@article{Sheng2025, 
author = {Kun Sheng and Shaokang Guan and Yufeng Sun and Yoshiaki Morisada and Hidetoshi Fujii},
title = {Research on strength-ductility and fracture behavior of ultra-fine bio-magnesium alloys via double-sided friction stir processing using liquid CO2 cooling},
year = {2025},
journal = {Journal of Magnesium and Alloys},
volume = {13},
number = {8},
pages = {3725-3739},
keywords = {Fracture behavior, Bio-magnesium alloys, Strength-ductility, Double-sided friction stir processing, Homogeneous microstructure, Ultra-fine grain},
url = {https://www.sciopen.com/article/10.1016/j.jma.2025.02.018},
doi = {10.1016/j.jma.2025.02.018},
abstract = {Bio-magnesium (Mg) alloys exhibit excellent biocompatibility and biodegradability, making them highly promising for implant applications. However, their limited strength-ductility balance remains a critical challenge restricting widespread use. In this study, ultra-fine-grained and homogeneous Mg alloys were fabricated using double-sided friction stir processing (DS-FSP) with liquid CO2 rapid cooling, leading to a significant enhancement in the strength-ductility synergy of the stirred zone. The results demonstrate that DS-FSP samples exhibit simultaneous improvements in ultimate tensile strength (UTS) and elongation, reaching 334.1 ± 15 MPa and 28.2 ± 7.3%, respectively. Compared to the non-uniform fine-grained microstructure obtained through single-sided friction stir processing, DS-FSP generates a uniform ultra-fine-grained structure, fundamentally altering the fracture behavior and mechanisms of Mg alloys. The DS-FSP samples exhibit irregular fracture patterns due to variations in basal slip system activation among different grains. In contrast, single-sided friction stir processing samples, characterized by a fine-grained yet heterogeneous microstructure, display flat shear fractures dominated by high-density dislocation initiation induced by twin formation, with fracture propagation dictated by the non-uniform texture. By achieving an ultra-fine grain size and homogeneous texture, DS-FSP effectively modifies the fracture mechanisms, thereby enhancing the strength-ductility balance of bio-magnesium alloys.}
}