The 4th International Conference on Matter and Radiation at Extremes (ICMRE 2019)

496 / 2019-03-18 21:49:07

Progress in Microstructure and Phase Transition of HMX by In-situ Neutron Diffraction

HMX; Neutron diffraction; Phase transition; Micro strain

Plenary track > High Pressure Physics and Materials Science

HMX and its Polymer Bonded Explosives (PBXs) are commonly used in economy and defense scope. The state of HMX and its PBXs has significant influence on detonation properties. Great efforts have been made to verify the true state of HMX under certain conditions. However, there are still problems in HMX phase transition or microstructure evolution under extreme conditions or other complicated environments.
In this report the recent progress in neutron powder diffraction study of HMX and its PBXs will be introduced, concerning problems of micro strain evolution and phase transition.
Neutron scattering is powerful approach to detect materials with high penetration and no damage to sample. The experiments introduced in the report are performed on Fenghuang and Xuanwu, two neutron powder diffractometer at CMRR.
The strain evolution of lattice in powder HMX and its PBXs under confined pressure is studied by in-situ neutron diffraction. The results are found to be inconsistent with those gained by single crystal mechanical test. In some extents, results of multi-crystal HMX is more closed to the practical application. Meanwhile, phase transition of HMX with common impurities is found to be different from pure HMX. Diffraction experiments are performed to gain better understanding of the mechanisms of phase transition.