A digital framework for the design and additive manufacturing of lattice metamaterial structures
There is significant interest in lattice metamaterials due to the potential they offer to tailor material behaviour at the microscale. This opens up new possibilities for facilitating extremely lightweight structures, with a high strength-to-weight ratio as well as energy absorption properties, mechanical strength and thermal management capacity.
However, the design and manufacture of metallic micro lattices can be a specialised and complex undertaking. Challenges include the handling of geometrically intricate structures, selection of suitable materials with appropriate properties, developing advanced fabrication techniques capable of producing precise structures, and addressing scaling and size limitations to achieve mass production while maintaining the targeted attributes. METAMAT aims to overcome these by creating an end-to-end digital framework that covers the entire spectrum of steps required for the design and manufacture of metallic micro lattices.
The project consortium partners are working in collaboration, and drawing on their respective areas of expertise and experience, to:
- Choose a suitable metallic material, such as an aluminium, titanium or steel alloy
- Determine the lattice structure and cell geometry, for example truss, honeycomb or octet
- Design the lattice structure using computer-aided design (CAD), including unit cell size, strut thickness and overall dimensions
- Employ finite element analysis (FEA), or other simulation techniques, to evaluate the mechanical behaviour of the lattice design and optimise accordingly
- Undertake selective laser sintering (SLS) to build the lattice, layer-by-layer, from powdered metal, allowing for complex geometries
- Perform post-processing activities to enhance the mechanical properties or surface finish of the metallic micro lattice
- Evaluate the mechanical properties of the fabricated micro lattice through various testing methods, such as compression, tension or bending, and characterise properties such as density, stiffness and fatigue resistance
- Ensure the design and fabrication processes are fully optimised
- Develop the approach into scaled-up manufacturing to produce the metallic micro lattices in larger quantities, which may involve production of custom manufacturing equipment or partnering with specialised manufacturing facilities
The initial focus of J4IC’s work on METAMAT is data analysis and the development of intelligent systems via machine learning, for electrochemical polishing (ECP) of additively manufactured metallic components. This began with establishing the relationship between ECP parameters and the surface quality metrics of products fabricated through additive manufacturing (AM). Subsequent work includes integrating these developments with a digital platform of data structures, predicting post-AM polishing effects, and creating simple user interfaces for optimised processing techniques and customised solutions. Then model exploration, establishment and evaluation follows next, with the aim of expanding the machine learning model's applicability, particularly considering the expansion of digital frameworks for post treatment of products fabricated by AM methods.
Anticipated benefits of the METAMAT project include provision of a novel solution for the manufacturing of lightweight parts and structures in larger sizes, which will also contribute to fuel efficiency in industries such as aerospace and automotive, and supporting the wider environmental goals of reduced materials consumption and carbon emissions.
Partners: Authentise, NS85Ltd, Holdson Limited and J4IC.
METATAMAT secured funding from Innovate UK under grant agreement No. 10081046.