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.

该提议是关于利用反应合成来处理硼化镁(MgB2)，该反应合成包括将B纤维与熔融的镁进行压力渗透，以在镁基质中形成连续的MgB2相。一个主要目标是在超过25K的温度下实现超导应用。利用金相、微探针、二次离子质谱仪、同步辐射X射线层析和透射电子显微镜等多种表征技术，研究了加工温度、硼体积分数、尺寸和形状对所得显微组织的影响。我们将评估反应后的镁纤维和镁-金属复合材料的力学性能和超导性能，并将其与微观结构相关联。在实验研究之后，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，然后是用于复合材料的经典和三相自洽方法。该项目的最终目标是为制造连续长度的超导金属-镁复合线而从固体B和液体镁合成镁B2的过程产生科学基础的理解。这项研究强调开发一种工艺，通过对涉及这些复合材料的合成、结构和性能的材料科学问题的科学和预测性理解，制造临界温度为39K的连续、低成本的金属-镁B2复合超导线材。与目前由液氦冷却的Nb3Sn型线材相比，在25-30K下不进行氦冷冻的复合超导线材的运行将导致成本显著下降。可能的应用包括用于储能设备的超导磁体、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。这项研究为本科生和研究生以及高中教师提供了机会，通过推广项目获得涉及材料加工和表征技术的实验室经验。计划包括建立一个关于二氧化二镁合成的网站，以及通过使用先进的光子源与阿贡国家实验室合作。