微米级金属纤维的功能特性及其应用基础问题

This project is based on the the background of development and application for functional characteristics including magnetics of amorphous material, and we try to carry out exploratory research mainly focused on the basic issues of functional characteristics and applications of microfibers, take the influence of trace element doping on magnetism and mechanical property and amorphous forming ability (GFA) of Co-based, RE-based, Fe-Ga alloys and Cu-based alloy as the cut-in and breakthrough point, further to investigate the mentioned alloy composition design and optimization, and break through the key techniques of melt-extraction forming process stability and quality control for microscale metallic fibers, selectively analyze the basic features of metallic fibers: basic issues of giant magneto-impedance (GMI) effect and magnetic sensor application, magnetocaloric effect (MCE) and its regulation mechanism, giant magnetostrictive effect (GMS) and magnetoelastic coupling mechanism, mechanical property and its fracture deformation mechanism of microfibers, etc. Meanwhile, we also explore the physical features and theoretical basis, establish the intrinsic relationship among alloy composition, microstructure, modulation processing and functional features, even open the novel application technology based on the above physical effects, which also can provide effectively technical supports for the areas such as their applications in microsensor for magnetic measurement, magnetic refrigeration components, magnetostrictive brake and microstructural down-lead devices lead, simultaneously all the related research work has an important significance and applied value for potentially functional applications.

本项目以非晶材料磁学等功能特性开发与应用为基础背景，从微米级金属纤维的功能特性及其应用基础问题开展探索性研究，以Co基、RE基、Fe-Ga和Cu基合金微量元素掺杂对磁学力学性能和非晶形成能力(GFA)影响为切入点，研究上述合金成分设计与优化，突破熔体抽拉成形微尺度金属纤维工艺稳定性与质量控制的关键技术，重点分析金属纤维基本功能特性：巨磁阻抗效应(GMI)与传感器应用基础问题、磁热效应(MCE)及其调控机理、巨磁致伸缩效应(GMS)及磁弹耦合机理、金属纤维的微观力学特性及其断裂机理等，探寻其功能特性的物理本质和理论依据，建立合金成分、微观结构、调制处理和功能特性间的内在联系，开启基于上述物理效应的新型应用技术途径，为其应用于微磁测量传感器、磁制冷元器件、磁致伸缩制动器和微结构引线器件等领域提供有效的技术支撑，同时具有重要研究意义和应用价值。

本项目重点针对Co基、Gd基、Fe基和Cu基微米级金属纤维进行结构表征、磁学和力学性能分析，实现了微尺度纤维熔体抽拉成形工艺稳定性与质量控制，优化了不同类型金属纤维的调制处理工艺参数，获得了具有优异功能特性可供应用的处理态金属纤维。同时，开展了基于磁阻抗效应(GMI)与传感器应用基础、磁热效应(MCE)及其调控机理、磁致伸缩效应(MS)及磁弹耦合机理、金属纤维的微观力学及其断裂机理等方面的研究工作，并建立了合金成分、微观结构、调制处理和功能特性间的内在联系，开启了基于上述物理效应的新型技术应用途径。.研究结果表明，Co基、Gd基、Fe基和Cu基金属纤维普遍具有良好的非晶形成能力和热稳定性，呈典型的非晶态特征。低温介质条件下150 mA电流调制态纤维GMI效应显著，其最大阻抗变化率[ΔZ/Zmax]max、磁场响应灵敏度ξmax分别达260.1 %和43.1 %/Oe（f=3 MHz）。所设计的GMI磁敏传感器在±1.0Oe内稳定工作，且具有较高线性度、灵敏度和较好重复性。当Hex=5 T时，经90mA电流退火后GdAlCoFe1金属纤维的磁热性能显著，最大磁熵变-ΔSmmax、制冷能力RC和相对制冷量RCP分别达12.77 J/kg•K、905.88 J/kg和1123.15 J/kg。稀土Pr、Y掺杂对Fe基金属纤维的磁致伸缩特性影响明显。微量Pr、Y和Dy元素掺杂利于改善Cu基金属纤维的拉伸特性和断裂可靠性。Cu-Zr-Ti-Dy纤维抗拉强度Rm和Weibull模数m分别达2.81 GPa、2.69；Cu-Zr-Ti-Pr纤维伸长率e和断裂门槛值σu分别为2.85%、1.42 GPa。Cu基金属纤维拉伸变形更符合Drucker-Prager屈服准则，其断口呈脆性断裂特征。.总之，上述工作为微米级金属纤维在微磁测量、磁制冷、磁致伸缩器件和引线框架中功能一体化应用提供有效的理论依据和技术支撑，具有重要研究意义和应用价值。.本项目在研期间，在Advanced Engineering Materials、Materials Today Communications、Journal of Alloys and Compounds、Materials & Design等国际期刊上发表SCI论文十八篇，其中第一作者和通讯作者九篇；申请或授权专利三项；参加七次国内外学术会议。