二硼化镁作为固体高能金属燃料应用研究进展

Research Progress of Application of Magnesium Diboride as Solid High Energy Metal Fuel

关键词:  二硼化镁  热分解  热氧化  点火燃烧性能  固体推进剂  综述

Key words:  Magnesium diboride  Thermal decomposition  Thermal oxidation  Ignition and combustion performance  Solid propellants  Review

摘要:

硼（B）在应用过程中存在点火困难、燃烧效率低的问题，为开发具有更高应用潜力的燃料，二硼化镁（MgB₂）由于其出色的点火燃烧性能引起了广泛关注。本文简要回顾了MgB₂在超导体、固体推进剂和储氢材料等方面的发展历程，介绍了MgB₂的主要制备方法，重点对MgB₂的热分解、热氧化特性和点火燃烧性能研究三方面对现有研究结果进行了综述。研究通过氧弹燃烧、热重差示扫描量热（TG-DSC）和X射线衍射（XRD）分析等，发现MgB₂相对于B具有更加优越的能量释放特性，其点火燃烧过程是以逐级分解释镁、多种硼镁化合物与镁协同氧化两个动力学过程为核心的复杂反应过程。通过总结现有研究，发现MgB₂热分解、热氧化具体反应过程及其内在关联机制尚未明确，存在缺乏微观层面的物质扩散过程和反应机理研究以及在不同环境条件下的点火燃烧研究等问题。未来应在微观角度对MgB₂点火燃烧的传热、传质过程等进行研究，并开展高温高压下的离散样品点火实验等，以提升MgB₂作为固体高能金属燃料的性能表现。

Abstract:

For the purpose of developing a fuel with higher application potential and solving the problems of ignition difficulty and low combustion efficiency in the utilization process of boron （B） fuel， magnesium diboride （MgB₂） has attracted much attention due to its excellent ignition and combustion performance. Development process of MgB₂ in superconductor， solid propellant and hydrogen storage materials and the major synthesis methods are briefly reviewed in this article， with focusing on reviewing the available research results of the thermal decomposition， thermal oxidation， ignition and combustion performance of MgB₂. With the help of technologies including oxygen bomb test， Thermogravimetry-Differential scanning calorimetry （TG-DSC） and X-ray diffraction （XRD）， researches showed that MgB₂ had a more superior energy release characteristics than B， and the ignition and combustion process of MgB₂ was a complex reaction process encompassing two kinetic processes： the releasing of magnesium step by step in decomposition and the synergistic oxidation of magnesium with various boric magnesium compounds. By summarizing existing researches， problems， including the unclarity of the inner relation of thermal oxidation and decomposition and the specific reaction process， the lack of researches in the diffusion process and reaction mechanism of MgB₂ at micro level and ignition and combustion under different environmental conditions， are found. To promote the performance of MgB₂ as solid high energy metal fuel， it is proposed that the researches should be conducted in heat and mass transfer process of MgB₂ in ignition combustion experiment at microscopic level， and the performance of discrete samples should be tested under high temperature and high pressure in the ignition experiments.