Research

[POSTECH research team develops a new alloy that maintains tensile properties from -196℃ to 600℃.]

A research team at POSTECH (Pohang University of Science and Technology), led by Professor Hyoung Seop Kim from the Department of Materials Science and Engineering, Graduate Institute of Ferrous Technology, and Department of Mechanical Engineering, has developed a new alloy that maintains its strength and ductility across extreme temperatures ranging from –196 °C to 600 °C. The findings, which have drawn attention from the aerospace and automotive industries, were published in the international journal Materials Research Letters.

 Most metals used in everyday life are sensitive to temperature changes—metal doorknobs feel icy in winter and scalding in summer. Consequently, conventional metal materials are typically optimized for performance within a narrow temperature range, limiting their effectiveness in environments with dramatic temperature fluctuations

 To overcome this challenge, the POSTECH research team introduced the concept of the "Hyperadaptor" and developed a nickel-based high-entropy alloy (HEA)^*1 ’ that embodies this idea.

 The newly developed HEA demonstrates nearly constant mechanical performance across a wide temperature range—from cryogenic conditions at -196°C (77 K) to high heat at 600°C (873 K). This remarkable stability is attributed to the presence of nanoscale L1₂ precipitates^*2 , which are uniformly distributed within the alloy. These fine particles act as reinforcements that inhibit deformation, while the alloy's internal structure accommodates stress through consistent slip behavior, regardless of temperature.

 This development holds significant promise for applications that involve sudden or extreme temperature changes, such as rocket or jet engines, automotive exhaust systems, power plant turbines, and pipelines. The alloy’s ability to maintain stable performance under such conditions can greatly enhance both safety and efficiency in these demanding environments. 

 “Our HEA breaks through the limitations of existing alloys and establishes a new class of temperature-insensitive materials,” said Professor Kim. “The Hyperadaptor concept represents a breakthrough in developing next-generation materials with consistent mechanical behavior even under extreme conditions.”

The study was supported by the Ministry of Science and ICT through the Nano and Materials Technology Development Program and by Hyundai Motor Group. 

DOI: https://doi.org/10.1080/21663831.2025.2457346

1. High-Entropy Alloy (HEA): Unlike conventional alloys with a single principal element, HEAs are composed of five or more elements mixed in near-equiatomic ratios. Due to their high configurational entropy, these alloys exhibit unique microstructures and excellent mechanical properties.

2. L1₂ Precipitate: A type of precipitate formed in FCC-based alloys, characterized by an ordered atomic arrangement. Representative examples include Ni₃Al and Ni₃Ti. These precipitates hinder dislocation motion, thereby enhancing the strength and ductility of the material.