Using microfluidic technology to prepare octogen high-energy microspheres containing copper–aluminum composite particles with enhanced combustion performance

Aluminized explosives are widely used in military applications. However, the easy agglomeration of aluminum (Al) powder and its high ignition temperature greatly hinder the reaction of nano aluminum (n-Al) in the process of explosion, thus affecting the combustion and explosion of aluminum-containing explosives. In the present study, copper (Cu) coated n-Al composite particles were introduced into aluminized explosives, and Cu coated n-Al composite particles and ball-milled octogen (HMX) energetic microspheres were prepared via droplet microfluidic technology using binder. The morphology, crystal form, thermal properties, combustion, and mechanical sensitivity of the microspheres were studied using a variety of techniques. The prepared microspheres had regular spherical morphology and uniform particle size, with an even distribution of particles. Using microfluidic technology will not destroy the crystal form of each particle. The introduction of Cu promoted the thermal decomposition of HMX. The mechanical sensitivity of the prepared Cu/Al microspheres was lower than that of the microspheres only containing n-Al. The Cu/Al microsphere samples exhibited excellent and stable combustion performance, and that the addition of Cu increased the combustion speed compared to the microspheres only containing n-Al. This technology represents an inexpensive and simple way to improve on existing aluminized explosives.