Analytical characteristics of the electron beam distribution density over the heated spot for optimizing the electron-beam welding process

Abstract

The control of the electron beam energy distribution density over the heated spot, realized by using different scanning trajectories, can significantly improve the quality of welded joints. Experimental research by the authors showed that the best quality of welded joints is provided by scanning the electron beam in the form of a raster. Therefore, to optimize the process of electron-beam welding, trajectories of the classical raster, sinusoidal raster and truncated raster were proposed, and by increasing the scanning amplitude along the joint, the vapour-gas channel of penetration transforms into a stable cavity, on the front wall of which the metal melts, with it then being transferred along the side walls to the tail end of the weld pool. It is advisable to investigate the effect of the formation of the penetration cavity in the EBW of various materials and different thicknesses. For this, an apparatus must be created that implements scanning in the form of various rasters. For optimizing the process of electron-beam welding, the trajectories of the classic sawtooth raster, sinusoidal raster and truncated raster are proposed. For these scanning trajectories, analytical expressions and calculated characteristics of the electron beam energy distribution density are obtained over the heated spot. The trajectory in the form of a sinusoid and a truncated raster makes it possible to obtain double-humped energy distribution over the heated spot. The obtained characteristics facilitate the optimization process of electron-beam welding of different materials.