Known for its ultra-exclusive, extreme-performance cars, Bugatti is adding a world first to its performance resume — the world’s first functional 3D-printed titanium brake calliper.
“Vehicle development is a never-ending process,” says Frank Götzke, Bugatti’s Head of New Technologies. “In our continuing development efforts, we are always considering how new materials and processes can be used to make our current model even better and how future vehicles of our brand could be designed.”
A collaboration between Bugatti and Hamburg’s Laser Zentrum Nord, the new 8-piston monobloc calliper is also the auto industry’s largest ever. The component is due to start trials over the first half of 2018, and reportedly represents the start of component 3D-printing for series production not just for the French ultra-luxury performance brand but also for other Volkswagen marques.
“Cooperation with Bugatti is a key lighthouse project for us,” says Prof. Dr.-Ing. Claus Emmelmann, Head of the Fraunhofer Institute for Additive Production Technologies (Laser Zentrum Nord’s parent) and also Head of the Institute of Laser and System Technologies at Hamburg University of Technology. “We were thrilled to be contacted by Bugatti. I do not know any other carmaker which makes such extreme demands of its products. We were pleased to face up to this challenge.”
The Chiron’s motorsports-inspired brake callipers are currently forged from an aluminum alloy block, with eight titanium pistons on the front and six on the back. The new titanium-alloy components are made from materials to date used in the aerospace industry (for highly stressed components in the undercarriage and on wings, and in engines). They are considerably stronger and weigh just 2.9 kg (compared to 4.9 for the current aluminum alloy callipers).
“Laser Zentrum Nord is one of many scientific institutes with which we have developed very good cooperation over the years,” says Götzke. “Thanks to the large number of projects completed, mainly for the aviation industry, the institute has comprehensive know-how especially in the field of titanium processing and offers mature technology.”
Development time for the new calliper was reportedly just three months, with Bugatti supplying the concept, strength and stiffness simulations, calculations and design drawings to Laser Zentrum Nord as a complete data package. The institute carried out process simulation, designed supporting structures, printed (over 45 hours, using 400-watt lasers) and treated the component, then sent it back to Bugatti for final finish.
For printing, titanium powder is deposited in layers (2,213 in total), melted by four lasers to take the desired shape, which cools immediately. Excess powder is collected, cleaned and preserved for reuse. Heat treatment for the finished calliper takes place in a furnace, starting at 700 degrees Celsius and falling to 100 Celsius to avoid residual stress and insure dimensional stability. Finally, the surface is smoothed mechanically and chemically for fatigue strength, before the functional surfaces (such as threads) are milled over another 11 hours (which is expected to shorten considerably once production cycles are set).
“In terms of volume, this is the largest functional component produced from titanium by additive manufacturing methods,” concludes Götzke. “Everyone who looks at the part is surprised at how light it is – despite its large size. Technically, this is an extremely impressive brake calliper, and it also looks great.”