| 摘要 |
PURPOSE:To drastically increase the number of durable times and durable life, by alternately laminating a fine refractory particle layer comprising a 150-500-mesh fine refractory powder and a large refractory particle layer comprising fine refractory particles with a particle size of 0.1-2.0mm. CONSTITUTION:A hollow part 2 for inserting a thermocouple is formed inside a tubular molded body 1 comprising ceramic and the lower end thereof is closed to form a bottomed hollow shape. The ceramics used in the tubular compact 1 are, for example, recrystallized alumina, mullite, zirconia, zircon, etc. The ceramic tubular compact 1 is formed by a method wherein an appropriate binder or sintering aid is added to a powdery stock material to perform molded while the molded one is sintered at high temp. and a plurality of a fine refractory particle layer comprising a 150-500-mesh fine refractory powder and a plurality of a large refractory particle layer 5 comprising coarse refractory particles with a particle size of 0.1-2.0mm are alternately laminated to the outer periphery of the ceramic tubular compact 1 to form a refractory coating layer 3. |
