A D.S.C study of the transformation of retained {beta} ({beta}{sub m}) obtained by quenching of Ti6Al4V

Journal Article · Wed May 01 00:00:00 EDT 1996 · Scripta Materialia

DOI:https://doi.org/10.1016/1359-6462(95)00665-6· OSTI ID:233887

Mekideche, A; Debuigne, J ^[1]; Matecki, M ^[2]

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1. INSA, Rennes (France). Laboratoire de Metallurgie et Physico-Chimie des Materiaux
2. Univ. de Rennes 1 (France)

{alpha} + {beta} titanium alloys are the most popular ones and therefore there is much information on phase transformation and mechanical properties for these alloys. Ti6Al4V belong to this group because of the Al and V additions. The vanadium stabilizes the {beta} (b.c.c.) phase of titanium and the aluminum stabilizes the {alpha} (h.c.p.) phase so that at low temperature it is possible to have in equilibrium a vanadium rich {beta} phase and an aluminum rich {alpha} phase. It is well known that {beta}-Ti6Al4V transforms into a h.c.p. martensitic phase {alpha}{prime} by rapid cooling from above the {beta} transus, for example by water quenching of not too thick samples. This transformation has no hardening effect for the alloy, however this {alpha}{prime} phase has very low ductility. In order to obtain better mechanical characteristics a lot of work has been performed on thermal and thermomechanical treatments. It was observed that the {beta} phase when water quenched from temperatures below the {beta} transus does not transform completely into {alpha}{prime} leaving retained {beta}, named {beta}{sub m}, at room temperature. This {beta}{sub m} phase is in a metastable condition and can transform to {alpha}{prime} if activated. There is no calorimetric analysis for this {beta}{sub m} {yields} {alpha}{prime} transition, the thermal effect being certainly very low as for all the processes which may be mechanically activated. In the authors` work they use the sensitive D.S.C. technique for the calorimetric investigation of the transformation {beta}{sub m} {yields} {alpha}{prime} up to 600 C. They determine also the optimal temperature range from which {beta}{sub m} may be obtained by water quenching of the alloy and they correlate the results with other previously published partial ones.

• OSTI ID: 233887
• Journal Information: Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 9 Vol. 34; ISSN 1359-6462; ISSN XZ503X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
ANNEALING
BCC LATTICES
CRYSTAL-PHASE TRANSFORMATIONS
EXPERIMENTAL DATA
FATIGUE
FRACTURE PROPERTIES
HCP LATTICES
HEAT FLUX
MARTENSITE
MECHANICAL PROPERTIES
TEMPERATURE DEPENDENCE
TITANIUM ALLOYS
VANADIUM ALLOYS
X-RAY DIFFRACTION