Synthesis and characterization of sputter-deposited Ni-rich Ni3Al hard coatings

Abstract

Ni3Al and Nickel (Ni) rich Ni3Al thin films were deposited on Si (100) substrate by magnetron sputtering and co-sputtering process respectively. Variations in elemental composition, microstructure, surface topography, and mechanical properties were investigated as a function of Ni enrichment via EDS, SEM, AFM, and nanoindentation respectively. Results revealed that the hardness and young's modulus decrease with increase in Ni content in the film. A maximum hardness of 12.75 GPa was achieved with the elemental composition of Al (20.8 at%) and Ni (79.2 at%). The increase in surface roughness as a result of Ni enrichment led to the increase in hydrophobic properties up to the elemental composition of Al (14.9 at%) and Ni (85.1 at%) beyond which it declined. This study shows that the surface roughness, microstructure, and elemental composition influence the mechanical and hydrophobic properties of the Nickel rich Ni3Al coatings. (C) 2022 Elsevier B.V. All rights reserved.