Energetics and kinematics of undercooled nonequilibrium interfacial molten layer in cyclotetramethylene-tetranitramine crystal

The main objective of this work is to investigate the energetics and kinematics of non-equilibrium interfacial nanoscale melt, hundreds of degrees below melting temperature during thermally activated β → δ phase transformation in cyclotetramethylene-tetranitramine. The analytical solutions for energy, width, and mobility are derived in detail for each of the propagating solid-melt and solid-solid interfaces which can be used to calibrate and characterize interface material properties. Additionally, an approximate expression for energy and equilibrium width of solid-melt-solid interface has been proposed. Different parametric studies on the energy, width, and mobility of propagating interfacial melt have been explored. It is found out that for some specific limit of these parameters, mobility of solid-melt-solid interface can be higher than pure dry solid-solid interface. The present study reveals different scale effects of interface interactions and nontrivial phase transformation mechanisms. •Presented MPF approach allows to formulate analytical solutions for energy, width, and mobility of each of the propagating interfaces.•Such analytical solutions can be used to calibrate and characterize interface material properties.•Different parametric studies on the energetics and kinematics of VM reveal interesting nontrivial effect of interface interaction.