Lightweighting

Lightweight materials enable an improvement in fuel economy through vehicle mass reduction.

Lightweighting has been a United States Department of Energy (DoE) target for a very long time (see below presentation link), but the rise of electric vehicles makes lightweighting of EV's an even larger focus given the greater impact to lower CO2 emissions to produce the electricity, better use of the batteries, higher performance, higher range and more. The United States is on the leading edge of aerial transportation as that is the next step for electric transport and weight is even more critical there.

Governments are taking measures to ensure good air quality by enacting regulations to limit emissions. That is today’s biggest challenge for the transportation industry – continually increasing efficiency while keeping our cars, trucks, and planes safe.

Transportation manufacturers are focused on solutions: making engines more efficient, implementing electrification, optimizing aerodynamics of vehicle bodies, and lowering the weight of components in all our modes of transportation.

According to the United States Environmental Protection Agency, the transportation sector is responsible for 27 percent of greenhouse gas emissions in the US and about 14 percent globally. Responsible governments are passing legislation to offset climate risk by reducing emissions and greenhouse gases, especially carbon dioxide, or CO2 – which causes 63 percent of global warming issues.

The simple answer and the acknowledged focus to making cars more energy efficient is to lightweight our transport. An accelerating lightweight vehicle uses less energy than accelerating a heavy one, so lightweight stronger materials are a clear solution. According to the U.S. Department of Energy vehicle technology office, a 10 percent reduction in vehicle weight can result in a 6 to 8 percent improvement in fuel economy. Regardless of whether cars are powered by petrol or electricity, or any other energy source, today there is a growing need for efficiency and lightweight materials in transport. China, the world's largest car manufacturer (manufacturing 25.7 million out of 91.7 million cars in 2019), has a 13-year plan to increase the magnesium in cars from 8.6kg in 2017 to 45kg in 2030. This will generate 1 million tonnes of new magnesium demand per annum.

There is no silver bullet but integral to the answer in lightweighting is magnesium metal, which when alloyed with aluminium, creates a lighter, stronger and more fuel-efficient transport. In the last 4 years, aluminium sheet containing up to 6% magnesium was used in cars for the first time, as manufacturers look to produce lighter, more CO2 efficient vehicles. Engineers are constantly searching for the best properties like strength, stiffness, and ease of moulding, while taking into consideration cost, safety, and ease of manufacturing.

Most of magnesium metal is produced in China through the Pidgeon process that has an intensive energy usage and generates a large amount of greenhouse gas (GHG) emissions, which offsets the potential advantage of using magnesium metal in EV's. The critical challenge for scaled magnesium metal adoption has been obtaining low-cost product and reducing the carbon footprint. Magnesium demand is set to drastically increase as car producers look to lightweight heavy EV's.

Both barriers to previous adoption of a magnesium as a lightweighting material have been resolved by the technology developed by CSIRO and exclusively licenced to Magnium.

Magnesium is not usually used as a pure element, and so how it is alloyed, processed, and then used makes a big difference to its impact on lightweighting. However even as we move toward vehicles that are fully electric, autonomous, and even solar-powered, the need for efficiency and lighter weight materials is today and will continue to be a major driver for the transportation industry. The Magnium plants will play a key part in lightweighting the automotive industry.

Download The Challenges of Lightweighting Vehicles (and how the government is here to help).pdf
by Sarah Kleinbaum, Technology Manager - Vehicle Technologies Office, DOE

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