Fe83Nb6B11非晶合金退火后的磁导率

研究了在不同温度（370～660℃）退火后Fe83Nb6B11合金的初始磁导率ui与温度T的关系。结果表明,退火温度Ta对ui～T曲线的开状有较大的影响。Ta=370℃,ui～T曲线出现尖锐的Hopkinson峰：Ta=420℃时,ui～T曲线尖锐的Hopkinson峰消失,但温度高于非晶居里温度时,ui迅速下降：Ta在460～660℃的范围内,ui随着Ta升高先以一定的斜率直线下降,降到非晶相的居里点后缓慢下降。分析了这三种类型的ui～T曲线对应的合金相结构、讨论了ui随T变化的原因及双相纳米晶合金中晶体相体积分数、剩余非晶相的磁特性及晶粒间的磁耦合作用对ui～T曲线形状的影响。     

FeCuNbCrSiB非晶合金的晶化及磁导率与温度的关系

对Fe6 8Cu1 Nb3Cr8Si1 0 B1 0 非晶合金在 40 0～ 5 40℃等温退火 1h后的晶化行为及初始磁导率 μi 与温度的关系进行了研究。结果表明 :用Cr取代部分Fe和Si的Fe6 8Cu1 Nb3Cr8Si1 0 B1 0 非晶合金经适当温度退火后可获得具有bcc结构的α Fe(Si)纳米晶 ,合金的居里温度 (Tc <15 0℃ )远低于Finemet合金的Tc(约为 3 40℃ ) ;合金在淬态和 40 0℃退火后的 μi T曲线上出现Hop kinson峰 ,经 5 0 0℃和 5 40℃退火后其 μi T曲线上Hopkinson峰消失 ,曲线具有明显的长尾特征。     

磁场强度对FeCuNbSiB合金μ-T曲线的影响*

研究了不同温度（350－620℃）退火后Fe73.5Cu1Nb3Si13.5B9合金在不同磁场强度（0.4-3.2A/m)条件下,磁导率μ与温度T的关系（μ－T曲线）。实验结果表明：磁场强度对μ－T曲线的形状有明显的影响,在非晶状态时,随着磁场强度的增加,μ－T曲线上尖锐的Hopkinson峰消失。     

（FexCo1-x）73.5Cu1Nb3Si13.5B9合金高温磁性的研究

研究了460～640℃等温退火后纳米晶（FexCo1-x）73.5Cu1Nb3Si13.5B9（x=0.5，1）合金的初始磁导率麒随温度变化。与双相纳米晶Fe73.5Nb3Si13.5B9合金相比，（Fe0.5Co0.5）73.5Cu1Nb3Si13.5B9合金室温下的磁导率降低，但晶化相和非晶相居里温度明显升高，并显著提高了合金在高温下的软磁性能。初步探讨了改善纳米晶合金高温磁性的机理。     

FeCo基纳米晶合金的结构及高频特性

研究了(Fe0.5Co0.5)73.5Nb2V1Si13.5B9Cu1合金经不同温度退火后的结构及磁谱曲线.XRD分析表明,随着退火温度的升高,晶化相体积增加;同时晶格常数减少说明更多的Co溶入到晶化相α-FeCo(Si)中.用阻抗分析仪测量了合金在1kHz-10MHz范围的磁谱曲线.结果表明,合金的截止使用频率可达103～106Hz,且随退火温度的升高,合金的截止使用频率逐渐提高,但初始磁导率μi和截止使用频率f0的乘积保持为常数,用畴壁运动方程及畴壁钉扎理论对此进行了解释.并讨论了进一步提高合金高频性能的途径.     

Co64Fe11Nb5Si12B8合金磁导率与温度的关系

采用铁芯测试仪测得合金样品的初始磁导率随温度的变化曲线, 用磁化强度小角旋转法测量非晶及晶化合金条带的饱和磁致伸缩系数λs;研究了不同温度退火后Co64Fe11Nb5Si12B8合金的磁导率随温度的变化、磁性以及磁致伸缩系数;结果表明:合金在580、590℃热处理磁性变好的反常现象是由于磁致伸缩系数变小所致.     

非晶Fe78Si9B13合金结构对磁性的影响

研究了普通退火对非晶Fe78Si9B13合金磁性能和结构的影响.实验发现:经不同温度退火1h后,试样的静态磁性能在Ta=390℃呈现最佳值;损耗则在Ta=440℃呈现最低值;在Ta=440℃经不同时间退火后,试样在ta=2h呈现横向感生磁各向异性.由退火后试样的初始磁导率与温度的关系及磁致伸缩系数的变化结果表明,当有极少量的α-Fe(Si)晶体相析出时,可明显改善合金的动态磁性能;当α-Fe(Si)晶体相进一步析出时,可使合金呈现良好的恒导磁特性.     

Fe基非晶纳米晶带材的快速热处理工艺研究

研究了Fe基非晶纳米晶带材采用较快升温速率和不同出炉温度对软磁性能的影响。研究结果表明,采用宽度为(10±0.2)mm、厚度(33±2)μm的带材卷绕成内径为20mm、外径为30mm的圆环磁芯,在以480℃为起始温度,再以1℃/min的速率升至退火温度,当退火温度540℃,退火时间60min,随炉冷却至200℃出炉磁性能最佳,当测试频率f=1kHz,初始磁导率μi=135800,最大饱和磁感应强度Bs为1.157T,剩余磁感应强度Hr为0.6781T,矫顽力Hc为0.6434A/m,与普通真空热处理最佳性能(测试频率f=1kHz,初始磁导率μi=159700,最大饱和磁感应强度Bs为1.122T,剩余磁感应强度Hr为0.5964T,矫顽力Hc为0.6828A/m)相差不大,在实际生产中可以将起始温度提高到480℃;同时,当出炉温度高于300℃时,带材磁性能下降剧烈。     

非晶纳米晶粉体/环氧树脂复合材料的制备及其软磁性能研究

以环氧树脂为基体,以经热处理的Fe73.5Cu1Nb3Si13.sB9非晶粉体为增强材料,制备了环形树脂基复合材料,并研究了非晶粉体退火工艺、纳米晶粉体含量及复合材料退火工艺对树脂基复合材料的起始磁导率μi和Q值的影响.结果表明:以经550℃×0.5h退火的Fe73.5Cu1Nb.Si13.5B9纳米晶粉体为组元的树脂基复合材料的起始磁导率μi最大,为2.528,Q值最小,其中心频率(34.426 MHz)对应的Q值为72.4;随着纳米晶粉体含量的增加,树脂基复合材料的起始磁导率μi增大,Q值减小;去应力退火可以提高树脂基磁性复合材料的起始磁导率μi.     

脉冲电沉积纳米晶Ni-Co合金镀层热稳定性的研究

采用X射线衍射(XRD)、能谱分析(EDS)等方法研究脉冲电沉积法制备的纳米晶Ni-Co合金镀层的组织结构和合金成分.测定不同退火温度下纳米晶Ni-Co合金镀层的显微硬度,并着重研究Ni-23.5%Co(质量分数)合金的热稳定性,结果表明:随着退火温度的升高,纳米晶Ni-Co合金在低温退火后显微硬度有所升高,在250℃时达到最高值,然后随退火温度的继续升高而降低.纳米晶Ni-23.5%Co合金镀层的晶粒尺寸逐渐增大,从原始晶粒尺寸13.5nm长大到300℃时的98.5nm,在升温速率为20K·min-1的DSC曲线中,Ni-23.5%Co合金在约300～350℃一直是低能放热,随后出现明显的放热峰,其峰值温度为372℃,放热焓为14.22J·g-1.通过测定不同升温速率条件下的DSC曲线峰值温度,由Kissinger方程求得纳米晶Ni-23.5%Co合金镀层的晶粒长大激活能为212.SkJ/mol.     

Simplified Approach Based on Polynomial Equations to Predict the Permeability of Micro‐perforated Polymeric Films

A simplified approach to predict the mass transport properties of micro‐perforated films was presented in this work. In particular, the proposed mathematical model was based on a second‐degree polynomial function. Different types of micro‐perforated films with two thicknesses (35 and 25 µm) were tested for gas and water vapour permeability, under proper conditions. The films differed in both number of holes per unit area and hole diameter. Corresponding non‐perforated films were also tested. The experimental data obtained were used to validate the model. Moreover, the surface response plot of the interactions between hole diameter and number of holes per area relative to oxygen, water vapour and carbon dioxide permeability were determined. Results of the mean relative deviation modulus (E%) between the experimental and predicted data confirmed the ability of the proposed model to predict the permeability of micro‐perforated films. Copyright © 2016 John Wiley & Sons, Ltd.     

安全气囊织物动态透气性与静态透气性的测试

通过自行设计的安全气囊织物动态透气性测试装置对 2 种不同的锦纶 66 安全气囊织物进行了测试研究, 发现在高压下安全气囊织物动态透气量与压差呈线性关系. 为了与动态透气性进行比较, 还通过 CFP-1100-AI 孔径仪对上述 2 种锦纶 66 安全气囊织物进行静态透气性测试, 发现在高压下安全气囊织物静态透气量与压差呈幂律关系. 对比研究表明: 在相同压差下安全气囊织物的静态透气量大于安全气囊织物的动态透气量, 且随着压差的增加, 安全气囊织物的动态透气量与静态透气量的差值也逐渐增加.     

Analysis of Transversal Permeability for Different Types of Glass Fiber Reinforcement

In some of the new processes to produce elements in composite materials, the innovation is due to the fact that the resin flow is perpendicular to the plane of the reinforcement during the impregnation.So a very important parameter is the transversal permeability of the reinforcing materials used in these processes. In fact for a high value of this parameter it is possible to increase the product quality and to reduce the process time.In this work, using Darcy's law and a particular permeameter, the transversal permeability of preforms constituted by fabric and mat layers of fiber glass has been valued for different injection pressures. In particular, the permeability of two types of preform, consisting respectively of only mat layers and of only fabric layers, have been determined by tests and calculated by Kozeny–Carman equation. The research has been also focalised on the evaluation of the permeability of preforms constituted by a mix of the two different types of reinforcement. Furthermore an analytical model has been studied to calculate the permeability of preforms consisting of layers of different reinforcement types, starting from the permeability data characterizing the single reinforcement type and determined by the tests or by Kozeny–Carman equation.     

[(Fe1-xCox)0.75B0.2Si0.05]96Nb4金属玻璃的磁谱研究

对[(Fe1-xCox)0.75B0.2Si0.05]96Nb4(x=0.1、0.2、0.3、0.4)金属玻璃在1kHz～15MHz间的磁谱进行了研究,该系列金属玻璃的磁谱是典型的德拜型谱线.由于钴元素的添加,表现出较高的弛豫频率(f0)和较高的电阻率(ρRT),但是复数磁导率实部幅值降低.当x=0.4时,弛豫频率达到最大值1.1×106Hz.电阻率随着钴元素加入从212μΩ·cm增加到272μΩ·cm.     

Surface crystallization of melt-spun Pd40Ni40P20 glass

The crystallization of Pd₄₀Ni₄₀P₂₀ glass, produced by melt-spinning in air, has been studied by optical metallography. Crystallization is predominantly from the surface and is more prevalent on the wheel-side. The non-uniformity is attributed to variation in quench rate during production. A three-stage anneal permits crystals which have nucleated at the surface to be identified and their size distribution to be analysed. The surface nucleation is heterogeneous and appears to be hindered by mild oxidation. The annealing atmosphere markedly affects the surface crystallization behaviour, as does removal of the original ribbon surface. When nucleation is sparse, partial crystallization causes the development of noticeable relief on the sample surfaces.