Outstanding cracking resistance in Mg-alloyed zinc coatings achieved via crystallographic texture control

Abstract

Cracking limits the formability of Mg-alloyed zinc coatings on steel substrates. Unfavorable crystal orientations and brittle microstructural components serve as the main sources of cracks in these coatings. In this study, we overcome the deformation-induced cracking and substantially enhance the formability of Zn-Al-Mg coatings by controlling their crystallographic texture. To demonstrate this, in-situ scanning electron microscopy uniaxial tensile tests and thorough orientation image microscopy have been employed. Ultimately, we validate our findings by implementing quantitative plastic deformation-based criteria, namely local strain hardening exponent and Schmid factor distributions within the examined coating microstructures. The approach and findings of the present work considerably resolve the long-lasting cracking problem of these coatings.