Magnesium (Mg) alloys are used extensively in automotive and aerospace applications because of their low density and higher strength. Rear earth elements (Gd, Y, Nd, Sm) are added to magnesium alloys for enhancing the mechanical properties [1]. However, their usage is largely restricted owing to poor corrosion resistance. In many industrial applications, these alloys are subjected severe stress under certain corrosive media [2]. Therefore, it is imperative to explore the stress corrosion cracking (SCC) behavior of these Mg alloys under various environments.

Current study aims to evaluate the susceptibility towards stress corrosion cracking of an as-cast Mg-10Y magnesium alloy under air and 3.5wt% NaCl solution at various strain rate (10⁻⁵ s⁻¹, 10⁻⁶ s⁻¹, and 10⁻⁷ s⁻¹) through slow strain rate tests (SSRT). Furthermore, to elucidate the effect of rolling on SCC susceptibility, cold rolled and hot rolled Mg-10Y alloy were considered and compared with the as-cast and solution treated Mg-10Y alloys. The SCC susceptibility indices, viz., strain to failure, ultimate tensile strength (UTS), and time to failure were utilized for quantification of susceptibility. It was observed that decrease in strain rate led to increase in SCC susceptibility. The higher SCC susceptibility of the cold rolled Mg-10Y alloy as compared to hot rolled and solution treated Mg-10Y alloy was attributed to the refined grain size, and this was validated with the fractographic analysis using scanning electron microscopy (SEM) together with energy dispersive x-ray spectroscopy (EDS).



References
[1] J. Bai, Y. Yang, C. Wen, J. Chen, G. Zhou, B. Jiang, X. Peng, F. Pan, Journal of Magnesium and Alloys, 2023, 11, 3609–3619.
[2] X. Zhang, D. Wang, F. Cao, C. Wang, M.-X. Li, Y. Yang, M. Zha, Corros Sci, 2024, 227, 111747.