Precision penetration control in electron beam welding of complex variable cross-section structures

ObjectiveThis study aims to address the forming and penetration control challenges of complex welds in dissimilar aluminum alloys for liquid cooling structures in avionics. Methods This paper systematically investigates the influence of electron beam welding parameters on the joint quality of 6061/5A06 dissimilar aluminum alloys. Through the optimization of welding parameters and the dynamic collaborative control of the scanning and beam currents, precision penetration welding of long welds, small curvature radius structures, and variable cross-section structures was achieved. Results The results indicated that scanning process effectively eliminated spike defects in aluminum alloy welding and optimized molten pool flow and energy distribution. By employing a scanning frequency of 200～500 Hz combined with an amplitude of 0.5～1.0 mm, penetration fluctuation was controlled within 0.2 mm. Conclusion Through dynamic collaborative regulation of beam current and focusing current, welding of complex paths and variable cross-section structures was accomplished, with penetration fluctuations controlled within 0.5 mm and 0.2 mm, respectively. The weld appearance, internal quality, and penetration depth all met the product requirements.