FEATURE ADDITIVE MANUFACTURING
known as SLA for stereo lithography apparatus), based on laser curing resin to build up the part; selective laser sintering (SLS), where the material is introduced layer by layer in powder form and the part laser sintered; and direct metal deposition (DMD), in which powder is sprayed on a point and melted by a laser, and then traced around the part design. Lambourne stated: ‘It’s exciting where people
are adopting it [AM], using it more and more in different areas, and we are here to help advise them which is the best material for their application. We may even help with the design process to ensure that the best result is achieved.’ Graphite works with carbon fibre reinforced polymer to provide parts that are rapidly processed, strong, and light. The company has made components for motorsport, aerospace and on the Bloodhound SSC, the 1,000mph world land-speed record car currently being built.
Lambourne said: ‘It’s not really a prototype Complex designs can be built using additive manufacturing
anymore; it’s a production piece,’ referring to the AM parts produced for motorsports. ‘They may only need a few to take to a race and a few spares, or they may build dozens of parts. SLS produces a lightweight, tough material that’s temperature resistant.
‘The beauty is that they can produce quite complicated designs, which would take weeks to manufacture normally, quite easily and quite quickly. Within hours, literally within hours, they could have parts to take to the race track.’ That is not to say that all the parts for racing teams are manufactured in this way. For strong and structural pieces, such as the wings, wishbones, and most of the body work, carbon fibre is still better.
The material will to a large extent determine the laser parameters, with polymers requiring lower laser power to fully melt the powder, while sintering metal needs much higher powers.
SLA machines typically use a UV laser to Interest in additive manufacturing is increasing from jewellery manufacturers
www.electrooptics.com | @electrooptics
cure the epoxy resin. Lambourne commented: ‘There have been three main types over the years, and have changed as laser development has progressed. The original small SLA machines used a helium-cadmium (HeCd) laser which only produced around 30mW. The first of the large frame SLA machines used an argon ion laser and these produced around 200mW, but were very inefficient and wasted a lot of heat and energy.’ All of Graphite’s current SLA machines are fitted with solid-state lasers, which are much more efficient and the power varies on machine size between 100mW and 1W. He went on to explain that for laser sintering machines running
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