Czapczyk Kazimierz, Zawadzki Paweł, Wierzbicka Natalia
Faculty of Mechanical Engineering and Ship Technology, Gdansk University of Technology, G. Narutowicza 11/12, 80-233 Gdansk, Poland.
Faculty of Mechanical Engineering, Poznan University of Technology, Piotrowo 3, 60-965 Poznan, Poland.
Materials (Basel). 2023 Sep 6;16(18):6100. doi: 10.3390/ma16186100.
The article presents the results of mechanical testing of Ni-P/SiN nanocomposite and hybrid Ni-P/SiN/graphite coatings deposited on AW-7075 aluminum alloy using the chemical reduction method. In terms of mechanical testing, microhardness was measured, and surface roughness and adhesion of the coatings to the aluminum substrate were determined using the "scratch test" method. The surface morphology of the deposited layers was also analyzed using light microscopy and scanning electron microscopy. Samples made of AW-7075 aluminum alloy with electroless deposited Ni-P/SiN nanocomposite, Ni-P/graphite composite and hybrid Ni-P/SiN/graphite coatings with different content of dispersed phases were tested, and also, for comparison purposes, the Ni-P layer that constituted the matrix of the tested materials. Reinforcing phases in the form of silicon nitride nanoparticles and graphite particles were used in the layers. The purpose of the research was a thorough characterization of the coating materials used on aluminum alloys in terms of mechanical properties. Graphite is considered in this paper as it enables the reduction of the coefficient of friction through its lubricating properties. Unfortunately, graphite is difficult to use in selected layers as the only dispersion phase, because it has much lower hardness than the Ni-P coating. For this reason, a layer with a single dispersion phase in the form of graphite will be characterized by worse mechanical properties. It is necessary to add particles or nanoparticles with hardness higher than the base Ni-P coating, e.g., SiN, which improve the mechanical properties of the coating. The presented analyses of the results of the conducted research complement the previous studies on selected properties of nanocomposite layers with an amorphous structure and supplement the knowledge regarding their suitability for application to aluminum machine parts.
本文介绍了采用化学还原法在AW-7075铝合金上沉积的Ni-P/SiN纳米复合材料涂层以及Ni-P/SiN/石墨混合涂层的力学性能测试结果。在力学性能测试方面，测量了涂层的显微硬度，并采用“划痕试验”方法测定了涂层的表面粗糙度及其与铝基体的附着力。还通过光学显微镜和扫描电子显微镜分析了沉积层的表面形貌。对由AW-7075铝合金制成的、具有不同分散相含量的化学镀Ni-P/SiN纳米复合涂层、Ni-P/石墨复合涂层以及Ni-P/SiN/石墨混合涂层的样品进行了测试，并且，为了进行比较，还测试了构成被测材料基体的Ni-P层。涂层中使用了氮化硅纳米颗粒和石墨颗粒形式的增强相。本研究的目的是全面表征用于铝合金的涂层材料的力学性能。本文考虑了石墨，因为它具有润滑性能，能够降低摩擦系数。不幸的是，石墨很难作为唯一的分散相用于特定涂层，因为它的硬度远低于Ni-P涂层。因此，仅以石墨为单一分散相的涂层的力学性能会较差。有必要添加硬度高于基础Ni-P涂层的颗粒或纳米颗粒，例如SiN，以改善涂层的力学性能。本文对所开展研究结果的分析补充了先前关于非晶结构纳米复合涂层特定性能的研究，并补充了有关其在铝制机械零件上应用适用性的知识。
