@article{liao_luan_zhang_liu_murty_liu_2020, title={A multi-deformation mechanisms assisted metastable beta-ZrTiAlV alloy exhibits high yield strength and high work hardening rate}, volume={816}, ISSN={["1873-4669"]}, DOI={10.1016/j.jallcom.2019.152642}, abstractNote={A metastable β-51.1Zr-40.2Ti-4.5Al-4.2V (wt.%) alloy with both TRIP and TWIP effects, exhibiting high yield strength of 800 MPa, high work hardening rate and good total elongation close to 17.5% was reported. The solid solution strengthening of high content of Ti and the special initial deformation mechanisms result in the outstanding yield strength. Microstructural analyses show that the dominant deformation mechanisms transformed from deformation-induced β→α′ martensitic transformation and kinking band at low strain to deformation-induced β→α′ martensitic transformation, widening and merging of α′ martensite, and {101‾1}α′ twinning at high strain. Changes in the dominant deformation mechanisms at different deformation stages lead to changes in special boundaries, resulting in a substantial high work hardening rate (2000–5440 MPa) until 10% strain. In addition, the reason for the TWIP effect in present alloy is internal {101‾1}α′ twin, which is different from that of the previously reported twins.}, journal={JOURNAL OF ALLOYS AND COMPOUNDS}, author={Liao, Zhongni and Luan, Baifeng and Zhang, Xinyu and Liu, Riping and Murty, Korukonda L. and Liu, Qing}, year={2020}, month={Mar} }
 @article{liao_luan_zhang_liu_murty_liu_2020, title={Effect of varying a phase fraction on the mechanical properties and deformation mechanisms in a metastable beta-ZrTiAlV alloy}, volume={772}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2019.138784}, abstractNote={We systematically investigated the effects of varying α phase fraction on the mechanical properties and deformation mechanisms in a metastable β-51.1Zr-40.2Ti-4.5Al-4.2V (wt. %) alloy containing mixed α + β phase. Various heat treatments from single β phase regime to dual α+β phase regime were imposed in order to alter the volume fraction of α phase. The results show that the triggering stress increases and the total elongation decreases with the increasing α phase fraction. As the α phase fraction increases, the work hardening rate curve changes from an obvious parabolic evolution to a monotonically decreasing evolution and the work hardening effect is gradually reduced. Co-existence deformation mechanisms of kink bands, deformation-induced α′ martensite and {101‾1}α′ mechanical twinning were detected in low α phase fraction samples but not in high α phase fraction sample. In intermediate α phase fraction sample, only deformation-induced α′ martensite was activated. For the first time, the effects of α phase fraction on the deformation-induced α′ martensite, {101‾1}α′ mechanical twinning and kink bands were observed in metastable β-Zr alloy. These effects of varying α phase fraction on the mechanical properties and deformation mechanisms are discussed based on the β stability and the β domain size.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Liao, Zhongni and Luan, Baifeng and Zhang, Xinyu and Liu, Riping and Murty, Korukonda L. and Liu, Qing}, year={2020}, month={Jan} }
 @article{liao_luan_zhang_liu_murty_liu_2019, title={The effects of increasing deformation strain on the microstructural evolution of a metastable beta-Zr alloy}, volume={800}, ISSN={["1873-4669"]}, DOI={10.1016/j.jallcom.2019.05.334}, abstractNote={In this study, we investigated the morphology evolution of deformation-induced α', α″ martensite and retained β phase with increasing deformation strain in metastable β-Zr-43.2Ti-4.5Al-4.2V (wt. %) alloy by ex-situ and regular compression tests. Three types of deformation-induced α' martensite have been observed for the first time during deformation, namely, twinned α' martensite, untwinned α' martensite and paired α' martensite. Transitions in morphology of twinned α' martensite from thin plate to twinned plate and to widened twinned plate, eventually to {101¯2} twin-related domains and of untwinned α' martensite from thin plate to widened plate to domain have been observed with increasing deformation strains. The paired α' martensite is undergone a process in which the α' martensite impacted grain boundaries stimulating the nucleation of new α' martensite in neighboring grains, and then leading to martensite growth on both sides grow simultaneously. With progressive deformation, the nano-size deformation-induced α″ martensite changes from long thin plate to ladder-shaped plate to 90° rotation domains. The morphology evolution of untwinned α' martensite, paired α' martensite and α″ martensite are mainly related to the self-accommodation mechanism, while the morphology evolution of twinned α' martensite is mainly related to the plastic accommodation mechanism. The average hardness increased with increase in deformation strains, owing to the martensitic transformation strengthening along with dislocation multiplication strengthening.}, journal={JOURNAL OF ALLOYS AND COMPOUNDS}, author={Liao, Zhongni and Luan, Baifeng and Zhang, Xinyu and Liu, Riping and Murty, Korukonda L. and Liu, Qing}, year={2019}, month={Sep}, pages={208–218} }
 @article{zeng_luan_wang_zhang_liu_murty_liu_2018, title={Effect of initial orientation on dynamic recrystallization of a zirconium alloy during hot deformation}, volume={145}, ISSN={["1873-4189"]}, DOI={10.1016/j.matchar.2018.09.008}, abstractNote={The present study investigated the influence of the initial orientation on the dynamic recrystallization (DRX) behavior of a Zr-1Sn-0.3Nb alloy. A hot-rolled and annealed Zr sheet was compressed along two directions: along the normal direction so that the grains' ⟨c⟩-axis was nearly parallel to the loading direction (0° sample) and along the transverse direction so that the grains' ⟨c⟩-axis was nearly perpendicular to the loading direction (90° sample). The samples were compressed at 700 °C at a strain rate of 1 s−1. The microstructures at different strains were characterized by the electron backscatter diffraction (EBSD) technique, and conventional dislocation analysis using transmission electron microscope (TEM) was performed. A threshold value of grain orientation spread (GOS) equaled to 5° was used to distinguish the dynamically recrystallized grains from the deformed matrix. The results revealed that the DRX behavior strongly depended on the initial orientation. The Schmid factor analysis and TEM observation confirmed that pyramidal ⟨c + a⟩ slip operated from the first stage of deformation in the 0° sample but not in the 90° sample. For the 0° sample, in the early and medium stages of deformation, due to the high stored energy caused by the operation of pyramidal ⟨c + a⟩ slip, DDRX was mainly contributed to the formation of new fine grains. However, in the later stage of deformation, the DRX mechanism changed from DDRX to CDRX. In the 90° sample, although DDRX featured by grain boundary bulging occurred, the main DRX mechanism was CDRX in the whole deformation processing. Moreover, texture induced hardening in the early stage of deformation hides the softening induced by DDRX.}, journal={MATERIALS CHARACTERIZATION}, author={Zeng, Qinghui and Luan, Baifeng and Wang, Yuhui and Zhang, Xinyu and Liu, Riping and Murty, Korukonda Linga and Liu, Qing}, year={2018}, month={Nov}, pages={444–453} }
 @article{liao_luan_zhang_xing_liu_murty_liu_2019, title={Study of deformation mechanisms in a metastable beta Zr alloy during compression}, volume={237}, ISSN={["1873-4979"]}, DOI={10.1016/j.matlet.2018.11.043}, abstractNote={The deformation mechanisms in a metastable β-48.1Zr-43.2Ti-4.5Al-4.2V (wt%) alloy after room-temperature compression to ∼6% strain were investigated. The results indicated that the alloy deforms primarily by deformation-induced β → α′ martensitic transformation and 101¯2<101¯1> twinning, and limited deformation-induced β → α″ martensitic transformation. The 101¯2<101¯1> twinning was formed within the α′ plate to accommodate the local plastic deformation strain generated in α′ martensite plate during compression. Such a combination of deformation mechanisms were observed in metastable β Zr or Ti alloys for the first time, which can aid future development of superior β Zr alloys displaying a potentially combination of transformation-induced plasticity (TRIP) and transformation twinning-induced plasticity (TWIP) effects.}, journal={MATERIALS LETTERS}, author={Liao, Zhongni and Luan, Baifeng and Zhang, Xinyu and Xing, Qingfeng and Liu, Riping and Murty, K. L. and Liu, Qing}, year={2019}, month={Feb}, pages={172–175} }
 @inproceedings{luan_qiu_zhou_murty_zhou_liu_2014, title={Characterization of hot deformation behavior of Zr-1.0Sn-0.3Nb-0.3Fe-0.1Cr using processing map}, DOI={10.1115/icone21-15186}, abstractNote={Hot deformation characteristics of forged and β-quenched Zr-1.0Sn-0.3Nb-0.3Fe-0.1Cr (N18 alloy) in the temperature range 625–950°C and in the strain rate range 0.005–5 s−1 have been studied by uniaxial compression testing of Gleeble 3500. For this study, the approach of processing maps has been adopted and their interpretation done using the Dynamic Materials Model (DMM). Based on a series of true stress-true strain curves on various temperatures and strain rates, the flow stress has been summarized and both the strain rate sensitivity index (m) and deformation activation energy (Q) have been calculated by the constitutive equations that flow stress and the relationship of Z parameter and flow stress have been established subsequently. Furthermore, the efficiency of power dissipation (⬜) given by [2m/(m+1)] and improved by Murty has been plotted as a function of temperature and strain rate to obtain different processing maps at different true strain rates ranging from 0.1–0.7. Subsequently, the microstructures of the specimens after compression testing were characterized by electron channeling contrast (ECC) imaging techniques used an FEI Nova 400 field emission gun scanning electron microscopy (FEG-SEM). The results showed that: (i) The hyperbolic sine constitutive equation can describe the flow stress behavior of zirconium alloy, and the deformation activation energy and flow stress equation were calculated under the different temperature stages which insists that the deformation mechanism is not dynamic recovery. (ii) The hot processing maps and its validation were analyzed, which indicated that the DMM theory was reliable and could be adopted as useful tool for optimizing hot workability of Zr. The optimum parameters for extrusion and hammer forging were revealed on the processing maps of 830–950°C, 0.048–2.141 s−1 and 916–950°C, 2.465–5 s−1. (iii) The microstructure of the ingot exhibits a typical lamellar Widmanstatten structure. Under the different strain rates, the grains formed by dynamic recrystallization existed normally in the central zone of the compression samples while the no uniformity of grain size increased with the increasing of strain rate. Meanwhile, due to the dynamic recrystallization as a thermal activation process, the grains size and uniformity increased with the increasing of temperature. In brief, microstructure analysis showed that continuous dynamic recrystallization and geometric dynamic recrystallization operated concurrently during the isothermal compressive deformation.}, booktitle={Proceedings of the 21st International Conference on Nuclear Engineering - 2013, vol 1}, author={Luan, B. F. and Qiu, R. S. and Zhou, Z. and Murty, K. L. and Zhou, J. and Liu, Q.}, year={2014} }
 @inproceedings{luan_yang_wei_murty_long_liu_2014, title={Effect of Mo and Bi on mechanical properties of Zr-Fe-Cr alloy at room ternperature}, DOI={10.1115/icone21-15325}, abstractNote={To investigate the effects of Mo and Bi on mechanical properties of a Zr-Fe-Cr alloy at room temperature, seven Zr-Fe-Cr-Mo-Bi alloys with different compositions were designed. They were subjected to a series of rolling processes and heat treatments, and then sampled to measure mechanical properties by hardness and tensile test and to characterize microstructures by scanning electron microscope (SEM) and electron channel contrast (ECC) technique. Results indicated that among them two types of Zr-Fe-Cr-Mo-Bi alloys achieve the designed goals on mechanical properties and have the following advantages: (i) the hardness of the alloys, up to 334HV after annealing, is 40% higher than traditional Zr-4. (ii) The yield strength (YS) and ultimate tensile strength (UTS) of the alloys are 526 MP a and 889 MP a after hot rolling and annealing, markedly higher than the traditional Zr alloy. (iii) Good plasticity of the new Zr-Fe-Cr-Mo-Bi alloy is obtained with about 40% elongation, which is greatly higher than the Zr-Fe-Cr-Mo alloy thanks to the addition of Bi offsetting the disadvantage of addition Mo. Furthermore, according to observations of the microstructure observation, the reasons of the effect of the Mo and Bi elements on the mechanical performance of Zr-Fe-Cr alloy were studied and discussed.}, booktitle={Proceedings of the 21st International Conference on Nuclear Engineering - 2013, vol 1}, author={Luan, B. F. and Yang, L. Q. and Wei, T. G. and Murty, K. L. and Long, C. S. and Liu, Q.}, year={2014} }
 @article{chai_luan_zhang_murty_liu_2013, title={Experimental observation of 12 alpha variants inherited from one beta grain in a Zr alloy}, volume={440}, ISSN={["1873-4820"]}, DOI={10.1016/j.jnucmat.2013.05.053}, abstractNote={Local crystallographic orientation characteristics of a Zr alloy after β cooling are investigated by electron backscatter diffraction (EBSD) technique. All misorientation peaks and corresponding rotation axes predicted by Burgers relationship are exclusively verified for the obtained basket-weave structure. Furthermore, by correlating microstructures and crystallographic orientations, all 12 possible α variants inherited from one prior β grain are definitely revealed. It is believed that excessive β grain growth in the Zr alloy is responsible for the weak or absence of variant selection during β cooling.}, number={1-3}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Chai, Linjiang and Luan, Baifeng and Zhang, Min and Murty, Korukonda L. and Liu, Qing}, year={2013}, month={Sep}, pages={377–381} }