Effect of plasma-pulsed detonation treatment on microstructure and properties of the Ti-6Al-4V surface.

Abstract The modified layers were prepared on the Ti-6Al-4V surface using plasma-pulsed detonation (PPD) treatment. The effects of number of pulses on the microstructure, phase composition, microhardness and wear resistance of the modified layers were studied, and the strengthening mechanism of the modified layers was discussed. The results show that the modified layers are composed of TiN, Ti x O y and Ti phases. The grains of the modified layers are refined to nanoscale (≤100 nm) or near-nanometer (100–300 nm). The increase of the Ti-6Al-4V surface microhardness is mainly attributed to the second phase strengthening and the fine grain strengthening. The average microhardness of the modified layers increases with increasing the number of pulses, and the maximum microhardness value of the all modified layers is at 10 μm near the surface. In addition, the maximum microhardness value of the all modified layers can be up to 561 ± 9 HK 0.01 , which is about 69% higher than that of the substrate. After PPD treatment, the wear mechanism changes from typical abrasive wear and adhesive wear to three-body abrasive wear. Compared with the substrate, the wear volume decreases by about 70%, 79% and 87%, when number of pulses are 1, 2 and 3, respectively, indicating that the wear resistance of Ti-6Al-4V can be greatly improved after PPD treatment. Highlights • Plasma-pulsed detonation is used to improve wear resistance of Ti-6Al-4V. • The modified layers are composed of TiN, TixOy and Ti phases. • The second phase strengthening and the fine grain strengthening are the main mechanism. • The wear mechanism changes from abrasive wear and adhesive wear to three-body abrasive wear. [ABSTRACT FROM AUTHOR]