Effects of channel angles on extrusion-shear for AZ31 magnesium alloy: modeling and experiments

To improve the industrialization of the severe plastic deformations (SPD) technology for magnesium(Mg) alloy, a new extrusion-shear (ES) process has been explored and widely investigated owing to its potential ability to produce ultra-fine-grained microstructures in Mg alloys. It is crucial to understand the effect of die design on the deformation behavior, strain distribution, and load requirements during ES process. Three-dimensional geometric models with different channel angles (135 degrees, 120 degrees) in the ES dies have been designed. The plastic deformation heterogeneities of ES process with different channel angles have been analyzed from the simulation results. The results can be summarized as follows. The equivalent strains and loads during the whole ES process decrease with the increase of channel angles. The decrease of channel angle could improve the deformation inhomogeneity of ES process. Smaller channel angles could promote the higher cumulative strains and finer subgrains. The analysis results show that finer and more uniform microstructures can be obtained if channel angles in the ES dies are appropriate. It is demonstrated that the predicted results are in good agreement with experiments results and the theoretical calculations. Numerical simulations and experiments could help to understand the deformation behaviors of AZ31 Mg alloy during ES.