Properties of reactively RF magnetron-sputtered chromium nitride coatings

Hard coatings for wear and corrosion protection based on chromium nitride were deposited by means of a commercial RF magnetron sputtering unit. Their structural, compositional and mechanical properties were compared. All films were reactively sputtered with a mixture of nitrogen and argon from a target of the pure metal. This paper reports the influence of deposition parameters on coating morphology, crystallographical structure and hardness. We found that the surface morphology of the coatings is hardly influenced by the volume fraction of the reactive gas. Also, the hardness (HV,(0.05),, = 2500) is closely linked to the crystalline structure of the deposit. Finally, we have paid special attention to the evolution of the deposition rate and the total pressure as a function of nitrogen content in the vapor phase. (C) 1997 Elsevier Science S.A.