Analysis of Al-Si coatings in terms of bendability

Abstract

Protective coatings provide protection of structures against corrosion, but they also aim to meet marketing requirements – decorative qualities. One of the representatives of protective coatings are fire coatings based on Al and Al-Si, which have been used, among others, in the automotive industry. The production of Al-Si coatings using the fire method (known as: immersion) consists in immersing a previously degreased detail in a bath of molten coating metal. Al-Si coatings are applied permanently, and the connection between the coating and the substrate is ensured by the mutual diffusion of aluminum and iron, which leads to the formation of intermetallic phases. The study examines Al-Si coatings used in the automotive industry. The research included assessment of coatings in terms of structure, hardness distribution of elements, and surface condition (roughness). The chemical composition of the coatings was determined using EDX microanalysis and phase composition by diffractometric analysis. The final assessment focused on the impact of bending on the quality of the connection between the substrate and the coating.