Experimental investigation and thermodynamic assessment of the C-Co-Fe-Ni-W system

The liquid phase formation temperatures of WC-(Co,Fe,Ni) alloys with free carbon and M6C phase, respectively, were determined by means of Differential Scanning Calorimetry (DSC) analysis. Based on the experimental results, a thermodynamic modelling is conducted on the C-Co-Fe-Ni-W quinary system using the CALPHAD (CALculation of PHAse Diagram) technique. Temperature-composition sections and projections concerning the sintering areas of the WC-(Co,Fe,Ni) hardmetals are calculated to verify the rationality of the present modelling. Comprehensive comparisons between the experimental and calculated results show that all the experiments can be well reproduced by the present modelling.