Crack Growth Behavior in Cemented Carbide by Repeated Thermal Shock
- 1 National Institute of Technology, Toyama College, Toyama, Japan
- 2 National Institute of Technology, Toyama College, Toyama, Japan
- 3 Department of Mechanical Engineering, University of Toyama, Toyama, Japan
- 4 YKK Corporation, Kurobe, Japan
- 5 National Institute of Technology, Toyama College, Toyama, Japan
Abstract
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.
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