Kusmanov Sergei, Tambovskiy Ivan, Silkin Sergey, Nikiforov Roman, Belov Roman
Department of Chemistry, Institute of Mathematical and Natural Sciences, Kostroma State University, 156005 Kostroma, Russia.
Materials (Basel). 2023 Jan 27;16(3):1102. doi: 10.3390/ma16031102.
The possibility of increasing the hardness to 1420 HV and the corrosion resistance of the CP-Ti surface using a combined plasma electrolytic treatment consisting in anodic plasma electrolytic nitrocarburising in a solution of ammonia, acetone and ammonium chloride at 900 °C and subsequent plasma electrolytic polishing is shown. The morphology, surface roughness, phase composition, structure and microhardness of the modified layer were studied. The corrosion characteristics of the treated surface were studied through potentiodynamic tests and electrochemical impedance spectroscopy. It has been shown that an increase in the surface roughness has a negative effect on the corrosion resistance. The proposed plasma electrolytic polishing makes it possible to remove the outer porous oxide layer, providing increased corrosion resistance. The highest reduction in the corrosion current density, by 13 times compared to CP-Ti and by two orders compared to a plasma electrolytic nitrocarburising sample, is achieved after plasma electrolytic polishing in a solution of ammonium fluoride (4%) at 300 V for 3 min.
研究表明，通过在900℃下于氨、丙酮和氯化铵溶液中进行阳极等离子体电解氮碳共渗以及随后的等离子体电解抛光组成的联合等离子体电解处理，可将工业纯钛（CP-Ti）表面硬度提高至1420 HV，并提高其耐腐蚀性。研究了改性层的形貌、表面粗糙度、相组成、结构和显微硬度。通过动电位测试和电化学阻抗谱研究了处理后表面的腐蚀特性。结果表明，表面粗糙度的增加对耐腐蚀性有负面影响。所提出的等离子体电解抛光能够去除外部多孔氧化层，从而提高耐腐蚀性。在300 V下于4%氟化铵溶液中进行3分钟的等离子体电解抛光后，腐蚀电流密度降低幅度最大，与CP-Ti相比降低了13倍，与等离子体电解氮碳共渗样品相比降低了两个数量级。
