Study On Technology And Performance Of SiO₂ Coated Phosphor Powder Composite Coating Prepared By Detonation Spraying

Combining the excellent abrasion resistance of high-aluminum bronze alloys?Cu-14Al-X?with the luminous properties of long afterglow materials(SrAl₂O₄:Eu²⁺,Dy³⁺),a new self-sensitive detection coating prepared by detonation spray can be used to inspect the wear and corrosion of equipment and workpiece surfaces in real time through hand-held UV lamps.It is a new functional coating with abrasion protection and detection effects.High aluminum bronze alloys have been widely used in processing and manufacturing,marine protection,automobile production and other fields due to their excellent mechanical properties and wear resistance.The long afterglow material strontium aluminate is doped into the high-alumina bronze coating,which not only improves the wear resistance of the coating,but also gives the coating luminous detection function.However,in the detonation spray process,the high flame thermal effect and fast speed can cause the quenching of strontium aluminate powder,as well as the poor water resistance of the luminescent material strontium aluminate,which also seriously affect the luminescent indication effect and the abrasion resistance of the composite coating.This subject used sol-gel method to prepare SiO₂ coating layer on the surface of strontium aluminate powder to improve the water resistance and reduce the quenching in the preparation process.To study the influence of SiO₂ coating amount on the mechanical properties,luminous indicator function and friction and wear properties of composite coatings.The electrochemical characteristics and corrosion resistance of composite coatings in acid,alkali and salt solutions under different SiO₂ coating amounts were analyzed.The main research results are as follows:1.By adjusting the proportion of tetraethyl orthosilicate,inorganic SiO₂ coatings with 5%,10%,15%,and 20%coating ratios were prepared on the surface of strontium aluminate powder,the SiO₂-SrAl₂O₄/Cu-14Al-X composite coating with different coating amount was prepared by detonation spray.The mechanical and luminescent properties of the composite coating were studied by SEM,EDS,brovill hardness tester and fluorescence spectrophotometer.The structure of the strontium aluminate silica coating film in the composite coating is complete.The SiO₂ coating can enhance the powder hardness of the strontium aluminate particles.The hardness of the strontium aluminate powder with 20%SiO₂coating reaches 564.5 HV.With the increase of the coating amount,the hardness and luminous intensity of the composite coating both increased,and the hardness of the composite coating with 20%SiO₂ coating reached 506.7HV,which was 36.6%stronger than that of the uncoated composite coating.2.With the increase of silica coating amount,the emission peak of composite coating increases obviously.The coating does not destroy the luminescence mechanism of strontium aluminate,and it can also effectively reduce the mechanical quenching and thermal quenching of luminescent particles in spraying.The luminescence indicator of composite coating with20%SiO2 coating amount is the best.3.The composite coatings with different SiO2 coatings were immersed in 3.5%NaCl,5%H₂SO₄,and 5%NaOH solutions,respectively.The corrosion rate and depth were calculated.The electrochemical characteristics of the composite coatings with different SiO2coating amounts in acid,alkali and salt solution were analyzed by electrochemical workstation.With the increase of the coating amount of SiO₂,the coating film layer can effectively reduce the corrosion rate of the composite coating in the salt solution and the acid solution,and improve the corrosion resistance and luminous indicator performance.In alkaline solutions,the silicon dioxide film can only delay corrosion.4.Friction experiments were performed on composite coatings with different SiO2coating amounts by the HT-1000 friction and wear tester.The effects of different SiO₂ coating amounts on the friction coefficient,wear amount and wear morphology of composite coatings were studied.With the increase of SiO2 coating amount,the friction coefficient and wear rate of the composite coating decrease.The broken SiO₂ coating layer has a certain self-lubricating effect.The friction coefficient of the composite coating with 20%Si O2 coating amount is0.165,the wear is the lowest,and it has the best friction performance and luminous indication effect.5.At the same deposition rate of luminescent particles,the quenching of SrAl₂O₄:Eu²⁺,Dy3+particles in composite luminescent coatings prepared by hot-press sintering,cold spraying,detonation spray and plasma spraying was studied,and the quenching of strontium aluminate in plasma coatings was the most serious.Quenching in cold spray preparation is mainly concentrated in deep energy levels.The coating of SiO2 can effectively reduce the quenching of strontium aluminate during the preparation process,and improve the luminous performance of the coating.