A group of scientists of National University of Science and Technology (MISIS, Russia) and Tohoku University (Japan) under the guidance of professor Dmitry Luzgin started development of unique metallic glass for aerospace industry, micromechanics and health care industry. The team plans to make Russia leader in the segment of advanced materials. The amount of investments for 2014-2015 is 25 million rubles, MISIS reports.
Metallic glass is a metal/alloy without traditional crystal structure; in fact, it is a “solidified liquid”, a uniform amorphous material, which is in many ways like window glass. The first material of this type was developed in the second half of the 20th century. However, the material became popular in late 1990s and early 2000s, when the large-scale castings (called three-dimensional metallic glasses) were manufactured. The popularity of these materials is connected with unique and outstanding properties of the materials, the institute explained.
“Metallic glasses are two times more durable compared to crystalline alloys having similar chemical composition (parameters depend on the type of the alloy), have higher elasticity and corrosion resistance (including resistance to acids and sea water), increased hardness and wear resistance. This is possible, because metallic glasses have no grain structure and no grain boundaries typical of metals. And what are the obstacles for usage of these materials? The known metallic glasses have low plasticity, especially in the form of macroscopic products. It is no secret that window glass can be deformed, for example, curved to some limit. Elastic deformation is the type of deformation that allows a glass to return to its initial shape without sustaining any damage after removing the load. After reaching a limit load the material is no longer able to return to its initial shape and the plastic deformation begins. In case of a window glass such deformation destroys the glass. On the other hand a crystalline metal or alloy may bend and lose shape absorbing the energy of an external load. Metallic glasses are falling in between a crystalline metal, which has a high viscosity and ability lose shape easily, and the window glass, which is almost unable to sustain plastic deformation,” professor Luzgin said.
“The goal of the united team of scientists is to increase the elasticity and fracture toughness of the metallic glasses making them more resistant to damage sustained during deformation. Our previous studies demonstrated that some results might be obtained by means of improving the composition of the glass. However, recently we found out that it will be much easier to develop a new class of materials - hybrids. These are materials comprising different compositions: metallic glass and crystalline metal, metallic glass and polymer, metallic glass and quasi-crystal. In this case material combines the properties of metallic glass (durability, hardness and wear resistance) with elasticity of a crystalline metal or a polymer. If we combine metallic glass and polymer, we will get some additional improvements like lower weight and higher strength-to-weight ratio,” professor Luzgin noted.