延长,硬质相晶粒逐渐细化,粘结相中固溶合金元素含量增加,强度硬度均提高;当保温温度过高或保温时间过长时,环形相过度变厚,反而降低了材料的综合性能。经过1 240℃保温120min,并在1 400℃真空烧结60 min,金属陶瓷最终烧结体显微组织分布均匀,环形相厚度适中,致密度和力学性能较优异。ABSTRACT Ti（C,N）-based cermet was prepared by vacuum sintering. Before liquid phase appearing, the temperature was held between 1 220 ℃ and 1 260 ℃ for different time. The influences of solid state sintering parameters including temperature and soaking time on the microstrueture and mechanical properties of the sintered cermet were investigated by SEM, EDX, etc. It is shown that the microstructure of the cermet distributes more evenly and the rim phase becomes thicker with the increase of the solid state sintering temperature. In addition, the density and the transverse rupture strength （IllS） of the cermet apparently are improved. With the increase of the solid state holding time, the grain of the hard phase becomes finer and the contents of Ti, W and Mo in binder phase gradually increase. As a result, the hardness （I-IRA） and TRS of the cermet are improved. When the sintering temperature is too high or the soaking time is too long, excessive thickening rim phase decreases the mechanical properties of the cermet. The optimized mechanical properties are achieved for the cermet when holding at 1 240 ℃ for 120 min and then sintered at 1 400 ℃ for 60 min, which are characterized by refined microstructures, moderate thickness of rim phase and enhanced density.

关 键 词：TI(C N)基金属陶瓷 固相烧结阶段 保温温度 保温时间 显微组织 致密度 力学性能 

分 类 号：TG148[一般工业技术—材料科学与工程]