| 摘要 |
1,224,869. Discharge apparatus; electrode materials and processing. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 28 May, 1969 [31 May, 1968], No. 26980/69. Heading HID. [Also in Division C7] In a method of manufacturing an electric discharge tube including a cathode and a non- emissive electrode having a nickel surface, the electrode surface facing the cathode is coated with a layer of gold and the tube is then evacuated and degassed at a temperature such that the electrode is heated to 600‹ to 800‹ C., preferably 780‹ C., so that the gold fully dissolves into the nickel without losing its emission-suppressive effect. Preferably the tube is degassed at 780‹ C. for 100 to 110 sees., and the electrode may form the anode of a high-voltage rectifier tube and comprise iron plated with nickel 16Á thick on which is initially provided a layer of gold less than 1Á thick. The gold-plating may be carried out in a drum by means of a bath which contains potassium-gold-cyanide and ammonia. If the electrode support, Fig. 1 (not shown), is of oxidized chromium-iron alloy it is found that it is not covered with gold by this process. The gold-plated electrode may also be, for example, a concentration plate in a beam pentode or an anode for an X-ray tube. |
