Publication de 6 numéros par an
ISSN Imprimer: 2150-766X
ISSN En ligne: 2150-7678
Indexed in
HMX POLYMORPHISM: VIRTUAL MELTING GROWTH MECHANISM, CLUSTER-TO-CLUSTER NUCLEATION MECHANISM AND PHYSICALLY BASED KINETICS
RÉSUMÉ
A fully physically-based thermodynamic and kinetic model of the β ↵ δ phase transformation in energetic crystal HMX crystal embedded in polymeric binder is developed. It is based on a new nucleation mechanism via melt mediated nano-cluster transformation and the recently formulated growth mechanism via internal stress-induced virtual melting. During the nucleation, nano-sized clusters of β phase dissolve in a molten binder and transform diffusionally into δ phase clusters. During the interface propagation, internal stresses induced by transformation strain cause the melting of the stressed δ phase much below (120K) the melting temperature and its immediate resolidification into the unstressed δ phase. These mechanisms explain numerous puzzles of HMX polymorphism and result in local and overall transformation kinetics that are in good agreement with experiments.