Influence of Current Waveform on the Wear Resistance of Coatings Obtained on VT6 Titanium Alloy with the Electrolytic Plasma Treatment Method

Abstract

In the study on the “disk–disk” method the wear resistance of coatings deposited on a VT6 alloy by the plasma electrolytic treatment (PET) method in alkaline aqueous solutions containing different concentrations of sodium aluminate (NaAlO₂) at various ratios (0–1.4) of cathodic (I_C) and anodic (I_A) alternating current components while the value of anodic current density was constant (i_A = 5 A/dm²), was studied. It was determined that the maximum increase of wear resistance of a titanium alloy surface is provided for the coating fabricated by the following technological condition: an alkaline aqueous solution containing 40 g/L of sodium aluminate NaAlO₂; I_C/I_A = 0.8; and i_A = 5 A/dm². The high wear resistance of coating fabricated by this condition, as it was determined using the quantitative X-ray phase analysis, is caused by a high content of corundum (α-Al₂O₃) in the coating, which is a part of double-oxide (TiAl₂O₅) and its low porosity.