Optimization in strength-ductility synergy of extruded Mg-3Sn-2Al-1Zn-0.6Y-0.6Nd alloy via novel FPE processes

Abstract

Three novel FPE processes were proposed by integrating the advantages of conventional extrusion and ECAE, optimizing the strength-ductility synergy of extruded Mg-3Sn-2Al-1Zn-0.6Y-0.6Nd alloy. The deformation mechanism, evolution of texture and variation of the tensile properties of the alloy were investigated. Findings indicate that the alloys fabricated by the FPE processes exhibit a finer and more uniform microstructure with the lowest dislocation density, undergoing the most complete DRX. The FPE process breaks the strength-ductility tradeoff dilemma of the magnesium alloys, achieving a synergistic enhancement of both strength and ductility. The FPE-105 process was determined to be the best process for strengthening the alloy, with a 24.4% (340MPa) increase in UTS compared to the FE-10 sample, along with an impressive doubling of the ductility (18.6%). The excellent mechanical properties provided by the FPE-105 process are primarily stem from the uniform and fine grain distribution and texture modification. The successful application of the three FPE processes to the fabrication of extruded magnesium alloys demonstrates that the series of novel extrusion processes can be further optimized to create magnesium alloys with excellent strength-ductility.