Abstract:

Additive manufactured Ti alloys have been extensively studied and used widely in many industries. For a long time, oxygen has been referred to as the 'kryptonite' to Ti, capable of invoking a strong hardening effect but resulting in dramatic embrittlement. Here, we demonstrate that the precision control of oxygen addition can significantly benefit the mechanical properties of additive manufacturing Ti alloys.

On the one hand, the oxygens could be incorporated into an additive manufactured Ti-6Al-4V alloy to improve its mechanical properties by forming an oxygen-containing FCC solid solution phase. It was revealed that the oxygen-stabilized FCC-phase dramatically enhances the strength and ductility of the material. On the other hand, the introduction of oxygen in Ti-Fe alloys during additive manufacturing can lead to unexpected performance, in which the interstitial oxygen complex gathers near grain boundaries and impedes dislocation motion inside the material, significantly improving the strength of the alloy. These results provide a significant step towards fabricating low-cost and high-performance alloys using additive manufacturing.

Biography:

Dr. Zibin Chen is currently an Assistant Professor in the Department of Industrial and Systems Engineering at The Hong Kong Polytechnic University. He received his PhD from the University of Sydney, Australia, in 2017. His research primarily focuses on utilizing advanced electron microscopy techniques to investigate fundamental scientific and engineering issues related to advanced ferroelectric functional materials and additive manufacturing of metal materials. Dr. Chen has a solid research foundation in designing new materials, microstructure characterization, and mechanical performance testing.

Dr. Chen's research team has undertaken numerous international funding projects, including those from the Australian Research Council, the United States Office of Naval Research Global, the Hong Kong Research Grant Council, and the National Natural Science Foundation of China, with total funding exceeding 10 million Hong Kong dollars. Dr. Chen has published numerous high-impact papers in leading international journals such as Science, Nature, Nature Materials, Science Advances, Nature Communications, Physical Review Letters, Materials Today, and Acta Materialia.

Dr. Chen currently serves as a young executive editor for the international academic journal Microstructures and a young editorial board member for Materials Research Letters. He has received several honours, including The Hong Kong Polytechnic University Young Innovative Research Award (2022), the Ross Coffin Purdy Award from the American Ceramic Society (2020), and the China Outstanding Self-financed Student Abroad Award (2018).

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