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1.
超负磁致伸缩晶体Sm—Fe,Sm—Dy—Fe和Sm—Dy—Fe—Al的研究   总被引:1,自引:0,他引:1  
本文研究了轻稀土负磁致伸缩SmFex(1.40≤x≤1.94),SmxDy1-xFey(0.84≤x≤0.92,1.80≤y≤1.90),Sm0.90Dy0.10(Fe0.95Al0.05)1.80晶体的制备,热处理及磁学性能,发现SmFex合金的λ-x曲线存在两个峰值,峰值的x点热处理发生的变化有一定的规律性,还比较了热处理前后,Sm-Fe、Sm-Dy-Fe和Sm-Dy-Fe-Al的相组成对性能  相似文献   

2.
本文研究外加磁场情况下,Sm0.88Dy0.12Fe2合金的微观结构,确定了低磁场下,该合金中(Sm,Dy)Fe2相由立方晶转变为正方晶系,原子发生了位移,初步分析了微观晶格畸变与宏观磁致伸缩应变的关系。  相似文献   

3.
Tb0.27Dy0.73Fe1.9多晶与定向晶棒及其磁致伸缩特性   总被引:3,自引:0,他引:3  
邝马华  杜挺 《功能材料》1994,25(4):354-358
本文用自行设计的实验装置与工艺研制出Tb0.27Dy0.73Fe1.9磁致伸缩多晶棒和定向晶棒。用光学金相检验了定向晶棒的晶粒生长情况、晶粒大小与分布。测量了Tb0.27Dy0.73Fe1.9棒的居里温度、磁化曲线、磁致伸缩、机电耦合系数、弹性模量、共振频率及品质因素。比较了多晶棒与定向晶棒的磁性参数,讨论了晶粒定向对Tb0.27Dy0.73Fe1.9合金的磁致伸缩特性的影响.732.11kA/m磁场时,多晶棒和定向晶棒的磁致伸缩系数 分别是1250ppm和1610ppm.多晶棒和定向晶棒的有效机电耦合系数分别是0.85和0.92.定向结晶后,Tb0.27Dy0.73Fe1.9合金的磁致伸缩特性明显提高。  相似文献   

4.
用超声脉冲回波重迭法测量了超磁致伸缩材料Tb_(0.27)Dy_(0.73)Fe_(2-x)系列样品在不同磁场下的超声波速度,给出了该系列样品的弹性常数随磁场的变化情况,并对实验结果作了初步的解释和探讨。  相似文献   

5.
用差热分析(DTA),结合X射线衍射(XRD)研究了Sm8Fe83Si2C5Cu0.5Nb1.5非晶合金的晶化动力学。结果表明:温度在0 ̄1000℃范围内,该合金的晶化相为α-Fe和Sm2(FeSi)17Cx,α-Fe相的晶化表观激活能力349.53kJ/mol,Sm2(FeSi)17Cx的晶化表观激活能力316.19kJ/mol,两相在晶化初期激活能量小,随晶化量(xc)的增加激活能增大,当α-  相似文献   

6.
研究了Nb含量x对Fe_(76.5-x)Cu_(1.0)Nb_xSi_(13.5)B_(9.0)纳米软磁合金的结构与磁性影响。研究结果表明,当N6含量x约为3at%时,合金的软用性能最高;随Nb含量x的增加,最佳软磁性能下合金显微组织结构中的αFe-Si纳米晶晶粒尺寸D、Si含量、体积分数V_c均呈下降趋势,非晶相的短程有序范围δ增大;合金的磁性除与αFe-Si纳米晶有关外,还与合金中非晶相密切相关。用新近提出的双相无规磁各向异性模型讨论了合金的磁性与结构的关系。  相似文献   

7.
蒋成保  宫志凯 《功能材料》1997,28(6):570-572
研究了经超高温梯度向凝固制备的Tb0.3Dy0.7(Fe,M)1.95合金样品中存在的晶体缺陷的类型,分析其对该材料磁致伸缩性能的影响,探讨如何调整工艺来消除晶体缺陷,提高材料的磁致伸缩性能。  相似文献   

8.
Dy0.6Tb0.3Pr0.1(Fe0.95Mn0.05)x取向晶体的结构与磁致伸缩   总被引:1,自引:1,他引:0  
采用Czochralski方法生长了Dy0.6Tb0.3Pr0.1(Fe0.95Mn0.05)x(1.85≤x≤1.95)取向合金。所有合金主相为立方Laves相结构,择优取向不完整择优取向的方向与X的大小有关。研究了沿着这些样品的生长方向的磁致伸缩性能以及磁致伸缩性能与压力之间的关系。  相似文献   

9.
本文研究了Fe76.5-xCu1NbxSi13.5B9纳米晶合金中Nb含量的变化(x=1-7)对结构和磁性的影响。结果表明,随x值的增高,α-Fe(Si)纳米晶相的尺寸减小,体积分数,含Si量及其DO3有序度降低。Nb含量对残余非晶相的结构有影响。合金的饱和磁致伸缩系数(λs)随x值的增加而增大,在x=3时,合金的起始磁导率(μi)最大,矫顽力(Hc)最小。  相似文献   

10.
用化学共沉淀法,经热处理制得Zn_(1-y)Al_yO系敏感材料。实验发现,在y<0.08区间内,材料的电阻降低幅度较大,当y>0.08时,阻值开始随y值增大而上升。XRD分析表明Zn_(1-y)Al_yO(O<y<0.1)是固溶体,此体系中存在缺陷平衡,并探讨其导电机制。  相似文献   

11.
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.  相似文献   

12.
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……  相似文献   

13.
14.
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.  相似文献   

15.
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.……  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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  相似文献   

19.
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.  相似文献   

20.
新闻(英文)     
正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to  相似文献   

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