Design of High Temperature Shape Memory Alloys

高温形状记忆合金的设计

• 批准号: 1333884
• 负责人: Huseyin Sehitoglu
• 金额: $ 32.27万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1333884&HistoricalAwards=false
• 关键词: Design; Temperature; Shape; Memory; Alloys

There is a recent, significant interest in high temperature shape memory alloy capabilities that will broaden the utilization of these materials. Shape memory alloys are unique in their ability to return to their original shape after deformation. The research emphasis of this proposal is on the development of new high temperature shape memory alloys with capabilities above 400 degree Celsius. The crystallography and the atomic displacements leading to the creation of twins, a rearrangement of the atoms, will be investigated via meso-scale modeling. The compositions will be optimized to control the strengths of secondary phases within the material and hence the reversibility of the phase transformations which dictate the material behavior. The research will also hone in on the processing of these materials for sample preparation, including polycrystals and single crystals. The investigation will include experiments to measure the behavior during loading and unloading and heating and cooling under stress in order to develop high temperature resistance for several potential compositions of nickel, titanium, cobalt and iron based shape memory materials with ternary additions. The proposed measurements of local displacements and strains will provide a critical check on the atomic deformation planes and the predicted stress at the onset of twinning in these materials. These measurements will be made with digital image correlation techniques, which will also be advanced during this research. The expected benefit of the research is to establish multi-component shape memory alloys that can operate at higher temperatures with actuation capabilities that can benefit the aerospace and other high temperature industries. The aim is to develop high temperature alloys with shape memory functionality without compromising strength, ductility and durability. The scientific benefits of the research include a better understanding of the mechanical response based on the underlying composition, crystallography, and microstructure. The educational benefits of the research will be enhanced with the preparation of a monograph on shape memory and a series of lectures that combine atomistic calculations with mesoscopic theories. This will be an advancement in the pedagogical treatment of shape memory alloys elevating the materials science and continuum mechanics perspectives and understanding.

最近，人们对高温形状记忆合金的能力产生了极大的兴趣，这将扩大这些材料的利用。形状记忆合金的独特之处在于其在变形后恢复其原始形状的能力。 本课题的研究重点是开发性能在400 ℃以上的新型高温形状记忆合金。晶体学和原子位移导致双胞胎的创建，原子的重排，将通过介观尺度建模进行研究。组合物将被优化以控制材料内的第二相的强度，从而控制决定材料行为的相变的可逆性。该研究还将专注于这些材料的样品制备处理，包括多晶和单晶。研究将包括测量加载和卸载以及在应力下加热和冷却过程中的行为的实验，以开发具有三元添加物的镍、钛、钴和铁基形状记忆材料的几种潜在组合物的耐高温性。建议的局部位移和应变的测量将提供一个关键的检查原子变形平面和预测的应力在这些材料中的孪生开始。这些测量将与数字图像相关技术，这也将在本研究中先进。这项研究的预期好处是建立多组分形状记忆合金，可以在更高的温度下运行，具有致动能力，可以使航空航天和其他高温行业受益。其目的是开发具有形状记忆功能的高温合金，而不影响强度，延展性和耐久性。该研究的科学益处包括更好地了解基于潜在成分，晶体学和微观结构的机械响应。这项研究的教育效益将随着编写一本关于形状记忆的专著和一系列将联合收割机原子计算与介观理论相结合的讲座而得到加强。这将是一个进步的教学处理形状记忆合金提升材料科学和连续介质力学的观点和理解。