Young Faculty Member of the Institute of Strategic Materials and Components Publishes Research Findings in Nature Communications

 Recently, the Institute of Strategic Materials and Components of Shenyang University of Chemical Technology achieved a significant breakthrough in the study of microstructural analysis of magnesium alloys. The related findings were published in Nature Communications under the title “Discovery of Confined Two-Dimensional Laves Tiling in a Magnesium Alloy.” The research team discovered a fundamental two-dimensional building block common to all known Laves phase structures within a magnesium alloy, and systematically elucidated its atomic structural characteristics, formation mechanisms, and evolutionary behavior through integrated theoretical calculations. Dr. Li Shanshan, a young faculty member of the Institute of Strategic Materials and Components, is a co-corresponding author of the paper.

Laves phases represent an important class of intermetallic compound structures, primarily comprising three representative types: the MgZn₂-type, MgCu₂-type, and MgNi₂-type. Unlike conventional FCC or HCP structures, which employ single atomic layers as the fundamental stacking unit, Laves phases are composed of multilayer two-dimensional Laves tiling blocks. Their geometric essence derives from the periodic tiling of icosahedral columns, constituting the fundamental framework shared by all Laves structures. In recent years, with advances in aberration-corrected scanning transmission electron microscopy, researchers have progressively identified a growing number of complex structural types formed on the basis of Laves building blocks, including aperiodic structures and quasicrystalline structures exhibiting fivefold rotational symmetry. Nevertheless, direct experimental verification of atomically thin, monolayer Laves building blocks as fundamental structural units had remained elusive.

Figure 2. HAADF-STEM image of the confined two-dimensional Laves structure in the Mg alloy

By integrating aberration-corrected HAADF-STEM, atomic-resolution EDS, APT, first-principles calculations, and molecular dynamics simulations, the research team directly observed for the first time a confined two-dimensional Laves proto-structure embedded in the (0001)α basal plane of the magnesium matrix in a peak-aged Mg-Al-Ca alloy. The core thickness of this structure is approximately 4.62 Å, equivalent to a single Laves building unit. Internally, it exhibits an Al₂Ca-like configuration and achieves atomic-scale stabilization through the cooperative action of the surrounding Mg/Ca interfacial atomic layers. Further investigation revealed that the distinctive interfacial strain surrounding this precipitate structure effectively suppresses the diffusion of Al atoms along the [0001]α direction, thereby inhibiting thickening of the precipitate phase.

This discovery not only provides critical insights into the nucleation, stabilization, and phase transformation mechanisms of Laves structures, but also offers an important theoretical basis for regulating age-precipitation behavior in Mg-Al-Ca alloys and for the design of novel high-strength, lightweight alloy systems.

Primary Review and Translating: Chen Jiayu

Secondary Review and Translating: Zhao Wenhao

Final Review and Approval: Wang Meng