预镀镍时间对装饰铜合金化学镀镍基合金的影响

对装饰铜合金预镀Ni后再化学镀Ni–P合金、Ni–Mo–P合金或Ni–P/Ni–Mo–P合金,研究了预镀Ni时间对Ni–P合金和Ni–Mo–P合金镀层表面形貌、孔隙率和耐蚀性的影响,并对比了不同厚度组合的Ni–P/Ni–Mo–P合金镀层的性能。结果表明,预镀Ni有助于提高Ni–P合金和Ni–Mo–P合金镀层的性能,较佳的预镀Ni时间为5 min。当总厚度固定为20μm不变时,随内层Ni–P合金厚度增大,Ni–P/Ni–Mo–P组合镀层的各项性能均先改善后变差。当Ni–P合金和Ni–Mo–P合金厚度分别为14μm和6μm时,Ni–P/Ni–Mo–P组合镀层的耐蚀性最佳。     

田口法优化铝合金超声波辅助化学预镀镍工艺

先在超声波辅助下对6061铝合金进行碱性化学预镀Ni,再化学镀Ni–P合金。基于田口法设计试验,以后续化学镀Ni的沉积速率和Ni镀层耐蚀性为指标,分析了预镀时镀液pH、温度以及超声波频率和功率对化学预镀Ni效果的影响,得到较佳的预镀Ni工艺条件为：超声波频率40 kHz,超声波功率80 W,p H 12,温度45°C,时间6 min。在该条件下预镀Ni时,后续化学镀Ni的沉积速率为13.87μm/h,所得Ni–P合金镀层的耐蚀性最佳。     

镁-锂合金化学镀镍-铜-磷的研究

对镁-锂合金化学镀镍-铜-磷的酸洗、活化、预镀等前处理工序进行了研究,并对化学镀镍-铜-磷合金镀层的性能进行了测试。结果表明:相比浸锌处理,化学预镀镍更适合用于镁-锂合金的镀前预处理。化学镀镍-铜-磷合金镀层为膜层状的中磷混晶结构,其中铜的质量分数为3.66%。交流阻抗测试结果表明,化学镀镍-铜-磷合金镀层对镁-锂合金基体起到了较好的防护作用。     

化学镀Ni-P/PVDF复合镀层耐腐蚀性能研究

用化学镀法在20CrMo钢表面制备了Ni–P合金镀层和Ni–P/PVDF复合镀层。用扫描电镜观察了镀层的组织形貌,通过电化学实验和盐雾试验测试了镀层的耐蚀性能。20CrMo钢化学镀Ni–P合金和Ni–P/PVDF复合镀层后,腐蚀电位从?625mV分别提高到?510mV和?470mV,腐蚀电流密度从25.1A/cm2降低到19.9A/cm2和14.1A/cm2。结果表明,化学镀Ni–P合金和Ni–P/PVDF复合镀层均可提高20CrMo钢的耐蚀性能,而Ni–P/PVDF复合镀层的耐蚀性优于Ni–P合金镀层。     

化学镀Ni–Sn–P和磁控溅射TiN对Mn–Cu合金耐腐蚀性能和阻尼性能的影响

分别对Mn–Cu阻尼合金表面化学镀1 h和磁控溅射2 h,获得了5.42μm厚的Ni–Sn–P合金层和1.43μm厚的TiN层。对比了Mn–Cu合金及其表面化学镀Ni–Sn–P合金和磁控溅射TiN后的微观形貌、元素组成、结构、耐蚀性和阻尼性能。结果表明,化学镀和磁控溅射都能提高Mn–Cu合金的耐蚀性,Ni–Sn–P合金镀层的耐蚀性最好。化学镀Ni–Sn–P合金能够在一定程度上改善Mn–Cu合金的阻尼性能,而磁控溅射TiN会使基体的阻尼性能轻微下降。     

钢铁全光亮化学镀镍–钨–磷合金工艺研究

为了提高Ni–P合金镀层的耐蚀性和表观质量,在化学镀Ni–P二元合金镀液的基础上加入钨酸钠,在钢铁上制备了Ni–W–P三元合金镀层。探讨了镀液主要成分和工艺条件对镀层外观质量及耐蚀性的影响,获得了较佳的工艺规范:硫酸镍25~35 g/L,钨酸钠55~65 g/L,次磷酸钠30~40 g/L,复合配位剂80~100 g/L,组合光亮剂5~10 mg/L,p H 8.5~9.0,温度80~90°C。检测了镀层的相关性能。结果表明,所制备的Ni–W–P合金镀层结晶细致,光亮度和结合力好,具有良好的装饰效果,耐蚀性优于化学镀Ni–P合金镀层。     

外壳瓷件化学镀镍?磷及镍?硼镀液与镀层性能的对比

对比了外壳瓷件化学镀Ni–P合金和Ni–B合金的镀液性能,以及镀层的附着力、表面形貌、耐蚀性和焊料流淌性。化学镀Ni–P合金的镀液成本低、镀速高,但对加热设备的要求更高。厚度相同时,两种化学镀层的表面形貌相差不大。与Ni–B合金镀层相比,Ni–P合金镀层的粗糙度略低,附着力和耐蚀性较好,但焊料流淌性较差。镀层厚度增大后,两种镀层的附着力都减小,耐蚀性增强,可焊性却无明显变化。     

镁-锂合金电镀枪黑色锡-镍合金镀层的研究

先对镁-锂合金电镀枪黑色锡-镍合金镀层的预处理工艺进行了研究,再对发黑剂进行了选择,最后对镀液及镀层性能进行了测试。结果表明:化学预镀镍法比浸锌法更适合用作镁-锂合金的预处理;半胱氨酸是合适的发黑剂;枪黑色锡-镍合金镀层含Sn、Ni、P、S等元素,表面存在微裂纹;镀层为晶态结构;镀层的膜电阻为镁-锂合金基体的11.14倍。     

化学镀镍—铜—磷镀液性质的研究

本文通过大量试验数据及图表论述了化学镀Ni-Cu-P合金镀液的性质,即镀液中的主要组成、镀液的pH、施镀温度对镀层的沉积速度、镀层中Ni、Cu、P百分含量的影响;从热力学观点说明了镀液pH,施镀温度对镀层中Ni、Cu、P百分含量影响变化规律;试验测得了化学镀Ni-Cu-P合金总沉积反应的表观活化能△E为47.000kJ.mol~1;当施镀温度为80±2℃,pH在7.50时,Ni、Cu、P的原子沉积比例为11.23:1.00:2.31。     

化学镀镍-硼合金工艺和镀液稳定性

以铁片为基材进行化学镀Ni–B合金。研究了镀液中主盐、还原剂和配位剂用量及稳定剂种类对镀速、镀液稳定性，以及Ni–B合金镀层外观和显微硬度的影响，得到的较佳配方为：SF-815镍盐A 60 mL/L,SF-815配位剂B 200 mL/L,SF-815还原剂C 20 mL/L，含巯基化合物(用作稳定剂)5 mg/L。采用该体系镀液在pH 6.2～7.2、温度60～70℃的条件下化学镀1 h所得Ni–B合金镀层均匀，呈半光亮，结晶细致，B质量分数为1.62%～3.23%，显微硬度为683.0～753.1 HV。该体系镀液性能稳定，连续工作10个周期后镀液保持澄清，镀层外观和各项性能保持合格。     

国内外PET合金研究动态

本文主要介绍国内外以PET回收料为原料的工程塑料的加工现状,PET与其他聚合物组分共混的增韧和增容技术的进展。着重讨论了PET／PC合金中,共混物的相态结构、共混物的结晶状况、共混物的酯交换反应、共混组分的热降解和水解,以及反应挤出技术的应用等条件对该合金性能的影响。     

高分子固体合金

阐述了研究高分子固体合金的目的和意义，介绍了高分子固体合金化的手段和工艺。以机械合金和力化学原理为基础，讨论了高分子固体合金的形成机理和合金化过程的理论模型。报道了高分子固体合金的研究现状。     

电沉积Fe-Co-Ni合金工艺

研究了镀液温度及pH值对Fe-Co-Ni三元合金沉积及其性能的影响,并用X射线衍射分析了阴极电位对镀层性能的影响。结构表明,当加入一定有机添加剂、镀液温度为50—60℃、pH值3．0～4．5及阴极电位控制在-1．2V,得到的三元合金光亮、耐蚀性能好、显微硬度高,其综合性能接近硬铬镀层。     

Ni-Fe合金电镀的研究进展

回顾了Ni-Fe合金电镀的发展进程。总结了Ni-Fe合金电镀工艺的优点。介绍了其镀液类型、各种电沉积方法的特点、常用体系(柠檬酸体系、BNF体系、Nylon工艺、葡萄糖体系和抗坏血酸体系)的实用工艺配方。综述了Ni-Fe合金电沉积机理、晶体结构及其电沉积影响因素的研究现状,指出了今后的发展方向。     

铁-钨合金电镀工艺的研究

六价铬电镀具有毒性大、环境污染严重等缺点。为研制出一种合适的代铬镀导致 ，提出了一种铁－钨合金电镀工艺。研究了镀液中铁离子浓度、添加剂、电流密度、pH值和温度等因素对所得合金镀层钨含量和质量的影响。所得镀层外观与铬镀层相近，具有良好的耐蚀、耐热和耐磨性能。     

Mechanism of copper-nickel alloy electrodeposition

The codeposition kinetics of copper and nickel alloys in complexing citrate ammonia electrolytes has been investigated by means of polarization and electrochemical impedance techniques. It is confirmed that the two-step discharge of the complexed cupric species Cu(II)Cit is diffusion-controlled during the alloy deposition, resulting in an increase in the nickel content of the alloy with electrode polarization. Impedance spectra are also consistent with a two-step discharge of Ni(II) cations involving an intermediate adsorbate, Ni(I)_ads, originating from the reversible first step. A reaction model is developed for the parallel discharge of Cu(II)Cit and Ni(II) in which the reactions for nickel deposition are catalysed by active sites permanently renewed at the surface of the growing alloy. The surface density of these sites, slowly nucleated from Ni(I)_ads and included in the deposit, varies with the electrode polarization, thus generating a low-frequency feature specific of Cu–Ni codeposition. This reaction model reproduces to a reasonable extent the potential dependence of the partial current densities for nickel and copper discharge, the current dependence of the alloy nickel content and also most of the experimental relaxation processes observed on impedance spectra.Nomenclature b ₁,b ₂,b ₃,b ₃ b ₄,b ₅,b ₇ Tafel coefficients (V^–1) - C concentration of Cu(II)Cit at distancex (mol cm^–3) - [Cu(II)] bulk concentration of Cu(II)Cit (mol cm^–3) - C ₀ concentration of Cu(II)Cit atx=0 (mol cm^–3) - C* concentration of Cu(I)Cit atx=0 (mol cm^–3) - C ₀, C* variations inC ₀,C* due to E - (Cu), (Ni) molecular weights (g) - C _dl double layer capacitance (F cm^–2) - D diffusion coefficient of Cu(II)Cit (cm² s^–1) - E electrode potential (V) - f frequency (s^–1) - F Faraday (constant 96 487 A s mol^–1) - g interaction factor between adsorbates - i,i _Cu,i _Ni current densities (A cm^–2) - Im(Z) imaginary part ofZ - j (–1)^1/2 - k mass transfer coefficients (cm s^–1) - K ₁,K ₃ rate constants (cm s^–1) - K ₂ rate constants (s^–1) - K ₃,K ₄,K ₅,K ₆,K ₇ rate constants (cm^–2 s^–1) - [Ni(II)] bulk concentration of NiSO₄ (mol cm^–3) - R _t charge transfer resistance ( cm²) - Re(Z) real part ofZ - t time (s) - x distance from the electrode (cm) - Z _F faradaic impedance ( cm²) - Z electrode impedance - maximal surface concentration of Ni(I)_ads intermediates (mol cm^–1) - nickel content in the deposited alloy (wt %) - thickness of Nernst diffusion layer (cm) - ₁ electrode coverage by adsorbed Ni(I)_ads intermediate - ₂ electrode coverage by active sites - ₁, ₂ variations in ₁, ₂ die to E - * =K ₂ ^–1 (s) - _d diffusion time constant (s) - ₁ time constant relative to ₁ (s) - ₂ time constant relative to ₂ (s) - angular frequency (rad s^–1) - electrode rotation speed (rev min^–1)     

镁合金的动态再结晶

介绍了镁合金动态再结晶的应力应变曲线和组织特点,分析了变形温度、变形速度、变形程度以及原始晶粒组织等因素对镁合金的动态再结晶的形核及晶粒大小的影响。在一定范围内,降低变形温度提高变形速度可使动态再结晶晶粒尺寸减小,随变形程度增大,晶粒变得细小。同时也论述了镁合金动态再结晶的形核机制。     

锌镍磷合金电镀工艺的研究

研究了简单氯化物体系中锌镍磷合金电镀工艺,探讨了镀液组成及工艺条件对合金镀层中镍,磷含量的影响,并对合金镀层的耐蚀性进行了测试,结果表明,锌镍磷合金镀层的耐蚀性优于镍合金,且其耐蚀性随镀层中磷含量的增大而提高。     

Anodisation of a Nb-Zr alloy

Anodisation of a Nb-Zr alloy was studied in ammonium sulphate and hydrochloric acid electrolytes using electrochemical and surface analysis methods. Using electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry, a value of ε_r=27 was estimated for the relative permittivity and of 0.4 V nm⁻¹ for the electrical field in the oxide film. Annealing of a mechanically polished disc sample to 600 °C for 14 h in UHV resulted in a fourfold surface enrichment of zirconium. This enrichment remained after anodisation in the sulphate solution, but could be removed with an anodisation in hydrochloric acid. Auger electron spectroscopy was used to estimate the thickness and composition of the anodic oxides. The film thickness measurements suggested a logarithmic growth law. The surface concentration of zirconium at the outer film surface of heat-treated samples decreased logarithmically when anodisation was performed in 1 M hydrochloric acid. No corresponding decrease in zirconium concentration was observed during immersion at open circuit.     

一种聚烯烃合金"革命性"技术--Catalloy工艺的成因及应用

Catalloy工艺可生产出真正的合金化聚合物材料,是聚烯烃合金革命化的技术.本文介绍这种工艺的发展过程及应用.