非真空熔铸Cu-Cr-Zr合金研究进展

Cu-Cr-Zr合金经适当的形变及热处理后可获得高的强度、良好的导电及热稳定性.Cu-Cr-Zr合金作为一种高强、高导功能材料被广泛应用,其研究及推广也取得了重要成果.综述了Cu-Cr-Zr合金在非真空条件下的熔铸工艺及铸造缺陷,阐述了Cu-Cr-Zr合金的形变热处理工艺及其对合金性能的影响,讨论了合金元素Cr、Zr对合金组织性能的影响和Cu-Cr-Zr合金的合金化设计.     

精密仪器用耐蚀合金组织与性能的研究

对一种精密仪器用可高精密加工、高尺寸稳定性、无磁、耐腐蚀铸造合金进行了研究,分析了合金元素、热处理工艺对组织及性能的影响.新型合金比不锈钢抗均匀腐蚀性提高6倍,抗点蚀性能提高1.6倍,且无磁性能优于不锈钢,可作为高精密仪器用材料.     

一种提高DD3单晶高温合金蠕变性能的热处理工艺

根据DD3单晶高温合金的热分析和相分析结果,制定了新的热处理工艺.该优化工艺提高了合金的固溶处理温度,并增加了一级时效制度.研究了优化工艺热处理后DD3合金的蠕变及拉伸性能,对比分析了优化工艺和标准工艺处理后的组织、元素分布和力学性能.结果表明,优化后的热处理工艺改善了合金组织和元素的分布,显著提高了合金的蠕变性能.     

添加合金元素对CuCr触头材料组织和性能的影响

按主要作用的不同分类,较为详细地综述了几种常见合金元素对CuCr触头材料组织和性能的影响,比较了添加单一元素与添加多种元素对CuCr触头材料性能的不同影响效果,并展望了添加合金元素改善和提高CuCr触头材料性能的前景.     

合金元素对块体纳米晶Fe3Al材料磁学性能的影响

为了研究合金元素对块体纳米晶Fe3Al材料磁学性能的影响,通过铝热反应熔化法制备了纳米晶Fe3Al以及分别含Ni质量分数10%、Cr质量分数10%、Mn质量分数10%和含Ni质量分数10%-Cu质量分数2%的块体纳米晶Fe3Al.在振动样品磁强计(VSM)上测得合金的磁滞回线,分析其磁性能,采用X射线衍射仪进行结构分析和平均晶粒尺寸计算.结果表明:各样品的磁滞回线呈倾斜状且狭长,磁滞损耗很小;含Ni质量分数10%的样品饱和磁化强度Ms较大,剩余磁化强度Mr和矫顽力Hc较其他样品最小,具有较好的软磁性能;添加合金元素后几种材料的晶粒尺寸变小,磁性能有较大变化,合金元素对纳米晶Fe3Al块体材料的磁性能影响明显.     

JMS-1高弹性合金及其应用

JMS-1合金是一种导电弹性材料。它具有弹性好,强度高和良好的压延性能,是新型的代QSn6.5-0.1合金材料。本文研究了合金元素Ni、Sn、Zn、形变量和热处理工艺对Cu-Ni-Sn-Zn合金力学性能的影响,并对JMS-1合金与QSn6.5-0.1的各种性能进行了对比。同时,介绍了该合金的试验结果和应用情况。     

退火工艺对Finemet纳米合金磁性能的影响

为改善Finemet合金的磁性能,通过氩气退火和横、纵磁应力退火对合金进行热处理,研究退火工艺对合金磁性能及微观结构、形貌的影响.使用LCR数字电桥法、共地三电压法及冲击法测试磁性能,利用场发射扫描电镜观察Finemet合金的非晶、纳米晶形貌,采用X射线仪分析Finemet合金的结构.研究表明,540℃氩气退火使合金的初始导磁率μi达最高值且矫顽力H c最低,非晶基体出现bccα-Fe(Si)纳米晶颗粒,580℃氩气退火使纳米晶数量和尺寸增加,磁性能下降;540℃横磁退火可获得狭长扁平的磁滞回线、低剩磁比Br/Bs和铁损P c,540℃纵磁退火可获得矩形磁滞回线、高Br/Bs和P c,横、纵磁退火均使μi和H c降低.因此,合理的退火工艺可优化Finemet合金磁性能,以适应不同的应用领域.     

CoCrFeNi系高熵合金研究进展

高熵合金具有独特的微观结构和特性,作为一种新型的高性能材料,逐渐获得了国内外研究人员的广泛关注。高熵合金具备多元化的元素组成方式,不但没有形成传统概念中复杂的相结构,反而展现出了更优异的性能,在诸多领域均具有良好的应用前景。在当前的高熵合金体系中,CoCrFeNi系研究最为广泛,其研究内容主要体现在通过添加不同元素或进行退火热处理对原合金体系改性进而获得优异性能的材料。首先,结合CoCrFeNi体系对高熵合金的定义和性能特点进行了分析和总结;其次,从热力学和动力学角度论述了CoCrFeNi系高熵合金的结构预测、层错能计算及缺陷动力学分析;再次,总结了Al、Ti、Cu、Mn和C元素对CoCrFeNi系高熵合金显微组织和力学性能的影响;最后,分析了当前的研究现状并进行了展望。     

铝青铜合金研究进展

简要介绍了铝青铜合金的主要性能和应用现状.综述了铝青铜中主要合金元素及其他微量元素Al、Fe、Mn、Ti、Zn、Co、Zr等对其显微组织和性能的影响机理、作用效果.详细介绍并分析了热处理工艺,特别是固溶时效工艺参数,包括固溶温度、固溶保温时间、时效温度、时效保温时间和冷却速度对铝青铜组织与性能的影响,并概述了铝青铜合金今后的发展方向.     

真空熔炼的康铜合金的性能

真空熔炼是改善康铜合金细丝加工性能的有效方法。本文介绍了真空熔炼过程中,各元素含量的相对变化;合金的化学成分均匀性;采用不同熔炼工艺生产的康铜合金,拉制细丝时的加工性能对比以及制成细丝时的各项性能指标。认为真空熔炼的康铜合金,化学成分均匀、比电渣重熔以及其它非真空熔炼的康铜合金加工性能好,成材率高。采用真空熔炼的康铜合金,能稳定地生产出如.时mm细丝。本文还探讨了成品减面率、热处理工艺对康铜合金细丝性能的影响。认为减面率对成品细丝占(延伸率)和。。(抗张强度)无显著影响,成品热处理制度是影响合金细丝性能的主要因素。主张采用真空熔炼的康铜合金,大的冷加工减面率,高温快速连续退火的工艺生产康铜合金细丝。推荐按如.0关"3·o苦"1·尹"。·3芳"0.02井mm工艺生产和.肥mm合金细丝     

High performance of low cost soft magnetic materials

The consistent interest in supporting research and development of magnetic materials during the last century is revealed in their steadily increasing market. In this work, the soft magnetic nanocrystalline FINEMET alloy was prepared with commercial purity raw materials and compared for the first time with the generally studied high purity one. The exhaustive characterization covers several diverse techniques: X-ray diffraction, Mössbauer spectroscopy, differential scanning calorimetry, differential thermal analysis and magnetic properties. In addition, a brief economic analysis is presented. For the alloys annealed at 813 K, the value of the grain size was 16 nm with 19·5% of Si, the coercivity was 0·30 A m^?1 while the saturation was 1·2 T. These results prove that structural, magnetic and thermal properties of this material are very close to the expensive high purity FINEMET alloy, while a cost reduction of almost 98% seems highly attractive for laboratories and industry. The analysis should be useful not only for the production of FINEMETs, but for other type of systems with similar constitutive elements as well, including soft and hard magnetic materials.     

Fabrication and characterization of nano/amorphous dual-phase FINEMET microwires

A nano/amorphous dual-phase FINEMET microwire was fabricated directly from molten alloy without any interstage annealing by a home-built melt extraction technique (MET). The microstructure, mechanical and pronounced electromagnetic interference shielding (EMI) effectiveness of this dual-phase microwire has been systematically evaluated. The structural analysis reveals that the as-cast FINEMET microwire consists of two distinct structures, i.e., amorphous and nanocrystalline phase due to their different cooling characteristics. Compared with other reported FINEMET alloys, the extracted microwire exhibits a superior high tensile strength of 1800 MPa. These nanocrystals enabled dual-phase microwires also exhibit large EMI SE values in the frequency range of 8–12 GHz (X-band) due to the multiple magnetic loss mechanisms associated with their intrinsic structural characteristics. The combination of excellent mechanical properties and electromagnetic properties make this kind of melt-extracted dual-phase FINEMET microwire promising for a range of structure and multifunctional applications.     

高性能软磁合金的研究进展EI北大核心CSCD

软磁材料是一种极为重要且应用十分广泛的能源材料,近年来,随着磁性元件的日益高频化和小型化,以及节能环保的号召,开发和研究高性能软磁材料具有重要意义。本工作概述了软磁合金的发展历史,重点归纳出各类软磁合金(包括传统软磁合金、非晶/纳米晶软磁合金、高熵软磁合金)的成分、微观组织、磁性能以及应用范围,并总结出不同软磁合金的优、缺点;指出典型合金的微观组织对合金软磁性能(尤其矫顽力)具有关键性的主导作用,进而探讨了影响软磁合金矫顽力的因素及其微观机制,发现控制晶粒尺寸(或纳米粒子尺寸)是获得低矫顽力的关键,并描述了矫顽力的微观影响机制在高熵软磁合金中的发展;最后,展望了高熵软磁合金因多主元混合的成分特性带来的组织多样化,更有利于实现对合金性能的调控,并有望作为新一代高温软磁体材料。     

Soft Magnetic Properties of Fe-5wt%Al Alloy

In this investigation, a new soft magnetic material (iron with 5 wt% aluminum) has been developed using powder metallurgy processing. The microstructure and the magnetic properties of this new P/M alloy have been characterized at both room and elevated temperatures (up to 500°C). The influence of post-sintering (after initial processing) on the porosity and magnetic properties of this material has also been examined.

Test results show that the room temperature soft magnetic properties of this alloy are comparable to other commercially available soft magnetic materials such as P/M pure Fe, Fe-Si, Fe-P, etc. Post-sintering at 1316°C resulted in significant grain growth and lower porosity with more rounded pore morphology and improved the magnetic properties. While the magnetic induction of the alloy was essentially constant from room temperature to 500°C, the coercivity of the material decreased significantly at elevated temperature. This new P/M alloy may be a suitable soft magnetic material for high temperature (up to 500°C) applications.     

Influence of Annealing Conditions on Nanocrystalline and Ultra-Soft Magnetic Properties of Fe75.5Cu1Nb1Si13.5B9 Alloy

The magnetic and structural properties of FINEMET alloy with a composition of Fe75.5Cu1Nb1Si13.5B9 were investigated after primary and secondary crystallization of amorphous ribbon sample.The crystallization behavior and the nanocrystal formation of the samples were performed by differential thermal analysis(DTA) which in turn was supported by X-ray diffraction(XRD) study.Temperature dependence of initial permeability of amorphous and devitrified toroid shaped samples has been measured.Enhancement of Curie temperature of the amorphous alloy has been observed due to the irreversible structural relaxation.With the appearance of nanocrystalline phase the Curie temperature of the residual amorphous phase gradually decrease with the increase of annealing temperature.Their temperature dependence reflects the characteristic annealing temperature evolution of the basic magnetic parameters in these nanocrystalline systems.Saturation magnetization,Ms,increases with annealing temperature Ta for the samples and finally decreases during annealing at a temperature much higher than peak crystallization temperature.     

软磁合金粉末特性对金属软磁粉芯的影响

软磁合金粉末作为制备金属软磁粉芯的原材料,是决定磁粉芯性能的关键因素之一。本文综述了软磁合金粉末的合金成分、形貌、粒度以及粉末纯度对软磁粉芯性能的影响。分析结果表明,铁硅铝磁粉芯具有最佳性价比,采用气雾化法生产的球形粉末具有最佳的软磁特性,软磁粉末越细,纯度越高,所制备的磁粉芯软磁性能越好。     

Enhanced giant magnetoimpedance effect in FINEMET/TiO2 composite ribbons

In order to study the influence of semiconductors on the magnetic properties and giant magnetoimpedance effect of FINEMET ribbon, titanium dioxide coating layer with different thickness was sputtered onto the free surface of the FINEMET ribbon by RF magnetron sputtering to prepare the FINEMET/TiO₂ composite ribbons. The morphology, magnetic properties, and giant magnetoimpedance of the FINEMET/TiO₂ composite ribbons were analyzed. The results show that the GMI ratio of composite ribbons first increases and then decreases with the increase of TiO₂ layer thickness (0?~?150 nm). When the thickness of TiO₂ thin film is 100 nm, the GMI ratio reaches the maximum 57.3%, which indicates that a certain thickness of TiO₂ thin film can significantly improve the GMI effect. The result can be explained by the combined result of electromagnetic interaction and stress between TiO₂ thin film and the FINEMET ribbon.

     

矩形回线软磁合金损耗谱的分形性质

研究了矩形回线软磁合金的磁性，发现铁芯损耗谱具有分形结构，研究了热处理条件及带厚对分形维数Ｄ的影响。     

Accelerated and conventional development of magnetic high entropy alloys

High-entropy alloys (HEA) are of high current interest due to their unique and attractive combination of structural, physical, chemical or magnetic properties. HEA comprise multiple principal elements, unlike conventional alloys. The composition space of HEA is enormous and only a minuscule fraction has been studied. Magnetic HEA are a promising alternative to conventional soft magnetic metallic materials, which typically exhibit poor mechanical properties. We review the progress in the development of magnetic HEA. The influence of alloy composition, crystal structure, phase fraction and processing parameters on the magnetic properties are discussed. Magnetic HEA processed by advanced experimental high throughput techniques such as additive manufacturing, co-sputtering, diffusion multiples, rapid prototyping, and designed via combinatorial computational techniques, such as thermodynamic and phase diagram calculations, density functional theory, machine learning etc. are reviewed. Conventional processing techniques are also discussed. Future trends in magnetic HEA are outlined.     

纳米高频软磁薄膜材料研究进展

由于高频软磁薄膜材料具有巨大的应用前景因此获得了人们广泛的关注。对纳米合金软磁薄膜、纳米软磁颗粒膜、多层膜以及图形化薄膜进行了分类综述,分别介绍了各类薄膜的制备方法、化学成分、微观结构特点和高频物理性能,并对影响其性能的主要因素进行了讨论。由于纳米高频软磁薄膜材料相对于传统磁性材料具有显著优势,所以纳米合金软磁薄膜有望取代铁氧体作为制作高频磁性器件的主要应用材料。由于纳米软磁颗粒膜、多层膜以及新兴的图形化薄膜具有材料结构设计和物性剪裁的自由度,因此将是今后的重点研究方向。