Structural and properties of Zn-Al2O3-SiC nano-composite coatings by direct electrolytic process

In this paper, Zn-SiC and Zn-Al 2 O 3 -SiC composite coating were fabricated by electrodeposition technique from sulfates bath. The resulting composite coating was carried out by adding Al 2 O 3 /SiC particulate to a zinc-containing bath. The properties of the composite coating were investigated by SEM equipped with EDS, XRD, and AFM. The electrochemical behavior of the coating alloy was evaluated in 3.65 % NaCl with linear polarization technique and mechanically examined by durascan microhardness tester. The morphology of the thermal treated coatings at 400 °C in 6 h was viewed with high optical microscope (OPM). The results show hardness, thermal stability, and anti-corrosion properties of Zn-Al 2 O 3 -SiC were improved significantly as against Zn-SiC coating matrixes. This was attributed to dispersive strengthening effect and grain induced effort of Al 2 O 3 /SiC particulate. The decrease in corrosion and thermal stability at 15 g/L of SiC concentration may be as a result of agglomeration and the superimposed particle in the plating bath.