Achieving High Strength and Ductility in Hot-Rolled Mg-3.5Al-3Nd Alloy via Microstructure Adjustment

Mg-Al-RE series alloys with good mechanical properties are always utilized in as-cast or die-cast states; however, further performance improvement via common processing techniques is quite required. In this paper, a high strength and ductility Mg-3.5Al-3Nd alloy sheet was completely prepared by optimizing hot-rolling parameters and controllably refining microstructure from as-cast sample. The optimal sheet rolled at 648 K with deformation degree of 70% exhibits high yield strength, ultimate tensile strength and elongation to failure of 220, 277 MPa and 12.0%, respectively. The strengthening phases Al₂Nd and Al₁₁Nd₃ exhibit good thermal stability, whose morphology and distribution are insensitive to the rolling temperature. Both grain size and texture strength of the matrix first decrease, and then increase with the increase in the rolling temperature. The initial blocky Al₁₁Nd₃ phase is obviously refined and distributed along rolling direction with increasing the rolling deformation degree, which significantly improves the strength of the rolled sheet.