Characterization of structures and properties of amorphous nanostructured SiC thin films deposited on AISI 304 stainless steel using pulsed laser deposition

Abstract

Amorphous nanostructure silicon carbide (a-SiC) recently received great attention for its use as protective coating for metallic substrates due to its good mechanical properties and corrosion resistance. In this article, a-SiC thin films were deposited on AISI 304 stainless steel substrates at room temperature for deposition times of 4 and 6 h using pulsed laser deposition technique. The deposition process was stopped every 2 h then resumed for an hour. The effect of interval time during deposition process and substrate type on the properties of the produced films was extensively investigated. The morphological features of the deposited SiC films were investigated using field-emission scanning electron microscope and atomic force microscope. The film structures were determined by transmission electron microscopy, X-ray photoelectron spectroscopy and energy-dispersive X-ray. The mechanical and tribological properties, such as Young’s modulus, hardness and scratch resistance, were determined using nanoindenter. The results showed the formation of uniform monocrystalline nanostructured Si interface between two a-SiC layers after the 2 h of no-deposition time intervals. The formation of crystalline Si interface attributed to the effect of high kinetic energy of the incoming ablated particles deposited on the grown a-SiC layers. The a-SiC films were amorphous having nanostructure grains with dimensions ≤ 100 nm. All films showed smooth surfaces with fine cracks due to the presence of intrinsic stresses. The deposited films showed low mechanical properties due to their amorphous structures.