In-Situ Processing of Superconducting MgB2-Metal Composites

超导 MgB2-金属复合材料的原位加工

• 批准号: 0319051
• 负责人: David Dunand
• 金额: $ 40万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0319051&HistoricalAwards=false
• 关键词: Situ; Processing; Superconducting; MgB2; Metal

The proposal is on the processing of magnesium boride (MgB2) using reaction synthesis involving pressure infiltration of B fibers with molten magnesium to form a continuous MgB2 phase in an Mg matrix. A major goal is to achieve superconducting applications at temperatures in excess of 25K. The influence of processing temperature, volume fraction of boron, size and shape on the resulting microstructures will be studied using various characterization techniques including metallography, microprobe, secondary ion mass spectroscopy, synchrotron x-ray tomography and transmission electron microscopy. The mechanical and superconducting properties of reacted MgB2 fibers and MgB2-metal composites will be assessed and correlated with the microstructures. Experimental studies will be followed by modeling efforts first using 1-dimensional model to predict fracture strength and elastic modulus of boron fibers followed by classical and three-phase self-consistent methods for composites. The ultimate goal of the project is to generate a science-base understanding of the synthesis of MgB2 from solid B and liquid Mg for the fabrication of continuous lengths of superconducting metal-MgB2 composite wires. The research emphasizes the development of a process for creating continuous, low-cost metal-MgB2 composite superconducting wires with a critical temperature of 39 K, through a science-based, predictive understanding of the materials science issues involved with synthesis, structure and properties of these composites.Operation of the composite superconducting wires at 25-30 K without helium cryo-cooling will result in a significant drop in costs as compared to current Nb3Sn-type wires cooled by liquid helium, which is an expensive, non- renewable resource. Possible applications include superconducting magnets for energy storage devices, levitation systems (for trains), motors, wires for power transmission and superconducting quantum interference device (SQUID) systems. The research provides opportunities for undergraduate and graduate students as well as high school teachers through outreach programs for laboratory experience involving materials processing and characterization techniques. Plans include creation of a website on MgB2 synthesis and collaboration with Argonne National Laboratory through the use of Advanced Photon Source.

该提案涉及采用反应合成法加工硼化镁 (MgB2)，其中涉及用熔融镁对 B 纤维进行压力渗透，以在镁基体中形成连续的 MgB2 相。主要目标是在超过 25K 的温度下实现超导应用。将使用各种表征技术，包括金相学、微探针、二次离子质谱、同步加速器 X 射线断层扫描和透射电子显微镜，研究加工温度、硼的体积分数、尺寸和形状对所得微观结构的影响。将评估反应后的 MgB2 纤维和 MgB2-金属复合材料的机械和超导性能，并将其与微观结构相关联。实验研究之后将进行建模工作，首先使用一维模型来预测硼纤维的断裂强度和弹性模量，然后使用复合材料的经典和三相自洽方法。该项目的最终目标是对从固体 B 和液体 Mg 合成 MgB2 的过程产生科学基础的理解，以制造连续长度的超导金属-MgB2 复合线。该研究强调通过对涉及合成、结构和性能的材料科学问题进行基于科学的预测性理解，开发一种连续、低成本的金属-MgB2复合超导线材的制造工艺，其临界温度为39 K。与当前使用液氦冷却的 Nb3Sn 型导线相比，复合超导线材在 25-30 K 温度下运行且无需氦低温冷却，成本将显着下降。昂贵的、不可再生的资源。可能的应用包括用于储能装置的超导磁体、悬浮系统（用于火车）、电机、用于电力传输的电线和超导量子干涉装置（SQUID）系统。该研究通过外展计划为本科生、研究生以及高中教师提供涉及材料加工和表征技术的实验室经验的机会。计划包括创建一个关于 MgB2 合成的网站，以及通过使用先进光子源与阿贡国家实验室合作。