摘要
采用三点弯曲疲劳法,研究了不同粘结相含量以及粘结相成分的硬质合金在两种不同应力比(R=0.1和R=0.5)加载时的疲劳行为,并结合SEM对疲劳机理进行了分析.结果表明:硬质合金疲劳断裂过程同时存在脆性断裂和韧性断裂.在两种应力比疲劳加载时都发现,增加钴含量,合金的疲劳敏感性先减小后增大,添加Ni和Cr能降低合金的疲劳敏感性.大应力比疲劳加载时,粘结相疲劳断裂过程由脆性断裂向韧性断裂转变.增大应力比对合金的疲劳敏感性也有影响.
The three-point bending fatigue behaviors of WC-Co cemented carbides with different binder phase content and composition under cyclic loading at two different stress ratios （R = 0.1 and R = 0.5） were investigated. The characterization of the fracture surfaces was carried out by using a scanning electron mi- croscope （SEM）, and the fatigue mechanism was also studied. The results show that the macroscopic frac- ture morphology exhibited brittle fracture and toughness fracture. With the increase of Co content, the fa- tigue sensitivity decreased firstly and then increased. Cemented carbides with complex binder phase （Co q- Ni q- Cr） exhibited lower fatigue sensitivity than that of pure Co cemented carbides. The fracture mecha- nism transformed from brittle to ductile at the stress ratio changing from 0.1 to 0.5. With the increase of the stress ratio, the fatigue sensitivity was changed.
出处
《湖南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2017年第6期1-6,共6页
Journal of Hunan University:Natural Sciences
基金
硬质合金国家重点实验室项目(201403001)~~
关键词
硬质合金
应力比
疲劳
粘结相
cemented carbides
stress ratio
fatigue
binder phase
