Changes in Selected Properties of Cemented Carbides upon Thermal Load
Cemented carbides (CC) tend to be seen by their users as indestructible materials whose only weakness is their high brittleness. Therefore, these users tend to treat these materials accordingly. In past, degradation processes in CC were clearly proven to occur in relation to thin film removal. In some cases, negative effects of ion bombardment prior to coating deposition have been found as well. The present paper responds to new findings associated with thermal loads that act on cemented carbides. It deals with changes which occur during thermal cycling, as well as during heating to temperatures which are routinely encountered in cutting processes. Experience shows that temperatures as low as 600 °C may already cause irreversible degradation. This is then reflected not only in surface oxidation but also in altered mechanical properties.