铝合金Ni-Co-P合金电镀工艺优化

在铝及其合金表面沉积Ni或Ni基合金,可以提高基体表面的硬度和耐磨性.通过正交试验,研究了铝硅合金基体上电镀Ni-Co-P镀层的工艺,得到了电流密度、镀液温度、pH值、电镀时间、镀液成分对镀层厚度、硬度、成分和沉积速率的影响规律,同时,还考察了镀层的耐磨性.结果表明:延长电镀时间、提高镀液温度和pH值时,镀层厚度和镀层硬度均增大;提高电流密度时,镀层厚度增大,但镀层硬度减小.提高电流密度、升高温度和提高pH值时,沉积速率增大.     

碱性条件下Fe-P-B合金电镀

研究了碱性溶液中镀液组成、阴极电流密度、温度、pH值对Fe-P-B合金电镀层沉积速率和组成的影响,优化了工艺,在最佳工艺条件下获得Fe-P-B镀层,并对镀层的耐腐蚀性、结构和结合力进行了分析.结果表明:提高镀液中硫酸亚铁铵含量、溶液pH值、温度和电流密度,镀层沉积速率增加;提高镀液中次亚磷酸钠、丙二酸和硼氢化钠含量,镀层沉积速率先增后降低,出现一个极大值;镀层中B含量的增加会使P含量降低,但提高电流密度和镀液温度时二者都有所增加;在最佳工艺条件下获得的Fe-P-B合金镀层为非晶态结构,和基体结合力优良,耐蚀性良好,在15%NaoH溶液中的耐腐蚀性优于在5%NaCl溶液中.     

Ni-Fe合金电沉积工艺参数对镀层铁含量的影响

以Ni-Fe合金电沉积层代替纯Ni层,可以节约贵金属Ni.在铝箔上电沉积了Ni-Fe合金镀层,研究了电镀液中不同Fe2+/Ni2+摩尔比、电流密度、pH值及温度等因素对Ni-Fe合金镀层中Fe含量及镀层结构的影响.结果表明:随Fe2+/Ni2+摩尔比增加,镀层中的Fe含量呈线性增加;开始时随着电流密度的增加,镀层中的Fe含量不断增加,超过4.5 A/dm2后,Fe含量反而不断减少;随镀液pH值的增大,镀层中Fe含量不断增加;随镀液温度提高,镀层中Fe含量不断下降;铝箔上的Ni-P合金镀层具有纳米晶体结构.     

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.     

电镀工艺条件对钯铁合金镀层成分的影响

在由FeS04*7H2O、Pd(NH3)2Cl2、磺基水杨酸和(NH4)2SO4组成的镀液中,采用脉冲电沉积方法制备了Pd-Fe合金镀层,并研究了各种电镀工艺条件对钯铁合金镀层成分的影响规律.结果表明:增大Fe2 浓度与增大脉冲电压均使镀层中铁含量增加;在导电盐浓度低于0.1 mol/L时,随着浓度的增加,镀层中铁含量增加;用乙二胺调节溶液pH值所获得的镀层铁含量比用氨水调节要高些;增大镀液pH值、延长脉冲关断时间和延长施镀时间均使镀层中铁含量减少;升高镀液温度,镀层中铁含量先减少后增加,在约60 ℃时有最小值.因此,采用不同的工艺条件,可获得所需Pd/Fe原子比不同的钯铁合金镀层,为制备L10型晶体结构钯铁合金中Fe/Pd原子比为1:1的基本要求提供了重要的参考价值.     

碱性锌酸盐体系锌钴合金电镀工艺研究

目前国内对碱性锌酸盐体系电镀锌钴合金的研究较少。研究了碱性锌酸盐Zn-Co合金电镀体系中合金镀液组成及工艺条件对镀层Co含量的影响,得到了最佳镀液组成及工艺条件:锌钴离子总浓度0.3 mol/L,锌钴离子摩尔比9∶1,150 g/L氢氧化钠,15.0 m L/L添加剂A,1.0 m L/L添加剂B,电流密度Jc3 A/dm2,温度25~30℃。在最佳工艺条件下可得到Co含量为2.0%~2.2%的Zn-Co合金镀层。结果表明:Zn-Co金的沉积表现为异常共沉积;在一定范围内,镀层中钴含量的变化会影响镀层光亮度的变化;钴配位剂对Zn-Co合金的共沉积电化学行为不造成影响。     

钕铁硼永磁材料电镀Ni-P非晶态镀层

研究了钕铁硼永磁材料电沉积Ni-P合金非晶态镀层的镀液组成、工艺参数和工艺流程,分析了影响镀层性能的影响因素,包括电流密度、温度、镀液pH值及亚磷酸的含量等。测定了镀层与基体的结合强度;用中性盐雾试验评定了镀层的耐蚀性。结果表明,Ni-P非晶态镀层导磁率高,矫顽力低,化学稳定性好,耐蚀性优异,是钕铁硼永磁材料的一种理想保护镀层。     

无镍枪色锡-钴合金电镀工艺

为了节约镍资源及降低传统枪色电镀产品的毒性,开发了一种无镍枪色锡-钴合金电镀工艺:采用焦磷酸盐体系并添加光亮剂直接在铜片表面进行锡-钴合金电镀。探讨了镀液组成、温度、pH值及电流密度对镀层外观、镀液稳定性的影响,确定了其最佳工艺参数:250.0 g/L焦磷酸钾,20.0 g/L硫酸亚锡,15.0 g/L硫酸钴,0.6 g/L光亮剂1,2.0 g/L光亮剂2,3 mL/L 25%氨水,温度45℃,pH值8.5,电流密度0.5 A/dm2,施镀时间3 min。该工艺所得镀层颜色呈枪色,均匀致密,附着力好,且镀液稳定。     

工艺条件对化学镀Ni-Co-P合金的影响

采用硼酸为缓冲剂 ,柠檬酸钠为络合剂化学镀Ni Co P合金。考察了镀液pH值、钴离子浓度和温度对化学镀Ni Co P沉积速度的影响 ;研究了钴离子浓度对镀层组成的影响 ,获得了化学镀Ni Co P合金的最佳工艺条件为 :镀液pH值为 7.0 ,操作温度 90℃ ,CoSO4 ·7H2 O浓度为 11g/L。此工艺下镀液稳定性好 ,镀层沉积速度快 ;所得镀层为非晶结构。     

碱性镀液电沉积非晶-纳米晶Ni-Mo合金工艺探讨

用非晶态合金和纳米晶合金作电极材料各有利弊,而用酸性溶液制备的Ni-Co合金镀层存在内应力较大且电流效率低等不足.为此,采用电沉积技术在碱性镀液中制备了非晶-纳米晶Ni·Mo合金,利用X射线衍射(XRD)、扫描电镜(SEM)、能谱(EDS)、极化曲线等研究了电沉积工艺对镀层Mo含量、结构及形貌的影响.结果表明:镀层Mo含量随镀液中钼酸盐浓度增加而增加,随柠檬酸盐浓度增加、镀液温度升高、电流密度增大先增加后减小,pH值对镀层结构有显著影响;镀层Mo含量在21.00%～26.00%时,Ni-Mo合金镀层为非晶与纳米晶混合结构,非晶态相含量占60%以上,纳米晶的晶粒尺寸较小,镀层表面均匀、颗粒细小、致密性较高;10.0 g/LNa2MoO4·2H2O,64.0 g/L Na3C6H5O7·H2O,pH值10.0,电流密度5～8 A/dm2,温度35℃时,获得的镀层为非晶与纳米晶混合结构,且表面质量较好.     

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