Two scientists from the Institute of Physics of Materials, Czech Academy of Sciences, Dr. Veronika Mazánová and Dr. Milan Heczko, were part of an international study, which led to the development of new CrCoNi alloy exhibiting unique combination of yield strength and fracture toughness at room and cryogenic temperatures (77 K, -196 °C), exceeding the values reported for other metallic materials up to date.
Study published in prestigious journal Communications Materials from the Nature portfolio is focused on the concept of tunable partially recrystallized heterogeneous microstructures in materials, using techniques of easily industrially accessible thermo-mechanical treatments. It is then possible to imagine resulting microstructure of composite character as a combination of so-called “hard domains”, which provide strength related properties, and “soft domains”, which on the other hand enable plastic deformation and strain hardening using mechanisms of nano-twinning (TWIP) and local transformation induced plasticity (TRIP). Mutual correlation of mechanisms acting in such composite microstructure at several different length-scales from hundreds of micrometers to nanometers then contributes to dissipation of energy that would otherwise contribute to crack propagation, further leading to the fracture.
Findings of the study indicate that by tuning the degree of recrystallization through thermo-mechanical processing techniques, it will be possible to further expand the envelope bounding the strength and toughness of a range of structural metallic materials at engineering component scales. Additionally, the results suggest great potential to use this concept to create extraordinarily strong, ductile, and tough partially recrystallized microstructures in additively manufactured net-shape or near-net shape components.
Published work is a result of international collaboration with scientists from The Ohio State University, Lawrence Berkeley National Laboratory, University of California Berkeley, Oak Ridge National Laboratory, University of Tennessee and company Exponent.
Communications Materials belongs to the Nature Portfolio, and it is a fully open-access journal with IF = 7.5 and ranking in Q1.
