Researchers from Graduate Institute of Ferrous & Eco Materials Technology (GIFT) and Materials Science and Engineering (MSE) at POSTECH, led by Professor Hyoung Seop Kim, have proposed an innovative alloy design strategy that achieves superior mechanical properties, cost-efficiency, and lightweight characteristics through the development of heterostructures at various scales. This research was recently published in the international journal Acta Materialia, a leading publication in the field of metals.

In industries such as construction, machinery, aerospace, nuclear, and energy, alloys composed of various metals are widely used. Alloys intended for high-temperature applications often rely on nickel (Ni) and cobalt (Co) for their excellent mechanical properties and stability at elevated temperatures. However, the high cost and increased weight associated with these metals have limited their industrial applications, despite their exceptional performance in high-temperature environments.

The POSTECH research team developed a novel method to maintain outstanding mechanical properties at high temperatures while achieving improved cost efficiency and lightweight characteristics by using iron (Fe)-based alloys. They introduced a hierarchical heterostructure in the alloy, where different microstructures coexist to complement one another, resulting in synergistically enhanced strength and ductility. By creating heterostructures at various scales—micrometer (μm), nanometer (nm), and sub-nanometer levels—they significantly boosted the mechanical properties of the alloy.

The alloy developed by the research team is not only lighter than pure iron but also achieves lightweight characteristics at less than half the cost of conventional high-temperature materials. Additionally, the alloy maintains mechanical performance comparable to those of existing high-temperature commercial materials at both high and room temperatures, offering an exceptional balance of price, weight, and high-temperature performance.

Prof. Kim stated, “We have presented a new direction for developing next-generation high-performance materials through alloy designs optimized for industrial applications,” adding, “This alloy is expected to find use in various industries, including automotive, battery packs, and aerospace.”

This research was supported by POSCO and the National Research Foundation of Korea’s Mid-Career Researcher Program.