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

YAG:Ce fluorescent coating deposited on titanium alloy surface by plasma spraying technology has high bonding strength and luminescent properties.The study of fluorescence intensity of coatings in corrosive environment is meaningful to the develop ment of monitoring technology in corrosive environment.Existing plasma sprayed YAG:Ce coatings in acid corrosion environment lead to a rapid decrease in bonding strength of coatings,which limits the service life of coatings.In this paper,the effect of substrate temperature on flattening of single YAG:Ce particle,phase composition,microstructure and fluorescence intensity of the coating were studied by plasma jet preheating.On this basis,YAG:Ce coating with dif-ferent substrate temperatures were prepared,and the changes of structure,properties and fluorescence intensity after corrosion in sulfuric acid solution were studied.It is found that when the substrate temperature is room temperature,the splashing occurs during droplet flattening which results in the formation of the splats with an irregular morphology.When the preheating temperature up to 120?,the splats present regular disc shape,and the porosity of the splats increases gradually with the increase of the substrate temperature.The phase composition of the coating deposited at different substrate temperatures is mainly YAG phase.The crystallinity of the coatings and the bonding strength between the coatings and the substrate increase with the increase of substrate temperature.On the contrary,the porosity of the coatings decreases.The fluorescence intensity of coatings deposited at different substrate temperatures is good.Thickness shows some influence to the fluorescence intensity of coating.During 150 hours of corrosion in 1.5 mol/L sulfuric acid solution,the porosity of YAG:Ce coatings deposited at different substrate temperatures increased,the phase structure and fluorescence intensity of the coatings also changed.The higher the substrate temperature is,the less increasing trend of the porosity is;the intensity of the diffraction peak of the coating increases,and the position of the diffraction peak fluctuates in 1°;the fluorescence intensity of the coating rises and then tends to decline steadily.The higher the substrate temperature,the smaller the variation range of the fluorescence intensity of the coating.When the substrate temperature is higher than the transition temperature,the fluorescence intensity of the coating will decrease,the change of fluorescence intensity with corrosion time is more stable.