光亮镀铑

介绍了铑镀液的制备、电镀技术、镀层性能及其应用。     

一次性Ni—P合金化学镀酸性镀浴多次重复利用经济分析模型的建立

一、前言与长效补加型配方相比，一次性配方因为无需在镀覆过程中进行药剂补加，因此镀液的均匀性好。镀层表面质量高、孔隙率低．尤其适用于大型设备（入槽量≥200mm2）的整体化学镀。但是，作为企业关心的不仅仅是质量，还有利润，希望在质量不变的情况下，用小的投入得到大的产出，即产成比大。为此，希望能在现有基础上将一次性酸性洗浴配方进行多次重复利用。事实上，一次性酸性治配方多次重复使用是不成问题的，只是与长效配方相比在补加方式上有所不同。一次性配方重复使用时的补加是在工件入槽前进行，并非在镀覆过程中进行，而且补…     

稀土对Ni-Fe合金镀液性能的影响

本文以获得含铁量为20％的镍铁台金镀层的电镀工艺为基础．在简单硫酸盐镀液中．全面系统地研究了穑土添加剂对该体系镀渡性能的影响。结果表明：(1)稀土有稳定镀液、减少F03 的作用；(2)稀土可扩大获得光亮镀层的电流密度范围；（3)稀土可明显提高镀渡分散能力和阴极电流效率．促使阴极饺化增大；(4)稀土的最佳添加量为0.2-0.5g/100文中还阐明了稀土的作用机理。     

银锑合金镀液中锑的光度测定

银锑合金镀液中的锑是主要成份之一,在氰化镀银溶液中也常用锑的化合物作光亮剂.用火焰原子吸收法测定其含锑量,无疑是个简便快速的方法,但受设备条件的限制,本文用碘化钾作显色剂分光光度测定锑,获得了较满意的结果.     

从三价铬镀液电沉积非晶态Cr—C镀层的研究

1 前言 非晶态材料具有优良的物理、化学和力学性能,已获得较为广泛的应用。 制造非晶态材料的方法有急冷法,离子注入法,CVD法,激光及化学镀和电镀等,其中电镀法所用设备简单,可制成面积大和形状复杂的非晶态薄层材料,适合于连续作业和大规模生产,且可制备其它方法无法获得的非晶态材料。     

Ni—P—Al2O3化学复合镀工艺研究

简要叙述化学复合镀的机理和特点,并就新近研究成功的Ni-P-Al_2O_3化学复合镀的施镀工艺、镀液的调整与控制进行详尽的阐述,介绍实行该工艺所获得的镀层的优异性能。     

如何防止镀液中积累杂质并净化镀液

0前言 杂质是镀液中无用且影响镀液性能和镀层质量的组分,是不可避免的有害物质。不少电镀故障是由于镀液中的杂质引起的,如果及时把进入镀液的杂质清理掉,镀液中的杂质就不会积累起来,杂质的含量也就不会达到危害镀液性能和镀层质量的程度。     

电刷镀复合镀层工艺及性能研究

对电刷镀复合镀工艺以及镀层性能作了深入的研究,通过研制的一种高粘度胶状刷镀Ｎｉ溶液,解决了固体微粒悬浮的均匀性和稳定性问题,在此种镀液为基础添加各种不同的固体微粒,制备出复合镀液,并施以电刷镀工艺,从而得到各种不同性能的复合镀层。     

沉淀滴定法测定镍钼合金镀层和镀液中钼的含量

在乙酸盐缓冲溶液介质中，ＭｏＯ＾２－４与Ｐｂ＾２＋形成了水溶解的沉淀化合物，研究了该方法是在Ｎｉ＾２＋和其它金属离子存在下，用沉淀滴定法测定钼，以ＸＯ，ＣＰＢ为混合指示剂，Ｐｂ＾２＋标准溶液为滴定剂。终点变化额外敏锐。实验结果说明，各种阳离子均完全不干扰。已用于测定镍钼合金镀层，镀液中的钼含量，结果满意。     

Sn-Bi合金电镀

概述了 Ｓｎ－Ｂｉ合金镀液,可以获得外观良好及合金组成稳定的 Ｓｎ－Ｂｉ合金镀层．适用于印制板、电子元器件等的可焊性镀层,以取代传统含Ｐｈ的Ｓｎ－Ｐｈ合金镀层。     

A New Nontoxic Bath for Low-Temperature Nitrocarburizing of Metals and Alloys

Metal Science and Heat Treatment -     

Ni-Zn-P三元合金化学镀镀液配方优化研究

研究了镀液配方对化学镀Ni-Zn-P三元合金施镀效果的影响,探明了镀速、镀层硬度及其腐蚀防护性,以及镀层Ni,Zn和P含量的变化规律,确定了含Zn 9.50~16.57和P 7.55~13.59 (质量分数,%) 的Ni-Zn-P镀层制备工艺。对典型试样进行了SEM和XRD分析以及耐酸、耐碱及耐盐溶液腐蚀性能测试,结果表明：镀层表面平整、均匀,结构致密,具有典型的胞状/球状及条带状微观形貌;镀层主要由非晶、微晶或其混合相组成,其中Zn和P固溶于fcc的Ni晶格中;镀层耐盐、耐碱腐蚀能力较强。     

Al、Zn元素对镁合金的晶粒细化机理分析

从结晶游离的角度研究了Al、Zn元素对镁合金晶粒的细化机理,建立了一类可用于评估游离晶对合金组织细化能力的数学模型。分析结果表明,Mg-Al合金中的游离晶对合金组织的细化能力高于相同溶质浓度的Mg-Zn合金,并且溶质浓度越高,游离晶的细化能力差别越大,这可能是导致相同浓度的Mg-Al合金晶粒尺寸更加细小的主要原因。     

Microstructures and Properties of Extruded Mg-Gd-Y-Zr Alloys Containing Zn

Microstructure and mechanical properties of Mg-10Gd-3.8Y-xZn-0.5Zr (x?=?0, 1, 3?wt.%) alloys during extrusion and following isothermal aging at 200?°C were investigated using digital microhardness testing, mechanical testing, optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and x-ray diffraction (XRD). The results showed that Zn can refine grains of the alloy, and improved mechanical properties of the as-extruded alloys. In T5 (peak-aging) condition, the average grains of the alloy without Zn addition were about 20.10???m; the average grains of the alloys with 1?wt.% Zn addition and 3?wt.% Zn addition were about 15.35 and 10.04???m, respectively. For the alloy with 1?wt.% Zn addition in as-extruded and peak-aged states, the values of tensile strength reached 345 and 429?MPa, yield strength reached 260 and 342?MPa, as well as ductility rate reached 10.8 and 5.7%, respectively, exhibiting superior mechanical properties.     

Electrodeposition of Copper-Nickel Alloys from a Citrate Bath Containing Boric Acid

Copper-nickel alloys have been electrodeposited on steel substrates from a bath containing copper sulphate, nickel sulphate, sodium sulphate, sodium citrate and boric acid. Galvanostatic cathodic polarization, cathodic current efficiency and composition of the alloys were studied as influenced by bath composition, current density and temperature.

The bath is characterized by high cathodic current efficiency. Current density is found to strongly influence the composition of the deposits. At low current densities (lower than a certain transition current density), a copper-rich alloy is deposited with copper (the more noble metal) being the preferentially deposited metal. At larger current densities, nickel becomes the nobler metal and is deposited preferentially. The magnitude of the transition current density depends upon the bath composition and temperature. The structure and surface morphology of the as-deposited alloys were examined by XRD and SEM. The results reveal the presence of a single solid solution phase with face centred cubic structure. The morphology of the deposits is mainly controlled by the alloy composition.     

Ba—P复合变质对铝硅合金初晶硅的细化作用

研究了钡、磷及钡磷复台变质对过共晶铝硅合金初晶硅的细化作用，发现钡变质可细化初晶硅的尺寸，同时使硅晶体由板块状改变为树枝状；磷变质可明显细化初晶硅，但对其形状因子改变不大；但磷复合变质综合了二者的优势。硅晶体表面有钡或钡的化合物的吸附，认为吸附抑制机制是钡变质的实质。     

The Effect of Adding Corrosion Inhibitors into an Electroless Nickel Plating Bath for Magnesium Alloys

Journal of Materials Engineering and Performance - In this work, corrosion inhibitors were added into an electroless nickel plating bath to realize nickel-phosphorus (Ni-P) coating deposition on...     

Ce对Zn—Cu合金变质效果的研究

Ｃｅ能使Ｚｎ－Ｃｕ合金晶粒细化，不仅提高了它的力学性能，而且改善了它的抗“老化”性能。     

Mg-7.0Al-0.2Zn合金的超塑性及其变形机制

研究不具有典型细晶组织的挤压态Mg-7.0Al-0.2Zn(AZ70)合金的超塑性及其变形机制。结果表明:AZ70镁合金具有良好的超塑性变形行为。在380℃及1×10-3s-1的最佳变形条件下,最大伸长率为191.5%。380℃时具有良好的高应变速率(1×10-2s-1)超塑性变形能力,伸长率为161.5%。晶粒尺寸随温度的升高与应变速率的降低而增大。超塑性变形是以晶界滑移为主,表现为变形过程中晶粒组织基本保持等轴,且孔洞沿晶界形成并长大。同时孔洞的长大及连接导致最终断裂,断口形貌显示为典型的韧窝断裂特征。     

A Study into the Electrodeposition Mechanisms of Zinc-Nickel Alloys from an Acid-Sulphate Bath

Zinc-nickel alloys were electrodeposited under galvanostatic conditions from a sulphate based electrolyte. The effect of deposition current density on alloy composition was determined for an electrolyte containing 0.58 mol/l nickel and 0.92 mol/l zinc (as sulphates). At current densities exceeding 0.01 A/dm², a transition from normal deposition to anomalous co-deposition (ie where the less noble metal deposits preferentially) was observed and alloys rich in zinc were obtained. The transition current density was observed to increase with an increase in electrolyte temperature or a decrease in electrolyte pH.

The electrodeposition mechanism for zinc-nickel alloys in the transition regions was studied in detail using potentiodynamic cathodic polarisation techniques. The results were consistent with the suppression of nickel deposition due to the precipitation of zinc hydroxide on the cathode surface. This was supported by pH measurements made in the vicinity of the cathode where a rise in pH was detected as the transition current density was approached and exceeded the critical pH for zinc hydroxide precipitation.