Even metals can lose weight
Engineers at the University of Liverpool are using a new manufacturing process to turn steel, titanium and other metals into light customized components. This technology, based on selective laser melting (SLM), allows to assemble parts with lattice-like structures. These components are 50% lighter as those built with conventional processes even if they are as strong. And as the resulting parts are built layer by layer, the engineers can build components for almost anything, from miniaturized chemical reactors to heat sinks for computers, and from composite components for the automotive industry to lighter planes.
This new rapid manufacturing process has been developed in collaboration with Mining & Chemical Products (MCP) and with a research grant from the Engineering and Physical Sciences Research Council (EPSRC) in the UK. Here are the opening paragraphs of the EPSRC news release.
A pioneering manufacturing process that can turn titanium, stainless steel and many other metals into a new breed of engineering components could have a big impact across industry.
Unlike conventional solid-metal components, the new parts have a tiny lattice-like structure, similar to scaffolding but with poles twice the diameter of a human hair, making them ultra-light. Because loads are channelled along the poles, the parts can comprise up to 70% air while remaining strong enough to perform correctly.
The selective laser melting (SLM) allows to create highly complex shapes such as cylindrical meshes or lattice constructions, like you can see below with these titanium cylinders (Credit: MCP).
Below is another example of ultra light structures in stainless steel. In this case, there are about 450 holes per cm³, and the density of pure stainless steel was reduced by almost 90%, from about 8 g per cm³ to 0.6 g per cm³ (Credit: MCP).
Here are more details about how the SLM technique was used to develop this rapid manufacturing process.
Harnessing a technique known as selective laser melting (SLM), this fully automated system builds up components, layer by layer, from fine metal powders using an infra-red laser beam to melt the powders into the required structure. Layers can be as thin as 25 microns, making it possible to produce complex parts in which thermal, impact-absorption and many other properties can be distributed in specific places to meet the requirements of particular applications. This is not possible with conventionally manufactured 'solid' metals.
This is not the only advantage of this engineering process.
Although other ways of making some types of latticed metals exist, they do not enable the features of the lattice to be precisely 'designed in' to meet customised requirements. The metals they produce are also limited in their usefulness because they have to be machined into the final required shape, rather than 'built for purpose' step by step. A typical example is the manufacture of composite components used in motor sport.
For more information, this process was developed by Dr Chris Sutcliffe at the University of Liverpool who received a grant of about £450,000 from EPSRC for this project named "Rapid Manufacture of Industrially Relevant Hierarchical Structures." You also might be interested in a previous work 'spiral growth manufacturing'.
This industrial process should be in full production next year.
Sources: Engineering and Physical Sciences Research Council (EPSRC) news release, December 12, 2005; and various web sites
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