Atomized Mg-Li spherical alloys: A new strategy for promoting reactivity of Mg

• Published in: Journal of alloys and compounds 2024-09, Vol.998, p.174974, Article 174974
• Main Authors: Zhao, Wanjun, Tang, Xinyue, Li, Jianxin, Le, Wei, Jiao, Qingjie, Liu, Dazhi, Jia, Yuxin
• Format: Article
• Language: English
• Subjects: Burn rate; Flame temperature; High reactivity; Spherical Mg-Li alloys; Thermal behavior
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2024.174974

In this study, to improve the reactivity Mg, which is a frequently used fuel, Li was incorporated into it. Mg-Li alloys with 3 and 5 wt% Li, prepared via centrifugal atomization, displayed a high degree of sphericity and consisted of αMg. Thermal behaviors indicated that the initiation oxidization temperature of Mg-Li powders was ∼170–200°C lower than that of pure Mg, owing to the lower melting point of soluble Li than that of Mg. Li passes through oxide shells and initiates the oxidization of metals in the core. The apparent activation energy of Mg decreased significantly from ∼361.2 kJ/mol to ∼141.1 kJ/mol with the incorporation of Li. For combustion in air, the Li content should be 5 wt% to achieve increased combustion intensity compared to Mg powders. When Mg-Li alloys and Mg powders were composited with polytetrafluorethylene (PTFE) serving as an oxidizer, the burn rates of MgLi3/PTFE and MgLi5/PTFE were ∼7.1 and 12.1 m/s, respectively, which were ∼1.8 and 6.8 m/s higher than that of Mg/PTFE. The flame temperature of Mg-Li/PTFE (∼1537–1552℃) of 3–5 µm was slightly lower than that of Mg/PTFE (∼1637℃). Therefore, the prepared Mg-Li alloys are promising candidates for use as fuels for energetic materials. •Spherical Mg-Li powders were originally obtianed by incorporating Li into Mg.•The addition of Li effectively advanced the onset oxidization of Mg.•Mg-Li alloys displayed visibly intenser combustion when compared to Mg.•The prepared Mg-Li alloys were applied in the field of energetic materials.•Mg-Li/PTFE composites showed significantly higher burn rate than Mg/PTFE mixtures.