Obtaining of pure nanostructured titanium for medicine by severe deformation at cryogenic temperatures

Abstract

The purpose of this study was to obtain pure nanostructured titanium by drawing at cryogenic temperatures and to investigate its structural and mechanical properties. Titanium rods were obtained by severe plastic deformation under the scheme of upsetting-extrusion-drawing. Upsetting and extrusion were performed at 800 K, obtained rod was initially drawn at 300 K to diameter of 3.7 mm (degree of true strain e = 3.2). Further deformation of the finish drawing was performed at 77 K (liquid nitrogen) and at 300 K.Keywords: titanium / medical implants / plastic deformation / nanostructure / mechanical properties / Das Ziel dieser Arbeit war die Herstellung von reinem nanostrukturiertem Titan durch die Tiefzieh-Verformung bei kryogenen Temperaturen und die Untersuchung seiner strukturellen und mechanischen Eigenschaften. Titanproben (Stäbe) wurden durch die starke plastische Verformung beim Pressen-Extrusions-Tiefziehen hergestellt. Das Pressen und die Extrusion wurden bei 800 K durchgeführt, der erhaltene Stab wurde zuerst bei 300 K zu einem Durchmesser von 3,7 mm gezogen (wahre Dehnung e = 3,2%). Eine weitere endgültige Verformung wurde durch Tiefziehen bei 77 K (flüssiger Stickstoff) und bei 300 K durchgeführt.

The Lattice Parameters and Residual Stresses in Bulk Nanocrystalline and Ultrafine-Grained Titanium

“…Встановлено, що одержання нанокристалічного/ультрадрібнозернистого титану з використанням методу кріомеханічної фрагментації зерна супроводжується формуванням однорідних стискувальних залишкових напружень по глибині інформативного шару деформовної заготовки. [1,2].…”

“…На рис. 2 представлены результаты по влиянию степени обжатия при криопрокатке |е| на остаточные внутренние напряжения σ, рассчитанные согласно формуле (2). Видно, что в исходном материале эти напряжения являются сжимающими, как следствие технологического процесса изготовления плиты (горячая прокатка плюс отжиг).…”

Evaluation of the Cutting Force Components and the Surface Roughness in the Milling Process of Micro- and Nanocrystalline Titanium

“…Some titanium alloys used in medicine contain toxic elements, such as vanadium. Therefore, from a biological point of view it is preferable to use implants made of pure titanium [13]. Obtaining information on process quality indicators is a way of supporting decisions in the design stage: tool life, surface roughness, state of technological surface layer [14], chip control and cutting force compnents [15].…”

Structural State Effect on Mechanical Properties and Acoustic Emission of High-Purity Titanium at Different Types of Deformation

“…To obtain ultra-fine grains and extremely high strength characteristics, it seems natural to combine both considered methods of extreme impact on the material (SPD and CD) in the same technological chain [4]. Many schemes for the implementation of SPD [5][6][7][8][9][10] and CD [11][12][13][14][15] have been proposed. In the case of titanium, such a combination was realized in [12][13][14].…”

“…Many schemes for the implementation of SPD [5][6][7][8][9][10] and CD [11][12][13][14][15] have been proposed. In the case of titanium, such a combination was realized in [12][13][14]. The SPD application by the method of «upsetting-extrusion-drawing» with subsequent additional drawing at liquid nitrogen temperature [13] allowed to obtain a wire from iodide titanium with the ultimate tensile strength of 1250 MPa, which is, apparently, one of the highest values for the material of a given purity.…”