STRUCTURE CONTROLL AND IMPROVEMENT OF HIGH TEMPERATURE SHAPE MEMORY PROPERYIES OF TiPdNi ALLOY WITH NEW PRECIPITATE PHASE

新型析出相TiPdNi合金的组织控制及高温形状记忆性能的改善

• 批准号: 12650700
• 负责人: NISHIDA Minoru
• 金额: $ 2.56万
• 依托单位: KUMAMOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650700/
• 关键词: SHAPE MEMORY ALLOY; AGING AND PRECIPITATION; ORDER-DISORDER TRNSITION; THERMOELASTIC MARTENSITIC TRANSFORMATION; TRANSMISSION ELECTRON MICROSCOPY; ELECTRON DIFFRACTION; LONG PERIOD STACKING STRUCTURE; ANTIPHASE DOMAIN BOUNDARY; TiPdNi合金; 高温形状記憶合金

Since martensitic transformation temperature of Ti-Pd-Ni alloys can be controlled from ambient temperature to around 800 K by substitutional ratio of Pd and Ni, the application of me alloys have been expected in various fields. To improve the materials properties the microstructure control with precipitation of secondary phase has been attempted in Ti-rich and Pd and Ni-rich alloys.The authors have found out that quenched Ti_<45>Pd_<45>Ni_<10> alloy shows peculiar phase transformations. Upon heating in DSC measurement, an endothermic reaction occurs firstly around 373 K, which corresponds to the reverse martensitic transformation from B19 to B2 structure. Subsequently, a pair of exothermic and endothermic peaks is observed from 550 to 740 K, which is due to the appearance and disappearance of new order phase with long period stacking structure. One of characteristic feature in electron diffraction pattern of the new phase is superlattice spots at 1/8 position in the row of reflections of 111_<B2>*. Finally, an exothermic reaction which corresponds to the formation of Ti_2(PdNi)_3 phase is detected around 850 K. More interesting phenomenon, which is the parent phase stabilization with low temperature aging below 500 K, is discovered. The ω diffuse streak with rather strong intensity is observed in electron diffraction patterns taken from the stabilized B2 phase. It is confirmed that the diffuse streak is a kind of precursor phenomena of the ordering. Morphological and crystallographic aspects of the new order phase are also discussed. The reversible shape memory effect can be generated by using the new order phase. However, the amount of shape change is smaller than that of Ni-rich Ti-Ni alloy with Ti_3Mi_4 precipitates.

由于Pd-Ni合金的马氏体相变温度可以通过Pd和Ni的取代比从室温控制到800 K左右，因此me合金在各个领域的应用是有希望的。为改善材料性能，对富钛、富钯、富镍合金进行了二次相析出控制组织的尝试。结果表明，淬火Ti_<45>Pd_<45>Ni_<10>合金表现出特殊的相变。DSC测量加热后，在373 K左右首先发生吸热反应，对应于B19组织向B2组织的反向马氏体转变。随后，在550 ~ 740 K范围内观察到一对放热和吸热峰，这是由于具有长周期堆积结构的新阶相的出现和消失所致。新相电子衍射图的特征之一是在111_<B2>*反射排的1/8位置有超晶格斑点。最后，在850 K左右发生了Ti_2(PdNi)_3相的放热反应。发现了更有趣的现象，即在500 K以下的低温时效下，母相稳定。在稳定的B2相的电子衍射图中观察到具有较强强度的ω扩散条纹。证实了扩散条纹是有序的一种前兆现象。还讨论了新阶相的形态和晶体学方面。利用新阶相可以产生可逆形状记忆效应。而Ti_3Mi_4析出的富ni Ti-Ni合金的形状变化量较小。

项目成果

S.Ii: "Morphology and Crystallography of Twins in Mantensite in Ti-Pd High Temperature Shape Memory Alloys"Proc. of PRICM 4, The Jap. Inst. Metals. 1879-1882 (2001)

S.Ii：“Ti-Pd 高温形状记忆合金中曼氏体孪晶的形态和晶体学”Proc。

V. C. Solomon and M. Nishida: "Phase Decomosition and Successive Two-Step Transformation in Ti-Rich Ti-Pd Shape Memory Alloy"Transaction of the Materials Research Society of Japan. Vol. 26, No. 1. 231-234 (2001)

V. C. Solomon 和 M. Nishida：“富钛 Ti-Pd 形状记忆合金的相分解和连续两步转变”日本材料研究学会会刊。

V.C.Solomon: "Effect of Aging on the Mantensitic Transformation of Ti-Rich Ti-Pd Shape Memory Alloy"Materials Transactions. 43(印刷中). (2002)

V.C.Solomon：“时效对富钛钛钯形状记忆合金的曼氏体转变的影响”材料交易 43（出版中）。

V. C. Solomon and M. Nishida: "Martensitic Transformation of Ti-Rich Ti-Pd Shape Memory Alloy"Materials Transactions. Vol. 43, No. 5, (in press). (2002)

V. C. Solomon 和 M. Nishida：“富钛 Ti-Pd 形状记忆合金的马氏体转变”材料交易。

S.Ii: "Crystallography and Morphology of twins in 9R martensite in Ti-Pd-Fe shape Memory alloy"Scripta Materialia. 46・8(印刷中). (2002)

S.Ii：“Ti-Pd-Fe 形状记忆合金中 9R 马氏体孪晶的晶体学和形态”Scripta Materialia（2002 年）。