Cracking behavior and formability of Zn-Al-Mg coatings: Understanding the influence of steel substrates

Zn-Al-Mg coatings are important materials for the corrosion protection of steel sheets. However, susceptibility towards cracking limits formability performance these coatings. In this study, we focus on effect underlying substrate behavior in order to elucidate this, a high-strength low-alloy (HSLA) and an interstitial-free (IF) coated with two different ZnAlMg without binary eutectic microstructures. Meticulous in-situ tensile bending tests conducted scanning electron microscope. To quantify strain distribution damage incidents, micro macro digital image correlation techniques utilized illuminate associated causes across length scales. Furthermore, backscatter diffraction method is applied study role crystallographic orientation tendency. Crack opening crack area fractions correlated angles. The findings denote that discontinuous yielding (Lüders banding) HSLA generates substantial surface roughening heterogeneous deformation facilitates cracking. contrast, IF induces more uniform within leading much reduced size fraction. This has resulted key element guideline crack-resistant formable Mg-alloyed zinc