电沉积Ni-Cr合金工艺研究

含有一定量Cr的Ni-Cr镀层具有良好的耐磨、耐腐蚀性能.选取柠檬酸钠作为配位剂,用动电位扫描法研究了电沉积Ni-Cr合金时的阴极行为,同时对镀层的耐腐蚀性进行了试验.试验结果表明:镀液中加入配位剂柠檬酸钠可以提高阴极极化;pH值、阴极电流密度、配位剂对镀层中铬含量影响较大,在一定范围内增大pH值,增加配位剂的用量,提高电流密度,有利于提高镀层中铬的含量,最佳工艺条件为pH值为2.5,阴极电流密度为25A/dm2,镀液中柠檬酸钠的含量为35g/L,镀层中铬质量分数为20%左右时,Ni-Cr合金镀层的耐腐蚀性能最好.     

固溶体型Fe-Co-Ni多元合金镀层在海水环境下的耐蚀性研究

采用电沉积技术,在Q235钢基体上用硫酸盐溶液制备Fe-Co-Ni多元合金镀层。研究温度、电流密度、pH值等工艺参数对该多元合金镀层在模拟海水环境下耐蚀性能的影响。采用XRD、SEM、EDS等分析手段,分别研究Fe-Co-Ni合金镀层的结构、表面形貌及其化学成分,表明该多元合金镀层由94.92%(质量分数)Ni,2.58%(质量分数)Co和1.47%(质量分数)Fe构成,为固溶体结构,且表面平整、组织致密。电化学方法研究该多元合金镀层在海水环境下的耐蚀性,结果表明其耐蚀性显著优于304不锈钢,且在pH值为3.8、电流密度为6A/dm2、温度为50℃的工艺条件下制备的合金镀层具有最好的耐蚀性能。     

Fe-Ni-Cr合金电沉积工艺参数对镀层铬含量的影响

为了在铁基上获得耐腐蚀性能好的、光亮致密的Fe-Ni-Cr合金镀层,在氯化物-硫酸盐混合体系中,研究了在铁基上电沉积Fe-Ni-Cr合金的工艺,确定出电沉积铁镍铬合金的最佳工艺条件:阴极电流密度14 A/dm2,镀液温度30℃,pH值2.0,镀液中CrCl3·6H2O浓度为25g/L.结果表明,合金镀层中Cr含量越高,镀层耐蚀性能越好,在最佳工艺条件下,镀层中Cr的含量接近6%,Fe的含量为54%,镀层光亮致密且耐蚀性好.     

镍铁钨合金电沉积工艺

为获得性能良好的镍铁钨合金镀层,研究了电解液pH值、温度、电流密度、柠檬酸钠浓度对施镀阴极电流效率和镍铁钨合金镀层组分、表面形貌、显微硬度的影响.结果表明:镀液pH值对镀层形貌和阴极电流效率影响较大;随柠檬酸钠浓度增加,电流效率逐渐降低,镀层表面形貌更加粗糙.在镀液pH=8,温度70℃,电流密度7 A/dm2,柠檬酸钠...     

二次正交旋转组合法优化Ni-W-P脉冲电沉积工艺

为解决油田设备中油管与油杆的磨损与腐蚀问题,通过脉冲电沉积方法在抽油杆常用钢材30Cr Mo基体上制备了Ni-W-P三元合金镀层,采用5因素5水平的二次正交旋转回归组合试验,对温度、pH值、占空比、电流密度、频率等工艺参数进行了优选。采用显微硬度计对36组镀层进行显微硬度测试,利用DPS软件分析获得5因素与镀层硬度之间的数学模型,并研究了各参数的影响规律,获得了电沉积工艺参数最优组合。结果表明:pH值对镀层硬度影响效果最显著,温度、占空比和平均电流密度对镀层硬度的影响规律与pH值相似,均随变量的增大呈先增后减的趋势;在温度为60℃、pH值为8、占空比为0.8、平均电流密度为6 A/dm2、频率为80 Hz的优化工艺下获得的镀层硬度为812.4 HV2 N,自腐蚀电流密度为2.576μA/cm2,且镀层为非晶镀层,具有优良的耐磨、耐蚀性。     

阴极电流密度对Ni-SiC复合镀层性能的影响

随着现代工业的发展,材料的单一功能已难以满足要求,为此,采用复合电沉积技术,沉积含有弥散硬质相SiC的复合镀层.研究了当pH值、阴阳极间距及面积比一定时,阴极电流密度与温度的关系,阴极电流密度对沉积速度、内应力、镀层硬度及SiC含量的影响.试验结果表明,当阴极电流密度在8～10A/dm2时,镀层沉积速度大,SiC含量较高,硬度高,内应力较小.本试验为完善Ni-SiC复合电镀工艺提供了试验数据.     

电沉积钯钴合金的工艺研究

电沉积钯镍合金存在质量控制困难、热稳定性差及易引起皮肤过敏等问题,而钯钴合金能克服这些不足,且比Pd-Ni合金具有更高的耐磨性、耐蚀性及热稳定性.通过极化曲线研究了钯钴合金的电沉积行为,并讨论了镀液中钴钯离子质量比、温度、pH值以及电流密度等工艺参数对电沉积钯钴合金组成的影响,获得了电沉积钯钴合金的最佳工艺条件为:镀液温度35℃,pH值8.5,电流密度10 A/dm2.结果表明:钴的极化大,极化度也大;电沉积时,钯催化钴沉积,钯钴合金共沉积时呈现与钯相似的阴极行为.合金组成是各工艺参数的函数,钯钴合金镀层中钴的含量随镀液中Co2 /Pd2 质量比的增大而线性增加,随电流密度的增大而显著增大.镀液温度、pH值均对镀层成分有一定的影响.     

三价铬体系铬-镍合金电镀工艺及镀层性能的研究

以工业级的革鞣剂和硫酸镍为主盐,研究了硫酸盐体系电镀铬-镍合金工艺配方与工艺规范、阴极电流密度、pH值、温度对镀层的影响,讨论了镀层中的铬含量对镀层耐腐蚀性和钎焊性的影响.通过工艺调整使合金中铬质量分数控制在10%～50%.镀层中铬质量分数在10%以下时,镀层有良好的钎焊性.通过测定镀层腐蚀电流,比较其耐腐蚀性,镀层中铬质量分数在25%～40%时,镀层的耐腐蚀性较好,铬质量分数为30%时,腐蚀电流最小可达4.18×10-7 A,采用有隔膜电镀槽,提高了镀液的稳定性.     

电沉积RE-Ni-W-P-SiC复合材料镀层的阴极过程

为了进一步掌握电沉积RE-Ni-W-P-SiC复合材料镀层的阴极过程,采用电位线性扫描测绘法、镀液pH值测定法研究了复合镀层阴极过程,结果表明,当镀液中加入SiC微粒和稀土后,复合材料的阴极沉积电流密度增加,有利于Ni-W-P合金在阴极沉积,并形成Ni-W-P-SiC和RE-Ni-W-P-SiC复合材料：而镀液中加入PTFE后却降低了复合材料镀层的阴极沉积电流密度。当稀土的添加量为7～9g／L时,复合材料镀层的阴极沉积电流密度增加并不明显;随着稀土添加量的增加,复合材料镀层的阴极沉积电流密度增加较明显,当添加量达到11～13g／L时,镀层的阴极沉积电流密度增加并达到最大值;若进一步增加稀土用量,则阴极沉积电流密度有所下降。如此可以加大SiC和RE对阴极电沉积的影响。     

Ni-Co-P合金镀层显微硬度及其耐海水腐蚀性

采用电沉积技术制备了Ni-Co-P合金镀层,并对镀层的表面形貌、晶相结构、显微硬度及耐腐蚀性进行了表征和分析.研究结果表明:Ni-Co-P合金镀层表面均匀平整,晶粒尺寸细小,显微硬度均优于Ni-P合金镀层;当镀液中CoSO4·7H2 O含量为50 g/L时,Ni-Co-P合金镀层的显微硬度达到766.3 HV0.2.在人工海水环境中,Ni-Co-P合金镀层的开路电位稳定值更正,腐蚀电流密度与腐蚀速度最小分别为0.68μA·cm-2和8.25μm·year-1;且Ni-Co-P合金镀层的容抗弧半径均大于Ni-P合金镀层,电荷转移电阻(Rct)高达9.902×104Ω·cm-2,约为Ni-P合金镀层的6倍,表现出优异的耐海水腐蚀性能.     

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.……     

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.     

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     

Win-Win Cooperation

正The Chinese Premier Li Keqiang's recent trip to the UK has reinforced the China-UK comprehensive strategic partnership;just as the British Prime Minister David Cameron put it,"the relationship is gaining in strength,depth and understanding"after a bucket of business deals being inked worth more than 30 billion US dollars.From the first agreement signing in 2004 to the new agreement of mutual standards recognition and adoption in     

Systematic Approach for Emerging Industry

正A national directory of standards complexes for strategic emerging sectors was recently developed and released jointly by 12governmental departments,namely,SAC,NDRC,MOST,MIIT,MEP,MOA,AQSIQ,State Forest Administration,State Administration of Science and Technology for National Defense,State Oceanic Administration and National Railway Administration.     

Strictest Pollutants Emission Standards

正Four new national standards on air pollutant emission control offi cially issued by the Ministry of Environment Protection(MEP)together with AQSIQ and SAC has been brought into force from July 1,2014.The Emission standard for air pollutants of coal-burning,oil-burning and gasfi red boilers,which is the strictest emission standard historically,will tackle the stubborn pollution problem of boilers and waste incineration in most of China’s regions.     

Instructions to Authors

New Carbon Materials is a bimonthly journal published with the permission of the Ministry of Science and Technology and of the State News and Publication Agency.The journal is sponsored by the Institute of Coal Chemistry,Chinese Academy of Sciences,and is published by Science Press.Aims and Scope     

Progress on Standards Copyright Protection

正Recently,National Copyright Administration of China(NCAC)has rewarded 215 organizations and 179 individuals for their outstanding efforts on investigating standards copyright infringement and piracy in 2013.Hua Jianhua,the Deputy-Director of National Standards Copyright Protection Workgroup Office won a third prize of the national individual award.In 2012,SAC set up the national standards copyright protection working group,and developed policies to crack down standards infringement and piracy behaviors and to strengthen standards copyright protection.