Imperial College London
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Dr Minh-Son (Son) Pham

Faculty of Engineering, Department of Materials

Senior Lecturer
 
 
 
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Contact

 

+44 (0)20 7594 9529son.pham Website

 
 
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Location

 

B301FBessemer BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Lertthanasarn:2021:10.1016/j.msea.2021.141436,
author = {Lertthanasarn, J and Liu, C and Pham, MS},
doi = {10.1016/j.msea.2021.141436},
journal = {Materials Science and Engineering: A},
pages = {1--11},
title = {Synergistic effects of crystalline microstructure, architected mesostructure, and processing defects on the mechanical behaviour of Ti6Al4V meta-crystals},
url = {http://dx.doi.org/10.1016/j.msea.2021.141436},
volume = {818},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The mimicry of crystalline microstructure at the meso-scale creates a new class of architected materials, termed meta-crystals, and offers effective ways of significantly improving the toughness and eliminating the post-yield collapse of architected materials. The application of meta-crystal approach to crystalline alloys provides exciting opportunities for high strength structural components. This study investigated the mechanical behaviour of polycrystal-like meta-crystals fabricated from a widely used alloy, Ti6Al4V, by laser powder bed fusion (LPBF). The use of Ti6Al4V in fabricating meta-crystals created materials containing hierarchical lattice structures across length-scales: the atomic lattice, the intrinsic crystalline microstructure, and the architected polycrystal-like mesostructure, with each hierarchical feature playing an influential role in the mechanical behaviour of meta-crystals. This present study examined the hierarchical lattice structures at different lengthscales and their contribution to the behaviour of meta-crystals. In particular, the presence of acicular α’ martensitic microstructure was responsible for low ductility in the as-printed meta-crystals. Although heat-treatment was able to transform the martensitic microstructure to a typical α+β microstructure thus increasing the ductility, it was found that notch-like defects from lack of fusion at the free surface of struts were significantly detrimental. The study subsequently altered the meso-structural parameters to reduce the influence of the process defects and explored the effects of the heat treatment on the altered meta-crystals. Such alternations of structural design and crystalline microstructure appeared to be successful in minimising the processing effect, enabling the crystal-mimicry approach to effectively improve the toughness of Ti6Al4V meta-crystals.
AU  - Lertthanasarn,J
AU  - Liu,C
AU  - Pham,MS
DO  - 10.1016/j.msea.2021.141436
EP  - 11
PY  - 2021///
SN  - 0921-5093
SP  - 1
TI  - Synergistic effects of crystalline microstructure, architected mesostructure, and processing defects on the mechanical behaviour of Ti6Al4V meta-crystals
T2  - Materials Science and Engineering: A
UR  - http://dx.doi.org/10.1016/j.msea.2021.141436
UR  - https://www.sciencedirect.com/science/article/pii/S092150932100705X?via%3Dihub
UR  - http://hdl.handle.net/10044/1/88847
VL  - 818
ER  -
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