Room Temperature Flow Behavior of Ti Deformed by Equal‐Channel Angular Pressing Using Core–Sheath Method

The present investigation is conducted to successfully deform a commercially pure titanium as a hard‐to‐deform metal by equal‐channel angular pressing (ECAP, φ = 90°) using core‐sheath configuration at room temperature. Analyzing the flow behavior of metal via three‐dimensional finite element modeling (FEM) and analytical calculation reveals that the friction force between the sheath and inner surface of the die in the exit channel is the source of back pressure and its magnitude is dependent on the length of the billet and strength of the sheath. The ultimate tensile strength of Ti increases by a factor of ≈1.8 after processing through one pass of ECAP and the material exhibits total elongation of ≈17% after testing at room temperature, regardless of core size.