| 摘要 |
PURPOSE:To obtain at low cost the title ceramic tubular form of high precision in high efficiency, by calcination of a tubular form made from ceramic raw powder with a ceramic pin having a specified outer diameter inserted thereinto. CONSTITUTION:Ceramic raw powder such as of alumina or zirconia is spiked with necessary ingredients such as sintering aid and binder followed by forming into a tubular form. On this tubular form 1, a slit 2 in the axis direction is provided. Thence, a ceramic pin P having a specified outer diameter (e.g. made of alumina) is inserted into said tubular form 1 to control and set the inner diameter after calcination. The tubular form 1 with said ceramic pin P kept inserted thereinto is then calcined to effect shrinkage of said form 1, resulting in pressing of the tubular form 1 on the outer periphery of the pin P. After the calcination, the pin P is drawn out, thus obtaining the title ceramic tubular form with precise and dense inner wall surface. |
