Texture Of AZ31 Magnesium Alloy Research Articles

Effect of Deformation Degree on Microstructure and Texture of AZ31 Magnesium Alloy in Hot Drawing

Microstructure and texture evolution of the AZ31 magnesium alloy wire under different deformation degrees was investigated by continuous hot drawing deformation. With the increase of cumulative deformation degree, the grain refinement effect is remarkable. However, there is a critical deformation degree, and excessive deformation will increase the grain size. During the deformation process of hot drawing, the dynamic recrystallization mechanism of AZ31 magnesium alloy wire changed from twin dynamic recrystallization to rotary dynamic recrystallization. With the increase of cumulative deformation, the initial {0001} <11-20> silk texture gradually changed into {0001} <10-10> silk texture.

高温平面ひずみ圧縮変形下でAZ31マグネシウム合金に生ずる特異な結晶粒組織と集合組織の繰り返し変化

高温平面ひずみ圧縮変形下でAZ31マグネシウム合金に生ずる特異な結晶粒組織と集合組織の繰り返し変化

Effects of Continue Compressing Deformation on Texture of AZ31 Magnesium Alloy

The annealed AZ31 magnesium alloy with 400°C and 1.5hour was selected and compressed under different deformation amount. The orientation and microstructure were investigated too. The results shown that the twinning type and amount changed the orientation of new grain after compressed largely. The tension twinning made the orientation deviated form TD to ED in the {10-10} pole figure, but contraction and double twinning mad the orientation concentrated in the TD.

Effect of Strain to the Microstructure and Texture of AZ31 Magnesium Alloy during Compression Deformation at Room Temperature

AZ31 magnesium alloy samples were compressed to different strains at room temperature and examined through the optical microscope, X-ray diffraction (XRD) and scanning electronic microscope. The results show that the produced twins were mainly the {102} type, and then the {101} type and {102}-{101} type. The size and amount of the twins increased with the strains growth, and after the saturation of twins in the grains the samples fractured. The compressed texture with the basal planes perpendicular to the compression direction also become stronger with strain increase. The {102} twinning deformation played an important role in changing the microstructure and properties of the magnesium alloy at room temperature.

Modeling of Extrusion Texture of AZ31 Magnesium Alloy with Consideration of Dynamic Recrystallization

In order to model the extrusion textures of alloy AZ31 at high temperatures, a new dynamic recrystallization (DRX) model is developed and integrated into polycrystal plasticity model as a contributor to texture development and softening behaviors. New grains are allowed to nucleate and give birth to new recrystallization grains, which enables the dominant aspects of the DRX to be simulated. In so doing, the investigation of DRX behaviors becomes less dependent of experiments. The initial orientations of new grains are determined by making assumptions and eliminating the false ones by verifications. Therefore, the deformation textures at high temperatures are simulated based on a reliable hypothesis and show good agreement with published experiments. Furthermore, finite element model (FEM) with Eulerian adaptive meshing approach is used to simulate the extrusion process at high temperatures with isotropic material properties assumed. History strains are tracked by tracers flowing through the Eulerian domain and used as input when simulating extrusion textures.

Effects of Annealing Technique on Texture Attenuation of Hot-Rolling AZ31 Magnesium Alloy Sheets

A strong basal plane texture of AZ31 magnesium alloy was obtained by severe hot-rolling with three passes falling temperature. The effects of annealing time and annealing temperature on the evolution of texture at different layers were studied by means of X-ray texture analysis. The results showed that the orientation density of basal plane texture component was reduced greatly tending to dispersion with increasing annealing time and temperature. The hard orientation can be greatly weakened by softening annealing, the best basal plane orientation was obtained when the annealing time is 60min and the annealing temperature is 150~300°C. A texture gradient along thickness direction with annealing has been found in the sheet. The texture gradient was the lowest when the annealing time is 60min and the annealing temperature is 300°C.

Microstructure, mechanical properties and texture evolution of AZ31 alloy containing trace levels of strontium

The effect of low levels of Sr (0.01, 0.03, 0.05 wt.%) on the microstructure, mechanical properties and texture of AZ31 magnesium alloy has been investigated. Thermodynamic modeling has been used to study the effect of Sr on phase precipitation at different temperatures. Cooling curve analysis reveals a decrease in solidification superheat with the addition of 0.03 wt.% Sr to AZ31. The as-cast microstructures of the alloys have been studied using optical microscopy (OM) and electron probe micro analysis (EPMA). Results show the refining effect of Sr on the grain size and on the β-Mg17Al12 precipitates through growth poisoning and inoculation, respectively. To investigate the mechanical properties of the alloys, as-cast samples were compression tested at elevated temperatures. Hot compression peak stress (σmax) and critical strain before recrystallization (εc) initially drop but then increase. σmax first decreases due to the depletion of Al from solid solution and then increases when the amount of the Al–Sr precipitates reach a significant amount. εc drops due to the acceleration of dynamic recrystallization kinetics as a result of grain refinement. It increases with increasing Sr when the concentration Sr in solid solution is increased leading to dislocation pinning and retardation of recrystallization. X-ray texture measurements on the hot compressed and extruded samples show a decrease in maximum intensity of the basal pole figures with increasing Sr as a result of reduced twining and the changes in Al and Sr concentrations in solid solution.