Electroplated reactive nanoparticle dispersed coatings

反应层体系是至少两种材料（主要是金属）的组合，它们之间的反应表现出强烈的负焓。例如，目前的技术状况是通过PVD工艺生产的Ni-Al多层材料。反应层的应用出现在连接技术中，其中需要在一个小的，明确的空间内快速释放大量的热量。在这个项目中，微粒反应层系统将通过离子液体（ILs）的电化学沉积来生产。一种特殊的气相工艺将用于制备纳米到微尺度的颗粒，在这种工艺中，颗粒作为分散体在IL中获得。然后，这种分散体作为电镀浴的基础，从电镀浴中电化学沉积层。对于反应性Ni-Al体系，Ni颗粒可以分散在Al电解质中，或者Al颗粒分散在Ni电解质中。利用各种分析方法（高速热成像，XRD， FIB， TEM等）研究沉积层的结构-反应性关系。其中，粒子的大小和分布如何影响层的反应速度的问题将被研究。在电化学制备过程中，将特别关注IL中颗粒的稳定性以及对沉积过程的更好理解。关于颗粒表面电荷在IL中的作用，出现了一些悬而未决的问题。复合涂层在水介质中沉积机制的经典理论能否描述该项目所考虑的过程？总的来说，预计有关反应层体系的制备方法和结构-性质关系的知识状态将大大扩展。这些基本知识将形成为新应用定制活性涂层系统的基础。

Reactive layer systems are combinations of at least two materials (mostly metals) whose reaction with each other shows a strongly negative enthalpy. State of the art are e.g. Ni-Al multilayers, which are produced by PVD processes. Applications for reactive layers arise in joining technology, where the rapid release of large amounts of heat in a small, well-defined space is required. In this project, particulate reactive layer systems will be produced by electrochemical deposition from ionic liquids (ILs). A special gas phase process will be used for the preparation of nano- to micro-scale particles, in which the particles are obtained as a dispersion in an IL. This dispersion then serves as the basis for an electroplating bath from which the layers are electrochemically deposited. For a reactive Ni-Al system, Ni particles can be dispersed in an Al electrolyte, or Al particles in a Ni electrolyte. Structure-reactivity relationships will be investigated at the deposited layers with various analytical methods (high speed thermography, XRD, FIB, TEM etc.). Among others, the question of how the size and distribution of the particles affect the reaction speed of the layer will be investigated. In the electrochemical preparation process, particular attention will be paid to the stabilization of the particles in the IL and a better understanding of the deposition process. Open questions arise regarding the role of the surface charge of the particles in the IL. Can classical theories for the deposition mechanism of composite coatings in aqueous media describe the process under consideration in this project? Overall, it is expected that the state of knowledge regarding the preparation methods and structure-property relationships of reactive layer systems will be significantly expanded. This basic knowledge will then form the basis for tailoring reactive coating systems for new applications.