| 摘要 |
PURPOSE:To permit the restriction of the generation of crack as well as the saving of the amount of ventilation by a method wherein the title tool is formed of the ceramic sintering body of alumina or alumina zirconia, which includes air holes of a specified volume percent. CONSTITUTION:A tool 10 for heat treatment is constituted of ceramic blended material of alumina or alumina zirconia added with 9-40 weight % of air hole forming material consisting of combustible heat-shrinkable organic substance while the air hole forming material is removed by combustion upon sintering to produce air holes 14 of 30-70 volume % in the ceramic sintered body. The main body 11 of the tool 10 for heat treatment accommodates a member to be heat-treated 20 and is inserted into a heat treating furnace, regulated at a proper temperature, under a condition that a lid 12 is attached to the opening of the main body 11 whereby the member 20 to be heat-treated may be heat- treated. Upon the heat treatment, the growth of cracks 16 or spalling may be precluded by the air holes 14 even when they are generated and the generation of spalling may be restricted while sealed holes are increased whereby the amount of ventilation of hot air may be saved remarkably and energy cost may be reduced. |
