Crack-Deflecting Lattice Metamaterials Inspired by Precipitation Hardening

Area of Science:

• Materials Science
• Mechanical Engineering
• Solid Mechanics

Background:

• Lattice structures exhibit lightweight and unique mechanical properties but are prone to failure initiated by stress concentration points.
• Failure in lattice structures often resembles the accumulation of damage at defects in metallic crystals, leading to collapse.

Purpose of the Study:

• To investigate the application of precipitation hardening mechanisms to enhance the mechanical robustness of lattice structures.
• To introduce a multiscale hierarchical design methodology for engineering materials with tailored properties.

Main Methods:

• Employing the precipitation hardening mechanism to strategically place strengthening units at stress concentration points.
• Utilizing the finite element method (FEM) to model and analyze stress distribution and failure paths.
• Investigating the influence of both mesostructure (crystal-inspired arrangement) and microstructure of base materials on macro-lattice properties.

Main Results:

• Successfully deflected initial failure paths in lattice structures by strategically incorporating strengthening units.
• Demonstrated that both mesostructure and microstructure significantly influence the mechanical performance of macro-lattices.
• Developed a novel multiscale hierarchical design methodology applicable to a range of engineering materials.

Conclusions:

• The precipitation hardening mechanism is effective in mitigating failure in lattice structures.
• A multiscale hierarchical design approach offers a versatile framework for developing advanced engineering materials.
• This methodology provides a spectrum of design concepts for creating materials with specific desired properties.