Severe plastic deformation in impact extrusion processes

Gradation Extrusion, a process which combines common impact extrusion with severe plastic deformation is used to create property graded materials. The processed material exhibits an increased strength in the near-surface layers and a relatively ductile core with lower strength. The process is evaluated by subjecting aluminum material to the method. Investigation of the material after processing focusses on the microstructure and hardness examination. The advantages of the process principle with respect to applications are shown for aluminum bolts. Possible process chains for such components are illustrated and first results of forming experiments are demonstrated.