Syntheses and mechanical properties of Mo-Si-N coatings by a hybrid coating system

Abstract

In this work, comparative studies on microstructure and mechanical properties between Mo2N and Mo-Si-N coatings were conducted. Ternary Mo-Si-N coatings were deposited on steel substrates (AISI 132) and Si wafers by a hybrid method, where arc ion plating (ALP) technique was combined with a magnetron sputtering technique. Instrumental analyses of X-ray diffractometer (XRD), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS) revealed that the Mo-Si-N coatings must be a composite consisting of fine Mo2N crystallites and amorphous Si3N4. The hardness value of Mo-Si-N coatings significantly increased from 22 GPa Of Mo2N coatings to about 37 GPa with Si content of 10 at.% due to the refinement Of Mo2N crystallites and the composite microstructure characteristics. The average fiction coefficient of the Mo-Si-N coatings gradually decreased from 0.65 to 0.4 with increasing Si content up to 15 at.%. The effects of Si content on microstructure and mechanical properties of Mo-N coatings were systematically investigated. (c) 2006 Elsevier B.V All rights reserved.