Development of Composite-and-Functional Gradient Material by using Supercooling

利用过冷技术开发复合功能梯度材料

• 批准号: 06555059
• 负责人: HAYASHI Yujiro
• 金额: $ 7.62万
• 依托单位: Kanazawa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06555059/
• 关键词: Micro-Solidification; Supercooling; Crystal growth; Morphology; Composition

Solidification is due to the restriction of rotational motion of liquid molecules and results in the fixation of solid structure as a regular and/or dense assembly of atoms with release of latent heat of fusion. From the viewpoint of the way that the latent-heat extraction should be, the solidification can be largely classified into three types in relating with cooling rates.In low cooling rate, the latent heat is removed out by heat transfer and solidification proceeds quasisteadily with a solid-liquid interface kept at an equilibrium temperature. In high cooling rate, as for "rapid solidification of material processing", a supercooling state easily appears and this brings massive solidification due to crystal growth initiated by nucleation. The supercooling which makes a rapid and insitu solidification possible, may result in the formation of new meta-stable phases of crystalline and of amorphous. In intermediate cooling rate, the supercooling also appears and distributes in close region from the cooling surface to some internal position being equilibrium. These imply that the solidification proceeds under two kinds of heat extraction sources ; the initially distributed supercooling and the external cooling.The emphasis in the discussion is on fundamentals of solidification of mixtures with supercooling under external heat transfer cooling : solidification process, appearance of micro-structure and microsegregation in the solid, and macro-micro conjugation of heat transfer with the solidification.

凝固是由于液体分子的旋转运动受到限制，导致固体结构固定为规则和/或致密的原子组装体，并释放熔化潜热。从潜热提取方式的角度看，与冷却速度有关的凝固大致可分为三种类型：在低冷却速度下，潜热通过传热被带走，凝固过程在固液界面保持平衡温度的情况下准稳态进行;在高冷却速率下，对于“材料快速凝固加工”，由于形核引发晶体生长，容易出现过冷状态，导致大块凝固。过冷使快速原位凝固成为可能，可能导致新的亚稳结晶相和非晶相的形成。在中等冷却速度下，也出现过冷，且过冷分布在冷却表面到内部某个平衡位置的较近区域。本文着重讨论了外部传热冷却条件下过冷混合物凝固过程的基本原理：凝固过程、凝固过程中微观结构和微观偏析的出现以及传热与凝固的宏微观耦合。

项目成果

義岡秀晃: "過冷却を伴う合金融液のミクロ凝固" 第33回日本伝熱シンポジウム講演論文集. I. 223-224 (1996)

Hideaki Yoshioka：“过冷合金液体的微凝固”第 33 届日本传热研讨会论文集 I. 223-224 (1996)。

義岡 秀晃: "過冷却を伴う合金融液のミクロ凝固" 第33回日本伝熱シンポジウム講演論文集. (発表予定).

Hideaki Yoshioka：“过冷合金液体的微凝固”第 33 届日本传热研讨会论文集（预定演讲）。

Hayashi, Y., Yoshioka, H.: "Micro-Heat Transfer of Solidification of Mixture with Supercooling" ICHMT Symposium on Molecular and Microscale Heat Transfer in Materials Processing and Other Applications, Yokohama, Japan, 1996.

Hayashi, Y., Yoshioka, H.：“过冷混合物凝固的微传热”ICHMT 材料加工和其他应用中分子和微尺度传热研讨会，日本横滨，1996 年。

Y.Hayashi: "Micro-solidification of Alloy Melt with Supercooling" Proceeding of 3rd KSME-JSME Thermal Engineering Conference. 1. 245-250 (1996)

Y.Hayashi：“过冷合金熔体的微凝固”第三届 KSME-JSME 热工会议论文集。

Yujiro Hayashi, Hideaki Yoshioka and Satoki Sakai: "Micro-Solidification of Alloy Melt with Supercooling" 32st National Heat Transfer Symposium of Japan. I. 413-414 (1995)

Yujiro Hayashi、Hideaki Yoshioka 和 Satoki Sakai：“过冷合金熔体的微观凝固”第 32 届日本全国传热研讨会。