The 15th Global Conference on Materials Science and Engineering (CMSE 2026)

Abstract: Lightweight Mg-Li alloys are promising structural materials, yet their strength is fundamentally limited by the anisotropy and detwinning susceptibility of conventional nanotwinned architectures. We recently demonstrated that a two-step high-pressure and high-temperature (HPHT) treatment can trigger a BCC-to-HCP martensite-like phase transformation in an Mg-9Li alloy, spontaneously generating triple-interlocked nanotwinned (TIT) networks with a twin boundary fraction of ~65.7% and an extraordinary yield strength of 508.6 MPa, accompanied by unprecedented ageing resistance (only 6% hardness loss after 730 days). The formation of TIT structures arises from the impingement of multiple {10-11} contraction twin variants under a tailored stress-temperature field, theoretically enabling the manipulation of twin types through external constraints.

Building on this TIT strategy, we propose a high-pressure-induced regulatory framework for Mg-Li-X (X = Sc, Y, Zn, Al, etc.) alloys, wherein the selection of X elements and the calibration of HPHT parameters (pressure 1~6 GPa, temperature 400~1200 °C) collectively govern the crystallographic orientation relationships, variant intersections, and ultimately the population of TIT configurations. The dissolution behavior and redistribution kinetics of X solutes at twin boundaries—analogous to the periodic Li segregation observed at {10-11} interfaces—are expected to further tailor the disclination dipoles at triple junctions, modulate the elastic stress fields, and stabilize the TIT networks. By establishing quantitative among composition, pressure, phase transformation dynamics, and twin architecture, this work aims to extend the TIT concept into a broad Mg-Li-X family, delivering a new class of ultra-strong, ageing-resistant, and anisotropy-free lightweight structural materials.

Keywords: High-pressure treatment, Mg-Li-X alloys, Mechanical properties, Triple-interlocked nanotwinned.

Biography: Dr. Qiuming Peng is a Professor, Ph.D. Supervisor and Deputy Director at State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, China. Dr. Qiuming Peng received his Ph.D in Inorganic Chemistry from the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences in 2008. From 2009 to 2011, he worked as an Alexander von Humboldt Research Fellow at the GKSS Innovation Center for Magnesium Technology (now Helmholtz-Zentrum Hereon), Germany. He was selected into the Program for New Century Excellent Talents in University by the Ministry of Education of China in 2012. In 2014, he was awarded the National Science Fund for Excellent Young Scholars. In 2020, he was honored as a Changjiang Scholar Distinguished Professor by the Ministry of Education of China. Published over 200 research papers, including 105 papers as first author and/or corresponding author in prestigious journals such as Nature Communications, Cell Reports Physical Science, Advanced Energy Materials, Advanced Functional Materials, ACS Nano, Journal of the American Chemical Society, Nano Letters, and Acta Materialia.