Study on Dynamical Structure Change during Reversion in Aluminium Alloys

铝合金回复过程中动态结构变化的研究

• 批准号: 60460202
• 负责人: OSAMURA Kozo
• 金额: $ 4.61万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1985
• 资助国家: 日本
• 起止时间: 1985 至 1986
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-60460202/
• 关键词: Aluminium Alloys; Reversion Process; Small-Angle Scattering; In-Situ Measurements; G.P. Zones; Diffusion Equation with Moving Boundary; Ising Model; 局所平衡; 小角散乱その場測定; GPゾーン

In order to study the dynamical structure change during reversion in aluminium alloys, the synchrotron radiation-small-angle scattering measurements have been preformed. The major results obtained in the present study are summarized as follows.(1) Depending on reversion temperatures, the structure changes have been classified into two categories as the complete reversion and the partial one. In the case of the complete reversion, the time-dependence of volume fraction of G.P. zones could be described in terms of Johnson-Mehl equation. Here the time exponent changed from 0.5 to 2.5 with increasing temperature.(2) When the pre-aged specimen was annealed at temperatures above the zone solvus, the reversion process followed by two satges. At the first stage, the zone size did not decrease, but the solute concentration inside zones decreased. In the next stage, the zone size decreased to vanish.(3) When the specimen was annealed at temperatures below the zone solvus, a part of zones survive … More d, of which the volume fraction could be calculated from the coexistence curve.(4) When the pre-aged specimen was heated-up from room temperature with a constant heating rate, the solute concentration decreased firstly at relatively lower temperatures, but the zone size did not change. Temperature became enoughly so high that the zones resolved into the matrix according to the equilibrium relationship.(5) In order to explain the above-mentioned experimental data, the theoretical model calculation using the diffusion equation with moving boundary has been performed.(6) By using the fcc Ising lattice, the reversion process has been investigated.(7) In conclusion, we made clear the mechanism of reversion process, by which the zones resolve into the matrix keeping the local equilibrium at the zone boundary.(8) The structural change during the precipitation process in A1-Zn and A1-Ag alloys has been also investigated by means of the small angle scattering technique as well as the atom-probe field ion microscopy. Less

为了研究铝合金在回复过程中的动态结构变化，进行了同步辐射小角散射测量。本研究的主要结果总结如下。(1)根据回复温度的不同，结构变化可分为完全回复和部分回复两类。在完全逆转的情况下，G. P.区的体积分数随时间的变化可用Johnson-Mehl方程描述。在这里，时间指数随着温度的升高从0.5变化到2.5。(2)当预时效试样在高于固溶线温度下退火时，回复过程分为两个阶段。在第一阶段，区域尺寸没有减小，但区域内的溶质浓度降低。在下一阶段，区域大小减小到消失。(3)当试样在低于区固溶线的温度下退火时，部分区存在 ...更多信息 d，其体积分数可由共存曲线计算。(4)当预时效试样从室温以恒定的升温速率升温时，溶质浓度在相对较低的温度下首先下降，但区域尺寸没有变化。温度变得足够高，以至于这些区域根据平衡关系分解成基质。(5)为了解释上述实验数据，采用具有移动边界的扩散方程进行了理论模型计算。(6)利用面心立方伊辛格点，研究了反转过程. (7)最后，我们明确了反转过程的机制，即区域分解为保持区域边界局部平衡的矩阵。(8)用小角散射技术和原子探针场离子显微镜研究了Al-Zn和Al-Ag合金在沉淀过程中的结构变化。少

项目成果

Kozo Osamura et al: "Isothermal Phase Decomposition Diagram in A1-Zn Alloys" Scripta Metallurgica. 19. 1379-1384 (1985)

Kozo Osamura 等人：“A1-Zn 合金中的等温相分解图”Scripta Metallurgica。

Kozo Osamura: Acta Metallurgica. 34. 1563-1570 (1986)

小村幸三：冶金学报。

Kozo Osamura: Proceedings on Inter. Symp. on Dynamics of Ordering Processes in Condensed Matter, ed. by K.Kawasaki et al. (1988)

大村幸三：国际米兰的报道。

Hiroshi Okuda: Acta Metallurgica. (1988)

奥田浩：冶金学报。

Kozo Osamura: Metallurgical Transactions. (1987)

Kozo Osamura：冶金交易。