Fundamental investigations on the pre-process and in-operando oxidation of triboactive hard thin films

在本研究项目中，对富al溅射AlCrVY(O)N薄膜的原子结构、微观结构、抗氧化性和摩擦行为的关系有了基本的了解。为此，薄膜通过磁控溅射沉积在WC-Co衬底上，其中包括许多工具。目的是沉积AlCrVY(O)N涂层，在500°C至1000°C的高温下形成自润滑的氧化钒相，即所谓的magn<s:1>相，这大大降低了摩擦系数。同时，在这些高温下保持AlCrN涂层已知的正力学性能是非常重要的。然而，纯AlCrN薄膜不适合摩擦学，特别是摩擦最小化应用，因为在高温下摩擦系数增加。重点分析了薄膜合成过程中预氧化对摩擦学性能的影响，以及在实验室使用过程中氧化相的变化。同时制备了无氧AlCrVYN薄膜，并进行了对比。为此，利用同步辐射x射线衍射仪（XRD）和x射线吸收近边结构能谱仪（XANES）在宏观和原子尺度上研究了采用不同高能沉积方法合成的AlCrVY(O)N薄膜在温度诱导下的结构变化，包括钒相的氧化形成以及Al和Cr相的抗氧化性。目的是基本了解沉积参数和预氧化状态对涂层性能结构效应的影响，从而有可能开发出在高温应用中具有良好机械性能的摩擦最小化涂层。

In the proposed research project, a basic understanding of the relationships of atomic structure, microstructure, oxidation resistance and frictional behavior of Al-rich sputtered AlCrVY(O)N thin films is to be obtained. For this purpose, the thin films are deposited by means of magnetron sputtering on a WC-Co substrate, of which many tools consist. The aim is the deposition of AlCrVY(O)N coatings, which form self-lubricating vanadium oxide phases, so-called Magnéli phases, at elevated temperatures of 500°C to 1000°C, which significantly reduce the coefficient of friction. At the same time, it is of great importance that the known positive mechanical properties of the AlCrN coatings are maintained at these high temperatures. However, pure AlCrN thin films are not suitable for tribological and, in particular, friction-minimizing applications due to an increased coefficient of friction at elevated temperatures. The central aspect is the analysis of the influence of the pre-oxidation during the thin film synthesis on the tribological properties as well as the change of the oxide phases during use in laboratory scale. In comparison, oxygen-free AlCrVYN thin films are also produced and compared. For this purpose, the temperature-induced change in the structure of AlCrVY(O)N thin films, which are synthesized using different energetically high deposition methods, are investigated by means of X-ray diffraction (XRD) and X-ray absorption near-edge structure spectroscopy (XANES) using synchrotron radiation on the macroscopic and atomic scale with respect to oxidation formation of vanadium phases and oxidation resistance of the Al and Cr phases. The aim is the basic understanding of the influence of the deposition parameters and the pre-oxidized state on the structural effects of the coating properties and thus the possibility to develop friction-minimizing coatings with good mechanical properties at high temperature applications.