Strength–ductility synergy in Mg-Gd-Y-Zr alloys via texture engineering in bi-directional forging

In this work, we successfully fabricate an ultra-high strength Mg-11Gd-3Y-0.5Zr alloy with ultimate tensile strength of 523 MPa and enhanced ductility via cost-effective bi-directional forging (BDF) and subsequent annealing heat treatments. To elucidate the role of BDF and gain a fundamental understanding of the remarkable simultaneous increase of strength and ductility, systematic microstructure characterization and analysis are performed. It is revealed that the double-peak basal texture, with basal poles located at the center of two mutually perpendicular forging directions, serves as an essential factor for the strength–ductility synergy of the Mg-11Gd-3Y-0.5Zr alloy processed with BDF. Roles of the double-peak basal texture in overcoming the strength–ductility trade-off include promoting non-basal slip, increasing ductility, and enlarging the Hall–Petch effect along the sample elongation direction while reducing the extent of anisotropy in critical resolved shear stresses of different slip systems. This study demonstrates that texture engineering is a powerful strategy to control magnesium alloy performance and BDF is a promising processing technique for enhancing mechanical properties of magnesium alloys.