Multiscale Modeling of Metal-Metal Contact Dynamics under High Electromagnetic Stress: Timescales and Mechanisms for Joule Melting of Al-Cu Asperities

An analysis and initial results from a multiscale continuum-atomistic simulation of the Joule heating and melting of Cu-Al asperity contacts is presented. An analytic expression is given for the time needed to reach the Al melting point for an asperity as a function of the voltage drop and the asperity contact area. The coupled continuum-atomistic simulations capture the initial stages of the formation of Al-Cu alloys that arises from the solvation of Cu atoms into the Al melt. Implications of these results for understanding contacts in electromagnetic launchers are discussed.