摘要 |
1,176,121. Electrode materials and processing. SIEMENS A.G. 2 Jan., 1968 [4 Jan., 1967], No. 258/68. Heading H1D. In a grid electrode, e.g. for a transmitter tube, in which the grid wire or element consists of a high melting point metal, such as Mo or Ta, with a coating of zirconium, zirconium oxide is incorporated in the electrode either as an addition to the base metal of the grid wire or element in an amount of 0À1 to 2À0% by weight, or in the zirconium coating which is formed from a zirconium powder prepared by the incomplete reduction of zirconium oxide and having a zirconium oxide content of from 10 to 50% by weight. When the zirconium oxide is present in the coating, its content therein is preferably 25% by weight. It is stated that the presence of zirconium oxide at the grain boundaries of the wire metal prevents the undesirable diffusion thereat of zirconium itself. |