| 摘要 |
<p>PURPOSE:To increase the reliability of welding between a cathode sleeve and a cathode holding tube by welding by inserting a welding ring which consists of an alloy including gold or a rhenium metallic plate, between the cathode sleeve and the cathode holding tube. CONSTITUTION:Tungsten powder is press-compacted, and it is sintered in a reducing atmosphere to obtain a porous tungsten. The porous tungsten is pressed to form tungsten pellets, which are inserted into a cathode sleeve 3, and a solder material 2 is applied on the rear side of the pellets, and melted and fixed in a reducing atmosphere. A Ba aluminate compound mainly of Ba is applied on the porous tungsten pellets, and it is melted and impregnated in a reducing atmosphere so as to obtain an impregnated type cathode 1. Then, a welding ring 5 which consists of an alloy plate including gold or a rhenium metallic plate is inserted between the sleeve 3 and a cathode holding tube 4, and it is fixed by a resistance welding.</p> |
