Lighter motor cars for the 21st century

An Australian-developed magnesium alloy has answered the global car industry’s call for lighter engines.

• 7 December 2007 | Updated 14 October 2011

• Overview
• Lighter and stronger 
• Greenhouse savings
• Further applications

Overview

In a significant global technology coup, an Australian-invented magnesium alloy, AM-SC1, has been chosen by the United States Automotive Materials Partnership (USAMP) to be the basis for its new low pressure/sand cast engine research project.

USAMP is sponsored by the US Council for Automotive Research which includes:

• DaimlerChrysler
• Ford
• General Motors.

The alloy will form the basis for a new generation of motor vehicles that are:

• lighter
• stronger
• environmentally cleaner
• much more fuel-efficient.

It was developed by the Cooperative Research Centre for Cast Metals Manufacturing (CAST). Former CSIRO scientist Dr Colleen Bettles, led the research team assembled through CAST.

Lighter and stronger

The new magnesium alloy is 33 per cent lighter than aluminium alloy and stronger than the same weight of steel. 

AM-SC1 was selected because it can be manufactured at a comparable cost to existing metals and meets the extreme physical demands of a combustion engine.

The metal will be used to build and test a magnesium intensive V6 engine.

Greenhouse savings

CAST’s Chief Executive Officer, Professor David St John, says that using magnesium instead of iron in a car’s engine block could result in greenhouse gas savings of 2.75 tonnes of 'CO₂ equivalent' over the car’s life.

Professor St John says the development of a magnesium alloy that can be used in the high temperature conditions found in modern car engines has been the goal of international research for years.

'That Australia was able to achieve this goal is testimony to our ability to assemble a team of the best magnesium alloy researchers from across the country' says Professor St John.

Dr Bettles says that aside from the weight, the other critical issue that had to be resolved was minimising the long-term 'deformation' that can occur at high running temperatures.

This is the reason that cast iron engines used to be returned to service centres to have everything tightened after an initial wearing-in.

The alloy not only boasts a high strength-to-weight ratio, it also has high shock and dent resistance, and dampens noise and vibration more than either aluminium or steel.

Further applications

The alloy development team included researchers from:

• CSIRO
• University of Queensland, Brisbane, Australia
• Monash University , Melbournem, Victoria, Australia
• the Australian Magnesium Corporation (AMC).

Commercial rights to this new alloy belong to AMC, which is being restructured to form a new entity, Advanced Magnesium Technologies (AMT).

In its initial phase, AMT will concentrate entirely on further developing and commercialising this alloy, together with five other patented end-use magnesium technologies.

'Once the engine is lighter,' says Professor St John, 'it allows a flow-on to the rest of the car. Magnesium is a logical lightweight alternative to traditional automotive materials, especially in power train components.'

Find out more about Light Metals Flagship.