An Improved Wear-resistant PTA Hardfacing: VWC/Stellite 21

Abstract

A novel compound carbide, VWC, is designed to incorporate into Stellite 21, in order to achieve an improved wear-resistant composite, plasma transferred arc (PTA) hardfacing. Different contents of VWC in the composite, 5, 10, and 20% (in weight), are tested. The microstructures of the hardfacing specimens are studied using, scanning electron microscopy (SEM) plus, energy dispersive X-ray (EDX) and X-ray techniques. The influence of VWC additive on the mechanical properties of the Co solid solution in Stellite 21 matrix is investigated with a nano-indentation technique. The hardness and wear resistance of the hardfacing specimens are evaluated on a Wilson Rockwell machine and a ball-on-disc tribometer, respectively. It is found that the hardness and wear resistance of the VWC/Stellite 21 composite layer are much higher than those of pure Stellite 21. The presence of the VWC reinforcement changes the microstructure of the Stellite 21 matrix and strengthens the Co solid solution.