Enhanced Creep Resistance of an Ultrafine‐Grained Ti–6Al–4V Alloy with Modified Surface by Ion Implantation and (Ti + V)N Coating

This research examines the creep behavior of an ultrafine‐grained (UFG) Ti−6Al−4V alloy processed by equal‐channel angular pressing followed by extrusion. It is shown that modifying the surface of the UFG alloy with nitrogen ions and then applying of a coating of (Ti + V)N inhibits the softening of the UFG alloy at temperatures up to 700 K due to a barrier effect in which the coating hinders the release of dislocations onto the surface. The differences in the mechanisms of crack initiation and failure of UFG samples are also examined both with and without a coating. The prospects of the proposed approach to the improving of titanium alloys are discussed, including the formation of an UFG structure in the bulk of the material and subsequent modification by ion‐plasma methods for the manufacture of highly loaded parts operating at elevated operating temperatures.