Rational design of gradient structured fluorocarbon/Al composites towards tunable combustion performance

摘要

Polytetrafluoroethylene/Aluminum (PTFE/Al) composite with high energy density and combustion reactionperformance has received widespread attention in the field of propellants, explosives, and pyrotechnics.In order to precisely control combustion reaction and energy output performance, gradient structuredPTFE/Al composite (mass and diameter gradient) has been designed and constructed through 3Dprinting technology. PTFE/Al ink is prepared by acoustic resonance mixing to control rheological properties(viscosity and modulus) for 3D printing technology. The largest reaction heat (7749.95 J/g) andburning rate (~130 mm/s) are achieved for gradient lines with diameter of 2.42 mm and mass ratio of60:40 (PTFE/Al). Moreover, the progressive change from steady combustion to deflagration containingthree stages of pressure output is observed for gradient structured PTFE/Al cylinder. This work revealsthat gradient structure could provide new strategy to tune energy output and combustion performances,which can promote the practical application of PTFE/Al reactive materials.