Influence of carbon content on fatigue strength of cemented carbides

Abstract

In this study, the influence of carbon content on fatigue strength of fine grade cemented carbides (WC-12Co) was investigated. Thereby, the carbon content was varied systematically in the two- and three-phase region. Specimens from the different alloys were fabricated and tested in flat bending fatigue experiments. Results show no significant influence of the carbon content as long as no graphite was precipitated. In accordance with findings in the literature, the fatigue strength decreases significantly when graphite precipitations occur. Both, wavelength dispersive x-ray spectroscopy (WDS) and energy dispersive spectroscopy (EDS) were used for analysis of the chemical composition of the binder phase. No significant influence of the global carbon content on the morphology of WC-grains as well as the local carbon content in the cobalt-binder was found.