Material scientists of NITU MISIS together with colleagues from Moscow Polytechnic proposed to use calcium instead of rare earth metals in alloys based on aluminum and copper. The resulting material is not only more than twice as economical in production, but also more resistant to high temperature fluctuations compared to analogs. The alloy will be perfect for manufacturing complex parts used at extreme temperatures, for example, in aircraft construction. This was reported in the press service of MISIS.
Selective laser melting (SLM) is an advanced technology for manufacturing complex in shape and structure products from metal powders. Due to its flexibility and ease of use, SLP is increasingly used in various industries: automotive, medical and aerospace for the manufacture of structures of complex shape and structure.
However, not every material is suitable for SLP, as the alloy must meet a set of physical and chemical properties that allow both to manufacture the product itself and to achieve the required performance characteristics. One of the promising types of materials for this technology are eutectic alloys based on aluminum, copper and rare earth metals (Al-Cu-REM). But such alloys have a big disadvantage – rather high cost.
Scientists of the MISIS University of Science and Technology together with colleagues from Moscow Polytechnic University for the first time in the world proposed an alternative system with calcium Al-Ca-Cu, which has a number of significant advantages in comparison with Al-Cu-REM. The use of calcium allows to significantly reduce the cost of the alloy, so, for example, the cost of calcium is twice less than such REMs as cerium and lanthanum, and it is almost 10 times cheaper than erbium. At the same time, the Al-Ca-Cu system is not inferior to systems with rare earth metals in terms of technological and physical and mechanical properties.
“Calcium is cheaper than rare-earth metals, has low density, which allows to further reduce the specific mass of the alloy. At the same time, the eutectic formed by the addition of calcium also has a very fine structure, which is necessary to obtain the required combination of physical and mechanical properties of the alloy,” explains the author of the study, Torgom Hakobyan, Ph.D., senior researcher at the Department of Metal Forming at MISIS University.
Despite the fact that the alloys of the basic Al-Ca-Cu system already by themselves have quite a successful combination of technological and physical-mechanical properties, this triple system, as the researchers note, can be used to develop more complex high-tech materials designed for operation in extreme temperature conditions, for example, for ground and air vehicles.
“Due to the natural-composite structure, which can contain up to 30 vol.% of the second phase, alloys based on the new Al-Ca-Cu system appear to be very promising for the application of digital laser processing methods, the study of the impact of which is the subject of further research,” concludes Torgom Hakobyan.
