Enhanced thermal conductivity and mechanical properties of extruded Mg-4La-2Al-0.3Mn alloy via hot forging

Abstract

The Mg-4La-2Al-0.3Mn (LA42) alloy, known for its remarkable thermal conductivity of 110 W/(m⋅K), faces limitations owing to its inherently low strength. In this study, a composite deformation process, involving hot forging and extrusion, was investigated to enhance both the thermal conductivity and mechanical properties of the LA42 alloy. The findings revealed that the composite deformation process effectively precipitated an increased number of solute atoms from the matrix, thereby mitigating the lattice distortion effect and resulting in a superior thermal conductivity of 148.2 W/(m⋅K). Additionally, the combination of hot forging and extrusion proved to be efficient in achieving more pronounced grain refinement with increased dislocation density. Consequently, the yield strength of LA42 alloy was substantially enhanced while maintaining a high elongation, reaching values of 211.1 MPa and 12.5 %, respectively. These exceptional overall properties establish a competitive edge when compared to other state-of-the-art magnesium alloys reported previously.