Advanced Structural Materials Group at PolyU Logo

Research Areas

(1) Advanced ultrahigh-strength steels

Advanced ultrahigh-strength steels are of paramount importance in aerospace, automotive, nuclear power, maritime, and other high-tech industries. We are working on the development of next-generation ultra-high strength steels via co-precipitation of coherent nanoparticles.

 

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Selected publications:

1) Co-precipitation of nanoscale particles in steels with ultra-high strength for a new era, Materials Today 20(3), 142, 2017.

2) Atomic-scale understanding of solute interaction effects on GB segregation, precipitation, and fracture of maraging steels, Acta Materialia 253, 118972, 2023.

3) Design of ultra-strong but ductile iron-based alloys with low supersaturations, Acta Materialia 254, 119000, 2023.

4) Heterogenous structure and formation mechanism of white and brown etching layers in bainitic rail steel, Acta Materialia 250, 118887, 2023.

5) Mechanisms for suppressing discontinuous precipitation and improving mechanical properties of NiAl-strengthened steels, Acta Materialia 205, 116561, 2021.

6) Synergistic alloying effects on nanoscale precipitation and mechanical properties of ultrahigh-strength steels, Acta Materialia 209, 116788, 2021.

7) Precipitation behavior in G-phase strengthened ferritic stainless steels, Acta Materialia 205,116542, 2021.

8) Hardening mechanisms and impact toughening of a high-strength steel containing low Ni and Cu additions, Acta Materialia 172,150, 2019.

9) Effects of welding and post-weld heat treatments on nanoscale precipitation and mechanical properties of a high strength steel, Acta Materialia 120, 216, 2016.

10) Precipitate transformation from NiAl-type to Ni2AlMn-type and its influence on the mechanical properties of high-strength steels, Acta Materialia 110, 31, 2016.

11) Precipitation mechanism and mechanical properties of an ultra-high strength steel hardened by nanoscale NiAl and Cu particles, Acta Materialia 97, 58, 2015.

12) Effects of Mn partitioning on nanoscale precipitation and mechanical properties of ferritic steels strengthened by NiAl particles, Acta Materialia 84, 283, 2015.

13) Synergistic effects of Cu and Ni on nanoscale precipitation and mechanical properties of high-strength steels, Acta Materialia 61, 5996, 2013.

 

 

(2) High-entropy alloys

Over the past decade, a new alloy design philosophy, i.e., high-entropy alloys which have equimolar or near-equimolar atomic fractions of multiple constituents, have drawn intensive interests. We are studying the phase relations, nanoscale precipitation and mechanical behavior of high-entropy alloys.

 

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Selected publications:

1) Ultrahigh-strength and ductile superlattice alloys with nanoscale disordered interfaces, Science 369, 427-432, 2020.

2) Multicomponent intermetallic nanoparticles and superb mechanical behaviors of complex alloys, Science 362, 933-937, 2018.

3) Ultrahigh strength and ductility in newly developed materials with coherent nanolamellar architectures, Nature Communications 11, 6240, 2020.

4) High-entropy induced a glass-to-glass transition in a metallic glass, Nature Communications 13, 2183, 2022.

5) Unraveling the two-stage precipitation mechanism in a hierarchical-structured high-entropy alloy: Experiments and modeling, Acta Materialia 262, 119426, 2024.

6) Developing novel high-temperature soft-magnetic B2-based multi-principal-element alloys with coherent bcc nanoprecipitates, Acta Materialia 266, 119686, 2024.

7) L12-strengthened multicomponent Co-Al-Nb-based alloys with high strength and matrix-confined SF-mediated plasticity, Acta Materialia 228, 117763, 2022.

8) Control of nanoscale precipitation and elimination of intermediate-temperature embrittlement in multicomponent high-entropy alloys, Acta Materialia 189, 47, 2020.

9) Superior high-temperature properties and deformation-induced planar faults in a novel L12-strengthened high-entropy alloy, Acta Materialia 188, 517, 2020.

10) Achieving exceptional wear resistance in a compositionally complex alloy via tuning the interfacial structure and chemistry, Acta Materialia 188, 697, 2020.

11) Heterogeneous precipitation behavior and stacking-fault-mediated deformation in a CoCrNi-based medium-entropy alloy, Acta Materialia 138, 72, 2017.

 

 

(3) High-temperature superalloys and intermetallics

High-temperature superalloys and intermetallics are used for critical components in gas turbines for aero engines and power plants. We are working on the design of advanced high-temperature materials with superior mechanical properties and oxidation resistance at high temperatures.

 

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Selected publications:

1) Ultra-strong tungsten refractory high-entropy alloy via stepwise controllable coherent nanoprecipitations, Nature Communications 14, 3006, 2023.

2) Alloying effects on site preference, mechanical properties, and deformation behavior of Co–Ti-based alloys, J. Mater. Res. Technol. 24, 1429, 2023.

3) Strategies for improving ductility of ordered intermetallics, Progress in Natural Science: Materials International 26, 1, 2016.

4) Superior high-temperature properties and deformation-induced planar faults in a novel L12-strengthened high-entropy alloy, Acta Materialia 188, 517-527, 2020.

5) Control of nanoscale precipitation and elimination of intermediate-temperature embrittlement in high-entropy alloys, Acta Materialia 189, 47-59, 2020.

6) Thermal stability and high-temperature mechanical performance of nanostructured W–Cu–Cr–ZrC composite, Composites Part B: Engineering 208, 108600, 2021.

7) High-temperature mechanical behavior of ultra-coarse cemented carbide with grain strengthening, Journal of Materials Science & Technology 104, 8, 2022.

 

 

(4) Nanocrystalline alloys (

Nanocrystalline materials are desirable in a wide variety of applications; however, nanocrystalline pure metals suffer from poor stability. We are examining the effect of solute species and segregation profiles on the stability of nanocrystalline alloys.

 

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Selected publications:

1) Nanocrystalline Ag-W alloys lose stability upon solute desegregation from grain boundaries, Acta Materialia 161, 194-206, 2018.

2) Strengthening nanocrystalline immiscible bimetallic composite by high-entropy effect, Composites Part B: Engineering, 2022.

3) Single-element amorphous palladium nanoparticles formed via phase separation, Nano Research  15, 5575, 2022.

4) Attractive in situ self‐reconstructed hierarchical gradient structure of metallic glass for high efficiency, Advanced Functional Materials 1, 1807857, 2019.

5) Formation and crystallization behavior of Fe-based amorphous precursors with pre-existing particles, Journal of Materials Science & Technology 65, 171, 2021.

 

 

Research Equipment

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