Plasma deposition by a coaxial discharge in powder

Abstract

Different types of material powder have been placed at the breach of a coaxial discharge for impulse plasma deposition. The coaxial discharge is powered with a 46.26 μF, 24 kV capacitor bank. When the discharge takes place at the breach, the powder is evaporated and ionized to form a sheath of its material. The plasma sheath is ejected from the discharge zone with a high velocity to be deposited on a glass substrate. It has been found from scanning electron microscopy analysis that the deposited material is almost homogeneous for ceramic and graphite powders. The grain size is estimated to be of the order of a few microns. To measure the deposited material thickness, a microdensitometer, a laser interferometer and an optical microscope are used. It has also been found that the deposited material thickness depends on the discharge number of shots and the capacitor bank energy.