Deposition of the system Mo-N-(Ag) by using highly-ionized PVD methods and its investigation with regard to high performance wear protection and electrical sliding contact

在能源效率的约束下，材料被迫走到了弹性的边缘。例如，高温和机械磨损的组合是一个重负荷的机械过程。类金刚石(DLC)涂层对这一应用的适用性有限。以Mo-N为基础的涂层似乎更有前景。此外，将在该项目内开发的Mo-N-(Ag)系统作为德国电力工业部门的电气滑动触头涂层材料具有一定的实用价值。这些涂层具有满足电源功率密度要求的潜力。分别由Mo-N和研究较少的Mo-N-Ag系统制备的高性能防磨涂层，由于形成了片状MoO_3相、Magnéli相或Ag钼酸盐相而表现出较低的摩擦系数。首次将三种不同的PVD技术--直流磁控溅射(DCMS)、高功率脉冲磁控溅射(HiPIMS)和脉冲激光沉积(PLD)--并行用于这些涂层的合成。这些技术在溅射物种的电离程度和氮气的电离/解离程度方面有很大的不同。可以通过控制等离子体条件来调节Mo-N-(Ag)系统的涂层性能。最基本的科学技术目标是化学计量比Mo-N涂层的严格沉积，通过与银的合金化开发新型高性能的Mo-N-(Ag)涂层，以及优化合适的电学和机械摩擦学性能。最后，通过获得等离子体和涂层的性能并将它们相互关联，系统地了解涂层系统的性能。所得结果将为建立Mo-N-Ag涂层的摩擦学和电学行为的经验模型提供依据。该项目将对以下问题做出重要贡献：我们需要多少电离和动能来使成膜物种选择性地定制涂层属性，例如，能够控制Mo-N的化学计量比。

With the constraint of energy efficiency, materials are forced to the border of resilience. The combination of high temperature and mechanical wear for example is a heavy-duty mechanical process. Diamond-like carbon (DLC) coatings are of limited suitability for this application. Coatings on the basis of Mo-N seem to be more promising. Additionally, the system Mo-N-(Ag) which will be developed within the project, has certain relevance as coating material for electrical sliding contacts for the industrial sector of German electrical power industry. These coatings have the potential to fulfill the requirements with respect to power density for the electrical power supply.High performance wear protecting coatings made from Mo-N or from the less studied system Mo-N-Ag, respectively, show low friction coefficients due to the formation of the lamellar MoO3 phase, Magnéli phases or Ag molybdate phases. For the first time three different PVD techniques - dc magnetron sputtering (dcMS), high power impulse magnetron sputtering (HiPIMS) and pulsed laser deposition (PLD) - are utilized in parallel for the synthesis of those coatings. These techniques differ drastically with respect to the ionization degree of the sputtered species and to the ionization/dissociation degree of the N2 gas. The coating properties of the system Mo-N-(Ag) can be tailored by the control of the plasma conditions. The essential scientific-technological goals are the demanding deposition of stoichiometric Mo-N coatings, the development of new high performance Mo-N-(Ag) coatings by alloying with silver and the optimization of appropriate electrical and mechanical-tribological properties.Finally, a systematic understanding of the performance of the coating systems will be achieved by acquiring the plasma and coatings properties and by correlating them with each other. The obtained results will serve for the setting up of an empirical model for the tribological and electrical behavior of Mo-N-Ag coatings. The project will deliver an important contribution to the question of how much ionization in combination with kinetic energy do we need for the film-forming species to tailor selectively coating properties like for example to be able to control the stoichiometry of Mo-N.