Electroplated reactive nanoparticle dispersed coatings

反应层系统是至少两种材料（主要是金属）的组合，它们彼此的反应显示出强烈的负焓。现有技术是例如通过PVD工艺生产的Ni-Al多层。反应层的应用出现在连接技术中，其中需要在小的、明确定义的空间中快速释放大量的热量。在这个项目中，颗粒反应层系统将由离子液体（IL）的电化学沉积产生。一种特殊的气相工艺将用于制备纳米至微米级颗粒，其中颗粒作为IL中的分散体获得。然后，该分散体用作电镀浴的基础，从该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。将使用各种分析方法（高速热成像、XRD、FIB、TEM等）研究沉积层的结构-反应性关系。其中，将研究颗粒的尺寸和分布如何影响层的反应速度的问题。在电化学制备过程中，将特别注意离子液体中颗粒的稳定性，并更好地理解沉积过程。关于IL中颗粒的表面电荷的作用，出现了悬而未决的问题。复合涂层在水介质中沉积机理的经典理论能否描述本项目所考虑的过程？总体而言，预计有关反应层系统的制备方法和结构-性质关系的知识状态将显著扩展。这些基础知识将成为为新应用定制反应性涂料体系的基础。

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.