Creating affordable alloys to save energy and costs

Materials World magazine
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29 May 2019

A cheaper variety of a ferrous alloy has been developed to save energy and costs. Idha Valeur reports.

A new iron-based alloy system could help produce more economical materials to supply the electronics and specialist metallics industries, for use in electromagnetic devices, pole transformers and electric motor cores.

As part of a global effort to lower emissions of dangerous gases in production and promote energy savings, new materials are being created to reduce loss of transmission and transformation of electricity.

An international team of scientists from the National University of Science and Technology (NUST MISIS) in Russia, Tianjin University in China, and researchers from Japan and the US are working on a joint project to achieve this.

Previously, they developed Fe-Si-B-Nb-Cu (iron-silicon-boron-niobium-copper) – an amorphous soft magnetic alloy system, but it proved too costly to produce at scale, so the team wanted to design out the niobium.

After studying several Fe82-85B13-16Si1Cu1 alloys, the scientists discovered how the chemical compositions and heat treatment modes affected the magnetic and mechanical properties of the alloys, which resulted in them forming alloys with technological plasticity, magnetic properties and high strength. The results were reported in the paper, Nanocrystallization, good soft magnetic properties and ultrahigh mechanical strength for Fe82-85B13-16Si1Cu1 amorphous alloys.

‘These alloys allow for reducing energy losses in work of electromagnetic devices and that leads to savings of energy and natural resources. In addition, less natural resources used leads to the reduction of CO2, SxOy and NxOy gas creation,’ MISIS NUST PhD student, Engineer and co-author Erzhena Zanaeva, told Materials Word.

Zanaeva explained that iron was chosen as one of the main ferromagnetic, non-metalloid elements, silicon and boron were important to form amorphous structures and Nb and Cu elements gave better conditions for nanocrystallisation processes.

When asked why this development is important, Zanaeva said, ‘There have been no reports in the literature on the formation of amorphous and nanocrystalline alloys in the Fe-B-Si-Cu system that exhibit good soft magnetic properties without the addition of transition metal elements such as Nb, molybdenum and chromium or the metalloid P (phosphorus), all of which increase the material cost.

‘In this paper, we reported the formation of an amorphous phase for simple and inexpensive Fe-rich alloy ribbons prepared by melt spinning,’ she said.

Melt spinning is where a thin stream of liquid is dropped onto a rotating wheel and cooled, causing rapid solidification. Zanaeva explained that it is this technique that gives the alloys their forms.

Following the success of this new material, the team is aiming to take its developments into production. Read the full paper in Journal of Alloys and Compounds, here: bit.ly/2HIp0HS