Transformation-start/finish conditions in an Fe-based shape memory alloy under multiaxial stresses

多轴应力下铁基形状记忆合金的转变开始/结束条件

• 批准号: 11650095
• 负责人: TANAKA Kikuaki
• 金额: $ 2.43万
• 依托单位: Tokyo Metropolitan Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650095/
• 关键词: Fe-based Shape memory alloy; Multiaxial stresses; Transformation-start condition; Transformation-start curve; Reverse transformation-start curve; Reverse transformation-start cone; 逆変態条件; 変態面; 応力―温度空間; 変態錐面; 応力第3不変量

The transformation-start and -finish conditions are identified in an Fe-based shape memory alloy by carrying out the tension/compression-torsion tests of thin-walled tubular specimens.The martensite-start condition determined in the isothermal proporional loading is represented by the ovalshape curves on the axial stress-shear stress plane, thus being different from the von Mises yield condition in plasticity. The temperature effect is isotropic. The third invariant of the stress should, therefore, be taken into account when constructing a transformation thermomechanical theory.The austenite-start condition (the reverse transformation-start condition) is represented by a plane in the stress-temperature space. The direction of its unit normal depends on the direction of the pre-stressing, meaning on the type of the martensite variants induced in the pre-stressing process. When several types of variants are induced during pre-stressing, a polygonal cone is formed to represent the austenite-start condition in the stress-temperature space. The position of the plane in the stress-temperature space is governed by the amount of the variants.

通过对薄壁管状试样进行拉/压-扭试验，确定了铁基形状记忆合金的相变开始和结束条件。等温比例加载确定的马氏体开始条件由轴向应力-剪应力平面上的椭圆形曲线表示，与塑性方面的von Mises屈服条件不同。温度效应是各向同性的。因此，在构建相变热机械理论时，应考虑应力的第三个不变量。奥氏体起始条件（逆相变起始条件）由应力-温度空间中的平面表示。其单位法线的方向取决于预应力的方向，即取决于预应力过程中引起的马氏体变体的类型。当预应力过程中引起几种类型的变化时，会形成一个多边形锥体来表示应力-温度空间中的奥氏体起始条件。应力-温度空间中平面的位置由变量的数量决定。

项目成果

Tatsumi Shimada, Tadamasa Kimura, & Yuko Shozugawa: "Nordic Countries as IT Nation (2) - Nordic model of information society and IT education"Local Government Computer. Vol.31, No.2. 55-62 (2001)

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Matsuba,F.,Asai,Y.and Tanaka,K.: "Transformation-start conditions in Fe-based shape memory alloys under axial-torsional loads : An experimental study"Transactions of the MRS Japan. (印刷中). (2001)

Matsuba, F.、Asai, Y. 和 Tanaka, K.：“轴向扭转载荷下铁基形状记忆合金的转变起始条件：实验研究”日本 MRS 报（2001 年出版）。 ）

田中喜久昭: "形状記憶合金の熱・力学"材料. 48-12. 1341-1349 (1999)

Kikuaki Tanaka：“形状记忆合金的热学和力学”材料。 48-12 1341-1349 (1999)

Nagayama,K.,Kitajima,Y.,Kigami,S.,Tanaka,K.,Fischer,F.D.and Cailletaud,G.,: "Transformation induced plasticity in maraging steel : An experimental study"Key Engineering Materials. 177/180. 443-448 (2000)

Nagayama,K.、Kitajima,Y.、Kigami,S.、Tanaka,K.、Fischer,F.D. 和 Cailletaud,G.，：“马氏体时效钢中的相变诱导塑性：实验研究”关键工程材料。

Tatsumi Shimada, Tadamasa Kimura, & Yuko Shozugawa: "Nordic Countries as IT Nation (1) - Nordic Countries as IT Nation Its Concept and Realization : What kind of society to make and how to utilize IT-"Local Government Computer. Vol.31, No.1. 49-55 (2001)

岛田辰美、木村忠正、