Evading Strength-Ductility Tradeoff in Mg Alloy via Uniform Microstructure and Unique Texture Modification Induced by Moderate Temperature ECAP

Tweaking the distribution of grains, precipitates, and texture components is a successful strategy employed to enhance the strength and formability of Mg alloys. Herein, moderate temperature equal channel angular pressing (ECAP) deformation was employed to control the microstructure and tune the corresponding mechanical properties of the Mg–6Zn–1Mn alloy. The analysis results indicated a uniform distribution of grains and second phases. The original strong basal texture of the extruded Mg–6Zn–1Mn alloy was disintegrated, and a weak basal texture gradually developed after 2 passes of ECAP deformation. The fine grains, second phases, and high-density dislocations provide high strength to the alloy, with contributions of 105.1 MPa, 47.1 MPa and 78.8 MPa, respectively. The excellent ductility (20.6%) is mainly attributed to the weak basal texture and high Schmid factor of prismatic <a> slip. The 2P sample exhibits good strength-ductility synergy effects with a value of YS × EL equal to 5.8. The results indicate that moderate temperature ECAP deformation can enable the formation of a uniform microstructure and unique texture to enhance the mechanical properties of the Mg–6Zn–1Mn alloy.