Development of low-alloyed Mg–Zn–Ca–Sn–Mn alloy with high strength-ductility synergy by sub-rapid solidification and hot rolling.

Achieving high strength-ductility synergy is a great challenge in low-alloyed Mg alloys. In this work, a new Mg–1.0Zn–0.45Ca–0.35Sn–0.2Mn (wt.%, ZXTM1000) alloy was designed and fabricated by sub-rapid solidification (SRS) to overcome the dilemma. After hot rolling and annealing, the new alloy sheet exhibited an excellent tensile yield strength (YS, ∼270 MPa) and elongation (∼21%). Microstructure characterization revealed that the high YS was mainly attributed to the fine grains (∼3 μm) and high density of spherical Ca 2 Mg 6 Zn 3 , Mg 2 Ca, and α-Mn precipitates. Moreover, the homogeneous grain size distribution, weakened TD-split texture and the activation of multiple types of slips contributed to the enhanced ductility. The findings demonstrate an effective way to fabricate low-alloyed Mg alloys with high strength and ductility by combining the SRS and hot rolling. Image 1 • A designed Mg–1.0Zn–0.45Ca–0.35Sn–0.2Mn (wt.%, ZXTM1000) alloy was fabricated by sub-rapid solidification. • The rolled and annealed ZXTM1000 alloy exhibits an good balance of yield strength (∼270 MPa) and elongation (∼21%). • EBSD-assisted slip trace analysis was utilized to determine the type of slips. • The reasons for the high strength-ductility synergy were discussed in detail. [ABSTRACT FROM AUTHOR]