Properties Of Hardmetals With Different Fe-Co-Ni Binder

The present work deals with an investigation of WC-(Fe,Co,Ni) hardmetals and investigations of their mechanical and physical properties. Grain-growth inhibitors (GGIs) in form of VC and Cr3C2 were added. To obtain the largest effect of GGI doping the concentration was set near the maximum soluble amount in the binder. The hardness, HV30 and Palmqvist toughness, KIC and magnetic properties (coercivity, Hc and magnetic saturation, Ms) was determined. In a refined part of this study, a deeper insight into four hardmetal grades, two γ-binder grades with Fe/Co/Ni=30/40/30 and 40/20/40, and two α+γ-binder grades with Fe/Co/Ni=62/20/18 and Fe/Ni=85/15 were investigated as a function of increasing C-content from +eta to free-C compositions in up to 13 steps. The magnetic behaviour of γ-binder is different to that of α+γ-binder, in the latter MS decreases with increasing C content. Evaluation of HV30 and KIC showed competitive values to standard submicron WC-10Co grades.