Affordable Access

Publisher Website

Effects of alloying on crack-tip deformation and shielding in gamma-based titanium aluminides

Authors
Journal
Acta Materialia
1359-6454
Publisher
Elsevier
Publication Date
Volume
45
Issue
3
Identifiers
DOI: 10.1016/s1359-6454(96)00239-x
Disciplines
  • Physics

Abstract

Abstract The effects of ternary alloying of Ti-48Al (with 1–3 at.% Mn, Cr and V), and micro-alloying with 0.2% W, on crack-tip deformation and shielding mechanisms are discussed in this paper, for failure under cyclic (fatigue) loading. Crack-tip deformation mechanisms are elucidated by crack-tip transmission electron microscopy examination. Twin process zone dimensions and the degree of deformation-induced twinning are also determined via optical interference and transmission electron microscopy techniques, respectively. A micromechanics-based model is proposed for the estimation of twin toughening ratios under monotonic or cyclic loading. The model, which is based on non-linear fracture mechanics concepts, assumes an average ‘smeared’ plastic stress distribution across the twin process zone. Differences in the resistance to crack growth in the ternary alloys are related to intrinsic microstructural features and crack-tip shielding phenomena.

There are no comments yet on this publication. Be the first to share your thoughts.