Effects of ECAP and subsequent recovery on microstructure, mechanical, tribological and corrosion properties of Ti–6Al–4V alloy

Ti–6Al–4V alloy is widely used in various industries such as aerospace and biomedical engineering. This article reports a study on effects of the equal channel angular pressing (ECAP) and subsequent recovery on microstructure, mechanical, tribiological, and corrosion properties of the alloy. The two passes of ECAP process were done at 540 °C with 120 ° inner angle and subsequent recovery was carried out at 340 °C for 1 h. Microstructure was examined with optical microscope, scanning electron microscope and transmission electron microscope. The mechanical properties and corrosion behavior were evaluated with compressive and polarization dynamic tests, respectively. The wear resistance was determined with scratching test, and the volume loss was measured with a profilometer. Obtained results show that the ECAP-recovery (i.e. ECAP + recovery) sample exhibits improved properties than the as-received one (annealed) and ECAP (ECAP treated) samples. The corrosion tests indicate that the ECAP sample has its corrosion resistance higher than that of the as-received one but lower than that of the ECAP-recovery sample. ECAP-recovery sample has the highest resistance to wear and corrosive wear among the three samples.