All metals have structural defects thatultimately affect their strength - the more defects in the metal, the softer or brittle it is. To solve this problem, scientists are creating new metal alloys. This approach allows to obtain more durable metal compounds, but at the same time leads to a loss of their conductivity. And this, in turn, limits the possibility of using new alloys in various tasks. The latest discovery of American scientists offers a solution to this issue. The discovery is reported in an article published by the journal Nature Materials.
A piece of the new silver alloy in the hands of study co-author Frederic Sanzose
Electrical conductivity - the property of the material to conduct electric current. It is very important in the production of various electronics.
The authors of the discovery were researchers fromUniversity of Vermont, who have developed a mechanism for the production of new alloys, which makes metals much stronger, but at the same time maintain their electrical conductivity.
How to create a durable and electrically conductive metal
The solution to the problem was surprisingly prettysimple. For example, at the nanoscale, scientists mixed a trace (in other words, a very insignificant) amount of copper with silver and as a result were able to get the most durable silver alloy - it is 42 percent stronger than any silver alloy existing today. But this is not the most important thing. The main thing is that, having become stronger, silver has not lost its electrical conductivity property. Recall that silver itself has the highest electrical conductivity among metals.
A model of the atomic structure of grains (particles) of silver interspersed with copper (marked in green) that fills metal defects
Thanks to the new production method, scientistsmanaged to overcome the so-called theoretical limit of Hall-Petch, which has been maintained for the past 70 years. It is also called the Hall-Petch law. According to this limit, the smaller the grain (particle) of the metal becomes, the stronger the structure of the substance becomes. However, there is some limitation. When metal grains become too small - a few nanometers in size - the boundaries of these grains become unstable, begin to move and deform, which leads to the fact that the metal again "softens".
Also interesting: Scientists have discovered metal to create the electronics of the future
Scientists have overcome this limit by creatingwhat they call "nanocrystalline nanotonated metal." Since copper atoms are slightly smaller in size than silver atoms, they are able to penetrate structural defects at the grain boundaries of silver. This prevents defects in its structure from movement, making the metal stronger. At the same time, copper particles do not create problems for the movement of electrons through silver, allowing the metal to maintain its electrical conductivity.
This is a new class of materials and we are just starting to understand how they work, ”comments Frederic Sanzos.
According to the researchers, a new approach inalloy production can be applied not only to silver, but also to other metals. As for the scope of use, the new method can one day be effectively applied, for example, in the production of more efficient solar panels, lighter fuselages for aircraft and even in the construction of more reliable nuclear power plants. It seems that these are not the only use cases. If our readers have their own ideas, you can express them in our Telegram chat.