Texture, elastic anisotropy and thermal stability of commercially pure titanium prepared by room temperature ECAP

Abstract

Severe plastic deformation of commercially pure titanium, leading to ultrafine-grained microstructure, can be used as an alternative to alloying to obtain better mechanical properties without the reduction of biocompatibility and corrosion resistance. However, the strong texture, induced by plastic deformation, results in anisotropy of mechanical properties, understanding of which is crucial to design and model perspective structural parts and devices. In this work, ultrafine-grained grade 2 Ti, obtained by equal channel angular pressing, is investigated. A detailed study of the texture and the elastic anisotropy of the material, heat-treated at several annealing temperatures, is conducted, complemented by ex-situ and indirect in-situ thermal experiments, which shed light on the stability and evolution of microstructure and material properties. The results show that the elastic properties only slightly evolve during annealing in contrast to other properties, such as thermal expansion, internal friction or hardness. The elastic anisotropy is directly linked to the (0001) texture, thus outlining the importance and possibilities of texture-based design and tailoring of mechanical properties.

Keywords

• Equal channel angular pressing
• Ultrafine-grained grade 2 Ti
• (0001) texture
• Resonant ultrasound spectroscopy
• Elastic anisotropy
• Defect annealing