FeSiB非晶薄带的压磁效应研究

采用单辊法制备了宽4.5mm厚25μm的Fe79Si15B16非晶薄带,压磁效应测试结果表明:当测试频率较低时,Fe79Si15B16非晶薄带的压磁效应较弱,随着频率的升高,薄带的压磁效应出现了明显的增强;当退火温度低于300℃时,退火后薄带的压磁效应增强,且薄带的压磁效应随着退火温度的升高而增强;经300℃×1.5h的退火后,薄带的压磁效应最强,当测试频率为50MHz,测试压应力为1.05MPa时,其压磁效应可达0.99%.     

硅橡胶表面状态的非晶带材压磁性能的研究

采用4284A阻抗分析仪,在0～1MHz频率范围内,研究了不同测试温度和退火条件下硅橡胶表面状态的非晶Fe73.5Cu1Nb3Si13.5B9带材的压磁性能.结果表明,非晶带材的阻抗变化|ΔZ|随着压应力和频率的增加而增加,对0.1MPa以下的微应力变化非常敏感;在13～37℃测试温度范围内,随着温度的升高,非晶带材压磁灵敏度增加,37℃时压磁性能最好;退火温度低于300℃时,非晶带材经300℃×0.5h退火处理后,其压磁性能最好.     

热处理温度对FeCoSiB薄膜及FeCoSiB/Cu/FeCoSiB三明治膜应力阻抗效应的影响

采用DC磁控溅射法在玻璃基片上制备了FeCoSiB薄膜和FeCoSiB/Cu/FeCoSiB 三明治膜,并进行磁场退火热处理以消除残余应力和形成磁织构,提高薄膜的应力阻抗效应。薄膜的磁性能采用振动样品磁强计(VSM)进行测试,采用HP4275A 型阻抗分析仪在200kHz~10MHz频率范围内测试薄膜的应力阻抗效应。结果表明,磁场退火热处理可形成感生磁各向异性,改善薄膜的软磁性能、提高薄膜的应力阻抗效应。在温度低于300℃时,随着退火温度的增加,薄膜的应力阻抗效应增大;当退火温度超过300℃时,薄膜的应力阻抗效应随退火温度增加而降低。与Fe CoSiB单层膜相比, FeCoSiB/Cu/FeCoSiB 三明治膜应力阻抗效应较大。10MHz测试频率下,在基片末端位移为450μm时,经300℃热处理的三明治膜达到了8.3%,而单层膜仅有1.86%。当测试频率较高为10和4MHz时,薄膜的应力阻抗效应变化不大,当测试频率下降到低于1MHz时,薄膜的应力阻抗效应显著降低。     

退火工艺对FeCuNbSiB非晶带材压磁效应的影响

研究了退火工艺对非晶FeCuNbSiB带材压磁性能的影响情况.结果表明,当退火温度为300℃时,FeCuNbSiB非晶带材开始慢慢晶化,当温度上升到500℃时,带材内部结构已由非晶态完全转变成晶态.当退火温度＜300℃时,退火能够消除部分内应力,使阻抗变化的灵敏度提高;退火温度高于300℃,随着退火温度的升高,压磁效应减弱.退火时间高于1h,带材的压磁性能变化不显著.非晶FeCuNbSiB带材经过100℃×2h退火,压力为2.7MPa时,阻抗变化最高可达40Ω.     

非晶Fe94Si6薄带压磁效应的研究

利用单辊法制备宽5mm厚25μm的非晶FeSi带材,利用XRD、SEM和EDS等手段对其进行了表征,并利用4294A阻抗分析仪,在0～100MHz频率范围内研究了样品的点压磁阻抗效应.结果表明,非晶带的阻抗随着频率的增加而增加,并随压力的增加变化更加敏感,尤其是频率在1～100MHz范围内时.非晶FeSi带材具有优越的压磁效应,在频率为100MHz,阻抗变化可达34.9433Ω.     

铁基非晶薄带的磁感应效应

研究了Fe73.5Cu1Nb3Si13.5B9非晶薄带磁感应效应的影响因数.结果表明,磁感应效应变化幅度随着磁场强度的增大而增大;当测试频率为30kHz,薄带长度为3cm,线圈匝数为300匝时,淬火态非晶薄带的磁感应效应变化幅度最大;与淬火态非晶薄带相比,退火可以提高磁感应效应变化幅度,且经300℃×1h退火后的磁感应效应变化幅度最大.     

表面处理和温度对铁基非晶带材压磁性能的影响

采用4284A阻抗分析仪,在0～1MHz频率范围内,研究了表面状态和测试温度对非晶Fe73.5Cu1Nb3Si13.5B9带材压磁性能的影响情况.结果表明,非晶带材的阻抗变化随着测试频率的增加而增加,对0.1MPa以下的微应力变化非常敏感;当压应力＞0.1MPa时,经硅橡胶和EVA胶处理的带材与未表面处理的带材相比压磁敏感度升高,尤其是经硅橡胶处理的非晶带材,其压磁灵敏度最大;测试温度升高后,非晶带材压磁灵敏度增加,30～40℃时压磁性能最好,经硅橡胶处理的非晶带材在40℃、0.2～1.0MPa条件下,压磁曲线斜率达到0.0506;当压应力＞0.2MPa时,非晶带材具有很好的压磁稳定性.     

焦耳-应力退火对Co基薄带巨磁阻抗的影响

采用焦耳-应力退火处理了Co_83.2Fe_5.2Si_8.8B_2.8非晶薄带,利用阻抗分析仪和磁光克尔效应显微镜分析了焦耳-应力退火前后Co基薄带的巨磁阻抗效应和磁畴结构。结果表明,经焦耳-应力退火后,薄带的GMI效应得到提高,24.5 MPa焦耳-应力退火后,0.4 MHz时,薄带的最大阻抗变化率达到47.6%,1 MHz时,其磁场响应灵敏度达到280.2%/(kA/m)。磁畴观察发现,随退火过程中拉应力的施加,薄带表层横向带状畴内部逐渐形成细小纵向畴,同时横向带状畴逐渐向纵向偏转,表明对于具有负磁滞伸缩系数的Co基薄带,焦耳-应力退火可以促进薄带内衍生纵向细畴,且纵向拉应力的施加,增强了薄带的纵向各向异性。因此,焦耳-应力退火改善了薄带的低频纵向驱动GMI效应,磁场响应灵敏度也大幅度提高。     

应力作用下电流退火对钴基非晶薄带的巨磁阻抗效应的影响研究

采用应力作用下的直流电流退火处理Co68.2Fe2.3Mo2Si12.5B15非晶薄带，详细讨论了应力退火前后Co基薄带的巨磁阻抗效应的变化，以及退火时间对巨磁阻抗效应的影响，研究表明：应力作用下的电流退火有利于巨磁阻抗效应的提高，并可以通过控制退火时间控制阻抗与外场变化关系曲线形状。     

FeCuNbSiBV非晶纳米晶合金带材压磁特性研究

研究了Fe71.5Cu1Nb3Si13.5B9V2非晶带材经不同退火工艺处理后的压磁特性,并对不同成分带材的压磁特性进行了对比分析。研究表明,在测试频率f=1 kHz、压应力σ≤0.2 MPa条件下,Fe71.5Cu1Nb3Si13.5B9V2非晶带材闭合回路的电感值随压应力的增大而增大,带材具有良好的压磁稳定性,当退火温度为550℃时,带材的压磁特性稳定性最好,电感值与加载时间、SI(%)与压应力均具有良好的线性关系;热处理工艺对Fe71.5Cu1Nb3Si13.5B9V2带材的压磁性能具有显著影响,退火工艺为300℃×30 min时SI(%)达到最大值0.183;带材的压磁效应与其成分有关,相同测试条件下,Fe73.5Cu1Nb3Si13.5B9带材具有最大的压磁效应,Fe78Si9B13带材次之,Fe71.5Cu1Nb3Si13.5B9V2带材压磁效应最小。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.