TY - JOUR
T1 - Evolution of equiaxed and lamellar α during hot compression in a near alpha titanium alloy with bimodal microstructure
AU - Zhou, Dadi
AU - Zeng, Weidong
AU - Xu, Jianwei
AU - Wang, Simin
AU - Chen, Wei
N1 - Publisher Copyright:
© 2019 Elsevier Inc.
PY - 2019/5
Y1 - 2019/5
N2 - Microstructural evolution of equiaxed α and lamellar α during hot compression in a bimodal-structure near alpha Ti-6Al-3Nb-2Zr-1Mo alloy were investigated. Focus was concentrated on their own dynamic restoration mechanism via electron backscatter diffraction (EBSD) technique. Based on analysis of grain boundary misorientation distribution and misorientation gradient within α grain, it was revealed that limited continuous dynamic recrystallization (CDRX) as well as adequate dynamic recovery (DRV) took place within equiaxed α whereas CDRX occurred as the main restoration mechanism in lamellar α. Further, the deformation heterogeneous among equiaxed α grains was found to be relevant to the difference in slip systems. Under the same nominal strain of 75% height reduction, process of weak DRV, strong DRV and CDRX coexisted in distinct equiaxed α grains owning to small, medium and high Schmid Factor of prismatic slip. Besides, globularization heterogeneity induced by CDRX in lamellar α was considered to be closely related with its initial orientation to compression axis and the imposed strain. For flat colony α the microstructure was relatively stable during straining showing a thinning process and a weak dynamic globularization, while the kinked colony α with large strain was globularized sufficiently.
AB - Microstructural evolution of equiaxed α and lamellar α during hot compression in a bimodal-structure near alpha Ti-6Al-3Nb-2Zr-1Mo alloy were investigated. Focus was concentrated on their own dynamic restoration mechanism via electron backscatter diffraction (EBSD) technique. Based on analysis of grain boundary misorientation distribution and misorientation gradient within α grain, it was revealed that limited continuous dynamic recrystallization (CDRX) as well as adequate dynamic recovery (DRV) took place within equiaxed α whereas CDRX occurred as the main restoration mechanism in lamellar α. Further, the deformation heterogeneous among equiaxed α grains was found to be relevant to the difference in slip systems. Under the same nominal strain of 75% height reduction, process of weak DRV, strong DRV and CDRX coexisted in distinct equiaxed α grains owning to small, medium and high Schmid Factor of prismatic slip. Besides, globularization heterogeneity induced by CDRX in lamellar α was considered to be closely related with its initial orientation to compression axis and the imposed strain. For flat colony α the microstructure was relatively stable during straining showing a thinning process and a weak dynamic globularization, while the kinked colony α with large strain was globularized sufficiently.
KW - Bimodal microstructure
KW - Continuous dynamic recrystallization
KW - Dynamic recovery
KW - Microstructural evolution
UR - http://www.scopus.com/inward/record.url?scp=85062356185&partnerID=8YFLogxK
U2 - 10.1016/j.matchar.2019.03.005
DO - 10.1016/j.matchar.2019.03.005
M3 - 文章
AN - SCOPUS:85062356185
SN - 1044-5803
VL - 151
SP - 103
EP - 111
JO - Materials Characterization
JF - Materials Characterization
ER -