Effect of External Shell Coating and Coating Layer on Fast Cook-off Test of HAE Charge.

To assess the vulnerability of HAE charge (HMX-based aluminized explosive), a roast bomb structure with different thermal conductivity of external shell coating and coating layer was designed. The response properties of explosive charge under fast cook-off condition were studied. The effects of different outer shell coating materials (organic insulating layer and polymer composite coating) and coating materials with different thermal conductivity on the fast cook-off time and response results of HAE explosive charge were analyzed. The results show that thermal conductivity of external shell coating and coating layer does not change the response grade of the explosive charge (explosives are combustion or thrown out), they mainly affect the time of pressure membrane breakage and the time of cook-off resistance, it is delayed to a different extent than the comparative formulation (the outer coating is uncoated and the coating is silicone rubber). The influence of organic coating on the response parameters of explosive charge is not obvious, the film breaking time(t1) and the time of cook-off resistance (t3) of the roast bomb were delayed by 0.06 min and 0.12 min, respectively, compared with the comparative formulation,when the polymer composite coating is used alone, the response parameters of explosive charge can be effectively prolonged, the values of t1 and t3 were delayed by 1.17 min and 2.81 min, respectively, compared with the comparative formulation. When the external coating layer is an organic coating and the coating is replaced by hollow glass microspheres (HGMs), the explosive charge was ejected at the same time when the pressure membrane was broken, and the explosive charge can be burned steadily by using the external coating of polymer composite coating and the coating layer of HGMs substituted silicone rubber. [ABSTRACT FROM AUTHOR]