Towards understanding plastic deformation in hardmetal turning inserts with different binders

This works investigates the deformation of coated hardmetal turning inserts used until the end of life. Three hardmetals with different binder phases, pure cobalt, 15 wt% iron 85 wt% nickel and 85 wt% iron 15 wt% nickel are tested. It is shown that grain boundary sliding accommodated by formation of binder phase lamellae is present in all tested inserts, given by a clear increase in number of lamellae in the microstructure of a tested cutting edge compared to a pristine cutting edge of the same material. The lamellae formation is discussed and can be explained by the stresses experienced by the cutting edge during turning. In addition the importance of good coating adhesion was shown by formation of cavities in inserts that experienced flaking of the coating.

Automated summary

This study investigates the deformation of coated hardmetal turning inserts used until the end of life. It is found that grain boundary sliding accommodated by formation of binder phase lamellae is present in all tested inserts, highlighting the importance of good coating adhesion for the performance of cutting inserts.