Preparation Of The Entangled Titanium Wire Materials And Their Surface Modification For Bio-application

Using home-made devices and original technology roadmap, entangled titanium wire materials with different porosity have been prepared. Their mechanical properties and deformation mechanism are studied through the compression test and loading - unloading cycle evaluation. The results show that the compressive curves can be divided into three stages: linear elastic stage, the platform stage and the densification stage. The mechanical response of the material behaves as having a certain "hysteresis effect." The Young's modulus of the material with 85% porosity is determined to be 127 MPa. The entangled titanium wire materials exhibit good energy absorption efficiency when deformation within 18%-30%. The highest efficiency appears in the deformation of 20% for the as-prepared materials with 85% porosity, where the absorption efficiency reaches 50%.To improve the biocompatibility of the materials, some wire surface modification, such as micro-arc oxidation (MAO) and anodic oxidation, has been carried out in this study. Titania coatings including hydroxyapatite (HA) on the entangled titanium wire were formed by MAO method in electrolyte containing sodium phosphate monobasic dihydrate (NaH2PO4·2H2O) and calcium acetate monohydrate (Ca(CH3COO)2·H2O). The surface of the entangled titanium wires demonstrates a porous and in silk and silk junction with the accumulation of the amorphous film. The oxidized coatings contain Ca and P as well as Ti and O. The porous coatings were made up of anatase, rutile and hydroxyapatite. The electrolyte concentration and the oxidation time have shown their significance in the formation of the coating. They strongly affect the phase composition and the element content in the coating, as well as the coating morphology. Based on the results, the formation mechanism of the special morphology of the coating can be well understood. The high temperature plasma discharge, which leads to surface melting, is the reasons for the special appearance such as the accumulation of compound. Through the anodic oxidation, the porous coating on titanium materials has been achieved. The parameters such as the electrolyte concentration, oxidation voltage and oxidation time reveal different impacts on the morphology of the coatings. By changing the concentration of electrolyte, microporous coating may be shaped to the "meteorite shape". Increasing the voltage, the morphology of the titania changes from microporous into nanotube.