Part 2: Application of Kanaya–Okayama heat source in modelling micro electron beam welding

Abstract

A three-dimensional finite element model of micro electron beam welding is developed where the Kanaya–Okayama heat source formulated in Part I of this work is used to represent the electron beam. The large number of process variables is grouped into two non-dimensional parameters, namely, Peclet number and relative beam penetration, and their effect is analysed numerically to arrive at the optimum conditions of microwelding. Based on the minimum heat input of the process, the optimum Peclet number is found to be 100, and the beam penetration is twice that of the weld depth. The optimum parameters obtained using the Kanaya–Okayama heat source model are similar to the previous findings using the exponential decay heat source model; however, the predictions of the temperature field in the solid as a result of microwelding are relatively lower in case of the Kanaya–Okayama heat source model because of the differences in distribution of heat into the condensed matter. The lower weld surface temperatures in microwelding using the electron beam suggest significantly less ablation than in laser beams.