Feb 8 2019
Researchers from the National University of Science and Technology MISIS (NUST MISIS) have joined hands with their colleagues from RUSAL’s Light Materials and Technologies Institute. to develop a highly durable alloy using the additive manufacturing method.
The superior strength properties of the alloy at elevated temperatures make it a quite promising lightweight material for high-temperature applications, including motor vehicles and aircraft. An article on this innovation was published in the Materials Letters journal.
Additive manufacturing is a versatile technology that promises to supersede conventional casting methods in the near future. Selective laser melting (SLM) is among the most popular additive manufacturing methods.
Aluminum-silicon (Al-Si) alloy components synthesized with SLM technology offer high strength at room temperature, but they do not usually show high levels of strength at temperatures higher than 200 degrees Celsius.
“Porosity and defects, such as hot cracks, balling and un-melted powder, are typical problems when fabricating parts by selective laser melting,” Alexander Churyumov, member of the project team and NUST MISIS assistant professor, told RIA Novosti.
NUST MISIS scientists and their colleagues from the Light Materials and Technologies Institute decided to improve the material’s mechanical makeup by adding new components to the aluminum-silicon (silumin) alloy.
“We have further developed the alloy’s chemical composition and SLM parameters so we can guarantee a defect-free structure and the mechanical properties of this new heat-resistant aluminum-silicon-nickel-iron (Al-Si-Ni-Fe) alloy. It is common knowledge that nickel can improve the mechanical properties of Al-Si-Fe alloys by reducing the size of the hardening phases,” Alexander Churymov explained.
Scientists have developed a high-capacity SLM mode for the new alloy; it guarantees an impressive volume density in the synthesized material, for 99.8 percent of the theoretical level. The material owes its high strength to the small structure formed by the Si, Al5Fe (Ni, Cu) and Al3 (Ni, Cu) phases.
According to the researchers, the new materials will help in the design of complex shaped parts with optimized geometry for automotive and aerospace technology.
Source: RIA