Research on strength-ductility and fracture behavior of ultra-fine bio-magnesium alloys via double-sided friction stir processing using liquid CO2 cooling

作者：Kun Sheng, Shaokang Guan, Yufeng Sun, Yoshiaki Morisada, Hidetoshi Fujii · 发表于：Journal of Magnesium and Alloys · 年份：2025 · DOI：10.1016/j.jma.2025.02.018 · 被引用次数：9 · 研究领域：Aluminum Alloys Composites Properties、Magnesium Alloys: Properties and Applications、Advanced Welding Techniques Analysis

• The strength and ductility of bio-magnesium alloys are improved by double-sided friction stir processing. • The relationship between microstructure characteristics and fracture behaviors is systematically studied. • The fracture mechanisms of bio-magnesium alloys are changed by double-sided friction stir machining • This method is expected to promote the application of bio-magnesium alloys. 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 ...