Scientists have significantly reduced the fragility of metal glasses

Scientists and researchers are constantly inventing new and different materials that are used in many of their inventions. One of these materials is amorphous metals, also called metallic glasses.

Due to its amorphous structure, metallic glass can be as strong as steel, and at the same time ductile, like polymeric materials. In addition, they are excellent in electrical current and have a high corrosion resistance. Such advantages of the material could lead to the idea of ​​using it in various electronics and other areas of science and technology, if not for one but - amorphous metals have a high degree of fragility. They are brittle and unevenly resist fatigue loads, which puts their daily use in question. There are so-called multicomponent amorphous metals, which partially solve this problem, but this feature is still relevant for monolithic metal glasses.

Scientists from the Berkeley Laboratory and the California Institute of Technology after a long study have found a way to increase the strength of bulk metal glasses. For the manufacture of more durable materials, palladium was used, the tired strength of which is comparable to the widely used polycrystalline metals and alloys, such as steel, titanium, aluminum.

Under load, a shear band is formed on the surface of palladium metallic glass — a local area of ​​significant deformation that assumes a stepped shape. At the same time, along the edges of the cracks separating the “steps”, the same shear bands appear, which dulls the tops of the cracks and prevents their further spreading, reports newscenter.lbl.gov.

Palladium is characterized by its high ratio of bulk compression and shear moduli, which reduces the inherent fragility of glassy materials. Since the formation of “multilevel” shear bands, which prevent further crack growth, is energetically more beneficial than the formation of large cracks, leading to the rapid destruction of the sample. Together with the high fatigue strength of the material, these mechanisms significantly increase the fatigue strength of the bulk metallic glass based on palladium.

The article is based on materials https://hi-news.ru/research-development/uchenye-znachitelno-snizili-xrupkost-metallicheskix-stekol.html.