Winning the lightweighting race

Materials World magazine
27 Feb 2019

UK manufacturing is breaking down barriers with a focus on lightweighting. The University of Sheffield’s Advanced Manufacturing Research Centre is setting out to advance capabilities in the UK.

Lightweighting is very much the buzzword of modern manufacturing, driven largely by the automotive and aerospace industries’ desires to use lighter materials to boost performance and increase fuel efficiency in planes, trains and automobiles.

Future mobility and clean growth are two of the big ticket items in the UK government’s Industrial Strategy, meaning a focus on electric drivetrains, and weight-reducing composites and metals. But the relentless focus on electric risks us losing sight of lightweighting, says the University of Sheffield’s Advanced Manufacturing Research Centre’s (AMRC) composite facility Partnership Lead, Hannah Tew.

It is only when the two come together that the UK will create fit-for-purpose future mobility, and that’s why the AMRC has positioned itself at the fore when it comes to lightweighting, gearing its research towards developing new manufacturing processes as manufacturers move to make more use of materials that reduce weight but retain the strength of their traditional, heavier counterparts.

‘Lightweighting does exactly what it says on the tin – it’s all about making designs lighter, in turn, saving money, fuel and meeting those all-important emissions targets being driven by government legislation to meet its climate change obligations,’ Tew said.

‘It also plays a major role the government’s Industrial Strategy which identified future mobility and clean growth within its grand challenges. This involves a shift to electric vehicles – and ultimately aircraft – which will require lightweight materials and processes to offset the increased weight of power systems, such as batteries, and to improve their efficiency and range.’

Eyes on emissions

The UK government’s intention to ban the sale of conventional diesel and petrol cars by 2040 in a bid to cut emissions has caused huge growth in demand for electric vehicles, with 2017 alone seeing a 54% increase in EV ownership, according to the International Energy Agency.

AMRC Head of Automotive, Ben Kitcher, said that increasing power and energy density of battery systems is critical to the automotive industry achieving adequate range in its electrified products. ‘Gravimetric and volumetrically speaking, fossil fuels for internal combustion vehicles are at least an order of magnitude more energy dense than even the latest battery technologies,’ he said.

‘As scientists develop new active battery materials to increase energy and power capacity, engineers must continue work to develop materials and systems that lower overall weight of the vehicle significantly.
To exceed the goal of 500km range per charge, both sides of the energy/weight equation must be evolved through continuous innovation.

‘In Preston, the AMRC is tackling this challenge in our AMRC North West facility. By understanding the materials and processes required
to turn battery cells into battery packs, the mass and volume of materials used in battery systems can be reduced. Key areas of opportunity to reduce overall mass are packaging structures, cooling systems and conductive components.’

Tew agreed, and added, ‘If you have powertrains and lightweighting working in harmony, you have a really strong base to put the UK at the forefront of electrification. With the Faraday Challenge, the UK has made the statement that we intend to lead the world. To secure the greatest possible value, lightweighting is the key to anchoring the whole thing in the UK.’

Accelerating manufacturing success

The research talent and capabilities of the AMRC Composite Centre has a track record of delivery to industry. They were key to British supercar manufacturer, McLaren, making the decision to re-shore its body-making plant from Austria to the purpose-built McLaren Composite Technology Centre (MCTC) in Rotherham, UK.

At the opening of the facility last year, McLaren CEO Mike Flewitt threw down a lightweight gauntlet for researchers, government and manufacturers, when he said, ‘It’s my belief that, through facilities like the MCTC, with a joined-up policy landscape that makes the natural link between lightweight and future powertrain as almost two halves of the same whole, Britain can become a world leader in lightweight materials technology that will help create more efficient future vehicles for use the world over.’

Sharing this vision, Tew said, ‘McLaren may only have a relatively small share of the automotive market, but they are innovators and ambitious to develop new materials and processes which will have a major impact on the future of the mass market, especially as we move towards electric vehicles.

‘For the AMRC, and for those innovative businesses like McLaren who believe lightweight manufacturing is important to grow UK gross value added, you can’t do batteries and power electronics and maximise the value to the UK without addressing the weight
issue as well’. Having supported the development of the advanced materials technologies and processes that were the key to helping McLaren Automotive move to Rotherham, the AMRC is keen to keep its foot on the lightweighting accelerator, as the scale of challenges
can’t be underestimated.

‘With evermore stringent requirements on improved fuel efficiency and CO2 emission reduction for road vehicles, a key enabling technology is the use of advanced composite materials to significantly reduce the mass of vehicles on the road,’ Tew added.

‘Lifecycle analysis has shown that approximately 15% of total CO2 emissions result from material and parts production, assembly and disposal. The remaining 85% of the CO2 is emitted during operation and driving. The lighter the vehicle is, the less fuel is burnt and the lower are the CO2 emissions. Research shows that a 10% reduction in vehicle mass improves fuel consumption by 7%, and every litre of fuel saved reduces CO2 emissions by 2.6kg.

‘Advanced composite materials have higher strength-to-weight ratios, better chemical and greater design flexibility, compared with many conventional automotive construction materials. We are looking to develop technologies that will significantly reduce the cost of using these advanced materials in vehicle structures, a traditional barrier to date. Through a combination of reduced material wastage and automated pre-form manufacture, these technologies will have a significant impact on the cost of resin transfer and wet moulded composite components. Not only will they be of benefit to the automotive industry, but also to other industrial sectors such as wind energy, sporting goods and aerospace.’

Sum of parts

Composite materials aren’t the only tool in the arsenal at AMRC.
AMRC Castings is setting a standard with its counter gravity aluminium casting, and with the UK’s only titanium casting unit, the facility is looking to put castings back onto the supply chain map for the UK. The improved materials properties from the innovative casting technology will equip manufacturers to remove weight and reduce cost.

The AMRC and colleagues within other high-value manufacturing catapult centres are able to take a national lead in this weight race by investing in talented people and a comprehensive portfolio of cutting-edge advancing manufacturing technologies. With significant funding support from the Aerospace Technology Institute (ATI), the AMRC lightweighting team now has an advanced triaxial robotic braiding system and 3D loom to accompany other new equipment, which will be used to manufacture preforms and develop enabling technologies for commercialisation, including joining, automation and impregnation. New equipment includes the 1000T Rhodes press and Krauss Maffei high-pressure RTM system, a tailored fibre placement machine, a high-temperature-high tension filament winder, a stitching robot, tow-spreading capability and robotic end effectors for automated handling.

AMRC Founder and Executive Dean , Professor Keith Ridgway, said, ‘Thanks to the support of government through the ATI, the AMRC now has the technology and the research talent in depth to support UK industry in winning the weight race, which is essential as we make the transition to a low-carbon economy by supporting the shift to electric cars, trucks and, eventually, aircraft. All we need now is a dedicated, purpose-built lightweighting centre to house the new machinery which is currently scattered across the campus as we try to juggle people and kit in response to the ever-increasing industrial demand for our expertise in novel materials and processes.’

Aerospace lightens up

But this is not just about automotive. The AMRC is leading the development of fuel tanks for small satellites by applying design for additive manufacturing and topology optimisation to develop a novel, lightweight geometry that maximises available volume for fuel storage.

The designs developed currently exceed the requirements of the brief and are indicated to meet the target cost for the end-user, with mass reduction under target and a volumetric utilisation of approximately 90%. This technology has the potential to translate to hydrogen tank storage, for example in automotive applications, also bringing solutions to the hydrogen economy. Composite materials and processes are also increasingly being used in aerospace to make aircraft lighter and more environmentally friendly and there are huge opportunities to adopt composites in many other industries in order to reap economic and environmental benefits.

Research undertaken with the equipment by the AMRC will bring down the cost of complex composite components, making it easier for aerospace and automotive sectors, and help UK manufacturers to secure a larger share of the lucrative and rapidly expanding aerospace and composite markets.

Grass roots

But for the AMRC, it is not all about digitally enabled, high-tech equipment. It’s about people. ‘We’ve recently set up a dedicated Advanced Textile Composites team to develop these capabilities, to produce composite components in ways not currently available in the supply chain from composite suppliers,’ said Tew.

‘This will improve the fit of the UK composites supply chain to the needs of the global aerospace and automotive markets and growing the economy through expansion in these sectors with composite materials and multi-material solutions, tooling and advanced manufacturing – positioning the country as Europe’s number one aerospace and automotive manufacturer.’

The team consists of Tew, University of Manchester Professor of Robotics and Textile Composites Prasad Potluri, and Chris McHugh, who has joined the AMRC Composite Centre with decades of textile experience under his belt having previously worked for James Dewhurst, NWTexnet and Sigmatex. This team is joined by Head of the AMRC Composite Centre Richard Scaife, and AMRC Senior Research Fellow Dr Hassan EL-Dessouky.

To achieve these goals, however, Tew believes the UK has to get up to speed and fast. Changes to emissions regulations mean the UK needs both lightweighting and power train solutions in place by 2021 and then for manufacturing processes to be established by 2023 with opportunities continuing as the manufacturing processes improve.

‘To develop the right materials and manufacturing choices for the next generation of vehicles in four or five years’ time, we need a strongly collaborative approach involving industry, government and research and innovation assets such as the AMRC,’ says Tew. ‘If we get the timing wrong, if we delay too long, the UK risks value chains being lost and investment may be made elsewhere.’