Al@PTFE composite powder explosion characteristics

Polytetrafluoroethylene (PTFE)-coated aluminum (Al) powder, denoted as Al@PTFE powder, combines the high energy density of Al with the unique reactivity of PTFE, making its explosion hazard a critical safety concern. In this study, a numerical model for Al@PTFE powder explosions was developed using computational fluid dynamics and combustion theory to characterize their transient explosion dynamics. The results show that, with increasing Al@PTFE powder concentration, the maximum explosion pressure (P_max) and the maximum rate of pressure rise ((dP/dt)_max) initially increased and then decreased, reaching peak values of 0.802 MPa and 556 MPa/s, respectively, at 300 g/m³ . Similarly, as the PTFE coating ratio increased, P_max and (dP/dt)_max exhibited the same non-monotonic trend, attaining maximum values of 0.755 MPa and 406 MPa/s, respectively, at a coating ratio of 5%. Furthermore, the dynamic evolution and propagation characteristics of the flame, combustion products, and temperature field were analyzed to elucidate the mechanism by which PTFE regulates the explosion behavior of Al powder. These findings provide useful guidance for the safe application of Al@PTFE powder and the prevention and mitigation of related explosion accidents.