Bugatti Uses 3 D printing to Make Trim Covers

3 D printing is a process that offers many benefits, yet it is a bit complex to carry out. The end result of 3 D printing are components that are extremely well designed and accurate as well as light and stable. Since it is expensive and complex, the process is generally used in the aerospace industry. Bugatti, the leading manufacturer of hyper sports cars used vehicle parts made with 3D printing technology in its Chiron Pur Sport and Chiron Super Sport 300+.

Stephan Winkelmann, President of Bugatti said that Bugatti is not just about French-style luxury and exceptional vehicles, but is also a brand that stands for innovative technology. Technical innovation is as much a part of the brand story as its iconic 8.0 litre 16-cylinder engine with 1,500 PS. This technical innovation extends to use of components made of titanium or a special alloy that are produced by 3D printing.”

Bugatti is thus staying true to is long-standing tradition here as the company’s founder Ettore Bugatti himself is known for having developed unique vehicles using groundbreaking technologies. His inventions include lightweight aluminum wheels and a hollow front axle.

Bugatti is the only automotive company that makes use of 3D printing to fashion tailpipe trim covers from titanium for its new hyper sports car. This cover is also the first visible part that is 3D-printed in metal to be officially approved for use in a roadworthy car. The trim cover of the Chiron Pur Sport’s has dimensions of 22 centimeters length, 48 centimeters breadth and 13 centimeters height but weighs only 1.85 kg. This weight is inclusive of its grille and bracket. The weight of this trim cover is 1.2 kilograms less than that of the cover on the Chiron.

The trim cover component is made by simultaneously using four 400-watt lasers to print titanium with the wall thickness at the thinnest point being just 0.4 millimeters. About 4,200 layers of metal powder are stacked on each other and are firmly fused together as part of the process. Nils Weimann, Head of Body Development at Bugatti said that wherever possible, the trim cover for the Chiron Pur Sport was designed with a single layer to further reduce the weight. The thinness of the material even in multi-layer areas was made possible by its unique lattice structure – where the cavity is filled with numerous filigree struts. With the walls providing stable support for each other during the construction process, only minimal material needs to be used while the surface rigidity of the walls has been increased with the use of a bionic honeycomb structure in the single-layer area. Even large components thus have a high degree of surface stiffness. The filigree cover can tolerate temperatures that exceed 650 degrees Celsius as the outer wall is double-layered for thermal insulation. Thus, the cover protects surrounding components from excessive heat dissipation under full engine load. Yet, at the same time, the component is cooled by the fresh air around the cover.

Bugatti has been using 3D printing since 2018
This is not the first time that Bugatti has made components using 3D printing. Bugatti’s engineering team has been making this special trim cover for the Chiron Sport and Divo from 2018. Other models in which this trim cover can be seen are the 2019 editions of “La Voiture Noire”, the ultimate Grand Tourisme, and the Centodieci, a fresh take on the EB110. The material that is used for the trim cover is Inconel 718, a nickel-chrome alloy which is known for its heat-resistance, hardness and lightweight. It is normally used in aircraft turbine blades, spaceships and in gas turbines. The material is used to fashion a 53-centimetre wide and 22-centimetre long trim cover for the Chiron Sport.

The trim cover of the Chiron Sport covers four tailpipes of the six-branch exhaust system at the rear. It offers not only visual benefits but technical advantages also. It minimizes heat accumulation as it helps conduct the waste heat from the hot exhaust gases away from the rear with its large and sturdy tubes.
Another advantage is that with a weight of 2.2 kilograms, it weighs 800 grams less than a normal cover, enhancing performance.
3D printing offers several advantages

With 3D printing carried out using a special laser printing system, one or more lasers successively melt a thin layer of powder with a thickness of three to four µ. “The advantage of the 3D printing process lies in the geometric shapes that are possible. It is possible to create very finely wrought, complex forms which would tear if made using other techniques such as forging or forming,” says Nils Weimann. This is an ideal production method for Bugatti: there are no tool costs, production is comparatively fast and individual adjustments to the shape are easily possible. As a result, organic geometries can be developed as if from the world of plants – there are virtually no limits.

Printing the exhaust trim cover takes several days. After printing the cover with the material Inconel® 718, the component is scanned in a computer tomograph to detect any misprints with air inclusions. When it comes to titanium printing for the Chiron Pur Sport and Chiron Super Sport 300+, test engineers use the 3 D process to evaluate the component optically. With its extremely thin-walled design, it is possible to detect sizable air inclusions on the outside. The cover blank of the Chiron Sport is then finely blasted with corundum and a high-temperature black ceramic paint finish is applied for greater protection. The titanium trim covers of the Chiron Pur Sport and Super Sport 300+ retain their elegant matt titanium look. Every component goes through a final check as only perfect trim covers are then fitted.

The new trim covers lend more harmonious contours and a more elegant and functional look to the exhaust systems of the hyper sports cars.