TY - JOUR
T1 - New aspects of globularization crystallography and dynamic phase evolution during thermomechanical processing of Ti–6Al–4V alloy
AU - Callegari, Bruna
AU - Oliveira, João Pedro
AU - Coelho, Rodrigo Santiago
AU - Brito, Pedro Paiva
AU - Schell, Norbert
AU - Soldera, Flavio
AU - Mücklich, Frank
AU - Pinto, Haroldo Cavalcanti
N1 - Funding Information:
info:eu-repo/grantAgreement/EC/H2020/730872/EU#
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB%2F00667%2F2020/PT#
This work was supported by the National Council for Scientific and Technological Development – CNPq (grant number 161959/2015-6 ), by the Coordination for the Improvement of Higher Education Personnel – CAPES (grant number 88887.302,880/2018-00 and PROBRAL project 88881.143948/2017-01 ), by the German Academic Exchange Service – DAAD (project DAAD PPP-Brazil 2018 – ID 57390937 ).
Funding Information:
This work was supported by the National Council for Scientific and Technological Development ? CNPq (grant number 161959/2015-6), by the Coordination for the Improvement of Higher Education Personnel ? CAPES (grant number 88887.302,880/2018-00 and PROBRAL project 88881.143948/2017-01), by the German Academic Exchange Service ? DAAD (project DAAD PPP-Brazil 2018 ? ID 57390937).
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2022/1/15
Y1 - 2022/1/15
N2 - Microstructural and crystallographic aspects arising from thermomechanical processing of a Ti–6Al–4V alloy in β and α+β phase fields were studied by electron backscatter diffraction and both conventional and high energy synchrotron X-ray diffraction. The impact of deformation in the single β field on the final microstructure has been acknowledged by an increase of the retained β phase content and decrease of martensitic c/a ratio with the reduction of strain rate, although no significant influence of strain rate on the well-defined fiber texture of α' has been observed. During deformation in the α+β field, texture weakening has been observed, and misorientation angle/axis distribution analysis has evidenced randomization and loss of the Burgers orientation relationship between α and β upon globularization. The behavior of deformed α lamellae in the α+β field was also evaluated in terms of internal misorientation spread and lattice rotation around the deformation axis, corroborating that globularization takes place through dynamic recrystallization, boundary splitting and shearing. Globularized grain size was shown to be exponentially proportional to strain rate decrease. Lower strain rates in the α+β field also increase the β phase fraction and decrease the c/a ratio of the α phase, leading to values closer to the ideal one for titanium. However, an excessive amount of β causes its instability during quenching, resulting in its decomposition into secondary α during cooling.
AB - Microstructural and crystallographic aspects arising from thermomechanical processing of a Ti–6Al–4V alloy in β and α+β phase fields were studied by electron backscatter diffraction and both conventional and high energy synchrotron X-ray diffraction. The impact of deformation in the single β field on the final microstructure has been acknowledged by an increase of the retained β phase content and decrease of martensitic c/a ratio with the reduction of strain rate, although no significant influence of strain rate on the well-defined fiber texture of α' has been observed. During deformation in the α+β field, texture weakening has been observed, and misorientation angle/axis distribution analysis has evidenced randomization and loss of the Burgers orientation relationship between α and β upon globularization. The behavior of deformed α lamellae in the α+β field was also evaluated in terms of internal misorientation spread and lattice rotation around the deformation axis, corroborating that globularization takes place through dynamic recrystallization, boundary splitting and shearing. Globularized grain size was shown to be exponentially proportional to strain rate decrease. Lower strain rates in the α+β field also increase the β phase fraction and decrease the c/a ratio of the α phase, leading to values closer to the ideal one for titanium. However, an excessive amount of β causes its instability during quenching, resulting in its decomposition into secondary α during cooling.
KW - Dynamic phase evolution
KW - Globularization
KW - Texture
KW - Thermomechanical processing
KW - Titanium alloys
UR - http://www.scopus.com/inward/record.url?scp=85118492816&partnerID=8YFLogxK
U2 - 10.1016/j.matchemphys.2021.125388
DO - 10.1016/j.matchemphys.2021.125388
M3 - Article
AN - SCOPUS:85118492816
SN - 0254-0584
VL - 276
JO - Materials Chemistry And Physics
JF - Materials Chemistry And Physics
M1 - 125388
ER -