On the implications of deformation-induced crack-tip deformation in a gamma-based titanium aluminide intermetallic

Journal Article · Wed Jun 15 04:00:00 EDT 1994 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(94)90300-X· OSTI ID:7114894

Soboyejo, W O; Mercer, C ^[1]

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1. Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering

Recent work on gamma-based titanium aluminides has shown that deformation-induced twinning can play a significant role in the shielding of the crack-tip in gamma-based titanium aluminides with large grain sizes. However, although the role of deformation-induced twinning has received some attention for monotonic loading at room temperature, there have been no efforts to examine the potential role of deformation-induced twinning on fatigue crack growth mechanisms at room temperature. This is examined in the current paper via crack-tip transmission electron microscopy (TEM) and optical interference microscopy techniques. The role of deformation-induced twinning is also assessed at the threshold condition using non-linear fracture mechanics concepts, and the implications of deformation-induced twinning are elucidated for kinematic irreversibility under cyclic loading. It is postulated that the faster fatigue crack growth rates in gamma alloys can be attributed partly to the higher incidence of irreversible deformation-induced crack-tip twinning phenomena.

• OSTI ID: 7114894
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 30:12; ISSN SCRMEX; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
CRACK PROPAGATION
DATA
DEFORMATION
EXPERIMENTAL DATA
FATIGUE
FRACTURE MECHANICS
INFORMATION
MECHANICAL PROPERTIES
MECHANICS
NUMERICAL DATA
TITANIUM ALLOYS
TITANIUM BASE ALLOYS
TWINNING