ECM: Development of Plasma-Based Techniques to Reduce the Environmental Hazards Associated with Wet-Bath Electroplating Processes

本研究的目的是研究等离子体源离子注入（PSII），一种干燥、无污染的表面改性技术，以减轻与湿化学镀液工艺相关的问题。PSII是一种非视线、干燥的表面改性技术，已被证明可以改善材料的磨损和腐蚀。在PSII中，待处理的部件被放置在等离子体（电离气体）中，脉冲偏置到高负电位。因此，等离子体中的离子以高速加速进入零件表面，从而增强了其表面性能。除了注入外，PSII工艺还可用于在涂层-基材界面沉积覆盖层，并具有一定程度的混合，以确保良好的附着力。本研究将涉及PSII工艺在离子注入和沉积模式中的应用。PSII中的工艺变量，如能量、剂量和脉冲形状，将被用来控制涂层的相和微观结构。psii处理后的涂层将使用俄歇光谱和电子显微镜进行微观结构方面的表征，如晶粒尺寸、裂纹和孔隙率。涂层的磨损、腐蚀和粘附特性将是主要的兴趣，将进行详细的研究，模拟计算，并与现有的电镀涂层进行比较。该研究将在多学科环境下进行，涉及等离子体物理学、材料科学、离子-材料相互作用、计算机建模和摩擦学。因此，它将在这些领域之间的界面开发新知识，并将这些领域的基本知识应用于具有环保意识的制造业，在那里它有可能对生态和工人的环境产生重大影响。这项研究将有很强的教育成分和工业参与。目前，湿化学镀液（例如，铬和镉）被广泛用于改善各种机床、工艺设备和制成品的耐磨、耐腐蚀和耐侵蚀性，并降低摩擦。然而，从电镀工厂产生的化学浴和冲洗水对环境有毒，在处理和处置方面都存在重大问题。PSII为这些湿式化学工艺提供了一个有吸引力的替代品，因为它能够以无化学品、环保的方式生产高性能材料表面。

9528746 Conrad The objective of this research is to investigate Plasma Source Ion Implantation (PSII), a dry, non-polluting surface modification technique, to mitigate the problems associated with wet chemical bath plating procedures. PSII is a non-line-of-sight, dry surface modification technique that has been shown tos improve wear and corrosion of materials. In PSII, the parts to be treated are placed in a plasma (ionized gas) and pulse-biased to a high negative potential. As a result, ions in the plasma are accelerated into the parts' surfaces at high velocities, resulting in the enhancement of its surface properties. In addition to implantation, the PSII process can be used to deposit overlay coatings with a degree of mixing at the coating-substrate interface that assures good adhesion. This research will involve the application of the PSII process in both the ion implantation and deposition modes. Process variables in PSII such as energy, dose, and pulse shape will be utilized to control the phases and microstructure of the coatings. The PSII-treated coatings will be characterized using Auger spectroscopy and electron microscopy for microstructural aspects such as grain size, cracks, and porosity. Wear, corrosion, and adhesion characteristics of the coatings will be of primary interest and will be studied in detail, modeled computationally, and compared to existing electroplated coatings. The research will be performed in a multi-disciplinary environment involving plasma physics, materials science, ion-materials interactions, computer modeling, and tribology. Consequently, it will develop new knowledge at the interfaces between these areas and apply the fundamental knowledge in these fields to environmentally conscious manufacturing, where it has the potential to make a significant impact on ecology and workers' environment. The research will have a strong educational component as well as industrial participation. Currently, wet chemical bath platings (e.g., chromium and cadmium) are widely used for improving wear, corrosion, and erosion resistances and lowering friction in a variety of machine tooling, process equipment, and manufactured goods. However, the chemical baths and the rinse water generated from the plating plants are environmentally toxic and present significant problems in both handling and disposal. PSII provides an appealing substitute to these wet chemical processes, because of its ability to produce high performance material surfaces in a chemical-free, environmentally-clean manner.