One key area of development in metallurgy today is the creation of new materials with especially high density, which can be used in the aerospace, aviation, military, and electric power industries. Researchers from South Ural State University are working with materials that are promising for all of these fields.
Articles dedicated to this topic are published in highly-rated journals in the USA, Japan, China, Australia, and European countries. One of the researchers’ recent papers was published in 2019 in the Lecture Notes in Mechanical Engineering journal. The authors of the article were Doctor of Sciences (Engineering), Professor Leonid Barkov; Candidate of Sciences, Associate Professor Marina Samodurova; and engineer and researcher of the SUSU Resource Centre of Specialized Metallurgy Yuliya Latfulina.
Mathematical Model Created for the Treatment of New Materials
“We have been working on difficult-to-form materials. They have such properties as elasticity, heat resistance, and improved hardness. But the process of pressure treating of these materials is very labour-intensive, so it requires special equipment and production tools, as well as special technological methods. We have patented the construction of a production tool and created a model of the technological process, which makes it possible to obtain compact objects from difficult-to-form new materials with certain properties. Using the results of the early studies, we are simulating the process of these new materials processing. Ultimately, we will be able to obtain a finished product from the new material, and with the characteristics that we need,” says Head of the SUSU Laboratory of Mechanics, Laser Processes, and Digital Production Technologies Marina Samodurova.
The researchers have obtained the experimental dependencies of specific moulding pressure on the breakdown. This makes it possible to determine the modes and technological parameters needed to create a piece with set qualities. In other words, the model of the technological process makes it possible to find the parameters for processing powder to obtain pieces with certain qualities.
New Generation of Super-strong Material to Be Used in Aviation
The basis of this model of the technological process is the earlier results of working with other materials with physical features similar to the new material. Before, the researchers studied refractory materials including tungsten, nickel, molybdenum, and others, as well as superalloys such as nickel titanium, which is used actively in the aviation industry.
Photo: Contact stripes made of graphite-reinforced plastic
In addition, the university’s researchers have created a press form to treat metals like tungsten and molybdenum. Where earlier there was no method to obtain quality items from tungsten because of the high melting point (more than 3500°С), there is equipment available today, which makes it possible to achieve this through tungsten powder pressing. At present, work is being conducted on composites based on graphite, one of the most promising modern materials (graphite-reinforced plastic). The composition used for this process includes a tungsten powder and polymer binder (formaldehyde resin).
“How is graphite different from other materials like nickel titanium? It is three times lighter than titanium. In addition, titanium’s maximum operable temperature is around 1000°С. Graphite-reinforced plastics become 3 times stronger at 2500°С than at the room temperature. This is why rocket bodies are made of graphite-reinforced plastics today. In addition, the surface of the new Russian airplane Irkut MS-21, known as the “long-haul aircraft of the 21st century” is covered in sheets of carbon fibre. The advantage of carbon fibre is that it is very strong and heat-resistant. It also has the highest conductivity,” notes Leonid Barkov.
Photo: Doctor of Sciences (Engineering), Professor Leonid Barkov
Other Fields of Application of New Materials: Space and Energy Sectors
Carbon fibre is most frequently used in military and civilian aviation. One other possible application is the creation of contact strips for electrical transport. At present, ARMA company, using technologies by SUSU researchers, is creating products in this field for regions of Russia, as well as for countries in Europe and the CIS.
“Carbon fibre is a promising material for space rockets, military and civilian aviation, and for nuclear industry. Our goal as technologists is not to make particular characteristics of the material worse, but to obtain small items with the highest possible density. In additive technologies, particularly in surface engineering, there are no competitors for us, because we are developing technologies for goods of constructional designation and are in demand in the market,” stresses Marina Samodurova.
In the future, the researchers are planning on continuing to work with difficult-to-form heat-resistant materials, including not only carbon fibre, but also molybdenum and tungsten alloys.