Research Progress of Ultrafine-Grained Pure Titanium Produced by Equal-Channel Angular Pressing

Recently, fabrication techniques of ultrafine-grained (UFG) pure titanium have been investigated to achieve enhanced performance. This paper reveals the process and properties of bulk ultrafine-grained pure titanium by equal-channel angular pressing (ECAP), with the influence of experimental parameters. Special attention is given to the deformation mechanisms via dislocation slip and twinning during ECAP. It is demonstrated that the change of microstructure in UFG Ti leads to significant enhancement of mechanical properties. Some mixed results about corrosion resistance of UFG Ti indicate the further investigations are necessary. Special emphasis is placed on the combination of ECAP and other treatments for improving overall properties. It is shown that significant enhancement has been made in UFG commercial-purity Ti after ECAP plus thermal-mechanical treatment, suggesting promising prospects of ECAP process for titanium alloys in various industries.