Study of rapid thermal treatment on the microstructural evolution and surface characteristics of the electrodeposited modify Zn/TiO2 composite coatings on AISI 1015 steel

Abstract

In this study, the effect of systematic homogenising annealing heat treatment on the morphology and hardness property of modified Zn-TiO2 nano-composite coatings, coated via electrocodeposition process was investigated. The morphological characteristics of the composite coatings were characterised by scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS) and the hardness examination was carried out using Dura-scan hardness tester. The result showed that the coatings systems were homogenised with refined microstructure after annealing at 250°C and 500°C. Three different inter-metallic structures; zeta, delta and gamma phase were observed after systematic homogenising annealing at 500°C. The hardness performance of the nano-composite coatings was better after the annealing at 250°C for five hours and showed outstanding improvement after systematically annealed at 500°C.