A small-angle X-ray scattering study of micro-defects in thermally treated HMX

Abstract

The defects in HMX, induced by thermal expansion, phase transition and chemical decomposition, have large effects on the performance of HMX. In this work, the defects of HMX samples under heat treatment are characterized by small angle X-ray scattering (SAXS) and atomic force microscopy. A large number of pores with an average size of 10 nm are found during the - phase transition of HMX (180℃), and the pores increase in size and decrease in number with time increasing. A new population of small pores with sizes of 58 nm are produced in HMX during the thermal decompositions (190℃ and 200℃). The size and the number of the small pores increase with temperature increasing.

Small-angle X-ray analysis of the effect of grain size on the thermal damage of octahydro-1, 3, 5, 7-tetranitro-1, 3, 5, 7 tetrazocine-based plastic-bounded expolsives

“…The increases in intensity of samples heated at 180 • C are attributed to the new populations of pores developed in the β → δ phase transitions, during which volume expansions and anisotropic variations of crystals [19] can cause obvious damages. [20] The X-ray diffraction (XRD) patterns of FHP and LHP samples after heating at 180 • C for 1 h and 3 h are shown in Fig. 5.…”