Researchers at the Indian Institute of Technology (IIT) Madras, the University of North Texas, and the US Army Research Laboratory have developed an engineered magnesium alloy that can replace steel and aluminum alloys in the automobile industry making vehicles more fuel-efficient.
The researchers say the current industrial application of wrought magnesium alloys in structural components is very limited due to their poor strength, poor ductility, yield strength asymmetry and lack of high strain rate superplasticity despite their density being two-third of aluminium and one-quarter of steel.
According to Sushanta Kumar Panigrahi, Associate Professor at Department of Mechanical Engineering, IIT Madras, the new engineered alloy is strong, highly ductile and its superplasticity is achieved at higher strain-rates which reduces overall manufacturing time, effort and costs.
"In addition to this, it is also lightweight, which helps lower the carbon footprint of vehicles. Lightweight vehicles need lesser fuel to run and are therefore more fuel efficient. In view of the compelling needs for economical usage of scarce energy resources and ever-stricter control over emissions to lower environmental impact, automotive and aerospace industries are searching for alternative advanced light-weight structural materials to existing conventional materials.
"Being one of the lightest and energy-efficient structural materials, magnesium alloys are potential candidates to replace steel and aluminium alloys in automotive and aerospace components since their density is two-thirds of aluminium and one-quarter of steel," Panigrahi said.
The research has also been published in the reputed peer-reviewed journal Material Research Letters.
For the research, the scientists used a magnesium alloy containing rare earth elements like Gadolinium (Gd), Yttrium (Y), and Zirconium (Zr). The alloy was subjected to a thermo-mechanical processing technique (severe plastic deformation and aging treatment) to obtain an ultrafine-grained version of this magnesium alloy.
Thereafter, the team engineered the nano-precipitates and thermally stable ultrafine intermetallic compounds in the ultra-fine-grained magnesium alloy.
According to the team, through this technique, the group was able to achieve the highest combination of strength-ductility and highest high strain rate superplasticity among all the existing magnesium alloys reported in the literature to date.
"We are also trying to increase the load-bearing capacity of metals and alloys through microstructural engineering and processing of metals. After this feat, the team is all set to apply the same strategy of processing to other known magnesium alloys and metallic alloys with the intention of obtaining highly efficient stronger materials with superior performance," Panigrahi said.