Forward shear normal extrusion (FSNE) as a new single pass severe plastic deformation (SPD) method was based on conventional extrusion combined with planar twist extrusion. The proposed method was studied by finite element analysis to investigate the effect of FSNE die geometrical parameters, i.e. deformation zone Length (LDZ) and distortion angle (α), on uniform stress-strain distribution during deformation. Consequently, the optimum condition was considered in design and the process was experimentally performed on aluminum alloy (0.27% Fe, 0.08% Si and balance Al (wt. %). It was found that L = 15 mm and α = 40° are the optimum die parameters that can result in higher effective plastic strain with a more uniform distribution. Microstructural evolution was also studied to demonstrate the capability of this technique in grain refinement and microstructure observations revealed the presence of ultra-fine grains after FSNE. Tensile testing results indicated that yield (YS) and ultimate (UTS) strengths increase 2.7 and 2 times for the processed sample compared to the annealed sample. Hardness results showed increase in hardness level from 25HV0.3/10 for non-processed to 53 HV0.3/10 for the processed state. The uniform distribution of hardness values in both transverse and longitudinal directions was achieved due to the uniform distribution of effective strain resulting from the optimum die design. Compared to other SPD methods, the present technique resulted in high accumulated plastic strain and hardness with uniform distribution and significant grain refinement after one pass.

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