Crystal structure selection

晶体结构选择

• 批准号: 10211205
• 负责人: YASUDA Hideyuki
• 金额: $ 33.98万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10211205/
• 关键词: High magnetic field; Crystal structure selection; Aligned structure; Structure control; Peritectic reaction; Monotectic reaction; Magnetic alignment

1.Periodic structure formation during unidirectional solidificationDuring unidirectional solidification of peritectic alloys, periodic structures in which faction of two constituent phases fluctuates in the growth direction have been observed. This study performed unidirectional solidification under a magnetic field up to 10T and indicated that the periodic structure was preferably observed by reducing convection. The results indicated that the periodic systems involved the periodic growth mode.2. Aligned structure formation due to the magnetic anisotropyThis study developed novel processing to obtain the magnetically aligned structure. In the alignment procedures, non-equilibrium structure produced by rapid solidification was used as a starting material. Heating the non-equilibrium structure of Bi-Mn system caused the semisolid state, while can be obtained during conventional solidification procedure. By imposing the magnetic field on the semisolid state, alignment of the BiMn compoun … More d were achieved. Furthermore, the aligned structure of BiMn was obtained during coarsening under a magnetic field. This study proposed mechanism of the alignment by using the non-equilibrium structure.3. Control of solidified structure of monotectic alloysThere is immiscibility gap of liquid state for monotectic alloys. In general, it is difficult to obtain uniform and fine solidified structure, since density difference between the two liquid phases initiates strong convection and leads to macrosegregation. This study indicated that imposition of a magnetic field, 10T, significantly reduced convection and consequently produced homogenous solidified structure for Cu-Pb alloysIn the case of unidirectional solidification for Al-In alloys, rod-type monotectic structure, which was basically similar to the regular eutectic structure, was obtained by imposing a magnetic field more than 2T. Imposition of the high magnetic fields was effective to obtain homogenous solidified structure for monotectic systems. Less

1.定向凝固过程中周期性组织的形成在包埋合金的定向凝固过程中，观察到两个组成相的比例沿生长方向波动的周期性组织。该研究在高达10 T的磁场下进行了定向凝固，并表明通过减少对流优选地观察到周期性结构。结果表明，周期系统具有周期生长模式.由于磁各向异性的排列结构的形成本研究开发了新的工艺来获得磁排列结构。在取向过程中，通过快速凝固产生的非平衡结构被用作起始材料。加热Bi-Mn系的非平衡结构导致半固态，而在常规凝固过程中可以获得。通过在半固态下施加磁场， ...更多信息 D已经实现。此外，在磁场下粗化过程中获得了BiMn的取向结构。本研究利用非平衡结构提出了取向的机理.一元系合金凝固组织的控制一元系合金在液态时存在着不相容间隙。一般来说，由于两种液相之间的密度差引起强烈的对流并导致宏观偏析，因此难以获得均匀和精细的凝固组织。10 T的磁场能显著地减少对流，从而使Cu-Pb合金获得均匀的凝固组织。在Al-In合金定向凝固的情况下，施加大于2 T的磁场，可获得与规则共晶组织基本相似的棒状单晶组织。强磁场的施加是有效的，以获得均匀的凝固组织的单晶系统。少

项目成果

H. Yasuda: "A Model for Oscillatory Structure during Unidirectional solidification of Peritectic Alloys"Materials Transactions, JIM. Vol 40. 373-376 (1999)

H. Yasuda：“包晶合金单向凝固过程中的振荡结构模型”Materials Transactions，JIM。

H. Yasuda: "Magnetic alignment by using non-equilibrium structure"Proc. 4th meeting of symposium on new magneto-science. 106-111 (2000)

H. Yasuda：“利用非平衡结构进行磁对准”Proc。

I. Ohnaka: "Solidification Structure Control by Magnetic Field"Proc. Oxford-Kobe Materiais Seminar on Solidification and Casting. 173-181 (1999)

I. Ohnaka：“磁场凝固结构控制”Proc。

H.Yasuda: "Periodic Structure during unidirectional solidification for peritectic Cd-Sn alloys"J. Cryst. Growth. 210. 637-644 (2000)

H.Yasuda：“包晶Cd-Sn合金单向凝固过程中的周期性结构”J。

安田秀幸: "非平衡組織を利用した磁場組織制御"Proc. 4th meeting of symposium on new magneto-science. 210. 106-111 (2000)

Hideyuki Yasuda：“使用非平衡纹理的磁场纹理控制”，新磁科学研讨会第四次会议。 210. 106-111 (2000)