Effect of Chromium Coating deposited by magnetron sputtering on mechanical and microstructural behaviour of Superni -718

Abstract

Shahnaz Bashir Bhat, Mukund Dutt Sharma and Atikur Rahman

For high-temperature applications, super alloys, especially those based on nickel, are recommended because of their superior mechanical strength at high service temperatures. To overcome such constraints, the coating has been done to enhance the mechanical properties of the substrate. This work investigated samples coated with Chromium coating using DC magnetron sputtering. The surface morphology and composition were evaluated using EDS and FE-SEM, XRD revealed different phases both on substrate and chromium coated sample, and atomic force microscopy revealed depth of indent. The microstructure showed that coated specimens exhibited high substrate adherence and little micros scaling. The hardness and elastic modulus of chromium coated sample was performed using Nano indentation based on Oliver and Pharr model and loads ranging from 200μN-1000μN and results exhibited that there is a 52% increase in hardness on every load as well as the modulus of elasticity has increased to 21% and to check the coating adherence three Nano scratches were performed on chromium coated sample at a load of 2000μN.

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