Lightweight magnesium alloy wheel produced using the T-Mag casting technology.

Travelling light with T-Mag™

An Australian development in light metals is leading towards increased use of magnesium to manufacture lightweight motor vehicle components.

• 20 November 2007 | Updated 14 October 2011

• Addressing an industry need
• Advantages of T-Mag™ 
• The future 

Addressing an industry need

Use of lightweight materials in the automotive industry is increasing, in line with a worldwide trend to improve fuel efficiency and reduce carbon-dioxide emissions.

A new Australian technology makes components made of super-light magnesium alloys an economically viable alternative to steel, iron and aluminium in car manufacture.

As part of the Light Metals Flagship, a team of research engineers headed by Dr Thang Nguyen from CSIRO has developed a new permanent-mould magnesium casting technology, called T-Mag™.

Using the T-Mag™ process, lightweight magnesium alloy engine blocks that are only two-thirds the weight of aluminium alloy blocks can be cast.

The Light Metals Flagship has partnered with three South Australian companies in a joint venture, T-Mag Pty Ltd, to take the technology to the international market.

'T-Mag™ technology makes magnesium competitive' says T-Mag Pty Ltd interim Chief Executive Officer Mr Steve Groat.

The T-Mag™ technology generated interest from car manufacturers in Europe and North America when it was exhibited at an international foundry exhibition in Germany in June 2007.

Advantages of T-Mag™

This technology consistently produces high-integrity magnesium alloy castings, free of the porosity and defects that have hindered the use of magnesium in the past.

T-Mag™ makes it possible to cast high-integrity magnesium alloy wheels, powertrain components and other load-critical applications, which are not economically viable with current casting technologies.

T-Mag™ offers several advantages over traditional casting technologies, such as high-pressure (HP) casting.

For example, it takes six to seven kilograms of metal to produce a 3.5 kilogram casting.

The unused metal cannot be recycled with ease because remelting creates oxides and intermetallic compounds, and both the initial melting process and remelting the scrap consume large amounts of energy.

In comparison, T-Mag™ requires only 3.7 kilograms of alloy for a three-and-a-half kilogram casting, reducing recycling and energy use, and providing savings in melt costs.

The T-Mag™ permanent-mould casting process requires neither high pressure nor a vacuum to fill the die, which fills smoothly from the bottom.

This minimises air entrapment and oxidation, and produces castings that are virtually free of defects.

T-Mag™ successfully combines melting and casting in a single compact unit, which is hermetically sealed to protect the magnesium from oxidation and to minimise gas usage.

Unlike conventional HP casting, the T-Mag™ process can be used with dies which incorporate sand cores to produce complex hollow features inside castings, for example, cooling water passages in engine blocks.

The future

The new company, T-Mag Pty Ltd, combines the skills of the casting team at the Light Metals Flagship with the abilities of:

• Alloy Technologies International (ATI)
• Flotek
• SAGE Automation.

T-Mag Pty Ltd will supply a turnkey package, machines and associated technologies for the manufacture of magnesium permanent mould castings to the international market.

Commercialisation of the technology received a significant boost from the Australian Government with the award of a A$1.9 million grant from the AusIndustry Commercial Ready program in July 2007.

Learn more about the Light Metals Flagship.