Effect of Amplitude Oscillation on Spiking in Electron Beam Welding of Copper Plate

Abstract

Both electron and laser beam welding are gaining importance and popularity due to their inherent advantages like high heat density, low heat affected area and fewer defects compared to traditional fusion welding. However, spiking defect is the most common in these high-power densities welding, where both melting and evaporation participate in the fusion process. Spiking is an instantaneous non-uniform rise in bead penetration throughout the joint, which can seriously affect the properties and strength of the joint. These defects can lead to premature failure of the welded components. Oscillation of electron beam could be an effective method to improve the welding fusion and solidification, so to eliminate defects in the weld. Here, the electron beam welding of highly conductive ETP-Cu alloy plate was conducted by varying the amplitude of oscillation. Spiking phenomenon was represented as the standard deviation of penetration in the study. Electron beam used without oscillation yielded the minimum spiking and the same was seen to increase with increase of amplitude of oscillation. It was found that spiking is mostly dependent on keyhole stability. It could also be concluded that an optimum combination of oscillation parameters is necessary to minimize the spiking phenomena in copper weld.