GOALI: Understanding Deformation Processing in Advanced Alloys

形状记忆合金是一种多功能材料，当暴露于热或外部负载时，会发生可逆的相变。这些转变可以导致有用的性质，如果可以理解在整个材料中分散的转变和细颗粒之间的关系，则可以控制它们的行为。一类由镍、钛和铌组成的形状记忆合金（NiTiNb）具有独特的组成形态结构。这项学术与工业联络资助机会（GOALI）奖支持寻求热与机械变形处理耦合的研究，并检查和理解由此产生的Nb颗粒与潜在相变和变形机制的相互作用。该工业合作伙伴专门制造NiTiNb材料，并采用基于激光的加工技术进行后处理，而不会影响形状记忆行为。这些方法和发现可以推广到一般不溶性第三元素的变形加工形状记忆合金。本研究建立的基本相互关系将释放制造多功能形状记忆材料的全部潜力，以调整新型可展开结构的性能。这项研究的成功将推进多功能合金加工的商业化，使其成为下一代材料，广泛应用于从生物医学植入物到无人驾驶车辆等领域，造福美国经济和社会。此外，教育和推广计划将紧密结合技术研究。为高中、本科和研究生水平设计的课程将加深少数民族和未被充分代表的群体在科学、技术、工程和数学等学科中的参与。这个小型企业产学研合作的GOALI项目将研究一种新型形状记忆材料响应的潜在物理马氏体相变（MT）机制，这种材料被称为应变诱发奥氏体（SIA），它是一类含有不溶性第三元素Nb的三元镍基形状记忆合金（sma）。三元合金化和热机械变形处理的结果是微/纳米结构的Nb颗粒组成形态。合作团队将(1)系统地改变可展开结构的热机械加工和后处理参数；(2)进行x射线、电子和光学显微镜表征微/纳米成分尺寸、间距、相干性以及晶粒尺寸和织构；(3)开展多尺度热力学实验，确定多功能材料性能和结构响应；(4)建立加工、微观结构和多功能性之间的定量和定性关系。

Shape memory alloys are multifunctional materials that undergo an reversible phase transformation when exposed to heat or external load. These transformations can led to useful properties, and their behavior can be controlled if the relationships between the transformational and fine particles dispersed throughout the material can be understood. A class of shape memory alloys comprised of nickel, titanium and niobium (NiTiNb) exhibit structures with unique constituent morphologies. This Grant Opportunity for Academic Liaison with Industry (GOALI) award supports research seeking to couple thermal and mechanical deformation processing and examine and understand the resulting Nb particle interactions with the underlying phase transformation and deformation mechanisms. The industrial partner specializes in fabrication of NiTiNb materials and employs laser-based machining techniques for post-processing without compromising the shape memory behavior. The approaches and findings can extend to deformation processed shape memory alloys with insoluble third elements in general. Fundamental interrelationships this research establishes will unlock the full potential of manufacturing multifunctional shape memory materials to tune performance for novel deployable structures. The success of this research will advance processing multifunctional alloys to commercialization as next-generation materials in broad ranging applications from biomedical implants to unmanned vehicles that benefit the U.S. economy and society. Furthermore, education and outreach programs will closely integrate the technical research. Programs designed for high school, undergraduate, and graduate levels will deepen the engagement of minorities and underrepresented groups in academic disciplines of science, technology, engineering, and mathematics. This small business industry-university collaborative GOALI project will investigate the underlying physical martensitic phase transformation (MT) mechanism of a novel shape memory material response referred to as strain-induced austenite (SIA) in a class of ternary NiTi-based shape memory alloys (SMAs) with an insoluble third element Nb. A consequence of ternary alloying and thermo-mechanical deformation processing is a micro-/nano-structured Nb particle constituent morphology.The collaborative team will (1) systematically vary thermo-mechanical processing and post-processing parameters of deployable structures; (2) conduct x-ray, electron, and optical microscopy characterizations of micro-/nano-constituent sizes, spacing, and coherency as well as grain size and texture; (3) undertake multi-scale thermo-mechanical experiments that determine multifunctional material properties and structural response; (4) establish quantitative and qualitative relationships between processing, microstructure and multifunctionality.