MANUFACTURING METHOD OF CERAMIC AND LOW THERMAL EXPANSION CERAMIC

PROBLEM TO BE SOLVED: To provide a ceramic exhibiting low thermal expansion and a manufacturing method therefor.SOLUTION: A process for preparing a first ceramic mixed powder of which temperature dependance of thermal expansion when becomes a sintered body exhibits a positive slope and a second ceramic mixed powder of which temperature dependance of thermal expansion when becomes a sintered body exhibits a negative slope, a process for preparing a first granulated body and a second granulated body respectively by binding a binder to the first ceramic mixed powder and the second ceramic mixed powder respectively, a process for preparing a mixed granulated body by mixing the first granulated body and the second granulated body, a process for manufacturing a molded body with a described shape from the mixed granulated body, and a process for burning the molded body are included. Cordierite is a main crystal phase, Ca, Al, Mn and Cr are contained as metal elements, a temperature where wire expansion rate exhibits minimum value is set as a center and temperature width with variation of wire expansion rate to wire expansion rate at the temperature within 6×10is 3K or more.SELECTED DRAWING: Figure 3 【課題】低熱膨張を示すセラミックスおよびその製造方法の提供。【解決手段】焼結体となったときの熱膨張の温度依存性が正の傾きを示す第１セラミック混合粉末および焼結体となったときの熱膨張の温度依存性が負の傾きを示す第２セラミック混合粉末を調製する工程と、第１セラミック混合粉末および第２セラミック混合粉末のそれぞれにバインダを加えて、第１造粒体および第２造粒体をそれぞれ調製する工程と、第１造粒体と第２造粒体とを混合して混合造粒体を調製する工程と、該混合造粒体から所定形状の成形体を作製する工程と、該成形体を焼成する工程と、を具備する。コージエライトを主結晶相とし、金属元素として、Ｃａ、Ａｌ、ＭｎおよびＣｒを含有するとともに、線膨張率が最低値を示す温度を中心とし、該温度における線膨張率に対する線膨張率の変化量が６×１０−５以内である温度幅が３Ｋ以上である。【選択図】図３