The high-performance sports car manufacturer, Bugatti Automobiles S.A.S, headquartered in Molsheim, France, is reported to be using Additive Manufacturing to develop and build a number of functional components for its iconic range. In addition to a previously announced brake caliper, which entered vehicle trials in the first half of 2018, the company has used AM technology to optimise component design, saving weight and increasing performance. Built using AM machines from SLM Solutions Group AG, Lübeck, Germany, the components demonstrate that AM can produce parts for a range of highly demanding applications.
Titanium brake caliper
The previously mentioned titanium brake caliper was manufactured on a SLM®500 system from Ti6Al4V, and developed along with Fraunhofer IAPT (formerly Laser Zentrum Nord) and Bionic Production AG. The results from testing the calipers showed that a tensile strength of 1250 N/mm2 and a material density over 99.7% was achieved. “Proof that additively produced metal components can cope with extreme strength, stiffness and temperature requirements at speeds of over 375 km/h with a braking force of 1.35 g [13.24 m/s2] and brake disc temperatures up to 1100°C,” stated Frank Götzke, Bugatti’s Head of New Technologies.
Active spoiler bracket
Bugatti has also developed an additively manufactured active spoiler bracket with Fraunhofer IAPT. Götzke explained, “We always strive for absolute perfection, stylistic as well as technical, as well as considering the perfect synergy of both elements – the tradition of Ettore Bugatti we uphold.” It was stated that the AM spoiler bracket aided the 1500 hp vehicle to reach speeds of up to 400 km/h in some 32.6 seconds, later bringing it to a stop within 9 seconds.
Additively manufactured spoiler bracket reduced weight by 5.4 kg (Courtesy VW Group)
The active rear spoiler can be adjusted in height and angle, supporting the sophisticated aerodynamics required to keep the car stable. Bugatti teamed with Siemens to optimise the bracket for production and reduce the number of iterations needed to achieve the required weight and rigidity. Using additively manufactured titanium with a tensile strength of 1250 MPa and a material density of over 99.7%, the spoiler bracket’s weight was reduced by 5.4 kg, with an increase in rigidity and no loss of function.
Motor bracket with integrated water cooling
A small metal additively manufactured motor bracket with integrated water cooling was developed for the Bugatti Chiron and has been installed in all series vehicles since its launch. The Chiron has two separate water-cooling circuits to keep the component and system temperatures at an acceptable level, even under the most extreme environmental and operating conditions. The high-temperature circuit is used to cool the 1,500 hp W16 engine of the car, while the low-temperature circuit ensures that the intake charge cooling temperature remains suitably low.
A bypass flow filter of the NT circuit supplies the console while isolating the electronic components from the temperatures of the transmission oil tank. The bracket acts as an active heat shield, resulting in a reduction in transferred heat. Its primary task is to engage the gears while opening and closing the two clutches of the seven-speed dual-clutch transmission, while including the control unit.
As a result, the temperature at the electric motor and at the control unit of the pump when driving through a demanding handling course can be lowered from 130°C to 90°C, a reduction of 40°C. The bracket was manufactured in the alloy AlSi10Mg on an SLM 280 Twin system, and was commissioned by SLM Solutions at Rolf Lenk Werkzeugbau GmbH.
Front axle differential housing
SLM Solutions and Bugatti date their collaboration back to late 2014/early 2015, when SLM Solutions worked with Bugatti’s parent company, Volkswagen Group, for the first time.
AM optimised front axle differential housing (Courtesy VW Group)
The project involved the design, calculation and later production of a bionically optimised front axle differential housing. This housing was manufactured by Audi AG at its Ingolstadt and Györ facilities on SLM 280 systems, with the objective of comparing the influencing factors of varying locations in regard to component quality.
Cylinder head cam covers
Although not yet in production, the SLM Solutions booth at Formnext 2018 featured eight Bugatti W16 cylinder head covers. The parts measuring 285 x 65 x 735 mm each were created in a single build on the company’s new SLM®800 machine.
Prototype cylinder head covers (Courtesy SLM Solutions Group AG)
(Source: Metal AM_Vol.5_N°1)