Team Bath Racing (TBR21), the University of Bath’s combustion Formula Student Team, have partnered with Progressive Additive Manufacturing to make use of a high strength Aluminium-Scandium alloy.
The key aim for this project was to maximise the TBR car’s steady state and transient handling performance, and the way to do this was identified as reducing the overall car mass, more specifically the vehicle’s unsprung mass; components that are in direct contact with the track. Reducing the unsprung mass ensures more consistent contact between the tyres and the track, whilst also reducing the vehicles yaw inertia allowing the vehicle to have increased response to steer inputs.
The task was to develop the lightweight suspension design with maximum stiffness, to maintain tyre angle control and handling predictability, with maximum cornering forces resulting in improved lap times.
The Challenge
Since 2016, TBR uprights had been additively manufactured from titanium alloys, to designs which have become prevalent across the Formula Student grid. The density of Titanium alloys capped potential weight savings due to the minimum material requirements for functional surfaces, such as bearing seats. TBR also found that it led to exceptionally thin-walled, highly load-optimised parts, which are not suited to the unpredictable loading scenarios of race-car driving.
Aluminium alloys would initially seem ideal for weight-savings, however the typical aluminium alloys available for additive manufacture have poor strength and exceptionally low fatigue life, making them unsuitable for the loads experienced during racing.
The Solution
One of the latest materials available to the team at Progressive Additive Manufacturing is a high-strength aluminium-scandium alloy. This alloy displays strength like Scalmalloy© comparable to that of wrought aerospace alloys such as 7075 and 2014, with significantly improved fatigue life over other AM aluminium alloys.
Combining the performance of this alloy with topology optimisation, and an internal lattice structure to reduce internal part density, has allowed TBR to design its lightest uprights to date, weighing in at just over 400g, and without any compromise in stiffness or fatigue life.
I was first aware of Aluminium-Scandium alloys from my prior experience in Formula One, however to see these alloys becoming commercially available, along with the experience of the team at Progressive Technology represents a really exciting step forward in the possibilities of additive manufacture in the automotive and
aerospace sectors.
Conor Smith
Outboard Suspension Designer
Team Bath Racing
Download the PDF for more detail on Formula Student, and for Team Bath Racing’s detailed Summary of Research.
