深过冷快速凝固

        深过冷是实现金属材料快速凝固的重要途径。本方向的研究侧重用同步辐射高能X射线衍射和高速摄影等原位表征技术对纯金属、二元和多元合金快速凝固过程中的亚稳凝固路径、枝晶或共晶生长速率、强磁场效应进行原位研究，旨在建立描述晶体快速生长的新理论，并认识金属材料在快速凝固条件下的微结构形成机理。

快速凝固理论研究成果：

1) D. D. Zhao, J. Gao (2022): "Theory and in situ diagnosis of growth kinetics of dendritic crystals in alloy solidification", Crystal Growth and Design 22, pp.5354-5362.

2) D. D. Zhao, J. Gao, A. Kao (2020): "Modeling of tip kinetics of undercooled Ti dendrites with consideration of forced flow and oxygen impurity effects", International Journal of Heat and Mass Transfer 159, p.120113.

3) J. Gao (2018): "A model for free growth of a lamellar eutectic dendrite with an incident flow", Philosophical Transactions of the Royal Society A 376, p.20170209.

4）J. Gao, A. Kao, V. Bojarevics, K. Pericleous, P. K. Galenko, D. V. Alexandrov (2017): "Modeling of convection, temperature distribution and dendritic growth in glass-fluxed nickel melts", Journal of Crystal Growth 471, pp.66-72.

5）C. Yang, J. Gao (2015): "Modeling of free eutectic growth and competitive solidification in undercooled near-eutectic alloys based on in-situ measurements", Journal of Materials Science 50, pp.268-278.

磁场效应研究成果：

1）D. D. Zhao, J. Gao (2019): "Liquid phase separation in undercooled Cu–Co alloys under the influence of static magnetic fields", Philosophical Transactions of the Royal Society A 377, p.20180207.

2) R. J. Zhao, J. Gao, A. Kao, K. Pericleous (2019): "Verification of thermoelectric magnetohydrodynamic flow effects on dendritic tip kinetics by in-situ observations", International Journal of Heat and Mass Transfer 136, pp.1139-1146.

3）R. J. Zhao, J. Gao, A. Kao, K. Pericleous (2017): "Measurements and modelling of dendritic growth velocities of pure Fe with thermoelectric magnetohydrodynamics convection", Journal of Crystal Growth 475, pp.354-361. 

4）J. Gao, M. K. Han, A. Kao, K. Pericleous, D. Alexandrov, P. Galenko (2016): "Dendritic growth velocities in an undercooled melt of pure nickel under static magnetic fields: a test of theory with convection", Acta Materialia 103, pp.184-191.

5）C. Yang, J. Gao (2014): "Dendritic growth kinetics and disorder trapping of the intermetallic compound Ni3Sn under a static magnetic field", Journal of Crystal Growth 394, pp. 24-27.

同步辐射原位研究成果：

1）Y. Q. Wang, J. Gao, M. Kolbe, A. Chuang, Y. Ren, D. Matson (2018): "Metastable solidification of hypereutectic Co₂Si–CoSi composition: microstructural studies and in-situ observations", Acta Materialia 142, pp.172-180.

2）D. D. Zhao, F. Yang, D. Holland-Moritz, M. Kolbe, T. Buslaps, J. Gao (2021): "In situ studies of liquid-liquid phase separation, solidification sequence and dendrite growth kinetics in electrostatically levitated Ti–Y alloys", Acta Materialia 213, p.116962.

3）R. J. Zhao, Y. Q. Wang, J. Gao, E. Baker, D. M. Matson, M. Kolbe, A. Chuang, Y. Ren (2020): "In situ and ex situ studies of anomalous eutectic formation in undercooled Ni–Sn alloys", Acta Materialia 197, pp.198-211.

4）R. J. Zhao, T. T. Yang, Y. Q. Wang, Y. Ren, J. Gao (2021): "In situ X-ray diffraction and HAADF-STEM study of disorder trapping in intermetallic Ni₃Sn compound", Scripta Materialia 193, pp.55-58.

5）Y. Q. Wang, J. Gao, W. H. Sun, A. Shahani (2022): "In situ observation of faceted growth and morphological instability of a complex-regular eutectic in Zn–Mg–Al system", Scripta Materialia 206, p.114224.

非平衡凝固组织研究成果：

1) Y. K. Zhang, J. Gao, M. Kolbe, S. Klein, C. Yang, H. Yasuda, D. M. Herlach, Ch.-A. Gandin (2013): "Phase selection and microstructure formation in undercooled Co–61.8at.%Si melts under various containerless processing conditions", Acta Materialia 61, pp.4861-4873.

2）C. Yang, J. Gao, Y. K. Zhang, M. Kolbe, D. M. Herlach (2011): "New evidence for dual origin of anomalous eutectic structures in undercooled Ni–Sn alloys: in-situ observations and EBSD characterization", Acta Materialia 59, pp.3915-3926.

3) Y. K. Zhang, J. Gao, D. Nagamatsu, T. Fukuda, H. Yasuda, M. Kolbe, J. C. He (2008): "Reduced droplet coarsening in electromagnetically levitated and phase-separated Cu–Co alloys by imposition of a static magnetic field", Scripta Materialia 59, pp.1002-1005.

4）Y. Q. Wang, C. Paul, S. Moniri, J. Gao, T. Volkenandt, V. De Andrade, A. J. Shahani (2020): "Integrated three-dimensional characterization of reactive phase formation and coarsening during isothermal annealing of metastable Zn–3Mg–4Al eutectic", Materials Characterization 170, p.110685.

5) Y. Q. Wang, J. Gao, Y. Ren, V. De Andrade, A. J. Shahani (2020): "Formation of a three-phase spiral structure due to competitive growth of a peritectic phase with a metastable eutectic", JOM 72, pp.2965-2973.