Tube Twist Pressing (TTP) as a New Severe Plastic Deformation Method

Tube twist pressing (TTP) as a new severe plastic deformation method for processing tubular parts was presented. The commercially pure aluminum tubes successfully were processed by TTP method. Microstructural examination by XRD analysis of the processed tubes revealed the formation of fine grains in the average size of 1.1 mu m after four TTP passes. Also, the obtained results of mechanical tests showed a notable increase in microhardness, yield and ultimate strengths. The capabilities of TTP method were verified via comparison of the obtained results with the results of other SPD processes. To further investigate the TTP method, FE modeling was carried out using the Abaqus/Explicit to study the macroscopic deformation and microstructural evolution (the evolution of dislocation density and grain size) during TTP via continuous dynamic recrystallization. In the FE model, the strain hardening behavior of the material was related to microstructure quantities based on the micromechanical constitutive model. The FEM simulated grain refinement behavior was consistent with the experimentally obtained results.