Nanjing Institute of Technology

The influence of pre-deformation on the microstructure and mechanical properties of a Mg-rich high-Cu Al-Mg-Si-Cu alloy was systematically investigated by hardness measurement, tensile test, and atomic resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). With the increase in pre-deformation strain (0–10%), the hardness and strength of the alloy after PB hardening increased progressively, accompanied by a continuous reduction in tensile elongation. Notably, increasing pre-deformation strain from 2% to 10% did not bring a significant enhancement in bake hardening response, despite the gradual improvement in the strain hardening capability of the alloy. An optimal pre-deformation strain of 5% is identified, which enabled the alloy to achieve a superior and industrially feasible combination of strength and ductility, balancing practical forming demand (T4 temper) and service performance (PB state). Pre-deformation can significantly affect the morphology and atomic structure of precipitates for the alloy. Dislocations introduced by pre-deformation acted as heterogeneous nucleation sites, inducing the formation of elongated and string-like precipitates along dislocation lines. A distinct Cu segregation behavior was observed in the pre-deformed alloy with the majority of Cu atoms segregated at the precipitate/α-Al interface, which was in sharp contrast to their dominant distribution within the precipitate interior in the non-pre-deformed alloy. These findings provide new insights into deformation-assisted precipitation regulation in Mg-rich high-Cu Al-Mg-Si-Cu alloys and offer practical guidance for optimizing the strength–ductility synergy of such alloys for automotive lightweight manufacturing applications.

By employing a model of a two-dimensional d-wave superconductor, we investigate the Fulde–Ferrell–Larkin–Ovchinnikov (FFLO) state under the influence of a Zeeman field and antiferromagnetic order. Through self-consistent solutions to the Bogoliubov–de Gennes equations, we derive the spatial distributions of the superconducting order parameter and magnetization, thereby revealing the interplay between antiferromagnetic and superconducting orders. The local density of states is computed to characterize low-energy excitations and the formation mechanism of the FFLO state. Our results show that the coexistence of antiferromagnetic and superconducting orders gives rise to a spatially modulated FFLO state, where the competition between these two orders significantly influences the spatial patterns of the order parameters and magnetic properties. These findings offer insights into the complex interplay between magnetism and superconductivity in strongly correlated systems, emphasizing the role of external fields and magnetic order in stabilizing exotic superconducting phases.