Synthesis and characterisation of single and duplex ZnO/TiO2 ceramic films on additively manufactured bimetallic material of 316L stainless steel and Ti6Al4V

Abstract

Selective laser melting (SLM), one of the Laser Powder Bed Fusion (LPBF) additive manufacturing methods, has enabled the layered production of Ti6Al4V/316L layered samples, thanks to the layer-by-layer construction. Although 316L and Ti6Al4V are used in many engineering applications, their wear performance is limited. This study aims to improve the tribological and electrochemical properties of Ti6Al4V/316L layered samples. Thus, ZnO, TiO2 monolayer, composite, and ZnO/TiO2, TiO2/ZnO multilayer ceramic films on Ti6Al4V/316L layered surface sample, were coated via the sol-gel dip-coating process. The structural, morphological, and tribological properties of ZnO-TiO2 ceramic films were analyzed via x-ray diffractometer, Scanning Electron Microscopy (SEM), and 3D profilometer. The tribological properties of these coatings were examined using a reciprocating tribo-tester, and the electrochemical properties of samples were evaluated through potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Structural and mechanical results indicated that ZnO and TiO2 films (monolayer, composite, and multilayer-coated) have higher surface roughness and hardness values than additively manufactured Ti6Al4V/316L layered models. Both single and multilayer ZnO and TiO2 ceramic-coated films improved the wear resistance of the Ti6Al4V/316L substrate. Also, The best tribological and corrosion resistance was acquired for the multilayer film (ZnO/TiO2) among all the coated models.