Enhancing tribocorrosion resistance of Ti6Al4V alloy by double glow plasma surface alloying with chromium

Ti6Al4V (TC4) alloy, valued for its light weight, high strength, and excellent corrosion resistance, is widely used in aerospace, medical devices, chemical engineering, and marine applications. However, under severe service conditions, the material is subjected to the combined effects of tribocorrosion, leading to reduced service life. To enhance the tribocorrosion resistance of TC4 alloy in marine environments, a chromizing coating was fabricated on the TC4 surface by double glow plasma surface alloying (DGPSA) technology. After maintaining at 800 ° C for 3 hours, a chromizing coating with a thickness of 51.80 μm was successfully prepared. Following the plasma surface alloying treatment, the coating comprised Cr 2 Ti intermetallic compounds and solid solutions, resulting in an increase in microhardness from 332.65 HV 0.1 to 637.29 HV 0.1 . Investigation of the tribological behavior of the alloy coating in simulated seawater revealed lower corrosion tendency and superior stability compared to the substrate. Under applied loads of 5 N and 10 N, the wear rates of the chromizing TC4 samples were 2.23×10 -4 mm 3 ·N -1 ·m -1 and 2.02×10 -4 mm 3 ·N -1 ·m -1 , respectively, which are 42.9% and 45.8% lower than those of the substrate. These results demonstrate that the chromizing treatment effectively improves the tribocorrosion performance of TC4 alloy.