Preparation of plasma-sprayed oxide cathode

In the conventional oxide cathode manufacturing process, a BaSrCa(CO₃) layer is either painted or sprayed on the Ni base under the normal temperature after the carbonate powders have been mixed with a nitrocellulose binder to provide adhesion to the nickel surface. However, the byproducts deposited in the coating of oxide cathode in the decomposing process and relatively weak adhesion resulting from this method may reduce the emission performance of oxide cathode.In order to improve its performance, plasma spraying has been applied to oxide cathode. Plasma spraying produces a high quality coating by combining a high temperature, a relatively inert spraying medium with high particle velocities. It is shown that few byproducts such as C or CO₂ are produced in the coating in the decomposing process, and that a firmer and denser oxides coating is formed on the oxide cathode surface.