Improving Ductility and Anisotropy by Dynamic Recrystallization in Ti/Mg Laminated Metal Composite

Ti/Mg laminated metal composites (LMCs) were processed by hot roll bonding and subsequent annealing at 200 °C and 300 °C for 1 h, and the effect of dynamic recrystallization on the microstructure and anisotropy behavior was investigated in detail. The results revealed that, in both as-rolled and annealed Ti/Mg LMCs, the inhomogeneous distribution in the microstructure of Mg layers near the interface and near the center was related to the effect of friction between the roller and sheet surface and uncoordinated deformation between constituent layers. With increasing annealing temperature, Ti/Mg LMCs exhibited excellent elongation without sacrificing strength properties, which was mainly due to the improvement in bonding strength and the increasing strain gradient at the interface between soft and hard layers after annealing treatment. Besides, the increasing Schmid factors (SFs) of prismatic < a > slip and pyramidal < c + a > slip in Mg layers contributed to the improved plastic deformation ability of Ti/Mg LMCs. The experimental analysis indicated that the presence of Mg alloys resulted in the microstructure and mechanical properties of LMCs were different along various loading directions, and annealing treatment can effectively inhibit the anisotropic behavior of Ti/Mg LMCs resulting from the weakening of basal texture in the Mg layer.