HVAF Sprayed Composite Coating with Ni-base Self-Fluxing Alloyand WC on a Copper Substrate

摘要

In order to improve the wear resistance and service life of thecopper, the composite coating consisting of a Ni-baseself-fluxing alloy (NiCrWB+50%AlAl2O3) and WC (WC-12%Co)alloy were sprayed on a copper substrate using High VelocityAir Fuel(HVAF). The coating could meet the operatingrequirements including high hardness, good wear resistance andlow cost. The Ni-base composite coating was analyzed bymeans of optical microscopy, scanning electron microscopy(SEM), electron probe microanalysis (EPMA) and X-raydiffraction (XRD). The results indicated that the structure ofcoating was composed of melted particles and partly unmeltedround particles of Ni-base alloy, and WC particle. Only a smallproportion of the Al) Al2O3 particles were retained in the coating.The phases in the coating consisted of γ-Ni, WC and a littleNiNi3B. Amorphous structures appeared and some Al B. Al2O3 phaseexisted. The adhesion strength between coating and coppersubstrate was more than 50MPa. Wear results showed that theNi-base composite coating exhibited better wear resistance thanthe coating with no WC particles.