Micromechanical Analysis of Metal-Ceramic Thin-Films on Steel Substrates

Abstract Thin-layered coatings on material surfaces can resist contact forces and provide protection against material wear. In this study, FeCrNi-Al 2 O 3 composite coatings were prepared by electrodeposition onto a 316L steel substrate. The effects of electrodeposition cathode current density (3 A·dm −2 , 5 A·dm −2 , 7 A·dm −2 and 9 A·dm −2 ) and post annealing at 500°C in Ar atmosphere were investigated. An increase in deposition rate resulted in a rougher coating surface and a thicker coating at a constant deposition duration. Post-deposition heat treatment caused the surface roughness to increase because of the introduction of denser micro-cracks. Higher current densities improved adhesion and prevented angled cracks during scratching, while annealing led to scratching-induced failures at lower applied loads. FeCrNi-Al 2 O 3 composite coatings showed higher hardness but lower Young's modulus compared to the steel substrate. The coating hardness is slightly enhanced by increasing the electrodeposition current density from 5 A·dm −2 to 9 A·dm −2 , and a more significant increase is observed after annealing. However, the hardness is negatively impacted by the combined effect of annealing and higher current density. These findings demonstrate the importance of carefully balancing the electrodeposition current density and annealing conditions to achieve optimal coating properties. To optimize metal-ceramic composite coatings, it is crucial to investigate multiple process parameters that may interact with each other.