Decomposition of the metastable beta phase in the all-beta alloy Ti-13V-11Cr-3Al

Narayanan, Gopal; Archbold, T.F.

doi:10.1007/bf02643446

Cited by 74 publications

(14 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This mechanism has not been observed experimentally for the formation of the omega phase, but has been reported recently with respect to the formation of the alpha phase [11], for which the same thermodynamic arguments hold. Other workers [12] have not been able to relate the beta phase precipitates in the Ti-V-Cr system directly to the formation of the alpha phase and have concluded that the precipitates are titanium-lean. On the other hand the precipitation of beta particles tentatively identified as titanium-rich has been found in a binary Ti-Cr alloy [13].…”

Section: Discussionmentioning

confidence: 97%

On the decomposition of the beta phase in titanium alloys

1971

View full text Add to dashboard Cite

A systematic analysis is made of the possible free energy diagrams for a binary titanium alloy consisting of a metastable beta phase, which tends to form either the alpha or the omega phase, or both. The predictions based on each of the possible free energy diagram configurations are compared with the available experimental data. Arguments are developed to show that it should be possible to nucleate an omega phase having an initial solute content less than the metastable equilibrium value and not necessarily a higher solute concentration, as suggested by other investigators. It is further shown that the observed precipitation of a solute-lean beta phase in certain binary and ternary beta alloys cannot be explained in terms of an ordinary miscibility gap resulting from a preference for bonds between like atoms rather than bonds between unlike atoms. An explanation is suggested on the basis of an early model proposed by M. K. McQuillan in which the electronic structure of the titanium atom can change with temperature leading to two possible types of bonding behaviour.

show abstract

Section: Discussionmentioning

confidence: 97%

On the decomposition of the beta phase in titanium alloys

1971

View full text Add to dashboard Cite

show abstract

“…After ageing treatment for relatively short time (two days), definite evidence of α phase and isothermal ω phase was not observed from bright field TEM image of the high Nb alloy. Instead, precipitation similar to the formation of a β +β structure 25,26) was found in these aged specimens (see Fig. 6(a)).…”

Section: Disscusionmentioning

confidence: 99%

“…6(a)). In the study of another β titanium alloy, Narayanan and Archbold 26) argued that when sufficient β stabilizing additions are present to retain β to room temperature, solute segregation or β-phase separation would occur during ageing. This decomposition mechanism can result in the formation of a β phase that is rich in β stabilising element, i.e., β .…”

Section: Disscusionmentioning

confidence: 99%

Effect of Nb on Microstructural Characteristics of Ti-Nb-Ta-Zr Alloy for Biomedical Applications

Hao

Yang

et al. 2002

Mater. Trans.

View full text Add to dashboard Cite

The effects of several commonly used heat treatment schemes on the microstructures of two Ti-Nb-Ta-Zr alloys aimed at biomedical applications were studied in this work using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The specimens were water quenched from 790 • C and then aged at temperatures between 300 • C and 600 • C. The experimental results showed that α and ω phase precipitated from the metastable β matrix in Ti-29Nb-13Ta-4.6Zr alloy during isothermal ageing. But for Ti-39Nb-13Ta-4.6Zr, the precipitation reaction was more sluggish than that in Ti-29Nb-13Ta-4.6Zr because of high amount of β stabilizing elements in the former alloy. As a result the α phase was unable to precipitate during short time ageing treatment. After longer time (12 days) ageing treatment at 500 • C or 400 • C, recognizable α precipitates were observed in the aged samples. It is concluded that Ti-29Nb-13Ta-4.6Zr can be heat treated to obtain different microstructures and is better than Ti-39Nb-13Ta-4.6Zr in terms of age hardenability.

show abstract

“…It seems reasonable to assume that the amount of precipitated a phase has a direct effect on the mechanical behavior of the Ti alloy. [35,36] As the deformation temperature is increased, the thermal energy of the dislocations is also increased, and, hence, their ability to overcome short-range barriers is enhanced. Therefore, at a strain rate of 8 · 10 2 s -1 and a temperature of 300°C, the dislocation cells have a looser structure and the dislocation density is reduced.…”

Section: Microstructural Observationsmentioning

confidence: 99%

Impact Response and Microstructural Evolution of Biomedical Titanium Alloy under Various Temperatures

Lee

Chen

Hwang

2008

Metall Mater Trans A

View full text Add to dashboard Cite

A compressive split-Hopkinson pressure bar and transmission electron microscope (TEM) are used to investigate the mechanical behavior and microstructural evolution of biomedical Ti alloy deformed at strain rates ranging from 8 · 10 2 s -1 to 8 · 10 3 s -1 at temperatures between 25°C and 900°C. In general, the results indicate that the mechanical behavior and microstructural evolution of the alloy are highly sensitive to both the strain rate and the temperature conditions. The flow-stress curves are found to include both a work-hardening region and a work-softening region. The strain-rate-sensitivity parameter, b, increases with increasing strain and strain rate but decreases with increasing temperature. The activation energy varies inversely with the flow stress and has a low value at high deformation strain rates and low temperatures. Microstructural observations reveal that the strengthening effect evident in the deformed alloy is a result primarily of dislocations and the formation of a phase. The dislocation density increases with increasing strain rate but decreases with increasing temperature. Additionally, the square root of the dislocation density varies linearly with the flow stress. Correlating the mechanical properties of the biomedical Ti alloy with the TEM observations, it is inferred that the precipitation of a phase dominates the fracture strain. Transmission electron microscope observations reveal that the amount of a phase increases with increasing temperature below the b-transus temperature. The maximum amount of a phase is formed at a temperature of 700°C and results in the minimum fracture strain observed under the current loading conditions.

show abstract

Decomposition of the metastable beta phase in the all-beta alloy Ti-13V-11Cr-3Al

Cited by 74 publications

References 4 publications

On the decomposition of the beta phase in titanium alloys

On the decomposition of the beta phase in titanium alloys

Effect of Nb on Microstructural Characteristics of Ti-Nb-Ta-Zr Alloy for Biomedical Applications

Impact Response and Microstructural Evolution of Biomedical Titanium Alloy under Various Temperatures

Contact Info

Product

Resources

About