Al-Mg@PVDF and Al-Si@PVDF composites with enhanced combustion and energy release characteristics

To investigate the differences in combustion and energy release characteristics of metastable intermolecular composite materials composed of aluminum alloys and polyvinylidene fluoride (PVDF) with different compositions, two types of alloys were selected: Al-Mg and Al-Si. Pure aluminum powder of the same size was also chosen for comparison. The PVDF-coated metal particle composites and the mixtures of PVDF with metal particles were prepared using electrospray (ES) and physical blending methods (PM), respectively. A systematic study was conducted on the morphology, compositional structure, combustion performance, energy release characteristics, and thermal reactivity of the fabricated composites and their combustion products through scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), combustion performance experiments, closed vessel pressure tests, and simultaneous thermogravimetric-differential scanning calorimetry (TG-DSC). The experimental results indicated that the PVDF-coated metal particles prepared by the electrospray method exhibited a distinct core-shell structure, with the metal particles in close contact with the PVDF matrix. Compared to the PM blended materials, the ES composites demonstrated superior combustion performance and energy release characteristics during combustion. Analysis of different metal fuel systems under identical preparation conditions revealed that Al-Mg and Al-Si fuels modulate the combustion and energy release properties of aluminum alloy-PVDF MICs through two distinct pathways.