Effect of annealing temperature on the microhardness of tungsten carbide coatings deposited by RF sputtering

Abstract

A systematic study on the eff ect of annealing temperature on the hardness of Tungsten carbides (WC) coatingswere deposited by RF magnetron sputtering onto steel substrate (XC70) was carried out in this study.  e asdeposited coatings were heat treated in vacuum at temperature range between 500-1000 °C for 25 minutes. e mechanical properties of these coatings were investigated by Vickers microhardness tests at diff erentapplied loads and penetration depth of the indenter into the coatings.  e microhardness tests were carriedout as a function of applied loads between 10 - 1000 g, annealing temperature in the range of 500-1000 °C,and penetration depth of the indenter up to 25 µm.  e microhardness of the coatings was found to decreaseas a function of applied load and the penetration depth.  e microhardness initially increases and thereafterdecreases as the annealing temperature increases.