SiO2包覆对爆炸喷涂自敏涂层发光和摩擦性能的影响

采用溶胶-凝胶法在铝酸锶荧光粉表面包覆SiO₂层,以45号钢为基体,采用爆炸喷涂技术制备不同SiO₂包覆质量分数下的SrAl₂O₄∶Eu²⁺, Dy³⁺/Cu-14Al-X自敏复合涂层.对比研究了不同包覆质量分数下铝酸锶粉末与自敏涂层的发射光谱和余辉衰减曲线,复合涂层的摩擦系数与磨损量以及SiO₂包覆质量分数对自敏涂层的发光性能和摩擦学行为的影响.结果表明:SiO₂包覆使得铝酸锶在爆炸喷涂制备过程中得到了保护,提高了涂层的发光性能.随着SiO₂包覆质量分数的增加,复合涂层结构致密度、硬度和耐磨性提高.20%包覆质量分数下铝酸锶粉末硬度为564.5HV,比未包覆铝酸锶粉末的涂层提高了38%.由于破碎后的SiO₂包覆层具有自润滑效果,包覆后复合涂层的摩擦系数相对稳定,15%SiO₂包覆质量分数下复合涂层摩擦系数为0.182,具有最优的摩擦性能.

Effect of SiO2 coating on luminescence and friction properties of self-sensitive coating prepared by detonation spray

The SiO₂ layer was coated on surface of the strontium aluminate phosphor by sol-gel method. The SrAl₂O₄∶Eu²⁺, Dy³⁺/Cu-14Al-X self-sensing composite coating with different amounts of SiO₂ coating was prepared by detonation spraying on steel 45# substrate. The emission spectra and afterglow attenuation curves of strontium aluminate powder along with self-sensing coating were compared in this paper, the corresponding friction coefficient together with wear of the composite coating were also compared, and further the effect of amount of SiO₂ coating on the luminescence and tribological behavior of the self-sensing coating was analyzed in details as well. The results show that SiO₂ coating can protect strontium aluminate during detonation spraying and improve luminous properties of the coating. With the increase of amount of SiO₂ coating, the structure of the composite coating becomes more compacted, and the hardness and wear resistance of the composite coating are improved as a consequence. Under 20% amount of the coating, the hardness of strontium aluminate powders takes 564.5HV, which is 38% higher than that of uncoated strontium aluminate powders. The friction coefficient of the composite coating after being coated is relatively stable due to a certain degree of self-lubricating effect of broken SiO₂ coating. The friction coefficient of the composite coating reaches 0.182 at 15% amount of SiO₂ coating in this case, which exhibits the best friction performance.