TITLE:
Crack Growth Behavior in Cemented Carbide by Repeated Thermal Shock
AUTHORS:
Sotomi Ishihara, Hiroshi Shibata, Kenichi Masuda, Hiroko Mikado, Minoru Ishiguro
KEYWORDS:
Fatigue, Cemented Carbide, Repeated Thermal Shock, Fatigue Crack Growth
JOURNAL NAME:
Materials Sciences and Applications,
Vol.9 No.4,
April
11,
2018
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 = σmin/σmax; σmin and σmax 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.