| 摘要 |
<p>PURPOSE:To obtain stable scales by calcining alumina ceramics having a specific purity and molding the same thereby forming a sound producing member. CONSTITUTION:An alumina ceramics material is used for the sound producing member 5 and MgO and zirconia, and in some cases, inorg. pigments are used as sintering assistants for the compounded material. About >=90% alumina purity is necessitated in order to assure >=4.4kg.cm/cm<2> impact strength. The stable scales are obtd. in this way even if humidity and temp. change.</p> |
