Summary of the High entropy alloy
High entropy alloy is an innovative material made of five or more types of metal elements. These materials have been concerned in the fields of metallurgy, materials, and engineering science due to their outstanding mechanical properties. Scholars at Pohang University of Science and Technology in Korea explain the creation process of high-entropy alloys and how their influence goes beyond the scope of metallurgy.
Human beings have created civilization by challenging the changing environment. In megacities, vehicles cross high-rise buildings, trains cross long Bridges, planes fly over the sky and across a white line, which is typical of modern civilization. The use and evolution of tools enhance industrial productivity, drive the expansion of human society, and then produce the development of human civilization. Materials are playing an extremely important role in improving the efficiency of tools and thus have become a standard for determining different stages of civilization development. Raw materials for making tools can be easily found in nature, such as common materials such as wood, straw, and stone. Objects and tools made from metal are more common. Due to the complex shape and the need for fire sources to smelting metal from the raw material, metal manufacturing tools started late. However, due to their outstanding strength and molding nature, metals have become one of the most important materials in today's industrial society. In different metals, steel has been playing a leading role due to its rich natural resources and can achieve high molding with only a relatively simple adjustment. Because of this, steel production and consumption can be regarded as indicators of a country's development level.
"Malposition" opens a whole new chapter in metallurgy
The metal usually solidifies at room temperature. We can imagine how a pile of industrial fragments is assembled
Become a single, large object. Many solids are formed through regular configurations of symmetric structures (such as cubes), which consist of atoms through infinite repetitive groups and fill three-dimensional space, which also becomes crystal structures. It is well known that the interatomic forces in metal crystals are weaker than in other solid morphologies. And a crystal structure usually contains crystal defects that are not arranged in normal rules. In these defects, the "dislocation" greatly affects the mechanical properties of the crystal structure.
In the dislocation, the gap between the atoms produces a long straight line. During the beating, bending, or stretching of the metal, a dislocation is created within the metal and rearranged. This is because the interaction force between metal solid atoms is low, and previously existing bonds can easily break and form new bonds.in other words,
It can be arranged by adjusting the dislocation, and new forms can be produced by applying the force. On the other hand, strong bonds of other solid-state substances-bound crystal structures, such as salt, are difficult to change their shape because they are not easily damaged by external forces.
Effective control of "dislocation" is the dream of metallurgists
Developing hard, unbreakable and flexible materials is a long-lasting dream of metallurgists. The key question to consider is how to control the dislocation motion within the metal. By mixing two or more atoms to form an alloy, different metal materials can be prepared, whose properties depend on the ratio of the atoms and the manufacturing process.
South Korea Poxiang steel company successfully put into commercial production of Gigabit steel is a kind of high strength steel, designed and developed a twin structure, the left and right mutually symmetrical, like the mirror, or through control dislocation, changed the crystal structure in the process of plastic deformation, it can be regarded as a high-tip metal material.
Beyond the conventional bondage
Metal materials have great potential, and metallurgists are good at tapping them. Among the great achievements in metallurgical research in recent years, the most striking one is the high entropy alloy.
Often, a metal material is an alloy developed by combining two or three small elements with one major element based on the desired properties. High entropy alloys are formed by combining five or more elements at the same or similar ratio, without the main elements. This method yields almost a variety of alloys by which excellent low temperature and corrosion resistance have been studied and proposed.
The results show that the high performance of the high entropy alloy is closely related to the twin deformation. The previous assumption was that these alloys exist outside the range of twin deformation and, therefore, were beyond the scope of conventional knowledge of metallurgy.
The Institute of Steel Technology of the University of Science and Technology in Korea cooperated with the Royal Swedish Institute of Technology to propose a general theory of atomic level and conduct atomic quantum mechanical calculations. The results show that the high entropy alloy is a completely different material, and the twin deformation is more effective and thus produces higher mechanical properties.
Super high intensity
The second biggest achievement worth emphasizing is the ultra-light and high-strength steel developed by the Steel Technology Research Institute of POSCO University of Science and Technology in South Korea. This alloy is designed with high content of manganese and aluminum in steel composition, while the nickel content is low, and small secondary crystals can be prepared through appropriate process control.
Secondary crystals are known to have chemical stability and can cause decreases in the performance of metal materials and should be avoided. In contrast, the recently proposed alloys are superior to conventional steels in terms of mechanical properties or even titanium alloys used as aircraft materials, indicating that the new generation of high-alloy steel such as Gigabit, high-entropy, and ultra-light high-strength steel has opened a new chapter in metallic materials.
The unremitting pursuit of security and sustainable development
Humans should fully consider the future of the planet and civilization, and only in this way can wisdom be demonstrated. So far, scientific knowledge has guided us to meet various challenges smoothly. The role of metallurgists is also crucial. In order to explore and apply various materials, and continue to promote the safe, efficient and sustainable development of society in the future, these scholars will also be committed to more in-depth research in the principles and application of materials to reveal the great power of natural science.
Heeger Materials provide high-quality spherical refractory high entropy alloy powder at a competitive price. Send emails to [email protected] to get a quote about the product you need.