Anode Plasma Electrolytic Saturation of Titanium Alloys with Nitrogen and Oxygen

作者：Belkin P N; Kusmanov S A^*; Zhirov A V; Belkin V S; Parfenyuk V I

来源：Journal of Materials Science & Technology, 2016, 32(10): 1027-1032.

DOI：10.1016/j.jmst.2016.06.005

• Plasma electrolysis
• Titanium
• Nitriding
• Wear
• Corrosion

In this work, we investigated the features of the anode plasma electrolytic saturation of titanium alloys with nitrogen and oxygen. In this case, the titanium samples may be heated to 1050 degrees C using aqueous solutions of ammonium chloride as working electrolyte. The weight of titanium samples is found to change due to their oxidation and anode dissolution. An X-ray diffractometer, a scanning electron microscope, nuclear proton backscattering and an optical microscope were used to characterize the phase and elemental composition of the modified layer. The electrolyte composition (10 wt% ammonium chloride, 5 wt% ammonia) and processing mode (850 degrees C, 5 min) of commercially pure titanium (CP-Ti) allowing to obtain the hardened surface layer up to 0.1 mm with microhardness of 220 HV were proposed. Surface roughness R-a of samples after their nitriding for 5 min at 800 degrees C decreases from 1.67 to 0.082 mu m. The anode plasma electrolytic nitriding could decrease friction coefficient and increase wear resistance of the CP-Ti. It is found that the anodic nitriding of low alloy titanium alloys reduces their corrosion rate in an aqueous solution of sulphuric (4.5%) and salt (0.2%) acids by 2 orders of magnitude. Results of cyclic testing show that anodic nitriding of commercial titanium leads to a decrease in corrosion rate by 8 times in solution of hydrochloric acid (6%) with addition of protein and vitamin.

• 出版日期2016-10