Deformation behavior in the tubular channel angular pressing (TCAP) as a noble SPD method for cylindrical tubes

Tubular channel angular pressing is a recently developed technique for producing ultrafine grained and nanostructured tubular components. The current study dealt with the influence of the channel angles, friction coefficient and back pressure on the plastic deformation behavior and strain homogeneity in TCAP processing. The FEM results demonstrated that the equivalent plastic strains of 1.65–2.15, 2.15–2.85, and 2.5–3.75 have been achieved after applying one pass TCAP with channel angles of 120°, 90°, and 60°, respectively. Increasing the channel angle leads to lower equivalent plastic strain while obtaining better strain homogeneity. The homogeneity of the strain through the length of the processed tube is very good for all channel angles. Increasing the back pressure leads to slightly higher strain level while the strain homogeneity is decreased. Force results showed that lower loads were required for lower channel angles. It was also observed that for different values of coefficient of friction and channel angles, the load values converged to a constant value at the end of the process. Microstructural observations showed a significant decrease in grain size from the initial value of ～150 μm to about?1?μm.