Structure and properties of hydrostatically extruded commercially pure titanium

The effect of hydrostatic extrusion on the structure and mechanical properties of commercially pure titanium was investigated at 20 °C, 350 °C, and 450 °C, up to the true strain of e = 2. At 20 °C extrusion to e = 1.8 resulted in the formation of a lamellar-type microstructure with fragments of about 100 nm within the laths. Higher deformation temperatures lead to the formation of mixed microstructures consisting of packs of lamellae alternating with fine-grained areas. Hydrostatic extrusion results in a remarkable increase in the strength of titanium. The ultimate tensile strength of titanium extruded at 20 °C and 350 °C was 1080 and 765 MPa, respectively. The strength and elongation at the fracture can be controlled by varying the temperature of the extruded billet. The optimal deformation parameters for various applications are proposed.