Hot compressive behaviors of Ti-6Al-2Zr-1Mo-1V alloy at 800℃, as well as the evolution of microstructure during deformation process, were investigated. The experimental results show that flow stress increases to a pe...Hot compressive behaviors of Ti-6Al-2Zr-1Mo-1V alloy at 800℃, as well as the evolution of microstructure during deformation process, were investigated. The experimental results show that flow stress increases to a peak stress followed by a decease with increasing strain, and finally forms a stable stage. Dislocations are generated at the interface of αβ phase, and the phase interface and dislocation loops play an important role in impeding the movement of dislocation. As strain increasing, micro-deformation bands with high-density dislocation are formed, and dynamic recrystallizaton occurs finally. XRD Fourier analysis reveals that dislocation density increases followed by a decrease during compressive deformation, and falls into the range from 10^10 to 10^11 cm^-2.展开更多
The deformation mode of{332}<113>twinning(hereafter called 332T)has often been observed under the plastic flow in metastableβtitanium alloys with body-centered cubic(BCC)structure,which contributes to improving...The deformation mode of{332}<113>twinning(hereafter called 332T)has often been observed under the plastic flow in metastableβtitanium alloys with body-centered cubic(BCC)structure,which contributes to improving the mechanical performance.Herein,we report a structure of compressive deformation-induced primary 332T with hierarchical and/or heterogeneous composite sub-structure in a Twin-Induced Plasticity(TWIP)βTi-alloy under uniaxial compression.The detailed structural characterization after compressive deformation revealed that the sub-structure,including secondary 332T and secondary{112}<111>twinning,formed inside the 332T structure,which constitutes a hierarchical and/or heterogeneous structure at micro-and nano-scale and consequently contributes to the high strength,large ductility and enhanced strain-hardening behavior.展开更多
The goal of this study is to establish relationships between the hot compression deformation behaviors and the fractal dimension of primary phase morphology of TA15 titanium alloy using the analytical methods of metal...The goal of this study is to establish relationships between the hot compression deformation behaviors and the fractal dimension of primary phase morphology of TA15 titanium alloy using the analytical methods of metallurgical microscope and transmission electron microscope coupled with box-counting dimension method. The hot compression deformation behaviors vary with decreasing fractal dimension owing to the change of microstructure caused by different parameters of the hot compressive deformation.The results indicate that TA15 alloy shows dynamic recrystallization characteristics at deformation temperature lower than 850℃while fractal dimension exhibits a moderate decreasing trend with the temperature increasing,and shows dynamic recovery characteristics at deformation temperature higher than 850℃while fractal dimension reduces rapidly with the temperature increasing.The fractal dimension displays non-linear relationship with fraction of primary phase and with aspect ratio of primary phase.展开更多
文摘Hot compressive behaviors of Ti-6Al-2Zr-1Mo-1V alloy at 800℃, as well as the evolution of microstructure during deformation process, were investigated. The experimental results show that flow stress increases to a peak stress followed by a decease with increasing strain, and finally forms a stable stage. Dislocations are generated at the interface of αβ phase, and the phase interface and dislocation loops play an important role in impeding the movement of dislocation. As strain increasing, micro-deformation bands with high-density dislocation are formed, and dynamic recrystallizaton occurs finally. XRD Fourier analysis reveals that dislocation density increases followed by a decrease during compressive deformation, and falls into the range from 10^10 to 10^11 cm^-2.
基金supported by the Fund of State Key Lab of Advanced Metals and Materials,University of Science and Technology Beijing(No.2019-ZD03)the Fund of the State Key Laboratory of Solidification Processing,Northwestern Polytechnical University(No.SKLSP201501)+2 种基金the National Natural Science Foundation of China(Nos.51601216 and 51901193)the Fundamental Research Funds for the Central Universities(Nos.2017XKQY009 and 2018GF13)sponsored by China Scholarship Council。
文摘The deformation mode of{332}<113>twinning(hereafter called 332T)has often been observed under the plastic flow in metastableβtitanium alloys with body-centered cubic(BCC)structure,which contributes to improving the mechanical performance.Herein,we report a structure of compressive deformation-induced primary 332T with hierarchical and/or heterogeneous composite sub-structure in a Twin-Induced Plasticity(TWIP)βTi-alloy under uniaxial compression.The detailed structural characterization after compressive deformation revealed that the sub-structure,including secondary 332T and secondary{112}<111>twinning,formed inside the 332T structure,which constitutes a hierarchical and/or heterogeneous structure at micro-and nano-scale and consequently contributes to the high strength,large ductility and enhanced strain-hardening behavior.
文摘The goal of this study is to establish relationships between the hot compression deformation behaviors and the fractal dimension of primary phase morphology of TA15 titanium alloy using the analytical methods of metallurgical microscope and transmission electron microscope coupled with box-counting dimension method. The hot compression deformation behaviors vary with decreasing fractal dimension owing to the change of microstructure caused by different parameters of the hot compressive deformation.The results indicate that TA15 alloy shows dynamic recrystallization characteristics at deformation temperature lower than 850℃while fractal dimension exhibits a moderate decreasing trend with the temperature increasing,and shows dynamic recovery characteristics at deformation temperature higher than 850℃while fractal dimension reduces rapidly with the temperature increasing.The fractal dimension displays non-linear relationship with fraction of primary phase and with aspect ratio of primary phase.
