Area of Specialization
Metallic materials; Nuclear materials; Nanotechnology; Environmental degradation of materials; Computational materials design and modeling
Prof. Shi received his B.Sc. degree and M.Sc. degree from University of Science and Technology Beijing in 1982 and 1984 respectively. He obtained his Ph.D. and postdoctoral fellowship in Materials Science from McMaster University, Canada in 1991. He then spent seven years at Canadian National Laboratory under Atomic Energy of Canada Limited (AECL) as a Research Scientist and Project Leader. At AECL, he made significant contributions to the understanding of delayed hydride cracking in zirconium alloys used in nuclear power industry, and actively involved in power plant safety assessment and research project management.
Prof. Shi joined the Department of Mechanical Engineering in The Hong Kong Polytechnic University in November 1998 as an Assistant Professor. He was promoted to Associate Professor in 2002, to Professor in 2005, and then to Chair Professor of Mechanical Engineering in 2015. At PolyU, Prof. Shi has won a number of research achievement awards. He has been the Acting Head and Interim Head of Department of Mechanical Engineering for two academic years (2010/2011 and 2014/2015) and Director of Research Centre on Mechanical Engineering at PolyU Shenzhen Base since 2012. Prof. Shi’s current research and consultancy interests are focused on environmental degradation of materials and protection, computational materials modelling and advanced materials. He is a member of Materials Research Society (MRS) in USA, The Metals, Minerals and Materials Society (TMS) in USA, Hong Kong Society of Theoretical and Applied Mechanics (HKSTAM), and a fellow of the Hong Kong Institution of Engineers (HKIE). He currently serves as the Associate Editor or member of editorial boards for several SCI international journals.
Brief Description of Three Research Projects
Quantitative Phase-Field Modeling of Microstructure Evolution of Zirconium Hydrides under Stress and Temperature Gradients with Plasticity (supported by GRF, NSFC)
Abstract of the Project:
Zirconium alloys are key materials used in the nuclear power industry. In service, these alloys are susceptible to a corrosion process that leads to a gradual pickup of hydrogen impurities from the environment. It is well known that hydrogen impurity will be attracted to stress concentrators such as notch and crack tips. At a certain hydrogen level, a complicated pattern of hydride precipitates can develop in the alloys, especially around stress concentrators or down to the temperature gradient. Hydride formation also involves a large volume expansion which causes plastic deformation. Because of the brittleness of these hydrides, the original strength of the alloys can be reduced by orders of magnitude, and the fracture through these hydrides may occur. It is believed that critical conditions for the initiation of fractures at hydrides are controlled by the morphology and microstructure of hydride precipitates. The objective of this modeling effort is to develop computational methodology for predicting the realistic 3-D morphological evolution of hydride precipitates, and ultimately to predict fracture initiation at hydrides in zirconium alloys. The analytic tools and methodologies developed in this project may find wide applications in studying engineering materials under chemical, stress and temperature gradients with plastic deformation.
Left: TEM image of hydrides by Bailey (Acta. Metal., 11 (1963) 267); right: quantitative phase field simulation by Shi and Xiao (J. Nucl. Mater., 459 (2015) 323). The edge length of each picture is about 4mm.
Left: experimental observation of hydrides at a notch; right: computer simulation (J. Nucl. Mater. 378 (2008) 120).
Development of A Phase Field Modeling Framework for Localized Corrosion Kinetics (supported by GRF)
Abstract of the Project:
In developed countries, corrosion of metals has been costing about 3% of gross national product every year, much more than the costs arisen from all natural disasters combined. Well-designed experimental tests can evaluate key parameters that affect and control the corrosion process, while theoretical work can improve our understanding of the phenomena, which is important for the development of design tools for corrosion prediction and protection. This project aims to develop a theoretical framework using PFM that can predict the corrosion processes occurred at the double layer (nanometer scale) up to micrometers of corrosion films on metal surface and into the metal bulk. Combining with the modeling methods in macro and atomistic scales, our project will deliver important tools for the development of new corrosion resistant materials as well as for the prediction of life time of engineering materials in corrosive environment.
核电站蒸汽发生器管道材料的应力腐蚀开裂的防护Stress Corrosion Cracking in steam generating tubes in nuclear power plants (supported by Shenzhen fundamental research grant)
Abstract of the Project:
经济和人口的快速增长导致人类对能源的需求急速增加。另一方面，温室效应气体的大量释放和原油价格的迅速提高已经危及到世界许多国家的社会经济发展。要解决这些问题，核能目前是，且在可预见的将来仍然是最好的选择之一。核能尤其适合于广东和香港地区，因为本地区的煤，风能， 水能和太阳能的资源相对贫乏。可供政府选择的方案非常有限，为此广东已经正在实行一个大型的核能发展计划，势在必行。但是，切尔诺贝利，三里岛和日本福岛事件却不断提醒我们，一定要注意核能的安全问题，尤其是在广东和香港这样高人口密度的地区。几十年来，尽管成千上万的科学家和工程师们呕心沥血，绞尽脑汁，想设计出更安全、更有效的反应堆，但我们必须记住，从本质上讲，当今的核能反应堆并不是先天的安全。我们估计，在未来10 到20年内，国内当今运行的和正在建造的新旧反应堆都会先后开始老化。 国际上的压水堆核电站，平均每年有0.3%的散热管道和热交换器管道需要更换，除了维修费用外，还造成停产和降低产能，造成不可忽视的损失。因此政府需要及早投资，作出技术和高级人才方面的准备。本研究计划基于研究团队主要人员20多年的经验，将针对散热管道和热交换器管道中的应力腐蚀问题，尤其是铅致应力腐蚀进行研究，以期找到问题的根源及解决方案。同时为国家培养这个领域的年轻人才。
Selected Journal and Book Chapter Publications
- K.C. Lam, B.L. Huang and S.Q. Shi, “Room temperature methane gas sensing properties based on in-situ reduced graphene oxide incorporated with tin dioxide”, Journal of Materials Chemistry A, 5, 11131-11142, 2017.
- W.B. Liu, L. Chen, X. Dong, J.Z. Yan, N. Li, S.Q. Shi and S.C. Zhang, “A facile one-pot oxidation-assisted dealloying protocol to massively synthesize monolithic core-shell architectured nanoporous copper@cuprous oxide nanonetworks for photodegradation of methyl orange ”, Scientific Report, 6, art. No. 36084, 2016.
- Y.D. Kuang, L. Lindsay, S.Q. Shi and G.P. Zheng, “Tensile strains give rise to strong size effects for thermal conductivities of silicene, germanene and stanine”, Nanoscale, 8, 3760-3767, 2016.
- B.T. Lu, L.P. Tian, R.K. Zhu, N.N. Li, S.Q. Shi and J.L. Luo, “Effects of Dissolved Ca2+ and Mg2+ on Passivity of UNS N08800 Alloy in Simulated Crevice Chemistries with and without Pb Contamination at 300 oC”, Corrosion Science, 100, 1-11, 2015.
- S.Q. Shi and Z.H. Xiao, “A quantitative phase field model for hydride precipitation in zirconium alloys: Part I. Development of quantitative free energy functional”, Journal of Nuclear Materials, 459, 323-329, 2015.
- Wang, Y.F. Ye, B.A. Sun, C.T. Liu, S.Q. Shi and Y. Yang, “Softening-Induced Plastic Flow Instability and Indentation Size Effect in Metallic Glass”, Journal of the Mechanics and Physics of Solids, 77, 70-85, 2015.
- C. Ng, S. Guo, J.H. Luan, S.Q. Shi, C.T. Liu, “Entropy-driven phase stability and slow diffusion kinetics in a Al0.5CoCrCuFeNi high entropy alloy”, Intermetallics, 31, pp.165~172, 2012.
- J. C. Wang, X. C. Ren, S. Q. Shi, C. W. Leung, Paddy K. L. Chan, "Charge accumulation induced S-shape J-V curves in bilayer heterojunction organic solar cells", Organic Electronics, 12, pp.880~885, 2011.
- Y. Bai, G.P. Zheng and S.Q. Shi, “Direct measurement of giant electrocaloric effect in BaTiO3 multilayer thick film structure beyond theoretical prediction”, Applied Physics Letters, 96, 192902, 2010.
- X.H. Guo, S.Q. Shi, Q.M. Zhang, X.Q. Ma, “An elastoplastic phase-field model for the evolution of hydride precipitation in zirconium, Part II: specimen with flaws”, Journal of Nuclear Materials, Vol.378, p.120~125, 2008.
- X.H. Guo, S.Q. Shi and X.Q. Ma, “Elastoplastic phase field model for microstructure evolution”, Applied Physics Letters, Vol. 87, Art. No. 221910, 2005.
- C.H. Xu, C.H. Woo and S.Q. Shi, “Formation of CuO Nanowires on Cu Foil”, Chemical Physics Letters, Vol. 399, pp.62~66, 2004.
- Jie Wang, San-Qiang Shi, Long-Qing Chen, Yulan Li, Tong-Yi Zhang, “Phase field simulations of ferroelectric/ferroelastic polarization switching”, Acta Materialia, Vol. 52, pp.749~764, 2004.
- L.G. Zhou and S.Q. Shi, “Formation energy of Stone-Wales defects in carbon nanotubes”, Applied Physics Letters, Vol. 83 (6), pp.1222~1224, 2003.