Fatigue life and failure characteristics of an ultrafine-grained Ti-6Al-4V alloy processed by ECAP and extrusion

Authors: Polyakov, A.V., Semenova, I.P., Huang, Y., Valiev, R.Z. and Langdon, T.G.

Journal: Advanced Engineering Materials

Volume: 16

Issue: 8

Pages: 1038-1043

eISSN: 1527-2648

ISSN: 1438-1656

DOI: 10.1002/adem.201300530

Abstract:

Experiments were conducted to investigate the low-cycle deformation behavior of an ultrafine-grained (UFG) Ti-6Al-4V alloy produced by severe plastic deformation (SPD) through a combination of equal-channel angular pressing (ECAP) and extrusion. The fatigue properties were examined by stress-controlled fatigue testing at stress amplitudes in the range of 700-1050 MPa. The specimens exhibited a dimpled final overload fracture mode. The results show the UFG alloy has a longer fatigue life and a finer dimple size than the coarse-grained material. A Ti-6Al-4V alloy is processed using equal-channel angular pressing and extrusion to produce an ultrafine-grained (UFG) material with a grain size of 240 nm. Tensile testing shows increased tensile strength compared with the coarse-grained (CG) material. In fatigue testing, the UFG alloy has a longer fatigue life than the CG material. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Source: Scopus