Decoding the annealing treatment-microstructure-thermal conductivity nexus in heterogeneous Mg-Mn-Ce alloy

In this work, the evolution of the microstructure and thermal conductivity of an extruded Mg-1.0Mn-0.5Ce (wt%) alloy with a heterogeneous microstructure during annealing treatment was investigated. Strong stored energy drove the static recrystallization in coarse deformed grains, and both the degree of recrystallization and the average grain size increased with increasing temperature and duration, resulting in a decrease in mechanical strength. In addition, a RE-component texture with parallel to the ED was generated during the annealing treatment because of the particle-stimulated nucleation mechanism induced by the nanoscale Mg 12 Ce and α -Mn phases, which contributed to the increase in ductility. Both the annealing temperature and duration affected the thermal conductivity. Specifically, the thermal conductivity gradually increased with increasing annealing duration because of the growth of grains and the release of residual stress. Moreover, the thermal conductivity decreased with increasing annealing temperature because the negative effects induced by solute atoms were more significant than the positive effects resulting from grain growth.