Preparation and Combustion Characteristics of Spherical Al@C Based on Electric Explosion

To investigate the combustion characteristics of spherical Al@C nanoparticles, an aluminum wire electrical explosion experimental system was constructed. A systematic investigation of the microstructural and morphological characteristics of Al@C nanoparticles was conducted, and comparative analyses were performed on their thermal decomposition properties and combustion behaviors using AP-based mixtures containing either the synthesized Al@C nanoparticles or the conventional nano-aluminum powder. Results demonstrate that the Al@C nanoparticles prepared via electrical explosion exhibit a distinct core-shell structure, with a carbon coating layer of approximately 10 nm thick, stable interfacial bonding between the carbon layer and aluminum core, forming an Al4C3 interface, and particle sizes ranging from 50 to200 nm (average particle size 99.50 nm, standard deviation ±34.00 nm). The carbon coating effectively isolates aluminum from oxygen and exhibits inherent thermal stability, with the Al@C nanoparticles showing a weak endothermic peak at 654.3°C corresponding to aluminum core melting. Compared with conventional nano-aluminum powder, the carbon-coated structure in Al@C nanoparticles offers the following advantages: reduces the AP decomposition temperature (exothermic peak shifted from 400.6°C to 331.27°C, a decrease of 69.33°C) and accelerates the AP decomposition reaction; maintains aluminum reactivity while significantly enhancing the combustion rate (burn duration reduced to 10% of that of conventional Al/AP systems, i.e. 90 ms for Al@C/AP vs. 900 ms for Al/AP); suppresses particle agglomeration during combustion; enhances energy release while stabilizing AP decomposition (the enhanced energy release capacity is reflected in a higher maximum combustion temperature of 2870.56°C and a stronger emission peak at 600 nm (8000 a.u.) compared with Al/AP (7450 a.u.)); promotes uniform heat diffusion during combustion, achieving higher core temperatures and more stable combustion wave propagation.