Novel crystal-inspired architected materials design guided by metallurgical hardening mechanisms
File(s)
Author(s)
Liu, Chen
Type
Thesis
Abstract
Lattice material is one type of architected materials which internal structures are architected by periodically arranging single type of unit cell with a defined orientation. There have been increasing attentions to lattice materials thanks to their characteristics of lightweight and relatively high strength. However, previously reported singly orientated lattice materials suffered severe post-yield strength collapse due to the formation of dominant shear band. To develop lattice materials with high strength and damage tolerant, this study reported a new lattice design approach that is inspired from the crystal microstructure of high performance alloys. It was demonstrated that the designed crystal-inspired lattice materials (called meta-crystals) can be strengthened by employing metallurgical hardening mechanisms, such as grain boundary hardening, precipitation hardening and phase hardening, despite of different bonding origins: atomic bonds in crystalline materials versus physical struts in architected materials. In-depth and thorough investigations were carried out to reveal the mechanisms responsible for the hardening effects in meta-crystals. The obtained insights in this study provide crucial knowledge in developing high strength and damage tolerant architected materials with great capacity in controlling and programming the mechanical strength and damage path.
Version
Open Access
Date Issued
2021-07
Date Awarded
2021-11
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Pham, Minh-Son
Dye, David
Publisher Department
Materials
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)