Influence of Accelerating Gas Flow Rate on Optical Property and Cohesion/Adhesion of Vacuum Cold Sprayed TiO₂ Scattering Layer

Submicro-sized anatase TiO₂ powder was used to prepare light scattering layers by vacuum cold spraying at room temperature. The microstructure of the TiO₂ coatings was characterized to be correlated with optical property and adhesion/cohesion of the coatings. Results show that the light-reflecting ability of the coatings decreased with the increase of accelerating gas flow rate from 3.5 to 7.5 L/min and increased with the increase of coating thickness from 2 to 10 µm. Both the cohesion and adhesion of the coatings increased with the increase of the accelerating gas flow rate, due to the improvement of the particle-particle contact and the particle-substrate contact by the high velocity impact resulting from the increased powder particle velocity.