| 摘要 |
PURPOSE:To obtain a high quality heater with high production efficiency and at low cost by electrodepositing alumina over the mandrel core of a heater assembly body, then successively electrodepositing dark suspensions of alumina and W or the like with specified grain sizes before sintering, being followed by dissolving and removing the core. CONSTITUTION:A W-Re wire 2 used as a heater is wound around a Mo wire used as a mandrel core 1 to make a heater assembly body 3 which is then immersed in an alumina suspension compound liquid to form an insulating alumina layer 4. The heater assembly body 3 coated with the insulating alumina layer 4 is subsequently immersed in a dark suspension compound liquid containing alumina with below 15mum mean grain size and W or its oxide with 0.3-3mum mean grain size to form a dark layer 5, then sintered. After that, the sintered body is immersed in mixed acid solution consisting of nitric acid, sulfuric acid and the like to dissolve the mandrel core 1, thereby completing a dark heater. |
