Non-Equilibrium Heating of a Solid Surface by a Short-Pulse Laser: A Closed-Form Solution Including Thermo-Mechanical Coupling

Abstract

A closed-form solution for temperature and stress fields is presented for short-pulse laser heating of the metal surface. Thermo-mechanical coupling between the heat and stress equations is incorporated in the analysis. The lattice site heat equation based on the non-equilibrium energy transport is used to account for the thermal field due to short-pulse heating. The Lie symmetry method is adopted to obtain the solution for the heat equation with the appropriate boundary conditions. In the analysis, stress wave dissipation is omitted in space due to mathematical simplifications. It is found that thermal displacement is negative in the early heating period and it becomes positive as the heating period progresses, which is attributed to thermo-mechanical coupling.