Microstructure and Properties of Cr3C2-rich binary Cr3C2-WC-Ni(Co) hardmetal coatings

Hardmetal coating compositions containing both WC and Cr₃C₂ are less intensively studied. In particular, compositions with Cr₃C₂ as the main phase are relatively new at the market. In this contribution, two commercial feedstock agglomerated and sintered feedstock powders with similar but not identical composition (45Cr₃C₂ - 37 WC - 18 NiCoCr and 42Cr₃C₂ - 42WC - 16Ni) were studied. Both powders differ in their porosity and in the melting behavior, as was found by DSC experiments. Coatings were deposited with a liquid-fueled HVOF process (JP 5000). Significant differences of the deposition efficiency were observed, while coating microstructure and phase composition, as well as coating properties (microhardness HV0.3 and abrasion wear resistance) were found to be similar. Coating microstructure and phase composition was studied with focus on the interaction between Cr₃C₂ and WC and will be discussed in detail.