| Abstract |
| In the study, we investigated a new type of severe plastic deformation method, `Twist Extrusion`, passing a workpiece through a die with a twist channel. Large strains in the workpiece can be generated by repeating the process, because of the characteristics of an equal channel, i.e. all cross-sections of the whole channel (before, middle and after a twisting section) are the same in geometry and size. Plastic deformation behavior of a metallic workpiece during the twist extrusion process was numerically analyzed using the finite element code, ABAQUS. The plastic deformation generated in the workpiece is as inhomogeneous as the case of simple torsion, i.e. increases with a distance from the center. However this feature of inhomogeneous deformation with distance from the center can be utilized as an effective way for surface hardening of pure metallic parts and composite materials due to the enhanced grain refinement in surface regions. The strain and stress distributions are parallel to the extrusion direction, which presents a prospective method to control an alignment of particles in composites, e.g. carbon nanotube reinforced metallic composites. |
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| Key Words |
| Twist extrusion, Severe plastic deformation, Surface hardening, Finite element analysis, Grain refinement, Strain hardening |
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