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1.
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   

2.
对Fe73.5Cu1Mo3Si13.5B9微晶软磁合金的结构及其对合金磁性的影响了研究,结果表明,在最佳磁性能下,晶相点阵常数a=0.2843nm,相当于Fe(Si)固溶体中含Si%(mol/mol):18-20,体积百分数V=74.8%,晶粒尺寸D=14.6nm;残余非晶层厚度δ=1.23nm;当T退火≥560℃时明显有Fe-B化合物析出。Fe73.5Cu1Mo3Si13.5B9合金的磁性不仅与  相似文献   

3.
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   

4.
预退火对Fe73.5Cu1Mo3Si13.5B9纳米晶合金形成的影响   总被引:5,自引:0,他引:5  
采用X射线衍射,电子衍射及透射电子显微技术研究了Fe73.5Cu1-xMo3Si13.5B9非晶合金410℃预退火对随后480℃退火所形成的纳米晶结构的影响。结果表明,预退火对Fe73。05,Cu1Mo3Si13.5B9合金纳米晶结构的形成有重要影响。当预退火时间从0小时增加到3小时,合金在480℃,小时退火形成的晶相化α-Fe(Si)的晶粒尺寸从15nm减小到8nm。预退火使α-Fe(Si)相的  相似文献   

5.
用Mossbauer谱学和XRD方法研究了快速凝固Al-5Fe-2Ni(原子百分数)合金的析出相,结果表明,析出相为三元化合物Al9FexNi2-x(0〈x〈2)属于单斜晶系,晶格参数a=0.858nm,b=0.631nm,c=0.621nm,β=94.8,它的Mossbauer谱为一套双线,同质异能移位IS=0.12mm.s^-1,四极分别QS=0.32mm.s^-1,线宽Г=0.26mm.s^  相似文献   

6.
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   

7.
本文研究了Fe(76.5-x)Cu1NbxSi(13.5)B9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DO_3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   

8.
纪松  杨国斌 《功能材料》1995,26(4):344-346,358
研究了Nb含量x对Fe76.5-xCu1.j0NbxSi13.5B9.0纳米软磁合金的结构与磁性影响。研究结果表明,当Nb含量x约为3at%时,合金的软磁性能下合金显微组织结构中的aFe-Si纳米晶晶晶粒尺寸D、Si含量、体积分数Vc均呈下降趋势,非晶相的短程序有序范围δ增大;含金的磁性除与aFe-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  相似文献   

9.
本文采用了不同温度下两次烧结的新方法,制备了系列X射线影象存储材料BaF_xCl_(2-x):Eu ̄(2+)(x=0.90,0.95,1.00,1.05,1.101.15)。通过改变F/Cl比值,研究了在X射线辐照后BaF_xCl_(2-x):Eu ̄(2+)的热释发光性质,给出了热释发光峰的温度与缺陷种类的关系。最后,我们研究了BaF_xCl_(2-x):Eu ̄(2+)的光激励发光性质,给出了F/Cl比值与光激励发光强度的关系。  相似文献   

10.
Zr1—xTix(Ni0.6Mn0.3V0.1Cr0.05)2(x=0~0.5)Laves相储氢合 …   总被引:1,自引:0,他引:1  
本文研究Zr1-xTix(Ni0.6Mn0.3V0.1Cr0.05)2(x=0,0.1,0.2,0.3,0.4,0.5)系Laves相储氢电极合金的气态P-C-T性能、晶体结构及电化学性能。XRD分析表明,Ti合金化使Zr基储氢合金主相从C15相转变为C14相。当x〉0.2时,第二相Zr7Ni10相消失,并出现TiNi相。Ti合金化使Zr基储氢合金中C15相和C14相的晶格常数线性递减。气态P-C  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.
13.
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   

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.
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 ...  相似文献   

19.
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   

20.
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   

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