Interface Formation of Zinc-Rich ZnAlCu Bearing Alloys on Pre-galvanized S355 Steel Substrates in Gravity Die Casting

Abstract

AbstractThe dependence of the interfacial formation of ZnAlCu alloys on S355 steel substrates on the aluminum content of the alloy and the cooling conditions is investigated for the gravity die casting process. Steel substrates pre-galvanized with ZnAl0.2 as well as with ZnAl5 are used as initial condition. The area fractions of the interfacial phases formed in the process are quantitatively determined by a binarization method and correlated with the compositions and the casting conditions in simple mathematical models. Under the test conditions, especially for hypoeutectic alloy variants with a maximum of 5.5 wt% Al, clear dependencies of the phase fractions in the interfacial formation on the aluminum content, but also on the cooling conditions could be demonstrated. The correlations of the forming phases with the type of pre-galvanization could also be shown over a wide range of compositions and solidification rates.