Zinc-based diffusion coating as an environmental-friendly alternative to conventional processes

The aim of the present work is to show the first results obtained in a project about an innovative and environmental-friendly galvanizing technology. This research activity is founded by Regione Lombardia. To this aim, commercial items coated by diffusion were analyzed and compared in terms of chemical composition, microstructure, corrosion and mechanical resistance. In particular two processes were considered: a conventional technique (sherardization) and an innovative technology that represents the starting point of the project. Morphology and chemical composition of the coated samples were studied, as well as corrosion resistance, hardness and coating adhesion. Moreover, an industrial pilot plant able to replicate the innovative technique was realized in order to optimize process parameters and to improve process efficiency. In these initial project steps, only small steel items were coated. However, one of the final project goal is to coat large structural parts with complex geometry.