Phase-Field Modeling of Aging of Energetic Thin Films*

Understanding effects of the evolution of microstructure of stored energetic materials is crucial for maintaining their long-term performance reliability. While stored, energetic material components may be subjected to harsh and variable environments, including elevated temperatures during which thermodynamic driving forces induce substantial microstructural changes, with potentially detrimental effects on performance. In this study, we develop a self-contained phase-field framework for modeling the growth of vapor deposited polycrystalline thin films and subsequent thermal aging of the films that promotes concurrent grain growth, void coarsening, and surface morphology evolution. Elements of the phase-field model are motivated by experimental observations derived from PETN thin films under accelerated aging conditions [1]. The model is used to predict changes in microstructure as a function of environment and storage conditions.

Ref:

[1] Knepper et al., APS SCCM 2023