等离子喷涂沉积Al₂O₃-SiO₂涂层的光学性能

Al₂O₃-SiO₂ coatings were prepared by plasma spraying at different process parameters. The influences of particle melting state, microstructure and phase composition on the optical reflectivity of the coatings prepared at different spraying parameters were investigated. The results show that melting state of the particles becomes more complete when the plasma spraying power increases. The SiO₂ of Al₂O₃-SiO₂ coating changes from amorphous to crystalline, and the solid phase reaction of some Al₂O₃ and SiO₂ generates Al₆Si₂O₁₃. The formation of the new phase can make the phase composition of the whole coating system more complex and rich in phase interface. The increase of phase interface is beneficial to the improvement of optical properties of coatings. In addition, the formation of the layered structure and the increase of the porosity in the interior of the coating both are beneficial to the improvement of the optical properties of the coating. It is thus possible to improve the optical properties of Al₂O₃-SiO₂ coating via the optimization of the melting state, microstructure and phase composition of the powder.