化学镀Ni—P—PTFE复合镀层的性能

本文对化学镀Ｎｉ－Ｐ－ＰＴＦＥ复合镀层的性能作了测定和评价。实验表明，用优化的镀液配方加工艺可获得含ＰＴＦＥ粒了２５－３０％ｖｏｌ的Ｎｉ－Ｐ－ＰＴＦＥ复合镀层。这种镀层具有优良的结合力和良好地耐蚀性，其硬度随ＰＴＦＥ含量增加而降低，其特别突出的性能是优异的减性和耐磨性，是一种具有自润滑功能的表面复合材料。     

Ni—P—PTFE复合镀层应用研究

将用正交试验法获得的Ｎｉ－Ｐ－ＰＴＦＥ施镀工艺应用于气体轴承中，探索其在气体轴承中应用的可行性。结果表明，Ｎｉ－ＰＴＦＥ复合镀层可使气体轴承的摩擦学性能明显提高。     

化学镀Ni—P—PTFE复合镀层沉积工艺研究

对化学镀Ｎｉ－Ｐ－ＰＴＦＥ复合镀层工艺进行了较全面的研究。详细测定和评述了表面活性剂浓度，ＰＴＦＥ浓度与镀层中ＰＴＦＥ粒子含量及镀速的关系，以及基础镀液性质和操作条件对复合镀的影响。提出了一种具有实用价值的化学镀Ｎｉ－Ｐ－ＰＴＦＥ复合镀层工艺技术。镀液稳定，镀层质量优良，镀层中ＰＴＦＥ含量达２５￣３０ｖｏｌ％。     

复合镀层的沉积规律和憎液性

研究了在Ｎｉ－Ｐ－ＰＴＦＥ化学复合液中，阳离子表面活性剂的种类含量，镀液中ＰＴＦＥ含量，镀液老化时间等对镀层中ＰＴＦＥ沉积状态的影响，给出了合理的解释，考察了该镀层的憎液性。     

电沉积RE-Ni-W-P-SiC-PTFE复合材料的耐磨性研究

采用多元复合电沉积技术,沉积含有弥散硬质相及自润滑减摩组分ＰＴＦＥ的复合镀层,研究了热处理条件对ＲＥ－Ｎｉ－Ｗ－Ｐ－ＳｉＣ－ＰＴＦＥ复合镀层的硬度及磨损率的影响。确定４００　℃,２　ｈ的热处理条件能使复合镀层具有最佳摩擦学特性：硬度最高,磨损率最低。试验发现,复合镀层中添加ＰＴＦＥ,会使镀层的硬度有所降低,但却能显著降低磨损率,大大提高镀层的耐磨性。     

国内期刊纵览

20 0 0 0 80 1　电沉积ＲＥ Ｎｉ Ｗ Ｐ Ｂ4 Ｃ ＰＴＦＥ———郭忠诚 .电镀与涂饰 (双月刊 ) ,2 0 0 0 ,19( 3 ) :1研究了ＲＥ Ｎｉ Ｗ Ｐ Ｂ4 Ｃ ＰＴＦＥ复合镀层的性能。结果表明 ,热处理温度对ＲＥ Ｎｉ Ｗ Ｐ Ｂ4 Ｃ ＰＴＦＥ复合镀层的硬度影响很大 ,当温度达到 40 0℃时 ,复合镀层的硬度达到极大值 ( 114 5ＨＶ) ;在同一热处理温度下 ,当保温时间达到 3ｈ ,镀层的硬度值最佳。当热处理温度达到 3 0 0℃时 ,ＲＥ Ｎｉ Ｗ Ｐ Ｂ4 Ｃ ＰＴＦＥ复合镀层的耐磨性最好。高温氧化试验表明 ,ＲＥ Ｎｉ Ｗ Ｐ Ｂ4 Ｃ ＰＴＦＥ复合镀层随氧化…     

Ni－P－PTFE复合镀层应用研究

将用正交试验法获得的Ｎｉ－Ｐ－ＰＴＦＥ施镀工艺应用于气体轴承中，探索其在气体轴承中应用的可行性。结果表明，Ｎｉ－Ｐ－ＰＴＦＥ复合镀层可使气体轴承的摩擦学性能明显提高。     

基体表面状况、表面活性剂浓度对Ni-P-PTFE化学镀层结构的影响

采用扫描电子显微镜研究了被镀基体表面的粗糙状况和表面活性剂浓度对Ｎｉ－Ｐ－ＰＴＦＥ化学复合镀镀层微结构的影响。前者的影响是：基体表面的道痕不能被复合镀层所填满,在通常情况下镀层的表面形貌会基本上保持基体的表面状况。但当基体表面过度粗糙,尤其是当道痕又细又密时,会使整个镀层比较疏松并出现较多的空洞。后者的影响是：在表面活性剂浓度过低时所沉积的镀层中只含有很少量的ＰＴＦＥ粒子,在其浓度过高时所沉积的镀     

化学镀Ni－P－B_4C复合镀层的耐磨性

本文通过比较化学镀Ｎｉ－Ｐ－Ｂ＿４Ｃ复合镀层、Ｎｉ－Ｐ－ＳｉＣ复合镀层、Ｎｉ－Ｐ合金层和电镀铬层的性能，发现Ｎｉ－Ｐ－Ｂ＿４Ｃ复合镀层是其中最理想的抗磨材料。试验证明：由于Ｂ＿４Ｃ微粒的硬度高于ＳｉＣ微粒，并且Ｂ＿４Ｃ本身又具有较高的抗显微切削能力，所以Ｎｉ－Ｐ－Ｂ＿４Ｃ复合镀层的耐磨性显著高于Ｎｉ－Ｐ－ＳｉＣ复合镀层和Ｎｉ－Ｐ合金层。由于电镀硬铬层的硬度随磨擦热的升高而迅速下降，所以其耐磨性远不及Ｎｉ－ＰＢ＿４Ｃ复合镀层。     

电沉积ＲＥ—Ｎi—W—P—SiC—PTFE复合材料的耐磨性研究

采用多元复合电沉积技术，沉积含有弥散硬质及自润滑减摩组分ＰＴＦＥ的复合镀层，研究了热处理条件对ＲＥ－Ｎi-P-SiC-PTFE复合镀层的硬度及磨损损率的影响，确定４００℃，２h的热处理条件能使复合镀层具有最佳磨擦学特性，硬度最高，磨损率最低，试验发现，复合支中添另ＰＴＦＥ，会使镀层的硬度有所降低，但却能显著降低磨损率，大大提高镀层的耐磨性。     

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.……     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

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...     

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.     

Roman iron and steel: A review

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.     

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.     

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