RUI: Anomalous Codeposition of Nickel-Iron and Nickel-Zinc Alloys

9404871 哈里斯 本研究是对镍-铁和镍-锌两种不同体系中异常共沉积的实验研究。 选择这些特定系统有几个原因： 1)以确定异常沉积的机理; 2）这两种体系都含有镍，但当镍与铁和锌结合时产生的合金具有不同的性质; 3）这两种体系在商业上都很重要。 实验对反常共沉积的模型或理论进行了严格的检验。 该项目首先在测试基质中生产合金沉积物，该测试基质包括以下变量：溶液中较少的贵金属浓度，pH值，电流密度和温度。 在这些实验中产生的沉积物的特征在于其组成，形态，微观结构和结晶相含量。 这些测试确定的条件下，不发生异常共沉积，以及制度的异常共沉积是足够不同的建议不同的机制。 另外两个问题将在本项目稍后阶段加以审查。 首先，次磷酸盐，这是能够消除异常共沉积（至少在镍-铁系统），将被用作探针，用于测试各种异常共沉积机制。 其次，氢的作用，这已被低估的镍-铁系统，但不能忽视的镍-锌，将使用电化学氢渗透技术进行检查。 这项工作将有助于进一步完善电沉积合金的商业生产和利用。 坡莫合金电沉积技术在硬盘驱动器的发展中发挥了不可或缺的作用，进一步的改进受到我们目前对这种材料电化学加工的理解的限制。 此外，更好地了解镍-锌系统应提高其作为汽车和其他应用中使用的钢板的耐腐蚀涂层的利用率。 ***

9404871 Harris This research is an experimental examination of anomalous codeposition in two different systems, nickel-iron and nickel-zinc. There are several reasons for choosing these particular systems: 1) to determine the mechanism of anomalous deposition; 2) the systems have nickel in common, but the alloys produced when nickel is combined with iron and zinc have different properties; 3) both systems are of importance commercially. Experiments critically test the models or theories of anomalous codeposition. The project starts with the production of alloy deposits within a test matrix that includes the following variables: less noble metal concentration in the solution, pH, current density, and temperature. The deposits produced in these experiments are characterized with respect to their composition, morphology, microstructure and crystalline phase content. These tests identify conditions under which anomalous codeposition does not occur, as well as regimes of anomalous codeposition that are sufficiently dissimilar to suggest different mechanisms. Two additional issues will be examined later in the project. First, hypophosphite, which is able to eliminate anomalous codeposition (at least in the nickel-iron system), will be used as a probe for testing the various anomalous codeposition mechanisms. Secondly, the role of hydrogen, which has been discounted in the nickel-iron system but cannot be ignored with nickel-zinc, will be examined using the electrochemical hydrogen permeation technique. %%% This work should assist in the further refinement of the commercial production and utilization of electrodeposited alloys. Permalloy electrodeposition technology has played an integral role in the evolution of the hard disk drive, and further improvements are limited by our present understanding of the electrochemical processing of this materials. Also, a better understanding of the nickel-zinc system should enhance its utilization as a corrosion- re sistant coating for steel sheet used in automobiles and other applications. ***