Frost on glass: how to make a heavy-duty metglass plastic

Metal glasses - metal glasses - almost an ideal material: durable, solid, corrosion-resistant, like glass, while elastic, like metal. Today, they are used in various fields: from magnetic materials and medical instruments, to transformer cores, micromotor gears and sports equipment.

However, to the point of view of the metglass, there is still not enough plasticity. This disadvantage eliminates "rejuvenation" - the transfer of the material to a higher energy state, which increases its resistance to plastic deformation without loss of strength.

Scientists of NITU "MISIS" were able to freeze metallic glass with the help of cryothermal treatment so that it became more "flexible" without losing its remarkable strength. For this was applied the method of cyclic cooling in liquid nitrogen. The resulting material with optimized properties can be in demand in modern engineering and energy.

Artem Trifonov, Ph.D., engineer, Department of Metallurgy of Nonferrous Metals, NITU “MISiS”: “We found that the use of cryothermal cycles can stimulate the“ rejuvenation ”of some glasses and relaxation (the opposite of the rejuvenation process) of others, depending on the composition ".

Cryothermal treatment also dramatically increases the ability of a material to resist stretching and compression during elastic deformation on the surface of samples (in a thin layer of tens of nanometers). This effect, however, disappears after the glass is kept at room temperature. The volumetric effect remains with time and allows to improve the ductility of the alloy.

“Cryothermal treatment looks like a universal and simple method for changing the properties, rejuvenation or relaxation of metal glasses. It is important that it can both improve and degrade plasticity - this requires careful selection of the composition of the alloy, based on the structure of atomic bonds in the material, ”says Artem Trifonov.

According to the authors, they will continue to study the effect of such processing on the structure and properties of various materials. The “taming” of the process will make it possible to make plastic not only bulk metal glasses, but also composites of the type “metallic glass-crystal” (whose “rejuvenation” may manifest itself even stronger due to the greater heterogeneity of the structure). An article about the study was published in the journal NPG Asia Materials.