Microstructure control of ceramics by solidification processing

通过凝固处理控制陶瓷的微观结构

• 批准号: 10555257
• 负责人: OHNAKA Itsuo
• 金额: $ 7.1万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10555257/
• 关键词: Ceramics; Eutectic Solidification; Refinement; Microstructure control; Faceted interface; Casting

Development of difference thermal analysis method, selection of the eutectic systems in Al2O3-Y2O3 system, effect of the ternary oxide on the eutectic structure and the coupled growth zone were investigated to develop solidification processing for the eutectic ceramics. An optical differential thermal analysis method was developed in the project, which was used up to 2500K.By using this equipment, Selection of the eutectic systems (equilibrium and metastable eutectic systems) was determined by nucleation temperature. Cooling rates more than 5K/s and/or melt temperature above 2373K depress the YAG nucleation and consequently the metastable eutectic system was selected. Addition of ternary oxide in the Al2O3-YAG system caused finer eutectic structure, because the addition deceased mass transfer at solidifying interface.The eutectic structure was formed in the eutectic composition in a wide growth rate range, although the coupled growth occurred only in a narrow composition range due to the faceted growth

本文通过差热分析方法的发展、Al_2O_3-Y_2O_3系共晶系的选择、三元氧化物对共晶组织和共生生长区的影响等研究，探索了共晶陶瓷的凝固工艺。本项目开发了一种光学差热分析方法，其温度范围可达2500 K，利用该装置，通过形核温度确定共晶体系（平衡和亚稳共晶体系）的选择。冷却速率大于5 K/s或熔体温度高于2373 K会抑制YAG的形核，因此选择亚稳共晶系统。在Al 2 O3-YAG系统中添加三元氧化物，由于其抑制了凝固界面的传质，使共晶组织细化，在较宽的生长速率范围内形成共晶组织，但由于小面生长，共晶组织的耦合生长仅在较窄的成分范围内发生

项目成果

Itsuo Ohnaka: "New Eutectic Ceramics - Future and Solidification Problems -"Proc. Oxford-Kobe Materials Seminar on Solidification and Casting. 44-58 (1999)

Ituo Ohnaka：“新型共晶陶瓷 - 未来和凝固问题 -”Proc。

Y.Mizutani: "New Eutectic Seramics-Future and Solidification Problem-"Proc.Oxford-Kobe Materials Seminar on Solidification and Casting. 45-58 (1999)

Y.Mizutani：“新共晶陶瓷-未来和凝固问题-”Proc.Oxford-Kobe 材料凝固和铸造研讨会。

Y,Mizutani: "Phase selection of the Al2O3-YAG system controlled by nucleation"Mater.Trans.. 42. 238-244 (2000)

Y，Mizutani：“由成核控制的 Al2O3-YAG 系统的相选择”Mater.Trans.. 42. 238-244 (2000)

H.Yasuda: "Selection of Eutectic Systems in Al2O3-Y2O3 Ceramics"Science and Technology for Advanced Materials. (in press). (2001)

H.Yasuda：“Al2O3-Y2O3陶瓷中共晶体系的选择”先进材料科学与技术。

Itsuo Ohnaka: "New Eutectic Ceramics -Future and Solidification Problem-"Proc. Oxford-Kobe Meterials Seminar on Solidification and Casting. 173-181 (1999)

Ituo Ohnaka：“新型共晶陶瓷-未来和凝固问题-”Proc。