Effects of microstructural parameters and back stress on damage mechanisms in {alpha}/{beta} titanium alloys

Journal Article · Fri Jan 23 04:00:00 EST 1998 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(97)00288-7· OSTI ID:599866

Helbert, A L; Feaugas, X; Clavel, M ^[1]

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1. Univ. de Technologie de Compiegne (France)

Damage initiation and kinetics in four {alpha}/{beta} titanium alloys have been experimentally and numerically investigated. Efforts were focused on triaxiality, {chi} = {Sigma}{sub m}/{Sigma}{sub eq} and internal stresses effects. The study of void nucleation has provided nucleation criteria corresponding to voids at the {alpha}/{beta} interface. This macroscopic nucleation criterion, written as {Sigma}{sub m} = f({var_epsilon}{sub peq}), was explained with the help of microscopic observations. Microscopic parameters such as plastic strain in the {alpha}-phase or local hydrostatic stress {sigma}{sub m}{sup loc} at the {alpha}/{beta} interface have been linked to the damage initiation. Also, the influence of the different heterogeneity levels on the macroscopic nucleation criterion was demonstrated. It has also been shown that internal stresses increased both nucleation and growth kinetics. Damage mechanisms are well described by a Gurson-Tvergaard model modified to take into account internal stresses. In particular, the existence of a material physical property, f{sub c} (void volume fraction at fracture) was shown.

• OSTI ID: 599866
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 3 Vol. 46; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL DEFECTS
FRACTURE PROPERTIES
MICROSTRUCTURE
NUCLEATION
TITANIUM ALLOYS