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1.
316不锈钢滤板上钯银合金的脉冲电镀   总被引:2,自引:0,他引:2  
研究了氨性溶液中在316不锈钢滤板上脉冲电沉积钯银合金时,电镀条件对镀层组成,表观形貌和金相结构的影响。镀层由钯银合金和少量游离银组成,合金相具有面心立方结构,择优取向为(111)面,镀层银含量随平均电流密度或导通时间的增大而减少,提高镀液中银的浓度有利于获得高银含量镀层。银含量小于26at.%的镀层外观光亮。研究证明钯银合金和银的沉积速率受控于银氨络离子的传质过程。确定了钯银合金选择渗氢膜的电镀  相似文献   

2.
介绍了渗氢用钯基膜的渗氢机理、影响因素以及制备技术的进展情况.重点阐述了钯基膜的种类及其各自的应用.钯膜的发展经历了从最初的纯钯膜、钯合金膜(主要为钯银、钯钇合金)到目前备受关注并具有良好应用前景的钯及钯基复合膜(如多孔陶瓷、多孔不锈钢基体等).钯膜的合金化,不仅能提高膜的氢渗透率,而且更重要的是可以提高钯膜的抗氢脆能力,延长钯膜的寿命,扩展钯膜的适用范围.而钯复合膜的研究成功,在保证膜的机械稳定性的前提下,降低了钯膜的厚度及成本,并极大地提高了钯膜的氢渗透率.  相似文献   

3.
钯基合金膜应用研究进展   总被引:9,自引:0,他引:9  
综述了钯基合金膜应用研究的进展状况 ,着重介绍了钯合金膜的制备方法、影响钯合金膜渗氢性能的因素等 ,并对钯基合金膜存在的技术问题及其发展方向进行了讨论 .  相似文献   

4.
随着膜分离技术的不断发展,渗氢用钯基膜由于具有优异的透氢速率、透氢选择性及良好的化学和热稳定性,已被广泛应用于氢提纯分离领域。介绍了钯透氢膜的种类、透氢机理和制备方法,总结了钯膜从最初的纯钯膜、钯合金膜到钯复合膜的发展历程和氢渗透性能研究,并重点介绍了以铌钯复合膜为代表的新型Pd/bcc型复合膜氢渗透性能的研究进展。  相似文献   

5.
包覆钯和镍后MmNi5基贮氢合金的电极特性   总被引:1,自引:0,他引:1  
Mm_(0.9)Ti_(0.1)Ni_(3.9)Mn_(0.4)Co_(0.4)Al_(0.3)合金包覆10wt%钯-镍后,电极循环寿命和快速充放电性能有明显提高。同时,钯是较好的吸氢元素,这也提高了负极贮氢合金的电容量利用率。包覆钯-镍的贮氢合金电极200次循环后电容量仅下降3%。  相似文献   

6.
氢处理对Ti3Al金属间化合物组织和性能的影响   总被引:4,自引:0,他引:4  
对一种Ti3Al基合金(Ti-24Al-14Nb-3V-0.5MOr(%)进行了氢处理,研究了合金的吸氢行为和组织变化,并对未渗氢和渗氢的试样进行了高温压缩试验,结果表明,合金的吸氢量在800℃达到峰值,渗氢使合金中的O相体积分数下降,并可显著降低热压压缩变形的流变应力。  相似文献   

7.
日本东北大学金属材料研究所和东京工业大学应用陶瓷研究所的研究人员计划开发可与原来的钯-银合金一样高效分离氢气的镍系金属玻璃复合材料氢分离膜。该材料作为可取代昂贵的钯-银合金的低价位材料备  相似文献   

8.
王丽丽 《材料保护》1994,27(5):24-25
概述钯-砷(Pd-As)合金电镀工艺。Pd-As合金镀层适用于制造装饰工艺品,电接触部件和非直立物品(波纹管)等。  相似文献   

9.
渗氢用非对称性复合陶瓷膜的制备技术   总被引:3,自引:2,他引:1  
简要介绍了渗氢用非对称性复合陶瓷膜的发展状况,着重介绍了载体的制备,载体表面涂覆技术和钯合金膜的沉积技术。  相似文献   

10.
浆料涂敷-化学镀技术在微孔陶瓷表面沉积钯银合金膜   总被引:5,自引:0,他引:5  
采用浆料涂敷法和化学镀技术分别研究3了微孔陶瓷载体表面钯银合金膜的制备技术,采用浆料涂敷法,将钯盐和银盐铵一定比例加入到一定配方的粘稠有机沉吟液中,形成涂敷浆料,然后采用刷涂法将涂敷浆料涂敷在多孔陶瓷载体的一个表面,干燥后经高温处理,可得到微孔钯雏事金膜,为了得到致密、光洁的钯银合金膜,采用化学镀进一步沉积,最终得到光洁度较高、厚度约为3μm、雏含量为23%(质量分数、合金化较完全的钯银合金膜,浆  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.
We associate a variety of innovations with the term "Industry 4.0". The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...  相似文献   

15.
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   

16.
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   

17.
ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.  相似文献   

18.
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   

19.
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   

20.
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   

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