Zn-Al pack co-cementation on AISI 1020 steel: structural, mechanical and tribological appraisal

This study examined the effect of different Al concentrations on the structural transformation of pack cementation Zn-Al coatings on AISI 1020 steel. The resultant Zn-Al coatings were investigated using scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction to observe the coating morphology, thickness, structure, and compositional migration. A laminated coating assembly was prepared, in which an initial intermediate Zn-rich layer was followed by an Fe-Zn inner layer and Fe-Al top layer. Elemental analysis revealed a correlation between the formation of voids and the diffusion of Al, Fe, and Zn. The coated specimen demonstrated desirable mechanical strength and improved abrasive resistance, whereas the tribological capability of the Zn-Al coating could be tailored by varying the Al concentration.