Strong and ductile alloys

A processing strategy for preparing molybdenum alloys with unprecedented strength and ductility is reported online this week in Nature Materials. Alloys based on molybdenum are attractive for high-performance applications where high strength and high thermal conductivity and stability are critical, such as in heat exchangers, corrosion-resistant storage vessels and nuclear reactors.

Molybdenum alloys are a group of refractory metals - a class of metals with high resistance to heat and wear - that are intrinsically strong yet brittle, that is, they are resistant to stress but fail when they are deformed at high stress. Sun Jun, En Ma and colleagues describe a processing approach that produces alloys with an improved nanostructure consisting of ultrafine submicrometre grains with oxide nanoparticles distributed uniformly in the grain interior. The researchers show that this results in an unprecedented ductility - the alloys are able to deform plastically by up to 40% without failing when under tension at room temperature - and increased strength, a combination of properties that exceeds those of conventional molybdenum alloys.

The researchers note that the approach can be readily adapted to industrial production, which would allow extensive processing and shaping of molybdenum alloys at low temperatures.