Sungkyunkwan University develops new index to identify metallic glass using electrical resistance

Researchers at Sungkyunkwan University have developed a new index that can rapidly identify the glass-forming ability of metallic glass using only changes in electrical resistance.

Sungkyunkwan University said the research team led by Lee Dong-woo, a professor in the Department of Mechanical Engineering, worked jointly with a team led by Yanhui Liu of the Chinese Academy of Sciences to propose the new metallic glass identification index. The findings were published in Advanced Materials, an international journal in the field of materials science.

Unlike ordinary metals, in which atoms are arranged in a regular pattern, metallic glass is an alloy with an irregular, glass-like atomic structure. Its high strength and wear resistance, combined with the ability to be precision-formed into complex shapes, make it a strong candidate for use in robot components, aerospace materials and medical devices.

The research team focused on changes in electrical resistance that occur when the internal structure of an alloy shifts. The team fabricated a thin-film alloy library of varying compositions and conducted heat-treatment experiments on approximately 3,500 alloy compositions.

The experiments showed that alloys with high glass-forming ability exhibited only a modest drop in electrical resistance during heat treatment, even when a crystalline structure began to form. By contrast, alloys that could not maintain a metallic glass structure and readily converted to crystalline metal showed a sharp decline in electrical resistance.

Measuring electrical resistance takes only a few seconds per composition, allowing materials to be screened far more quickly than with conventional analytical methods. The approach also enables simultaneous comparison of multiple alloy compositions without the need for complex microfabrication or expensive equipment.

The research team confirmed that the index applies not only to thin-film materials but also to ribbon-form metallic materials used in industrial settings. Lee said, "Changes in electrical resistance serve as an index that can quickly reveal atomic disorder and nanocrystallization processes," adding that the method "could be used to discover new bulk metallic glass materials in multicomponent alloy systems."