Effects of Cold Deformation on the Morphology of .ALPHA. Precipitates in .BETA. Titanium Alloys.

Ohyama, Hideto; Nakamori, Hideyuki; Ashida, Yoshio; Maki, Tadashi

doi:10.2355/isijinternational.32.222

Cited by 28 publications

(17 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In our study, it is supposed that dislocations act as the preferential nucleation sites for the formation of the aligned Į precipitates. It has been observed that Į precipitates nucleate along dislocations within slip bands during aging treatments of a cold rolled Ti-15V-3Cr-3Sn-3Al alloy [49,50]. During high strain rate deformations, structural defects like dislocations and vacancies will multiply in a much faster manner and the influence of networks of localized dislocations may increase.…”

Section: Novel į Precipitate Morphologies and Strain Localizationmentioning

confidence: 99%

The dynamic response of a β titanium alloy to high strain rates and elevated temperatures

Zhan

Kent

Wang

et al. 2014

Materials Science and Engineering: A

View full text Add to dashboard Cite

The stress-strain behaviour and microstructural evolution of the Ti-6Cr-5Mo-5V-4Al (Ti6554) alloy was systematically investigated using Split Hopkinson Pressure Bar (SHPB) tests over a wide range of strain rates from 1000 s -1 to 10000 s -1 and initial temperatures from 293K to 1173K. Dislocation slip is the main deformation mechanism for plastic flow of the Ti6554 alloy at high strain rates. The flow stress increases with increasing strain rate and decreasing temperature. Also the flow stress is more sensitive to temperature than to strain rate. For high strain rate deformations, the strain hardening rate is found to be negative at 293K and increases with increasing temperatures. Flow softening observed at 293K is potentially caused by adiabatic heating. The increment in the strain hardening rate with increasing temperatures may be the result of interactions between thermally activated solute Cr atoms and mobile dislocations. When the temperature is raised to 873K, a novel Į precipitate 2 morphology consisting of globular Į aligned in strings was observed in specimens deformed at strain rates of 4000 and 10000 s -1 . It has hardening effects on the ȕ matrix and is purported to nucleate on dislocations introduced by the high strain rate deformation. Adiabatic shear bands were observed in specimens deformed at higher temperatures (873K). The microstructure inside the shear bands is harder than that outside of the shear bands in the Ti6554 alloy.

show abstract

Section: Novel į Precipitate Morphologies and Strain Localizationmentioning

confidence: 99%

The dynamic response of a β titanium alloy to high strain rates and elevated temperatures

Zhan

Kent

Wang

et al. 2014

Materials Science and Engineering: A

View full text Add to dashboard Cite

show abstract

“…[21][22][23] The combination of lower aging temperature followed by a higher aging temperature appears to be more successful in improving the toughness. [24] With a metastable b phase at room temperature, Ti-15-3 alloys could be cold rolled [25] and further aged in a single step also. [26] Due to their excellent cold formability, the main applications of Ti-15-3 alloys are in fabrication from as-rolled strips.…”

Section: Introductionmentioning

confidence: 99%

Microstructure and Mechanical Properties of Gas-Tungsten-Arc–Welded Ti-15-3 Beta Titanium Alloy

Balachandar

Sarma

Pant

et al. 2009

Metall Mater Trans A

View full text Add to dashboard Cite

Microstructure and mechanical properties of gas-tungsten-arc (GTA)-welded Ti-15V-3Cr-3Sn-3Al alloy in direct current electrode negative mode are characterized. The thermal profile was measured during welding with continuous current (CC) and pulsed current (PC) at different frequencies. A single-step postweld aging of the welded samples at subtransus temperature was attempted to study precipitation of alpha phase. Two different morphologies of alpha phase are observed along with a partitioning of alloying elements into the two phases. Processing conditions for higher strength are identified and correlated with the thermal profile. Microstructure changes due to postweld heat treatment were characterized.

show abstract

“…The deformation of this phase involves slip, f332gh113i twinning and stressinduced martensitic transformation, depending on the stability of phase. [1][2][3][4] Crystallographic slip occurs in alloys with high stability of phase, while stress-induced martensitic transformation and f332gh113i twinning are formed in unstable phase alloys. Especially, the twinning is known to form in unstable phase containing finely distributed athermal !…”

Section: Introductionmentioning

confidence: 99%

Beta TiNbSn Alloys with Low Young’s Modulus and High Strength

2005

View full text Add to dashboard Cite

Young's modulus and tensile strength were investigated in relation to phase transformation and microstructural changes occurring during cold rolling and subsequent heat treatment using (Ti-35 mass%Nb)-4 mass%Sn and (Ti-35 mass%Nb)-7.9 mass%Sn alloys. Stress-induced 00 martensite is generated on cold rolling of (Ti-35Nb)-4Sn whose martensitic transformation start temperature is around room temperature. Young's modulus in the rolling direction is lowered by the generation of stress induced 00 phase with preferred texture, while it is recovered by the reverse martensitic transformation to at 523 K. The reverse transformation yields fine grains which are elongated approximately along the rolling direction and have an average grain size in width of less than 1 mm. This fine microstructure leads to high strength over 800 MPa with keeping low static Young's modulus of 43 GPa. In contrast, mechanical properties of (Ti-35Nb)-7.9Sn in which matensite is not stress-induced are not so significantly improved by cold rolling and heat treatment.

show abstract

Effects of Cold Deformation on the Morphology of .ALPHA. Precipitates in .BETA. Titanium Alloys.

Cited by 28 publications

References 0 publications

The dynamic response of a β titanium alloy to high strain rates and elevated temperatures

The dynamic response of a β titanium alloy to high strain rates and elevated temperatures

Microstructure and Mechanical Properties of Gas-Tungsten-Arc–Welded Ti-15-3 Beta Titanium Alloy

Beta TiNbSn Alloys with Low Young’s Modulus and High Strength

Contact Info

Product

Resources

About

Effects of Cold Deformation on the Morphology of .ALPHA. Precipitates in .BETA. Titanium Alloys.

Cited by 28 publications

References 0 publications

The dynamic response of a β titanium alloy to high strain rates and elevated temperatures

The dynamic response of a β titanium alloy to high strain rates and elevated temperatures

Microstructure and Mechanical Properties of Gas-Tungsten-Arc–Welded Ti-15-3 Beta Titanium Alloy

Beta TiNbSn Alloys with Low Young&rsquo;s Modulus and High Strength

Contact Info

Product

Resources

About

Beta TiNbSn Alloys with Low Young’s Modulus and High Strength