Author(s)

Sotomi Ishihara^1,2, Hiroshi Shibata¹, Kenichi Masuda², Hiroko Mikado³, Minoru Ishiguro¹

¹National Institute of Technology, Toyama College, Toyama, Japan.
²Department of Mechanical Engineering, University of Toyama, Toyama, Japan.
³YKK Corporation, Kurobe, Japan.

In this study, fatigue crack growth (FCG) behavior of cemented carbide under the repeated thermal shock (RTS) was experimentally evaluated by using the thermal-shock experiment method developed by the authors. Tests were carried out using cemented carbide having two different WC crystal grain sizes. In addition, FCG behavior under rotating bending fatigue (RBF) test was investigated using the same cemented carbides. Then the FCG results obtained by the RTS test and the results of the RBF test obtained at stress ratio, R = -1, were compared with each other. Here, the stress ratio R is defined as, R = σ_min/σ_max; σ_min and σ_max are the minimum and the maximum stresses, respectively. From this comparison, it was found that the relation between the rate of fatigue crack growth (FCG) and the maximum stress intensity factor in the RTS tests was equivalent to the one obtained under the RBF tests at stress ratio of -1. From a practical point of view, this result is important as it indicates that it is not necessary to purposely perform RTS experiments. In this research, the effect of WC grain size on the short surface FCG behavior of the cemented carbide was also studied and discussed.

Fatigue, Cemented Carbide, Repeated Thermal Shock, Fatigue Crack Growth

Ishihara, S. , Shibata, H. , Masuda, K. , Mikado, H. and Ishiguro, M. (2018) Crack Growth Behavior in Cemented Carbide by Repeated Thermal Shock. Materials Sciences and Applications, 9, 345-356. doi: 10.4236/msa.2018.94023.