The behavior and roles of antiphase boundaries in order-disorder transformation processes

有序-无序转换过程中反相边界的行为和作用

• 批准号: 03452247
• 负责人: OKI Kensuke
• 金额: $ 4.22万
• 依托单位: Kyushu 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: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03452247/
• 关键词: order-disorder transformation; antiphase boundary; free energy; kinetic equation; cupper-platinum alloy; iron-silicon alloy; simulation; electron microscopy; 規則・不規則転移; 相転移過程; 鉄ーシリコン合金; 銅ー白金合金; 自由エネルギ-; 時間依存ギンツブルグ-ランダウモデル; 規則合金; 長周期構造

The objective of the research is to clarify the behavior and the effects of antiphase boundaries on the order-disorder transformation process. The kinetic equation was formulated by developing a Ginzburg-Landau type expansion of the free energy in order to carry out simulation of the changes in antiphase boundary structures. From the simulations, the following results were drawn. (1) At T>T_c ( the critical temperature of ordering ), disordering undergoes by expansion of a disorder region which has formed on antiphase boundaries. (2) At T<T_c, antiphase boundaries can have unevenness on the surface where a pair of hairpins are formed. The transformation from L1_<2-s> ( long period antiphase superstructure ) to L1_2 proceeds by receding of the hairpins. (3) At a low temperature region, the surface energy of antiphase boundaries is relatively high so that antiphase boundaries tend to become flat. Therefore, periodic antiphase boundaries cannot move and then the L1_<2-s> becomes metastable.Transmission electron microscopy (TEM) and X-ray diffraction experiments were performed to examine the effects of antiphase boundaries on the order-disorder transformation. In the specimen of Cu_3Pt with a small variant size of L1_<2-s>, periodic antiphase boundaries are reduced by the hairpin mechanism to transform L1_<2-s> to L1_2. In the specimen with a large variant size, on the other hand, the L1_<2-s> phase remains metastable. High resolution TEM observation showed that in an alloy of Fe-Si the thickness of "wetting" on antiphase boundaries increases with annealing time. The results of the simulations and experiments confirmed that antiphase boundaries give significantly important effects on the process of order-disorder transformation in alloys.

研究的目的是阐明有序-无序转变过程中反相界的行为和影响。为了模拟反相边界结构的变化，通过发展自由能的Ginzburg-Landau型展开式来制定动力学方程。从模拟中得出以下结果。(1)当T>T_c（有序化的临界温度）时，无序化是通过反相界面上形成的无序区的扩展而实现的。(2)当T<T_c时，反相界面在表面上会出现不平整，形成一对发夹结构。从L1_<2-s>（长周期反相超结构）到L1_2的转变是通过发夹的后退进行的。(3)在低温区域，反相边界的表面能相对高，使得反相边界趋于变得平坦。利用<2-s>透射电子显微镜（TEM）和X射线衍射实验研究了周期性反相界对有序-无序转变的影响。在L_1_尺寸变化较小的Cu_3Pt样品中<2-s>，周期性反相界通过发夹机制减少，使L_1_转变<2-s>为L_1_2。另一方面，在具有大的变体尺寸的样品中，L1_<2-s>相保持亚稳态。高分辨透射电镜观察表明，在Fe-Si合金中，反相界的“润湿”厚度随退火时间的延长而增加。模拟和实验结果证实了反相界对合金有序-无序转变过程的重要影响。

项目成果

Tatsuji FURUSE et al.: "IKL-ALCHEMI Study of Atom Configuration with B2-type Order in a Cu-Pd-Au Ternary Alloy as a Function of Temperature" Proc. Int. Symp. Intermetallic Compounds, Structures and Mechanical Properties, Sendai. 281-285 (1991)

Tatsuji FURUSE 等人：“IKL-ALCHEMI 研究 Cu-Pd-Au 三元合金中 B2 型有序的原子构型作为温度的函数”Proc。

相根 博道 他: "X線サイドバンドの解析によるCu-Ni-Sn合金における変調構造の発達過程" 日本金属学会誌. 56. 998-1005 (1992)

Hiromichi Aine 等人：“通过 X 射线边带分析开发 Cu-Ni-Sn 合金中的调制结构”，日本金属学会杂志 56. 998-1005 (1992)。

Syo Matsumura: "Dynamical Monte Carlo Simulation of Ll_1(CuPt)ーtype Ordering during(001)Epitaxial Growth of IIIーV Semiconductor Alloy" Journal of Crystal Growth. 115. 194-198 (1991)

Syo Matsumura：“III－V半导体合金(001)外延生长过程中Ll_1(CuPt)型有序化的动态蒙特卡洛模拟”晶体生长杂志115. 194-198 (1991)。

T.Furuse et al.(古瀬 辰治 他): "IKL-ALCHEMI Study of Atom Configuration with B2-Type Order in a Cu-Pd-Au Ternary Alloy as a Function of Temperature" Proc.Int.Symp.Intermetalllic Compounds Structures and Mechanical Properties. 281-285 (1991)

T.Furuse 等人（Tatsuharu Furuse 等人）：“IKL-ALCHEMI 研究 Cu-Pd-Au 三元合金中 B2 型有序的原子构型作为温度的函数”Proc.Int.Symp.InterMetalliccompounds结构和机械性能。281-285 (1991)

S.Matsumura et al.(松村 晶 他): "An Analytical Electron Diffraction Technique for the Determination of Long-Range Order Parameters in Multi-Component Ordered Alloys" Materials Transactions,The Japan Institute of Metals. 32. 905-910 (1991)

S.Matsumura 等人：“用于确定多组分有序合金中的长范围有序参数的分析电子衍射技术”材料交易，日本金属研究所 32. 905-910 (1991)。