Electron beam welding parameters for copper and dissimilar copper joints: Review, research gaps, and future challenges

Abstract

Copper welding presents significant challenges due to its high thermal conductivity and reflectivity, making traditional welding methods largely ineffective. Electron Beam Welding (EBW) offers a promising solution but requires precise parameter control to achieve optimal results. This study is a systematic review following a structured search of Scopus and Web of Science. After title–abstract–full text screening using predefined inclusion criteria (experimental EBW of copper or copper–dissimilar joints reporting process parameters and weld performance), 163 peer-reviewed articles were retained. For each study, the authors extracted process parameters (accelerating voltage, beam current, welding speed, focus/defocus, beam oscillation), material characteristics (alloy type, thickness, surface preparation), and outcomes (penetration, porosity, microstructure, mechanical properties). Reported statistical measures were consolidated to quantify the dominant influences of the parameters, and a SWOT analysis, along with a research gap analysis, was performed. Research indicates that vacuum-based EBW effectively overcomes copper welding difficulties while producing superior joint quality compared to other fusion processes. EBW achieves deep weld penetrations of up to 30 mm with minimal defects in copper, producing joint strengths of up to 264 MPa, equivalent to approximately 95% of the base material strength. Key welding parameters, including beam current, welding speed, focus position, and oscillation patterns, significantly influence weld quality, with beam current exerting the strongest effect on penetration depth. When joining copper to different materials, careful beam positioning and oscillation techniques successfully control unwanted compound formation while maintaining joint strength. Key findings establish that beam current accounts for 81% of the variance in weld quality control; strategic beam positioning with 0.4–0.5 mm offsets optimizes dissimilar joints, achieving strengths of 250 MPa; oscillation patterns reduce porosity by 30% while controlling intermetallic formation; and significant research gaps remain in copper tube joining applications for thermal management systems. This framework enables precision joining of high-performance copper systems for next-generation energy and electronics applications.