锌-镍合金电镀层性能及耐腐蚀机理研究

通过X射线衍射、盐水浸泡、盐雾试验和极化曲线测试,对高速电镀Zn-Ni合金镀层钢板的性能进行了检测,主要检测了镀层的耐蚀性能、磷化性能、涂装性能、焊接性能,并对其耐蚀机理进行了初步探讨.试验结果表明,5%NaCl溶液浸泡试验生红锈时间Zn-Ni合金镀层是纯锌镀层的2.5～4.0倍,而且以Ni含量为13%为最好;磷化性能均优于冷轧板;涂装性能、焊接性能均达到工艺要求.在验证防蚀机理的同时,还发现在腐蚀过程中起钝化作用的不是Zn-Ni合金镀层中Ni的富集,而是腐蚀产物的隔离.     

BmimCl-AlCl3-MnCl2离子液体电沉积Al-Mn合金

在BmimCl-AlCl3-MnCl2离子液体中,采用恒电流沉积的方法在铁基体上获得Al-Mn合金镀层。通过线性扫描伏安测试研究了Al-Mn合金共沉积行为;采用X射线荧光、X射线衍射和扫描电镜分别对该合金镀层的组成、结构及形貌进行测试。结果表明:合金镀层中Mn含量随着离子液体中MnCl2含量和电流密度的增加而增加;当Mn含量低于8.7at%时,镀层为单相的Al(Mn)固溶体的面心立方结构;锰含量为15.3at%~26.8at%时,镀层为非晶态结构。     

不同脉冲电沉积电流密度制备的Ni-W合金镀层在固-液两相流硫酸溶液中的冲刷腐蚀

为了探究Ni-W合金镀层对材料表面冲刷腐蚀的影响,在不同电流密度下采用电沉积法在20R钢表面制备了Ni-W合金镀层,采用失重试验、固-液两相流冲刷腐蚀试验并结合X射线衍射(XRD)、电化学测试等方法研究Ni-W合金镀层在10%H_2SO_4中静态浸泡与在固-液两相流(10%H_2SO_4+SiO_2)中的冲蚀腐蚀行为。结果表明:Ni-W合金镀层具有良好的耐蚀性,20R在10%H_2SO_4中的静态腐蚀速率是电流密度5 A/dm~2制得的Ni-W合金镀层的4.6倍,20R的冲刷腐蚀速率是电流密度5 A/dm~2制得的Ni-W合金镀层的2.0倍。Ni-W合金镀层的冲蚀机制以腐蚀为主。     

脉冲电沉积纳米SiC/Ni-Co复合镀层腐蚀特性

采用X射线衍射(XRD)、扫描电镜(SEM)、能谱分析(EDS)研究了脉冲电沉积法制备的纳米晶Ni-Co合金镀层及其纳米 SiC/Ni-Co复合镀层的组织结构、表面形貌和成分。用浸泡法和电化学极化法对比测试了纳米晶Ni-Co合金镀层和纳米 SiC/Ni-Co复合镀层在3.5 wt% NaCl和5 wt% HCl溶液中的腐蚀行为。研究结果表明：通过脉冲电沉积法制备的Ni-Co合金镀层和纳米SiC/Ni-Co复合镀层具有典型的纳米晶结构;随着纳米SiC颗粒的增加,复合镀层的晶粒尺寸减小,硬度增加。所制备的纳米SiC/Ni-Co复合镀层颗粒分散均匀,其在3.5 wt% NaCl和5 wt% HCl溶液中的耐蚀性均优于纳米晶Ni-Co合金镀层。纳米晶Ni-Co合金镀层和纳米SiC/Ni-Co复合镀层在3.5 wt% NaCl溶液中的腐蚀速率极低,表现出极好的耐腐蚀性能,而在5 wt% HCl溶液中的腐蚀形态则表现为点蚀。     

Zn-Ni合金电镀、钝化工艺及镀层性能

为了简化碱性体系Zn-Ni合金电镀,进一步提高镀层质量,对自制、多功能镀锌添加剂SD-1采用多乙烯多胺、香草醛等改性后,进行Zn-Ni合金电镀.以控制变量法通过霍尔槽和小槽试验获得了光亮、平整、细致的Zn-Ni合金镀层.通过扫描电子显微镜(SEM)、能量弥散X射线(EDAX)、X射线衍射(XRD)能谱仪分别对Zn-Ni合金镀层的微观结构及镍含量进行了表征;讨论了改性SD-1、镍离子、三乙醇胺(TEA)、电流密度等对Zn-Ni合金镀层性能的影响.结果表明:改性SD-1能使镀液透明稳定,可获得含镍量13％左右、结构致密、均匀平整、单一相的Zn-Ni合金镀层;Zn-Ni合金镀层的结合力较大,经彩色钝化之后,耐盐雾腐蚀高达1200h以上.     

超高强度钢环保型电镀锌镍合金层的耐蚀性研究

采用氯化物-硫酸盐型无镉、无氰环保型镀液在300M超高强度钢基体上制备了Zn-Ni合金镀层,利用弯曲试验、电镜扫描、能谱分析、中性盐雾试验、X射线衍射和电化学极化方法分别研究了温度和电流密度等工艺参数对Zn-Ni合金镀层的外观和结合力的影响以及镀层镍含量和微观结构与耐蚀性的关系.结果表明,电流密度对Zn-Ni镀层成分的影响明显,未钝化镀层比松孔镀镉层更耐腐蚀;温度45℃镀层Ni含量质量分数为13.5%,最高耐盐雾腐蚀时间达1632h.     

Sn-Cu合金电沉积制备工艺及结构研究

利用电沉积法在铜箔上制备了锂电池负极材料Sn-Cu合金,研究了镀液组成对镀层铜含量的影响规律;采用X射线衍射分析,研究了不同组成Sn-Cu合金镀层热处理前后的结构.结果表明:镀液中焦磷酸铜与焦磷酸钾浓度对镀层中铜含量影响显著,改变二者组成,铜含量可由20.18%(质量分数,下同)提高到58.05%;铜含量为20.18%,31.01%和58.05%的Sn-Cu合金镀层,镀态结构相同,均为Cu,Sn和η-Cu6Sn5;经过300℃以上热处理1h,Sn-Cu合金镀层发生相变,相对于镀态,析出电子化合物中铜含量增加;温度升高对铜含量为20.18%和58.05%的镀层结构影响较小,而对铜含量为31.01%的合金镀层,其组织结构向着铜含量降低的物相结构转变.     

焦磷酸盐低锡青铜合金电镀工艺及辅助配位剂的功能

为了提高焦磷酸铜．焦磷酸亚锡电镀低锡青铜合金工艺的性能,在其镀液中加入辅助配位剂柠檬酸盐。用电化学、X射线衍射、腐蚀膏试验等方法对镀液及镀层性能进行分析。结果表明：合金镀液具有良好的分散能力,可在较宽的电流密度范围内获得色泽一致、锡含量约为10％的低锡合金镀层;电镀初始过程可实现钢铁表面的电位活化,提高了镀层与铁基体的...     

锌镍合金镀层耐腐蚀性的研究

锌镍合金层具有优异的耐蚀性,从全硫酸盐体系中用电沉积的方法制备了纯锌镀层和锌镍合金镀层.应用能量色散X射线分析仪检测了合金层的相对含量.通过中性盐雾试验、极化曲线、交流阻抗和腐蚀浸泡等试验方法研究了镀层的耐腐蚀性能.试验表明,含镍16%的锌镍合金镀层的腐蚀电位较纯锌镀层的腐蚀电位正移230 mV,该合金的耐盐雾性能达到1 000 h,是相同厚度纯锌镀层的4.5倍,具有优良的耐腐蚀性.     

碳掺杂对CrN镀层显微硬度与组织结构的影响

采用闭合场非平衡磁控溅射离子镀技术在单晶硅(111)衬底上沉积了CrCN镀层以研究C靶电流对镀层显微硬度的影响,并通过X射线衍射、原子力显微镜、X射线光电子能谱和透射电镜对镀层进行了分析。结果表明:当C靶电流由0增加到1.5 A时,镀层显微硬度由1930 HV增加到2300 HV,提高约19%,并且镀层的颗粒明显变小;X射线衍射和透射电镜分析表明,随着C靶电流增大,镀层由晶态向非晶态转变;X射线光电子能谱分析表明,镀层碳元素主要以sp2键、sp3键和C-Cr键的形式存在。     

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.     

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.     

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