Reciprocating Wear Resistance of PTAW Deposited WC/Ni-Based Composite Overlays

Abstract

Microstructure and tribological characteristics of WC/Ni-based plasma transferred arc welding (PTAW) overlays have been investigated. WC/Ni-based composite overlays were deposited under same conditions with different percent of WC particle (20-70 wt.%) in the 304L stainless steel. Reciprocating wear tests were undertaken according to the ASTM G133-05 standard. Microstructure and surface micrographs of the cross-section and worn surfaces were characterized. The results indicated that the wear rate decreased with the increasing percent of WC particle, revealing no visible decrease in wear when the percent of WC particle reached more than 50 wt.%. Coating with 50 wt.% WC particle possessed a fine abrasion resistance due to a homogeneous microstructure. Furthermore, at a low concentration (20 wt.% to 40 wt.%), the wear mechanism were adhesive wear and oxidation wear, whereas in 50wt.% WC particle, the main wear mechanism were adhesive wear and abrasive wear. In the case of high concentration of WC particle (above 50 wt.%), the predominant wear mechanism was three-body abrasive wear.