By Udbhav Bhargava
Researchers from the following 3 organizations have developed an engineered magnesium alloy with significantly improved properties. Indian Institute of Technology Madras, University of North Texas, and U.S. Army Research Laboratory.
Declined industrial application – The need to develop Magnesium
The current industrial application of wrought magnesium alloys in structural components is very limited due to their;
- Poor strength
- Poor ductility
- Yield strength asymmetry
- Lack of high strain rate super-plasticity.
- The density of Mg is 2/3rd of aluminium and 1/4th of steel
Description of scientific terms
Ductility is a measure of the capacity of a material to endure substantial plastic deformation until breaking or rupture.
The yield strength or yield stress is a material property and is the stress that corresponds to the yield point at which the material begins plastically deforming itself. The yield strength is used to calculate the maximum permissible load in a mechanical device, as it represents the upper limit of forces which can be applied without permanent deformation. A material will bend elastically until the yield point, and return to its original shape when the stress applied is removed. After reaching the yield point, some fraction of the deformation is permanent and non-reversible, and is known as plastic deformation.
Approach of the research team, the scientists used a magnesium alloy containing elements of rare earth such as Gadolinium (Gd), Yttrium (Y), and Zirconium (Zr). To produce an ultrafine grained variant of this magnesium alloy, the alloy was subjected to a thermo-mechanical processing technique (severe plastic deformation and ageing treatment).
The team then developed the nano-precipitates and ultrafine intermetallic compounds in the ultra-fine-grained magnesium alloy which were thermally stable. Using this method, the group has been able to achieve the highest combination of strength-ductility and highest super-plasticity strain rate of all the current magnesium alloys recorded in the literature to date.
The new engineered alloy is –
- Strong
- Lightweight
- Highly ductile
- Its super-plasticity is achieved at higher strain-rates.
Why is this development significant?
Such properties minimize overall time, energy and costs of manufacture. Vehicle emissions account for around 27 per cent of global emissions of carbon dioxide. Countries all over the world are focused on growing these. The reduction of the carbon emissions of vehicles by using lightweight material in their body has been a primary priority of the researchers. Light-weight vehicles require less energy (fuel) to run, and are thus one of the methods to improve the energy efficiency of automobiles. The new Magnesium alloy in automotive and aerospace parts will replace steel and aluminum alloys.
Eduindex News 