Effect Of Acid Corrosion On The Luminescence Intensity Of Ce Doped YAG Coatings

Rare-earth doped yttrium aluminum garnet (YAG) coating can be applied to fluorescent coatings. Using of the luminescent property of rare earth element, the influence of corrosive environment on the fluorescent coating is studied, so as to provide a new way for the monitoring of the corrosion environment. YAG powder doped with Ce is prepared using the high temperature solid state method in this study. And the YAG:Ce powder, made by this method have favorable luminescent properties and phase stability, and is feasible for plasma spraying. Coatings are prepared by atmospheric plasma spraying. And the changes of structure property and luminescence intensity of coating corrosion in acidic condition for different time are studied.The study finds that in the process of preparing powder by high temperature solid state method, the calcination temperature is 1300 degrees Celsius, the calcination time is 3 hours, the doping Ce ion concentration is 0.06, the prepared YAG:Ce powder has the best luminous effect. The powder re-prilled by spray dryer is feasible for plasma spraying.In the process of YAG:Ce coating corroded in nitric acid and sulfuric acid solution respectively for 25 hours, the porosity of the coating increases, and the phase structure and the fluorescence intensity of the coating are also changed. In nitric acid corrosion the intensity of diffraction peak shows increasing trend, and the positions of the diffraction peaks show first shifting to a large angle direction, then unchanged, and to the trend of small angle direction last. In addition, the luminescence intensity of the coating increases first and then decreases, at last increases; in sulphuric acid, the positions of the diffraction peaks appear first shifting to a small angle direction, then shifting to a large angle, and at last shifting to a small angle. It is a back and forth fluctuation trend. The luminescence intensity of the coating decreases first and then increases, and then decreases. So it has a fluctuated changing process. The luminous intensity of the coating is influenced by the porosity of the coating, the intensity of the diffraction peak and the offset of the diffraction peak.