共查询到19条相似文献,搜索用时 250 毫秒
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磁驱动相变材料利用外磁控制下铁弹马氏体变体重排或磁诱导一级相变产生的形状记忆效应来捕获应变,兼具铁弹形状记忆与磁致伸缩功效特征。Heusler型Ni-Mn-X(X=Ga或In)系磁驱动相变合金材料具有磁感生应变大、能量密度高、反应速度快等优点,是未来重要磁传感器和磁驱动器研制的关键。主要介绍了国内外Ni-Mn-Ga、Ni-Co-Mn-In、反铁磁体等磁驱动相变材料的研究进展,以及本课题组利用高能X射线衍射和中子散射技术对磁驱动相变材料的原位研究。最后,展望了磁驱动相变合金材料的发展趋势。 相似文献
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研究了铸态及快淬Ni50Mn26Ga19Fe5掺杂合金的磁致应变性能.结果表明,掺Fe的Ni-Mn-Ga合金也具有典型的热弹性马氏体相变过程和磁转变过程,但铸态合金的结构为7层调制型马氏体(7M),而快淬合金的结构为14层调制型马氏体(14M).铸态合金最大磁致应变可达0.1%,快淬薄带合金最大磁致应变只能达到0.0095%.Ni50Mn26Ga19Fe5铸态合金比快淬合金有更大的磁致应变,说明掺杂元素Fe在Ni-Mn-Ga合金中的作用较为复杂. 相似文献
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轻量化是汽车、航空航天、电子电器等工业领域发展的重要目标之一.镁合金作为重要的轻合金材料,在比强度、减振能力、可回收性等方面都有明显优势.磁脉冲成形技术是一种利用磁场力使金属坯料变形的高速率成形技术,可显著提高材料的成形性能.针对AZ31镁合金板材高速率本构关系建立、室温/温热磁脉冲成形、温热与驱动耦合磁脉冲成形和磁脉冲冲击介质温热复合成形进行了阐述.利用分离式霍普金森拉杆获得不同温度与高速率下的应力-应变曲线;通过试验与数值仿真数据,分析室温磁脉冲成形高度与应变分布变化规律,阐述温度与驱动耦合对成形性能的影响,剖析磁脉冲冲击介质温热复合塑性变形特性.结果表明,基于霍普金森拉杆试验可成功建立镁合金板材高速率下的本构关系;在磁脉冲冲击介质温热复合成形中,放电能量增加,成形高度增加,温度为200℃时,成形高度明显高于室温,且二次冲击下高度实现进一步提升.室温磁脉冲成形性能较准静态显著提高,在温度和驱动影响下,成形能力得到提升;采用磁脉冲冲击介质温热复合成形工艺可实现和提高镁合金板材多次冲击塑性变形能力. 相似文献
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<正>近年来,中国科学院宁波材料技术与工程研究所新型磁相变材料团队报道了数十种材料的弹热效应,并系统研究了受控凝固对弹热制冷材料的性能影响。最近,作为一种新型变磁性形状记忆合金Pd-In-Fe单晶理论上能够得到15%的拉伸马氏体相变应变,具有巨大的弹热潜力。团队用直接熔炼成型和退火的方法制备了Pd-In-Fe多晶合金,首次测量了Pd-In-Fe合金的弹热效应,发现 相似文献
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Huibin Xu Jingmin Wang Chengbao Jiang Yan Li 《Current Opinion in Solid State & Materials Science》2005,9(6):319-325
Study on Ni–Mn–Ga ferromagnetic shape memory alloys recently keeps active. Intermartensitic transformation was found. Magnetic field enhanced phase transformation strain was discovered, and achieved up to 4%. Fifteen percent super high strain induced by variant reorientation under stress was obtained in non-modulated martensite. Six percent large magnetic field induced strain was achieved, and the temperature dependence was investigated in 5-layered martensite single-variant Ni–Mn–Ga alloys. Several other systems of magnetic shape memory alloys and high temperature shape memory alloy Ni–Mn–Ga are also reviewed. 相似文献
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Ni-Mn基磁性形状记忆合金具有良好的温度场和磁场诱发的形状记忆效应、超弹性、磁热效应、磁阻效应、弹热效应、交换偏置效应等功能特性。作为一种新型多功能材料,有望应用于驱动器、传感器等多个工程领域。本文详细阐述了包含第二相的Ni-Mn基磁性形状记忆合金的研究现状,梳理和总结了第二相的形成及其对马氏体相变、功能特性和力学性能的影响,提出了一些有待解决的问题,如第二相对包括磁性形状记忆效应在内的磁功能特性的影响,并指出未来应着重于研究第二相形成与演化过程的热力学/动力学因素,对第二相进行合理调控,从而优化合金功能特性。 相似文献
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首先采用球磨法制备了不同粒度的Ni-Mn-Ga-Co合金粉末,然后通过3D打印技术成功制备了泡沫结构的多孔Ni-Mn-Ga-Co磁性形状记忆合金。利用SEM、DSC和XRD等研究了合金的微观组织特征、物相结构、相变特性和相关的磁性行为。结果表明,球磨后经过分筛得到的不同粒径尺寸的合金粉末均为不规则形状。Ni-Mn-Ga-Co合金粉末在室温下为非调制四方马氏体结构,其特征峰十分明显。Ni-Mn-Ga-Co合金的DSC曲线上出现宽峰相变,添加Co元素对马氏体转变温度开始值(Ms)基本没有影响,但其居里温度(Tc)有显著的提高。采用粒径为50~100μm的合金粉末烧结制备的磁性合金,饱和磁化强度最大可达68 Am^2/kg。合金粉末粒径越小,烧结制备的多孔Ni-Mn-Ga-Co磁性形状记忆合金致密度越高。当合金粉末粒径<50μm时,致密度可达90%;当合金粉末粒径为50~100μm时,致密度仅为75%。相较于粒径较小的合金粉末,粒径较大的合金粉末制备的磁性合金磁感生应变能力更高,这是由于泡沫结构能够有效减少内部和外部的约束,从而有利于提高磁场诱导应变。 相似文献
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Andreas Neudert Yin Wai Lai Rudolf Schäfer Mikhail Kustov Ludwig Schultz Jeffrey McCord 《Advanced Engineering Materials》2012,14(8):601-613
Time‐resolved metallographic optical microscopy techniques are used together with magnetic domain imaging to clarify the interaction between magnetic domains and twin boundary (TB) motion in magnetic shape memory NiMnGa single crystals. The magnetic field and stress induced magnetic domain formation is imaged by a magneto‐optical indicator film technique. Reversible TB motion is visualized up to high actuation speeds. From domain observation at adjacent crystal surfaces the fundamental volume magnetic processes during strain and field induced TB motions are derived. For magnetic field induced structural reorientations a concurrent absence of magnetic domain wall motion is found. In contrast, for strain induced reorientations processes, a complete rearrangement of the magnetic domain structure by the moving TB is observed. Dynamic actuation experiments on TB motion reveal non‐linear time effects on TB mobility. In addition to training effects, the maximum field induced strain increases with actuation speed. Both effects can be interpreted as the interaction of moving twin boundaries with local non‐fixed defects. The summarized results provide key information for the understanding of the connection of magnetic and crystallographic domains in magnetic shape memory alloys and for the optimization of devices for future technical applications. 相似文献
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Hee Young Kim Tatsuhito FukushimaPio John S. Buenconsejo Tae-hyun NamShuichi Miyazaki 《Materials Science and Engineering: A》2011,528(24):7238-7246
The effects of Ta and Sn contents on the martensitic transformation temperature, crystal structure and thermal stability of Ti-Ta-Sn alloys are investigated in order to develop novel high temperature shape memory alloys. The martensitic transformation temperature significantly decreases by aging or thermal cycling due to the formation of ω phase in the Ti-Ta binary alloys. The addition of Sn is effective for suppressing the formation of ω phase and improves stability of shape memory effect during thermal cycling. The amount of Sn content necessary for suppressing aging effect increases with decreasing Ta content. High martensitic transformation temperature with good thermal stability can be achieved by adjustment of the Ta and Sn contents. Furthermore, the addition of Sn as a substitute of Ta with keeping the transformation temperature same increases the transformation strain in the Ti-Ta-Sn alloys. A Ti-20Ta-3.5Sn alloy reveals stable shape memory effect with a martensitic transformation start temperature about 440 K and a larger recovery strain when compared with a Ti-Ta binary alloy showing similar martensitic transformation temperature. 相似文献
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Ti-Ni-Hf记忆合金因具有高相变温度、相对低廉的价格和高输出功等诸多优点而成为最具潜力的高温形状记忆合金之一。然而,Ti-Ni-Hf记忆合金基体强度低,变形过程中易优先发生塑性变形,从而使其可实现的可恢复应变远低于理论值。目前改善应变恢复特性的措施主要包括:热机械处理(冷轧+退火)、合金化、时效处理、制备单晶合金等。研究表明,Ti-Ni-Hf合金的应变恢复特性与微观组织结构密切相关。本文主要阐述了Ti-Ni-Hf记忆合金在近年来的最新研究进展,包含微观组织结构的演化规律、马氏体相变行为以及力学性能和应变恢复特性,并基于前期研究成果建立了微观组织结构-马氏体相变-力学与应变恢复特性的关联特性。当前,Ti-Ni-Hf高温形状记忆合金冷、热加工性能差是其广泛应用的瓶颈。因此,Ti-Ni-Hf高温记忆合金的粉末冶金和增材制造可能是未来研究的热点与重点。 相似文献
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Experimental Study on Characteristics of NiMnGa Magnetically Controlled Shape Memory Alloy 总被引:1,自引:0,他引:1
Fengxiang WANG Wenjun LI Qingxin ZHANG Chenxi LI Xinjie WU 《材料科学技术学报》2006,22(1):55-58
The static and dynamic magnetic controlling characteristics of NiMnGa magnetically controlled shape memory alloy (MSMA) were experimentally studied. The results show that the characteristics of induced strain with respect to the magnetic field are nonlinear with saturation nature, and dependent on the temperature as well as the load applied to the MSMA. The magnetic shape memory effect can be observed only in complete martensite phase at room temperature. The magnetic permeability of MSMA is not constant and reduces with the increment of magnetic field. The relative saturation magnetic permeability of MSMA is about 1.5. 相似文献