Effect of Flow Rate of Reactive Gas on Mechanical and Tribological Properties of Carbon Nitride Coatings

Abstract

This study discusses the mechanical and tribological properties of a series of carbon nitride coatings deposited by unbalanced DC magnetron sputtering using nitrogen-argon mixture gas and graphite targets. The carbon nitride coatings were with varying carbon/nitrogen ratio by varying the gas flow rate ratio of nitrogen gas/argon while kept the overall gas flow rate at constant. The carbon nitride coatings with C/N ratios from 2.01 to 3.27 were obtained. The coatings were characterized and studied by nanohardness, scratching, and wear testers. It was found that the carbon nitride coatings with C/N ratio=2.36 showed the best performance of all the evaluated properties.