Muntean Roxana, Brîndușoiu Mihai, Buzdugan Dragoș, Nemeș Nicoleta Sorina, Kellenberger Andrea, Uțu Ion Dragoș
Department of Materials and Manufacturing Engineering, Politehnica University Timișoara, Piața Victoriei 2, 300006 Timișoara, Romania.
Research Institute for Renewable Energy-ICER, Politehnica University Timișoara, Piața Victoriei 2, 300006 Timișoara, Romania.
Materials (Basel). 2023 Feb 8;16(4):1410. doi: 10.3390/ma16041410.
In order to modify the surface of light metals and alloys, plasma electrolytic oxidation (PEO) is a useful electrochemical technique. During the oxidation process, by applying a positive high voltage greater than the dielectric breakdown value of the oxide layer, the formation of a ceramic film onto the substrate material is enabled. The resulting surface presents hardness, chemical stability, biocompatibility, and increased corrosion wear resistance. The current study aims to investigate the corrosion resistance and tribological properties of PEO-modified coatings on titanium substrates produced by applying either direct or pulsed current in a silicate-alkaline electrolyte. In this way, a uniform TiO layer is formed, and subsequently, electrophoretic deposition of hydroxyapatite particles (HAP) is performed. The morpho-structural characteristics and chemical composition of the resulting coatings are investigated using scanning electron microscopy combined with energy dispersive spectroscopy analysis and X-ray diffraction. Dry sliding wear testing of the TiO and HAP-modified TiO coatings were carried out using a ball-on-disc configuration, while the corrosion resistance was electrochemically evaluated at 37 °C in a Ringer's solution. The corrosion rates of the investigated samples decreased significantly, up to two orders of magnitude, when the PEO treatment was applied, while the wear rate was 50% lower compared to the untreated titanium substrate.
为了改性轻金属及其合金的表面，等离子体电解氧化（PEO）是一种有用的电化学技术。在氧化过程中，通过施加高于氧化层介电击穿值的正高压，能够在基底材料上形成陶瓷膜。所得表面具有硬度、化学稳定性、生物相容性以及增强的耐腐蚀磨损性。当前研究旨在探究在硅酸盐碱性电解液中通过施加直流或脉冲电流在钛基底上制备的PEO改性涂层的耐腐蚀性和摩擦学性能。通过这种方式，形成均匀的TiO层，随后进行羟基磷灰石颗粒（HAP）的电泳沉积。使用扫描电子显微镜结合能量色散光谱分析和X射线衍射对所得涂层的形态结构特征和化学成分进行研究。采用球盘配置对TiO和HAP改性TiO涂层进行干滑动磨损测试，同时在37℃的林格氏溶液中对耐腐蚀性进行电化学评估。施加PEO处理后，所研究样品的腐蚀速率显著降低，降低了两个数量级，而磨损率比未处理的钛基底低50%。
