Formation of ceramic thin films using electrospray in cone-jet mode

An electrostatic atomization technique has been developed to generate ultra-fine spray droplets of ZrO₂ and SiC ceramic suspensions in a range of a few micrometers with a narrow size distribution. The aim of this work is to deposit uniform thin films of these ceramic materials on alloy substrates. Compared to some other thin film deposition techniques, such as chemical vapour deposition (CVD), physical vapour deposition (PVD) and plasma spray (PS) etc., the thin film deposition process using electrostatic atomization is not only cheap but also controllable. Preliminary results have shown that for low throughput atomization, the cone-jet is the most suitable method to produce a fine charged aerosol with a narrow size distribution, which is crucial to produce uniform thin films. It was found that the size of ceramic particles in ZrO₂ and SiC thin films is less than 10 μm. Microstructures of these thin films show very homogenous morphologies. These results indicate that ceramic thin films with high homogeneity can be deposited using electrostatic atomization