Lightweight aluminium driving innovation

March 8, 2016

Can a hollow aluminium car chassis be safe?

We are increasingly being asked to develop parts for electric vehicles, from self-driving cars through to buses and recycling trucks, what is striking about the enquiries is that they need to be lightweight dictating the need for hollow aluminium chassis components.

This might raise the question – how can a solid steel component be replaced with a hollow aluminium one and keep the same strength and safety of the heavier part?

Anthony Evans, managing director at Sarginsons, said: “Lightweighting is increasingly important in the automotive sector, particularly in electric vehicles as it contributes vastly to increased battery range andmakes electric a highly viable proposition.

“OEMs can save hundreds of kilos in weight on an average 4×4 vehicle just by installing hollow aluminium castings instead of the traditional steel.

“We’re also currently working on designs for completely hollow aluminium wishbones, combined wishbones and suspension housings and we are even looking at casting an entirely hollow sub-frame. These are very complicated parts which requiresophisticated engineering.

“Manufacturing hollow aluminium automotive components which are as strong as steel is extremely challenging so we’re particularly pleased with the breakthroughs we’ve been able to achieve.”

Due to the extensive development and testing already undertaken alongside some of the UK’s leading research institutions such as the Advanced Metal Casting Centre (AMCC) and the Lightweight Energy Absorbing Aluminium Structures for Transport (LEAAST), such hollow components meet or exceed the safety critical characteristics seen in heavyweight steel components.

Sarginsons are renowned for their expertise in gravity and low-pressure aluminium casting, and have recently been recognised as a specialist in lightweight safety critical aluminium components which has allowed us to take the early lead in hollow casting innovation.

Evans added: “We have to calculate how we can cast a part around a recoverable solid sand core to very consistent criteria whilst ensuring that there are no entrapped particulates preventing us from strengthening the part though heat treatment.

“This requires extensive 3D modelling and simulations and an in-depth knowledge of metallurgy and metal crystallisation.

“It is clear to us that low pressure casting is very much the future of vehicle chassis manufacture as it allows the mass production of hollow castings which the more common high pressure casting is unable to do.”

Sarginsons is already responsible for producing hollow sectioned components for the sub-frames of a number of market leading OEM vehicles. The company has also recently produced a hollow section wishbone which will be used in refuse trucks and is currently in discussions on a number of highly innovative prototype designs.

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