| 摘要 |
An alumina sintered body contains a main phase consisting of alumina crystal, and crystalline phases dispersed in the main phase. The crystalline phases consist of at least one selected from a group consisting of MgAl2O4, 2MgO.2Al2O3.5SiO2, 2MgO.SiO2 and MgO.SiO2. The average grain size of the crystalline phases is 0.4 μm to 5.3 μm. In an arbitrary area having a size of 100 μm×100 μm in a cross-section of the alumina sintered body,the number of the crystalline phases having grain sizes 1 μm to 5 μm is 8 to 412. |
