The research project “Extreme Grain Size Effect in Metals,” led by the Institute of Metal Research, Chinese Academy of Sciences (IMR, CAS), has been honored with the 2024 CAS Outstanding Scientific and Technological Achievement Award in the Basic Research category.

The award was presented at a ceremony in Beijing. The project team, including researchers LI Xiuyan, XU Wei, ZHANG Baobing, and LUO Zhaoping, focused on the structural and mechanical behavior of metals with grain sizes reduced to the nanometer scale.

Using self-developed extreme deformation techniques, the team successfully refined grain sizes in multiple metals to below ten nanometers, surpassing previous refinement limits. Their work revealed novel phenomena such as spontaneous grain boundary relaxation, confined crystal structures, and anomalous phase transformations at critical grain sizes. Notably, they discovered that metals can transform into a new metastable “confined crystal” structure under extreme geometric constraints, exhibiting near-theoretical strength, exceptional thermal stability, and extremely low diffusion coefficients.

These findings have led the international research frontier in nano-metallic materials and have been applied in developing advanced high-temperature alloys, aluminum alloys, and wear-resistant rolling mill components.

In 2024, CAS revised its reward regulations to strengthen the guidance of scientific recognition, establishing four award categories including the Basic Research Award, which honors significant scientific discoveries and original innovations in fundamental and applied basic research.