Development of dilute Mg–Bi alloy sheet with good synergy of corrosion-resistance and tensile properties

Abstract

In this study, the role of microstructure in tailoring the mechanical properties and corrosion behaviors of as-rolled dilute Mg–Bi binary alloys (MB-x, where x = 0.2 and 0.8 wt%) without/with Mg3Bi2 nanoprecipitates along the grain boundaries was systemically explored. The MB-0.8 alloy with Mg3Bi2 phases exhibited superior strength, ductility, and anticorrosion synergy (with a tensile yield stress of 235 MPa, ultimate tensile strength of 285 MPa, elongation of 10.3%, and Pi-168h of 0.105 mm/y). Strength–ductility synergy was achieved owing to the grain boundary strengthening and activation of prismatic and/or pyramidal slip systems. The transformation of the corrosion mode inhibited the corrosion of the MB-0.8 alloy. Therefore, our approach provides an effective strategy for developing Mg alloys that exhibit superior characteristics.

Keywords

• Dilute Mg–Bi binary alloys
• Rolling
• Microstructure
• Tensile properties
• Corrosion behavior