Abstract: In order to reduce the sensitivity of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), CL-20/1,3,5-triamino-2,4,6-trinitrobenzene (TATB) energetic composites were prepared by using one-step ball milling method. The properties of raw materials and energetic composites were characterized by using scanning electron microscope, X-ray diffractometer, infrared spectrometer and diffrential scanning calorimetery.The impact sensitivity test was carried out. The results show that the as-prepared product is not a simple physical mixture of CL-20 and TATB, but a new crystalline phase is formed. In the SEM pattern, compared with the raw materials, the morphology of CL-20/TATB composite is regular spherical or ellipsoidal, and the particle size is in the range of 50-200 nm. In the XRD pattern, the main diffraction peak in the final product is obviously different from the main diffraction peaks in the raw CL-20 and the raw TATB. New XRD diffraction peaks arise, which indicates that a new crystal form appears in the final product. The diffraction peak become wider due to the decrease in particle size. In FT-IR pattern, the position of characteristic vibration peak of the functional group in the CL-20/TATB composite is shifted due to the hydrogen bond between CL-20 (—NO₂ or —CH) and TATB (—NO₂ or —NH₂). In the DSC curve, compared with raw CL-20 and raw TATB, the exothermic peak of the CL-20/TATB composite is advanced, which indicates that the thermal decomposition activity of CL-20/TATB composite is stronger than those of raw CL-20 and raw TATB. In the impact sensitivity test, the characteristic height of CL-20/TATB composite is 62 cm higher than that of CL-20 , indicating that the impact safety of CL-20/TATB is better than that of CL-20. Key

Key words: CL-20, 1,3,5-triamino-2,4,6-trinitrobenzene, energeticcomposite, one-stepballmillingmethod, thermaldecomposition