Strengthening of Titanium by Equal Channel Angular Pressing ‐ Impact on Oxide Layer Properties of Pure Titanium and Ti6Al4V

Abstract

Equal channel angular pressing (ECAP) as a method applicable to large samples for strengthening metallic materials via severe plastic deformation has recently attracted considerable interest. For biomedical applications, ECAP‐treated pure titanium is a promising alternative for implants subjected to high mechanical loads as it contains no potentially cytotoxic alloying elements. The consequences of an ECAP treatment for the physico‐chemical properties of the air formed passive layers of pure or alloyed titanium, which are of the utmost importance for the biological response to these materials, are studied here for the first time. This includes mechanical, electron microscopic, and electrochemical investigations in protein containing media to study the reactions that occur immediately after implantation in the phase boundary between implant and biological system. The ECAP treatment results in a positive shift of the flatband potential and a particularly strong increase of the donor density for the native oxide layers. This is associated with increased electronic conductivity of the oxide layers under anodic polarization.

Texture-Governed Cell Response to Severely Deformed Titanium

“…It has been stated that physicochemical properties of the surface get altered when a material is subjected to various, complex plastic deformations. 30 Titania layer formed on the HE-manufactured Ti has shown to be slightly thicker and covered with a greater amount of hydroxyl groups when compared to the unprocessed substrates. 2 In addition, hydrostatically extruded titanium demonstrates anisotropy of corrosion resistance in synthetic saliva.…”

“…Apart from wettability and roughness, surface chemistry could also have a vital role in governing the biological properties of a material. It has been stated that physicochemical properties of the surface get altered when a material is subjected to various, complex plastic deformations . Titania layer formed on the HE-manufactured Ti has shown to be slightly thicker and covered with a greater amount of hydroxyl groups when compared to the unprocessed substrates .…”

Recent Advances in the Equal Channel Angular Pressing of Metallic Materials

“…Reducing the grain size can improve their mechanical properties and deformability, showing great application potential in the preparation of medical devices and medical materials [3]. Furthermore, a number of studies have shown that titanium and its alloys with ultrafine grains have superior strength, plasticity, fatigue resistance, corrosion resistance, and many other excellent properties, which have been widely used in the fields of aerospace, biomedicine and chemical machinery [4][5][6][7].…”