Soffritti Chiara, Fortini Annalisa, Nastruzzi Anna, Sola Ramona, Merlin Mattia, Garagnani Gian Luca
Department of Engineering, University of Ferrara, via Saragat 1, 44122 Ferrara, Italy.
Department of Industrial Engineering, University of Bologna, viale Risorgimento 4, 40136 Bologna, Italy.
Materials (Basel). 2021 Jun 14;14(12):3281. doi: 10.3390/ma14123281.
This work evaluates the dry sliding behavior of anodic aluminum oxides (AAO) formed during one traditional hard anodizing treatment (HA) and two golden hard anodizing treatments (named G and GP, respectively) on a EN AW-6060 aluminum alloy. Three different thicknesses of AAO layers were selected: 25, 50, and 100 μm. Prior to wear tests, microstructure and mechanical properties were determined by scanning electron microscopy (VPSEM/EDS), X-ray diffractometry, diffuse reflectance infrared Fourier transform (DRIFT-FTIR) spectroscopy, roughness, microhardness, and scratch tests. Wear tests were carried out by a pin-on-disc tribometer using a steel disc as the counterpart material. The friction coefficient was provided by the equipment. Anodized pins were weighed before and after tests to assess the wear rate. Worn surfaces were analyzed by VPSEM/EDS and DRITF-FTIR. Based on the results, the GP-treated surfaces with a thickness of 50 μm exhibit the lowest friction coefficients and wear rates. In any case, a tribofilm is observed on the wear tracks. During sliding, its detachment leads to delamination of the underlying anodic aluminum oxides and to abrasion of the aluminum substrate. Finally, the best tribological performance of G- and GP-treated surfaces may be related to the existence of a thin Ag-rich film at the coating/aluminum substrate interfaces.
本研究评估了在EN AW-6060铝合金上进行一种传统硬质阳极氧化处理（HA）和两种金色硬质阳极氧化处理（分别命名为G和GP）时形成的阳极氧化铝（AAO）的干滑动行为。选择了三种不同厚度的AAO层：25、50和100μm。在磨损试验之前，通过扫描电子显微镜（VPSEM/EDS）、X射线衍射、漫反射红外傅里叶变换（DRIFT-FTIR）光谱、粗糙度、显微硬度和划痕试验来确定微观结构和力学性能。磨损试验通过销盘摩擦磨损试验机进行，使用钢盘作为配对材料。摩擦系数由设备提供。在试验前后对阳极氧化销进行称重，以评估磨损率。通过VPSEM/EDS和DRITF-FTIR对磨损表面进行分析。根据结果，厚度为50μm的GP处理表面表现出最低的摩擦系数和磨损率。在任何情况下，在磨损轨迹上都观察到摩擦膜。在滑动过程中，其脱落会导致底层阳极氧化铝分层以及铝基体磨损。最后，G处理和GP处理表面的最佳摩擦学性能可能与涂层/铝基体界面处存在富银薄膜有关。
