Deformation structure and mechanical properties of pure titanium produced by rotary-die equal-channel angular pressing

Abstract

Pure titanium was efficiently processed up to four passes at 420°C by rotary-die equal-channel angular pressing (RD-ECAP). The deformation structure and mechanical properties of pure titanium with various RD-ECAP passes were subsequently investigated. Microstructure evolution revealed that plastic deformation was accommodated mainly by twins during the first and second passes, while the predominant deformation mechanism was dislocation slip during the third and fourth passes. {1012} twins were detected in the first pass, and {1011} twins occurred in the second pass of RD-ECAP. The ultimate tensile strength of pure titanium increased from 450 MPa in the as-received state to 627 MPa with a fracture elongation of 29% after four passes of RD-ECAP.