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 degrees C, 350 degrees C, and 450 degrees C, up to the true strain of e = 2. At 20 degrees 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 degrees C and 350 degrees 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. (C) 2010 Elsevier B.V. All rights reserved.