Materials World Network: U.S.-Japan Research Collaboration in Meta-Magnetic Shape Memory Alloys with Enhanced Ductility and Controlled Porosity

材料世界网络奖由金属材料和纳米结构计划以及德克萨斯工程和实验站材料研究分部的特别计划办公室颁发，旨在利用粉末冶金方法制造具有大磁场感应驱动功输出和增强延展性的多晶块状廉价亚磁形状记忆合金(MMSMA)。该奖项也由国际科学与工程办公室共同资助。磁性形状记忆合金(MSMA)在驱动、传感、能量采集和磁制冷等领域具有广阔的应用前景。这些材料的发展一直受到以下因素的限制：驱动功输出小、延展性差，以及缺乏系统的研究来将固态物理、传统冶金和应用领域的问题联系起来。最近，来自德克萨斯农工大学和东北大学的目前的美日团队通过对MMSMA的发现和初步了解，解决了工作量低的问题。然而，延展性问题仍然存在，对MMSMA的研究仅限于单晶，很难制造。此外，还将制备多孔MMSMA，以评估其在生物医学应用中的潜力，重点是生物活性的表征及其作为活性组织支架的应用。这些目标将通过材料设计、制造和多尺度表征的协同组合来实现，以便了解磁-热-机械响应和磁-微结构耦合，并评估它们的耐腐蚀性、细胞毒性和随场远程刺激组织生长的潜力。如果成功，这项革命性研究的成果将为以下方面提供机会：(A)通过培育全新的应用和性能景观，使形状记忆合金领域发生革命性的变化；(B)通过对新型记忆合金进行多尺度、多学科的表征，改变目前对磁场诱导的形状变化的理解；(C)创建能够对组织生长进行远程控制的机械刺激的全新组织支架家族。最终，这项工作中的方法论将有助于保持美国在活性材料和生物材料研究方面的领先地位的整体努力。研究生和本科生，包括几名少数民族学生，将通过与日本合作机构建立联合学位和交流计划、新课程开发、课堂教学和直接参与研究而受益。K-12学生和高中教师将与SMAS一起开展科学项目，以提高他们的科学和工程意识，并为他们提供第一手研究经验。

This Materials World Network award by the Metallic Materials and Nanostructures program and the Office of Special Programs in the Division of Materials Research to Texas Engineering and Experimental Station is to fabricate inexpensive meta-magnetic shape memory alloys (MMSMAs) in polycrystalline bulk form having large magnetic field-induced actuation work output and enhanced ductility using a powder metallurgy approach. This award is also cofunded by the Office of International Science and Engineering. Magnetic shape memory alloys (MSMAs) are promising candidates for actuation, sensing, energy harvesting and magnetic refrigeration. The development of these materials have been limited by small actuation work outputs, poor ductility, and a lack of systematic studies to connect the issues in solid-state physics, conventional metallurgy, and applications. The problem of low work output was recently resolved by the present U.S.-Japan team from Texas A&M and Tohoku Universities by the discovery and preliminary understanding of MMSMAs. Yet the ductility problem remains and the works on MMSMAs are limited only to single crystals, which are difficult to fabricate. In addition, porous MMSMAs will be fabricated for the evaluation of their potential in biomedical applications, focusing on the characterization of biological viability and their use as active tissue scaffolds. These goals will be achieved through the synergistic combination of materials design, fabrication, and multi-scale characterization in order to develop an understanding of the magneto-thermo-mechanical response and magneto-microstructural coupling, and evaluation of their corrosion resistance, cytotoxicity, and potential for stimulating tissue growth remotely with the field. If successful, the results of this transformative research will provide an opportunity for (a) revolutionizing the field of shape memory alloys by fertilizing completely new applications and property landscapes, (b) transformation of current understanding of field-induced shape change in MSMAs through a multi-scale, multidisciplinary characterization on the new MMSMAs; and (c) the creation of an entirely new family of tissue scaffolds that would allow remotely controlled mechanical stimulus for tissue growth. Ultimately, the methodologies in this work will contribute to the overall effort to maintain US-leading role in active and biomaterials research. Graduate and undergraduate students including several minority students will benefit through establishment of joint-degree and exchange programs with the Japanese partner institution, new course developments, classroom instruction and direct involvement in the research. K-12 students and high school teachers will be engaged in developing science projects with SMAs to increase the awareness of science and engineering among them and provide them firsthand research experience.