Light metals for lighter cars

The demand for lighter cars, trucks and airplanes to reduce the fuel consumption and hence CO2 emissions is driving a whole range of R,D & C activities into composites, ceramics and light metals technology around the world. In this week’s blog I’m going to take a look at the light metal industry in Australia and showcase a couple of recent innovative Australian technologies.

Light metals category predominantly includes Aluminium, Magnesium and Titanium. These metals are found in the ores of bauxite and magnesite and the mineral sands of rutile and ilmenite in the case of titanium. A basic snapshot of Australia’s resources in light metals is as follows:

  • Aluminium – Australia has 8.5Gt of bauxite and is the worlds largest exporter of bauxite and alumina. The industry is the second largest commondotity export behind coal with export earnings of A$8.9b in 2000-01. (
  • Magnesium – Some industry specialists predict Australia could produce 800,000 tonnes of magnesium every year by 2020, almost double the 450,000 tonne-a-year existing world market. Australian magnesium exports could account for 50 per cent of the growth in world demand over the next 20 years. (source)
  • Titanium – According to data from Geoscience Australia and USGS, Australia has the world’s largest EDR of ilmenite and rutile with 32%, 44% respectively. Australia supplies about 40 per cent of the world’s ilmenite and about 25 per cent of its rutile. (source)

Looking to the industry and its technology – the areas of innovation exist around the following aspects of refinement and manufacturing.

  • Reducing the energy intensity of refinement,
  • Improving the refinement process,
  • Development of stronger and lighter alloys, and
  • Forming and casting techniques.

Australia has and contines to provide significant support to light metals has a significant amount of government investment. The aluminium industry has received $3 billion since the early 1990s in technological improvements, upgrades and environmental improvements and continued expenditure on new technologies and processes of around $300 million per year.

In 2001 the australian government commited to the Light Metals Action Agenda to create dynamic, internationally competitive Light Metals Industries to 2020 and beyond, reflecting worlds best practice and sustainable development. Specific aims for these industries are:

  • Aluminium to expand its domestic and export market by 30%;
  • Magnesium metal output tonnage of 800,000tpa, with exports capturing 50% of the growth in world demand over the next 20 years;
  • Titanium to develop a metal output tonnage of 25,000tpa establishing a 25% share of the global market; and
  • The downstream sector to continue in the establishment of a vibrant export oriented industry using all three metals in new innovative products.

Now for the cleantech.
The two (paraphrased articles) below present two types of technology coming out of Australia’s focus on light metals I’ve decided to look at today are a new magnesium casting technology, T-mag , and a high temperature aluminium casting treatment technology. As a result of these technologies future cars will be far lighter and stronger as a result.

T-Mag: Magnesium casting technology
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The technology, called T-Mag, consistently produces high-integrity magnesium alloy castings from permanent moulds, free of the porosity and other defects that have hindered use of magnesium in the past.

A team of research engineers headed by Dr Thang Nguyen, from CSIRO Manufacturing and Infrastructure Technology (CMIT), has developed a new permanent-mould magnesium casting technology that promises to tame the featherweight but highly reactive metal for mass-production of vehicle components.

Barrie Finnin, leader of CMIT’s Manufacturing Technologies for Transport Theme, says T-Mag can cast lightweight magnesium-alloy engine blocks that will be only two-thirds the weight of current aluminium alloy blocks – a prospect that is already arousing the interest of high-performance car manufacturers in Europe.

It will also be possible to cast high-integrity magnesium alloy wheels. Current casting technology cannot produce wheels of sufficient integrity to be safe and practical at an acceptable cost.

cast magnesium wheel

T-Mag was developed through CSIRO’s Light Metals Flagship. A pilot-scale unit built for research and development has already produced successful demonstration castings, including alloy wheels, and magnesium alloy blocks for a 750cc, water-cooled, motorcycle engine will be cast shortly.

Oil price rises are forcing vehicle manufacturers to pursue further weight savings through use of strong, lightweight magnesium alloy components for powertrain and load-critical applications. But such applications are not economically viable with current casting technologies, Mr Finnin says. He describes T-Mag’s novel, integrated design as a critical enabling technology, with a range of applications beyond the high-pressure (HP) casting technique currently used to produce 85 per cent of the world’s magnesium alloy components.

HP casting is plagued by low as-cast yields: typically, it takes 6–7 kg of metal to produce a 3.5 kg casting. The unused metal cannot simply be recycled because remelting creates oxides and intermetallic compounds, and both the initial melting process and remelting the scrap consume large amounts of energy. “T-Mag requires only 3.7 kg of alloy for a 3.5 kg casting. This reduces recycling and energy use, and saves a lot of melt cost,” Mr Finnin says.

T-Mag could be used with a new magnesium alloy called AM-SC1 for engine blocks. Current magnesium alloys lack the mechanical properties required to operate for long times at high temperatures. However, the new AM-SC1, developed in Australia by a team including researchers from CSIRO, University of Queensland, Monash University and Australian Magnesium Corporation (now Advanced Magnesium Technologies – AMT)

Powertrain systems developer AVL in Europe has successfully trialled an engine made from the Australian alloy in a Volkswagen Lupo sedan. The alloy is being commercialised through AMT.

Mr Finnin says CSIRO will now seek industry partners to commercialise T-Mag: “We’ve only just started to talk to the market about the technology, which is so new that the patents aren’t even published yet.”

high temperature aluminium casting treatment technology
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Although heat treatment is commonly used to strengthen wrought and cast aluminium parts, it cannot be used on high-pressure die castings because air bubbles trapped during casting can blistering and distort the parts, making them unusable.

A new heat-treatment technique developed at CSIRO has overcome the problem, allowing high-pressure die cast parts to be strengthened without running the risk of these metal defects.

Dr Roger Lumley, leader of a Light Metals Flagship research team at CSIRO Manufacturing and Infrastructure Technology (CMIT), says high-pressure die casting is commonly used as a high-volume production process in a range of sectors, particularly the automotive industry, where it is used to manufacture parts such as engine blocks, transmission housings and many small parts.

Therefore a strengthening treatment that fits with this existing process is an important development.

“Most of the aluminium parts you see when you open the bonnet of your car are aluminium high-pressure die castings,” says Dr Lumley. The process allows parts to be made quickly – up to 20 small parts a minute.

CSIRO has overcome this manufacturing hurdle by developing a process where die casts can be heat treated. Dr Lumley says this results in quite large improvements in the strength of the part with an excellent surface finish.

Trials at CSIRO’s Clayton laboratories have shown the new process can at least double the strength of high-pressure die cast parts. This means they can be lighter and still do the same task – a factor that is particularly important in the automotive industry where lighter cars use less fuel and have lower greenhouse gas emissions.

“A lot of these parts are designed for their loads and basically the stronger the material, the lighter you can make the part,” says Dr Lumley. “We would like to think that we could see a 30 per cent weight reduction.

“The die casting industry is very, very cost-sensitive, and if you can use less metal per car part, you also save money.

Sam Tartaglia, business development manager at CMIT, says the industry has sought such a technique for many years.

“This is a major advance,” says Mr Tartaglia, who until recently was a senior executive at US-based company Teksid Aluminum, a world leader in the production of aluminium castings.

“While the new techniques will improve existing parts, it will be in new product design that the benefit will be the greatest. The big advantages will come when products are designed taking into account these new material properties.

Dr Lumley says that while aluminium die casting worldwide is dominated by the automotive industry, other industries can use the new process. Examples include builders’ nail-gun casings and even door handles.

“Basically anything that requires a fairly complex and strong part to be produced quite cheaply can be made using this process,” Dr Lumley says.


Nick Bruse is the General Manager of Clean Technology Australasia Pty Ltd, the organiser of the AustralAsian Cleantech Forums and Dealer Forums, and the leading advocate of Cleantech in Australia. Nick does a weekly blog column on Cleantechblog profiling innovative Australian cleantech, energy, water and environmental technology companies.

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