Dynamic Recrystallization, Texture Evolution, and Improved Mechanical Properties of Mg-Y-Zn-V Alloy during Forging and Subsequent Extruding Deformation

Abstract

In this paper, the electron backscatter diffraction (EBSD) technique was used to analyze the dynamic recrystallization (DRX), twinning, slip behavior, and texture evolution during forging and subsequent extruding deformation. The results show that, as the degree of strain increased (forging to extruding), the degree of DRX increased, and the DRX mechanism changed from discontinuous DRX (DDRX) during forging to DDRX and continuous DRX (CDRX) during extruding. Particle stimulation nucleation (PSN) promoting DRX occurred during deformation. The deformation process mainly produced {10–12} twins (TTW) and played a role in coordinating the deformation. The slip behavior also changed according to an analysis of in-grain misorientation axes (IGMA) results, changing from slip-dominated with a basal <a> slip to co-dominated with multiple slip modes, with the activation of mainly prismatic <a> and pyramidal <c+a> slip. Meanwhile, the strong basal texture at the beginning of the deformation also changed, and the texture strength decreased from 24.81 to 15.56. The weakening of the texture was mainly due to the formation of DRX grains and twins, as the newly formed DRX and twins reoriented. In the later stages of deformation, the activation of prismatic <a> slip and pyramidal <c+a> slip changed the basal texture component. Based on microstructural analysis, the improvement in mechanical properties was due to fine-grain strengthening and load-transfer strengthening. The ultimate tensile strength (UTS) was 370.5 MPa, the yield strength (YS) was 340.1 MPa, and the elongation (EL) was 15.6%.