A Numerical Model and Analysis of Microscale Explosive Initiator Integrated with Thin-Film Reactive Bridge of Nanoscale Aluminum/Nickel Multilayers

Abstract

A reactive bridge of nanoscale Al/Ni multilayers, or nanolaminates, is a recent advance in microscale thin-film initiator systems, potentially improving performances of explosive initiator. This numerical study introduces a three-dimensional (3D) modeling of initiator with a reactive bridge for more realistic and accurate system prediction as compared with the existing one-dimensional (1D) approximation of thin-film initiator. The model gives transient simulations for the atomic species and thermal diffusion, as well as prediction of electric potential distribution and pulsed energy deposition in the platinum bridge film. The computational results show that 3D effects are substantial such locally concentrated bridge joule heating and reduced reaction sensitivity in bimetallic multilayers by lateral heat loss. The horizontal reaction wave propagation from corners of the nanolaminates is also examined, as it effectively invalidates the 1D model of uniform bridge heating and vertical reaction advances across bimetallic multilayers. Optimization of various system design parameters is also discussed in view of achievement of best initiator performances.