Titanium alloy is widely used in the fields of aerospace, chemical industry and biological medicine, but its hardness is low, poor anti-wear and anti-friction function, which restricts its use.The most commonly used method is chemical treatment or chemical oxidation, to improve and improve the substrate and coating contact force and appearance of corrosion resistance.However, the oxidation film obtained by chemical oxidation is thinner and has poor corrosion resistance and durability.The oxide film on the surface of titanium alloy makes it difficult to electroplate and electroplate on titanium.In contrast, micro-arc oxidation treatment is currently widely accepted as the most promising treatment method for the appearance of titanium alloys.
Micro-arc oxidation is a process in which high voltage (dc, ac or pulse) is applied to an electrolyte solution (usually a weakly alkaline solution) to grow ceramic oxide film in situ on the surface of the data. This process is the collaborative result of physical discharge, electrochemical oxidation and plasma oxidation.This skill is developed on the basis of general anodic oxidation skills, further advances the voltage, the voltage exceeds the Faraday area, reach the oxide film breakdown voltage, will appear in the anode spark discharge appearance, appearance in the data form ceramic oxide film, the plasma oxidation film has high function of ceramic membrane, and adhere to the contact force of the anodic oxidation film and substrate.These features make it a hot topic in the field of appearance engineering skills.Using micro-arc oxidation ability of Harbin Institute of Technology, China joined the cobalt acetate in the electrolyte, thus generated on TC4 alloy heat-resistant ceramic membrane, membrane layer and basal contact above 10 mpa, alloy under 40 cycles of thermal sensation, still insist on stable, indicate the micro-arc oxidation treatment of TC4 alloy has excellent heat resistant to impact.
In recent years, the micro-arc oxide film generated in electrolytes containing calcium and phosphorus components has led to interest in bone transplantation due to its high resistance to abrasion, corrosion and biocompatibility.Micro-arc oxidation technique is used in Korea to generate nanocrystalline hydroapatite ceramic layer on the surface of pure titanium. The high crystallinity and strong biocompatibility of apatite ceramic in the film layer show the potential use in plastic surgery and dental repair skills.Xi 'an jiaotong university, China, studied the formation of bioactive films containing calcium and phosphorous titanium oxide by micro-arc oxidation, and the results indicated that the film was composed of anatase TiO2 and rutile TiO2, with a fine inner layer and a porous outer layer.The ratio of calcium and phosphorus atoms in the membrane increased gradually from inside to outside.After hydrothermal treatment, the film layer can be transformed into a bioactive titanium dioxide layer containing hydrogen apatite.The rutile membrane has common electrical and mechanical functions.
Beta-ti is considered by the medical community as the next generation of metal used in plastic surgery and dentistry due to its excellent physical function and biocompatibility.In order to improve the composition of beta-ti and human bone arrangements, microarc oxidation can be used to improve the biological activity of the appearance of beta-ti.TiO2 ceramic film was prepared by microarc oxidation on a beta-ti alloy in Taiwan, China, and tested in vitro and implanted in the thigh tips of Japanese mice.The results indicated that TiO2 film layer was generated and firmly connected with the substrate, which showed excellent bone formation ability compared with the base pure titanium, and was more suitable for medical implantation and correction.