Preparation And Properties Of Explosive,AP And Aluminum Co-crystal Composite Particle

"High energy"plays a significant role in solid propellant research,and two effective methods to increase the energy of solid propellants are to add high energy explosives to the formula and adjust the oxygen balance between the propellant formulas.In this paper,in order to improve the thermal decomposition effect and energy performance of traditional ammonium perchlorate-containing solid propellant oxidant particles,solvent evaporation method was used to prepare RDX,HMX,and CL-20 with ammonium perchlorate and micron aluminum powder with reference to the zero oxygen equilibrium ratio form composite particles,and perform a series of characterization and performance tests on the co-crystal composite particles.TEM,XPS,FTIR,PXRD,DSC,impact sensitivity test system and combustion test system were used to perform a series of characterization and performance tests on co-crystal composite particles.TEM and XPS characterization tests were performed on AP/RDX/Al composite particles.TEM test showed that the solvent evaporation method successfully made the AP and RDX crystals coated on the surface of the micron aluminum powder,and the particles were core-shell spherical.The XPS test analysis shows that the raw material composition of the composite particles has changed.Among them,AP/RDX adsorbs on the micron Al surface and formed new Al�N and Al�O bonds,resulting in the AP-RDX-Al ternary system.FTIR and PXRD characterization tests were performed on AP/RDX/Al,AP/HMX/Al,and AP/CL-20/Al composite particles,respectively.FTIR tests showed that the characteristic peaks of the three composite particles appeared in their respective infrared spectra,but some characteristic peaks were shifted,indicating that new intermolecular forces such as hydrogen bonding appeared in the composite particles.PXRD detection showed that the recombined particles produced new diffraction peaks and some old diffraction peaks disappeared,which indicates that the crystal forms of AP and high-energy explosive group components have changed,producing co-crystal,and CL-20 has undergone crystal transformation.?-CL-20 is converted to?-CL-20.DSC tests were performed on three co-crystal composite particles and raw materials.The results showed that the decomposition temperature of AP/RDX/Al co-crystal composite particles decreased from 238.7?to 211.5?of RDX;the decomposition temperature of AP/HMX/Al co-crystal composite particles decreased from 285.0?to 268.3?of HMX.;The decomposition temperature of AP/CL-20/Al co-crystal composite particles decreased from256.7?to 250.3?of CL-20,and the degree of decrease decreased with the increase of the energy density of the raw explosive.The combustion characteristics of three composite particles were tested using a closed combustion tank and a pressure test device.The explosion pressure of the three types of co-crystal composite particles has been improved compared to the raw explosives:AP/RDX/Al co-crystal composite particles increased from 109.73k Pa to 426.45k Pa,AP/RDX/Al co-crystal composite particles increased from 244.73k Pa to 489.92k Pa,AP/CL-20/Al co-crystal particles increased from 697.97 k Pa to 736.30 k Pa.The boosting speed of AP/RDX/Al co-crystal composite particles has reached 1.27 k Pa�ms^-1,which is 9.1 times the raw material RDX and5.5 times the physical mixture.The boosting speed of AP/HMX/Al co-crystal composite particles can reach 1.75 k Pa�ms^-1is 2.73 times of the raw HMX and 5.83 times of the physical mixture.The CL-20 energy level is much greater than other components in the system,so the AP/CL-20/Al co-crystal composite particles will have a slight"delay"phenomenon during the boosting process,which slightly increases the boosting time(57.24ms?129.02ms),so The boosting speed of AP/CL-20/Al co-crystal particles is 5.71 k Pa/ms^-1,which is lower than 12.19k Pa/ms^-1 of the raw material CL-20,but still 1.36 times that of the physical mixture.This also shows that there is a limit to the increase in energy brought by the co-crystal component,which weakens as the energy performance of the high-energy explosive component decreases.