Nanocrystalline powder metallurgy alloys offer lighter and harder alternative to aluminum and steel

Powdermet Inc., Ohio, USA has announced the development of a new powder metallurgy (PM) approach to the production of bulk nanocrystalline metallic composites. Working with the Army Research Laboratory and Case Western Reserve University, Powdermet recently demonstrated a unique, scalable processing route to the production of aluminum composites with stable nanocrystalline grain structures. Powdermet  claim that these unique, nanostructured PM alloys offer lower weight, higher strength, and increased hardness compared to currently available aluminum alloys, without reliance on rare-earth or other costly alloying elements. Strengths and hardnesses comparable to high strength Cr-Mn steels have been demonstrated in subscale mill products, including plate and sheet. The scalable, non-cryomilling based production process developed by Powdermet is able to produce nanocrystalline powders with a stably, highly refined grain structure that can be consolidated with combined PM and deformation processing conditions to produce high strength and hardness aluminium products.

The nanocrystalline aluminium products offer great potential to reduce weight and improve the performance of vehicles. Powdermet won a recent competition leading to a multi-year development and demonstration contract from the Army Research Laboratory, USA, to further develop and scale up the demonstrated production processes to produce aluminium mill products having strengths above 500MPa and hardnesses above 400VHN while retaining 8% or greater ductility.

The project will be carried out utilising Powdermet’s Microcomposite Deformation Centre, which includes a 5000 ton forging press, a 350 ton rolling mill, and a 1500 ton extrusion press, along with collaborations with researchers at Case Western Reserve University, the Army Research Laboratory, and Impact Ballistics, among others. Anticipated benefits to the Army will be an up-armouring system having 30-50% lower mass than current RHA steel solutions, bridging the gap between steel and titanium armour in terms of cost, weight and performance. Additional applications are envisioned in spacecraft, launch vehicle, and ground transportation systems where strength to weight improvements translate into significant lifetime operating cost and emissions/environmental impact reduction.

Andrew Sherman, Powdermet President and CEO, also adds, “Powdermet is excited to be part of the convergence of nanotechnology and advanced metallurgy, leading to a reduction in the environmental and economic footprint of transportation and military vehicles.”

For further information regarding the potential value of nanocrystalline metals in your products, or to participate in or contribute to the rapid development of these new materials, visit www.powdermetinc.com or contact Brian Doud, Program Manager, at [email protected]