Prepared Al-Ti-O Metal Oxide Films And Study It's Electrochemical Corrosion Behavior

The corrosion of metals not only causes significant economic losses,but also causes catastrophic accidents.Therefore,the research on corrosion prevention of metal materials has long been a hot topic in the field of materials.Oxide ceramics has excellent chemical stability and corrosion resistance and is expected to be applied as protective coatings of metal materials.However,due to the difference in the expansion coefficient,there is still a problem of the binding force between the oxide ceramics and the metal matrix.Aluminum titanate?Al₂TiO₅?is a typical oxide ceramic material,which has excellent corrosion resistance,high melting point,Low CTE and thermal shock resistance et.al.make it have broad application prospect in the field of metal material corrosion protection.In this paper,Al-Ti-O metal oxide films were fabricated by annealing an Al-Ti films on 316L stainless steel obtained by magnetron co-sputtering.And the effects of different Ti content,substrate temperature and sputtering pressure on the morphology,crystallization,phase structure and electrochemical properties of films were studied.The main research contents and results of this dissertation are as follows:?1?Ti content influences the morphology,crystal structure,porosity and corrosion resistance of Al-Ti-O films.By controlling the Ti target sputtering power prepared the Al-Ti-O films with different Ti content.When the Al and Ti atoms deposited on the surface of the matrix have higher order degree,the films tend to grow as Volmer-Weber pattern and increase in crystallinity.Al-Ti film is very easy to be oxidized in the air,and the heat treatment process makes the film oxidize more seriously and the crystallization increases,and the film defects decrease.Al₂TiO₅?Al₂O₃ and TiO₂ are the main substances produced by the crystallization of Al-Ti-O films.The thickness of the film will thicken with the increase of Ti target power,and the heat treatment process increase the film thickness about 90 nm.Ti content has influence on the porosity of film.The corrosion resistance of Al-Ti-O film is not only affected by the structure of the film,but also by the porosity of the film.The corrosion current of Al-Ti-O film prepared by Ti target at 210 W has the minimum icorr(6.7 nA·cm^-2),poriness 5.92%,this film has the best corrosion resistance.?2?Substrate temperature influences the morphology,crystal structure,porosity and corrosion resistance of Al-Ti-O films.Prepared the Al-Ti-O films under different substrate temperature.As the substrate temperature increased,the crystallization increases,the growth pattern of the film from Volmer-Weber pattern become Frank-Van der Merwe pattern and then become Volmer-Weber pattern.The heat treatment process makes the film oxidize more seriously and the crystallization increases.Al₂TiO₅?Al₂O₃ and TiO₂ are the main substances produced by the crystallization of Al-Ti-O films.The thickness of the film is less affected by temperature,and the thickness of the film after heat treatment increases about 90nm.The substrate temperature has a great influence on the porosity of the film,and the porosity is decrease ae the substrate temperature increase.The corrosion resistance of Al-Ti-O film increases with the substrate temperature increase.The corrosion resistance of Al-Ti-O films is mainly affected by films porosity.The corrosion resistance of Al-Ti-O film prepared under 400? was the best,with a small corrosion current density 2.66 nA·cm^-2 and poriness 1.73%.?3?Sputtering pressure influences the morphology,crystal structure,porosity and corrosion resistance of Al-Ti-O films.Prepared the Al-Ti-O films under different sputtering pressure.As the sputtering pressure increases,the film crystallization decreases and the growth pattern of the film from Volmer-Weber pattern become Frank-Van der Merwe pattern and then become Volmer-Weber pattern.The heat treatment process makes the film oxidize more seriously,the crystallization increases and the thinkness increase.Al₂TiO₅?Al₂O₃ and TiO₂ are the main substances produced by the crystallization of Al-Ti-O films.The effect of sputtering pressure on the film porosity is small,and the porosity undulate with the increase of sputtering pressure.The corrosion resistance of Al-Ti-O film was increase at first and then decrease with the sputtering pressure increase.The corrosion resistance of Al-Ti-O films is mainly affected by films porosity.The corrosion current density of Al-Ti-O films prepared under 0.4 Pa is 1.97 nA·cm^-2 and poriness is 0.94%,this film has the best corrosion resistance.