Study On The Preparation Process Of Micro-arc Oxidation Ceramic Film On Titanium Alloy Implants

Titanium is an attractive metal for implanted applications because of its combination ofexcellent biocompatibility and mechanical properties. However, there are some reactioncharacteristics of this metal, such as prone to poor biological activity, corrosion faster andeven more prone to dissolution of the metalions. Therefore, surface modification treatment isneeded for titanium implant to improve the biocompatibility. For this project, in this study, theTiO₂ceramic layer on the surface of titanium alloy was performed by micro-arc oxidationtechnology, the microstructure and morphosis of ceramic layer with different processingparameters such as electrolyte and electrical parameters were investigated, which may providea theoretical basis to improve the biological activity of titanium alloy surface. The resultsshow that: the layer papered for titanium permanent implant is mainly composed of TiO₂andcalcium and phosphorus elements, and rutile TiO₂content gradually increased with increasingof concentration of calcium and phosphorus, which cause high surface roughness andhardness of the layer.The additives in the phosphate system has significant effective on the microstructure oflayer for temporary implant by micro-arc oxidation technology. It is found that the pore sizeof the layer increased with increasing of additive concentration in single additive system andthis led to increase the roughness and hardness of the layer. While adding a variety ofadditives, the variation of microstructure of the layer is no longer depending on theconcentration of the electrolyte, but has a relationship with the types of additives. It isconsidered that A could cause the venation undulating structure on the surface of layer. Theroughness of the layer increases at first and then decreases with the increasing of theconcentration of C, roughness of the layer decreases at first and then increases with increasingof A. This phenomenon is considered to combined with the effect of the electrolyteconcentration and the metal ions in the electrolyte.