Al/CuF₂ Composite Materials with Ignition Characteristics and Pressure Output Ability for Nanothermites

Abstract

To improve the pressure output ability of nanothermites to meet the needs in many fields, with the more volatile advantage of metal fluoride products (AlF3), this paper proposes the scheme of nanothermites (Al/CuF2). The energy release process of Al/CuF2 with different equivalent ratios under slow and fast heating rates has been studied. Under the slow heating rates, it was found that the equivalent ratio (Φ) has a significant influence on the energy release process. When Φ ≤ 1, the product is dominated by Cu. With the increase of the equivalent ratio, Al2Cu gradually appeared in the product, indicating that the increase of Al powder contributed to the enhancement of the alloy reaction. On the other hand, to further investigate the actual application of the Al/CuF2 mixture, combustion experiments in a closed container and in open air were carried out and compared with those of Al/CuO. In accordance with our design concept, AlCuF2 shows more excellent gas release ability. Al/CuF2 (Φ = 3) has the most excellent pressure output capacity (2.67 MPa), which increases by 107% compared to 1.29 MPa (Al/CuO). In addition, Al/CuF2 displays more excellent ignition performances in terms of shorter delay time and less ignition energy. Therefore, Al/CuF2 composite particles, as a novel nanothermite design, are expected to be widely used in the gas generator, micropropulsion, and other military and civilian fields.