硬质合金疲劳裂纹的萌生与扩展行为  

Behavior of fatigue crack initiation and propagation of cemented carbides

作　　者：张忠健[1] 赵声志[1] 彭文[1] 张倩霞[2] 陈鼎[2] 

机构地区：[1]硬质合金国家重点实验室,株洲412000 [2]湖南大学材料科学与工程学院,长沙410082

出　　处：《中国有色金属学报》2014年第12期3031-3041,共11页The Chinese Journal of Nonferrous Metals

基　　金：湖南省"十一五"重大科技专项(2007FJl002);湖南省自然科学基金资助项目(14JJ1013)

摘　　要：硬质合金的服役环境通常十分恶劣,需要承受循环应力、温度(如高温或循环温度)和腐蚀环境的共同影响,机械疲劳、热疲劳和腐蚀疲劳等多种疲劳断裂机制是导致硬质合金材料失效的重要原因。从疲劳裂纹的萌生和扩展两方面系统地阐述硬质合金疲劳性能的影响因素。疲劳裂纹易沿着粗大的WC颗粒、孔洞、夹杂物和粘结相池等缺陷处萌生,而疲劳裂纹的扩展行为受到各种因素的影响,如应力比、频率、温度和环境等外部因素以及显微结构和化学成分等内部因素。Cemented carbides are often served in extreme environments, under which they need to suffer mutual influence of cyclic stress, temperature （such as high temperature and cyclic temperature） and corrosive environment. Various fatigue fracture mechanisms, such as mechanical fatigue, thermal fatigue and corrosion fatigue, are the main reasons for the failure of the alloys. In terms of the fatigue crack initiation and propagation, the fatigue performance in cemented carbide was systematically discussed. The analysis shows that the fatigue crack is prone to initiate at coarse WC grains, pores, inclusions or binder phase pools, while the propagation performance of fatigue crack is influenced by various factors, including external factors of stress ratio, frequency, temperature and environment, and internal factors of microstructure and chemical composition.

关 键 词：硬质合金 疲劳裂纹 萌生 扩展 

分 类 号：TB303[一般工业技术—材料科学与工程]