WT三元仿金镀液的电化学性能

表面处理的仿金工艺能使产品饰以各种类型的金色,达到代替黄金美化产品外表的目的.这些仿金工艺已越来越引起人们的兴趣而予以研究.过去用电镀黄铜(铜-锌合金)来代替金镀层,其最大缺点是易于变色,色彩单调,若要使这种铜-锌合金有良好的仿金效果,需要采取较复杂的电镀工艺过程.后来发展了电镀三元合金(铜锌-锡)以及添加其它金属(如钢、镍、钴、钯、锆、钌等)盐类的新型仿金镀层,近年来又在三元仿金电镀液中引入一些有机或无机添加剂,例如天津大学化工系开发的三元低氰仿金镀液中引入第二配位体和NCO光亮剂,使这种镀液的光亮电流密度范围加宽,成份简     

仿金铜合金腐蚀行为的研究

从１０种仿金铜合金中优选出一种抗变色性及耐腐蚀性的较好的铜合金，对其进行了电化学和表面分析研究，结果认为合金中某些微量元素可在合金表面膜中富集，使表面氧化物膜保持钝性，从而抑制腐蚀。     

无镍电镀与仿金电镀新工艺

由于首饰品不允许使用镍作中间层，针对我国在代镀层中使用的情况，研究了铜合金镀层的问题及ＮａＯＨ浓度对镀层色调的影响。在电镀Ｃｕ－Ｚｎ无元合金镀层中，添加极少量镍盐或锡盐可提高抗变色性。最近研究表明，二元、三元仿金电镀新工艺能够得到极似２４Ｋ的金色     

锌铁合金电镀工艺在仿金镀中的应用

0 前言 作为装饰品的仿金镀底层比较薄(厚1～2μm),耐蚀性极差.一般采用亮镍打底,也有用光亮铜锡合金-亮镍或暗镍-亮铜-亮镍作底镀层,然后再镀仿金层;以高耐蚀性全光亮锌铁合金电镀工艺取代镍系作仿金底镀层,不仅光亮度同镍镀层的一样,防护性能更优,生产成本也成倍降低.     

高锌铝合金合金化和加工工艺的研究现状及发展趋势

高锌铝合金是指含锌量为10%～45%的铝基合金,具有耐磨性好、强度硬度高和阻尼性能优异等优点,被广泛应用于滑动轴承、轴瓦等耐磨件,是锡铜合金和锌铝耐磨合金良好的替代品。高锌铝合金作为耐磨合金替代锡铜合金不仅降低了工件的生产成本,而且弥补了我国锡铜金属资源匮乏的缺憾。但是,高锌铝合金也存在尺寸稳定性差、塑性低、抗蠕变性能和耐腐蚀性差等缺点。现阶段,高锌铝合金的强韧化机制主要有以下几个方面：(1)对高锌铝合金进行合金化处理,如在Al-Zn合金中添加Cu、Si、Mn、Ti、Er、Sc、Zr等元素。首先合金元素与基体结合形成硬质颗粒可以增加合金的强度硬度;其次,合金元素在凝固过程中可以作为异质形核中心,导致晶粒尺寸减小。(2)在凝固过程中提高冷却速度,采用压铸或挤压铸造的方法可以获得较快的冷却速度。凝固过程中较快的冷却速度有利于提高形核速率,并显著细化第二相与晶粒的尺寸。(3)对高锌铝合金进行塑性变形处理,如挤压、轧制等加工工艺可以消除合金的铸造缺陷、细化晶粒、增加位错密度,从而提高高锌铝合金的强度。本文综述了近年来国内外高锌铝合金显微组织和性能的研究现状及主要存在的问题,介绍了Zn、Cu、S...     

混合稀土对ZA27合金高温力学性能的影响

研究了混合稀土对高铝锌基复合金高温力学性能的影响,结果表明;在ＺＡ２７合金中,添加适量的稀土后,晶界处形在了相当数量硬而分散的复杂成分化合物,从而使合金在１５０℃时的强度,硬度有明显提高,塑性和冲击韧性也有的改善。     

锌镀层高耐蚀抗变色黑色钝化工艺

介绍了以在Ａｇ＾＋为主发黑剂的锌层黑色钝化液中，加入适当的络合剂和促进剂，不仅能获得高耐蚀，抗变色黑色转化膜，而且能明显提高钝化液的稳定性，抗杂性，拓宽成膜工艺条件。还介绍了镀锌黑钝化的工艺流程，并对各主要成分的作用和工序作了说明。     

酸性体系中锌钛合金电沉积的研究

前言锌钛合金镀层于六十年代初期在日本首先出现,二十多年来不断取得新的进展。由于它具有优异的抗蚀能力,因而在国际上引起了广泛注意。现在,锌钛合金电镀液已从非水溶液发展到水溶液,从氰化发展到无氰;合金镀层中钛的含量也不断提高,从而使镀层在严酷的腐蚀环境中表现出更为显著的抗蚀性能。国内也有人从碱性溶液中沉积出含钛0.5％左右的锌钛合金镀层,并证实具有良好的抗蚀能力。为进一步提高合金     

Ti-6Al-4V合金表面超声振动滚压强化研究

采用超声振动滚压加工技术对Ti-6Al-4V合金表面进行处理,探究该项技术对Ti-6Al-4V合金表面质量的影响。通过对该工艺加工前后的Ti-6Al-4V合金进行表面粗糙度参数、XRD图谱、截面微观形貌、表层残余应力及显微硬度的对比分析,结果表明:经该工艺处理后的合金表面各项粗糙度参数皆有明显降低;加工后的合金表面XRD图谱的衍射峰减弱且宽化,衍射角向高角度方向偏移;加工后的合金表层β相组织相较加工前明显细化,且随着深度增加β相组织逐渐增大;在距离表面约50μm位置的残余应力值最大可达到-967 MPa;加工后的合金表面显微硬度可达到421HV,且在0~140μm的深度范围内,显微硬度随着深度的增加逐渐减小至与基体硬度一致。经超声振动滚压加工后的Ti-6Al-4V合金表面质量显著提高,有利于提高其零部件的使用性能。     

X射线光谱法测量仿金TiN装饰镀层厚度的程式设计

采用真空离子镀技术在单晶Si片、316不锈钢片表面制备金黄色仿金TiN装饰镀层。用扫描电子显微镜和能谱仪对离子镀仿金TiN装饰镀层厚度及成分进行研究分析。结果表明,离子镀仿金(金黄色)TiN镀层成分为Ti77 wt.%、Ni23 wt.%,Ti、N原子比为1:1.01;设计了一种现今装饰及钟表行业中316不锈钢制品上离子镀仿金(金黄色)TiN装饰镀层厚度的X射线荧光测试程式:Ti50%N50%/316。X射线荧光镀层厚度测试法在设计了准确的测试程式后,是一种准确、快速、无损检测方法,检测不受产品外观的影响,可极大地提高工作生产效率。     

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.