Metallic microlattices can enable extremely lightweight structures with high strength-to-weight ratios. Combining the benefits of lightweight construction, energy absorption, mechanical strength, thermal management, and design versatility, these lightweight structures have significant applications in aerospace, automotive, and transportation industries, where weight reduction is crucial for fuel efficiency and overall performance.
The main challenges in the design and manufacturing of lattice metamaterials involve handling the geometric complexity of intricate and complex structures, selecting suitable materials with desired properties, developing sophisticated fabrication techniques capable of producing precise structures, and addressing scaling and size limitations to achieve mass production while maintaining the desired properties. These challenges require advanced computational tools, optimisation techniques, material science expertise, and innovative manufacturing approaches to overcome the complexities and achieve the desired mechanical, acoustic, or electromagnetic properties in lattice metamaterials.
METAMAT will comprise an end-to-end digital framework covering the whole spectrum of steps required for the design and manufacture metallic microlattices:
1.Material Selection: Choose a suitable metallic material based on desired properties such as strength, stiffness, and weight. Common choices include aluminum, titanium, and steel alloys.
2.Design Concept: Determine the lattice structure and cell geometry that aligns with the desired mechanical properties. Various lattice types, such as truss, honeycomb, or octet, can be considered depending on the application.
3.Computer-Aided Design (CAD) to design the lattice structure at the desired dimensions, including the unit cell size, strut thickness, and overall lattice dimensions. Ensure the design meets the required specifications and consider any design constraints.
4.Simulation and Optimisation: Employ finite element analysis (FEA) or other simulation techniques to evaluate the mechanical behavior of the lattice design. Optimise the lattice structure for specific performance criteria, such as maximising strength-to-weight ratio or energy absorption capacity.
5.Additive Manufacturing (AM): Employ selective laser sintering (SLS) to build the lattice layer-by-layer from powdered metal, allowing for complex geometries.
6.Post-Processing: Perform post-processing steps to enhance the mechanical properties or surface finish of the metallic microlattice, using surface finishing techniques like polishing.
7.Testing and Characterisation: Evaluate the mechanical properties of the fabricated microlattice through various testing methods, such as compression, tension, or bending tests. Characterise other relevant properties like density, stiffness, and fatigue resistance.
8.Scale-up Manufacturing: Once the design and fabrication processes are optimised, develop a scaled-up manufacturing process to produce the metallic microlattices in larger quantities. This may involve developing custom manufacturing equipment or partnering with specialised manufacturing facilities.