Comparative Study of Self-Mated HVOF-Sprayed Hardmetal Coatings Under High Temperature Dry Sliding Conditions

摘要

Due to fast recent technological developments thermally sprayed hardmetal coatings have reached a new level which becomes comparable in microstructure and properties to those of sintered hardmetals. In the current study the tribological properties of self-mated hardmetal coatings with nominal compositions WC-10%Co4%Cr, WC-20%"CrC"-7%Ni, Cr_3C_2-25%NiCr, (Ti,Mo)(C,N)-29%Ni, (Ti,Mo)(C,N)-29% Co were compared in an unlubricated dry sliding wear test at room temperature, 400℃ and 600℃. Electrolytic hard chromium coatings were studied for comparison. Sliding velocities were varied in the range 0.1-1 m/s with a wear distance of 5,000 m and a normal force of 10 N. The results are linked with the results of unlubricated dry sliding wear tests against sintered alumina. Total wear rates (sum of wear of the rotating and stationary samples) are in some cases comparable to those typically measured under mixed/boundary conditions.