| 摘要 |
PROBLEM TO BE SOLVED: To constitute an electrode of a plurality of members without degrading the electrode performance.SOLUTION: A negative electrode 20 having an electrode tip composed of thoriated tungsten is bonded to a discharge lamp by SPS bonding. In the SPS bonding process, a columnar metallic member 110 composed of thoriated tungsten, and a columnar metallic member 120 of pure tungsten having a diameter D2 larger than the diameter D1 of the metallic member 110 are electrically heated via bonding surfaces 110S, 120S, and SPS bonded. Thereafter, it is cut so that a cross section shown by a broken-line K becomes the outer peripheral surface of an electrode. |
