| 摘要 |
PROBLEM TO BE SOLVED: To provide a ceramic container for use in a production process for a ceramic insulator(s) for a spark plug(s), that the container is not melted and stuck to a ceramic formed body for the spark plug and cracks, etc. are not caused and it has mechanical strength sufficient to withstand the stacking-up of such containers and also it can be repeatedly used having a long service life. SOLUTION: This container is made of an alumina-based sintered body consisting essentially of an Si component and an Al component, wherein: the weight ratio of (the Si component content expressed in terms of SiO2)/(the Al component content expressed in terms of Al2O3) is 5/95 to 20/80, or in particular 10/90 to 15/85; and the container has a 15-25%, or in particular 17-23% apparent porosity and a 2.5-3.2, or in particular 2.8-3.0 bulk density. Alternatively, the container contains coarse alumina particles, fine alumina particles and fine mullite particles and has a specified composition consisting of these constituent particles. Thus, particularly excellent performance of such a container can be stably obtained. |
