Investigation on microstructural, anti-corrosion and mechanical properties of doped Zn–Al–SnO2 metal matrix composite coating on mild steel

In this study, the microstructural, mechanical and anti-corrosion properties of nanocomposite Zn–Al coating containing SnO2 nanoparticles prepared from sulphates electrolyte by electrodeposition on mild steel substrate was investigated. The morphologies of the coating were analysed using SEM/EDS, AFM Raman and X-ray diffraction. The anticorrosion behaviour of the coating prepared with different concentrations of SnO2 (7 and 13 g/L) and potential of (0.3 and 0.5 V) was examined in 3.65% NaCl solution by using linear polarization techniques. The wear and hardness properties of the coatings were performed under accelerated reciprocating dry sliding wear tests and diamond micro-hardness tester respectively. The results obtained showed that the incorporation of SnO2 in the plating bath brings an increase in corrosion resistance and mechanical properties of Zn–Al–SnO2 composite coatings. The SEM images showed a homogeneous grain structure and finer morphology of the coatings. The hardness values was found to improve with the amount of the SnO2 embedded into the Zn–Al metal deposit and effective deposition parameter