Effect of Annealing Temperature on the Microhardness of Tungsten Carbide Coatings

Mourad Khechba,Chander Shekhar,Maria Plamenova Nikolova,Beddiaf Zaidi

doi:10.26701/ems.339309

Abstract

Tungsten carbides (WC) coatings have been deposited by RF magnetron sputtering onto steel substrate (XC70) temperature in the range of 500-1000 °C under vacuum for 25 minutes. The mechanical properties of WC were investigated by the measurements of microhardness by Vickers tests. We carried out microhardness tests with loads varying between 10 g and 1000 g, and the variations of the microhardness of our samples were followed as a function of the annealing temperature, the applied load and the penetration depth of the indenter.

Highlights

Tungsten carbide is a material used for a number of industrial applications and it is characterised by its high strength, toughness and hardness
Carbides and nitrides have shown to improve the mechanical properties of different materials employed for the industrial applications
The present study reports the variation of the microhardness of WC and W2C coatings as a function of the applied load, penetration dept and annealing temperature

Summary

INTRODUCTION

Tungsten carbide is a material used for a number of industrial applications and it is characterised by its high strength, toughness and hardness. Deposition of the tungsten carbide coatings on different materials have shown to enhance the tribological properties such as surface hardness and toughness significantly and the materials systems have shown to outperform many steel product equivalents [1,2,3,4]. Carbides and nitrides have shown to improve the mechanical properties of different materials employed for the industrial applications. Tungsten carbides (WC and W2C) are among these refractory materials and are characterized by: i) a relatively high hardness reaching ~2200Kg / mm and 3000Kg / mm respectively, ii) a very high melting temperature (≈ 2800 °C), iii) a low coefficient of thermal expansion [5], iv) an extremely high modulus of elasticity and good thermal conductivity [6, 7]. The present study reports the variation of the microhardness of WC and W2C coatings as a function of the applied load, penetration dept and annealing temperature

EXPERIMENTAL

RESULTS AND DISCUSSION

CONCLUSION