Laser Welders for Copper

Copper presents two fundamental challenges that make traditional welding difficult. First, its extremely high thermal conductivity (401 W/m·K — nearly ten times higher than stainless steel) pulls heat away from the weld zone so fast that it is difficult to build the local energy density needed to achieve fusion before the surrounding metal drains the heat away. Second, copper's high reflectivity at infrared wavelengths means a significant portion of the arc energy or laser energy bounces back rather than being absorbed into the workpiece. The result: inconsistent fusion, excessive total heat input required to achieve penetration, and welds prone to cracking and porosity. TIG welding copper requires high amperages, extensive preheat, and tight process control that is difficult to maintain consistently.

Yes — fiber laser welding overcomes copper's reflectivity through energy density rather than total energy. While copper does reflect a significant portion of near-infrared (1064–1080nm) laser light at the surface, once the beam initiates a keyhole — a small vapor cavity created by vaporizing the surface layer — absorption rises dramatically and welding proceeds efficiently. The key is having sufficient power density to initiate the keyhole, which is why 1500W+ is recommended for copper welding. Below that threshold, the beam may not consistently establish a keyhole, resulting in reflections and inconsistent fusion. Once keyhole mode is established, fiber laser welding produces clean copper welds significantly faster than TIG and with less total heat input to the surrounding material.

Argon is the standard shielding gas for copper laser welding, used at flow rates of 20–30 L/min. Helium or argon/helium mixes improve energy absorption and are used in higher-power industrial copper welding, but argon is appropriate for all handheld applications. For filler wire, ERCu (deoxidized copper wire) is the standard choice for welding pure copper. For copper-nickel alloys, use ERCuNi. For brass (copper-zinc), use ERCuSi-A silicon bronze wire — silicon bronze has better wettability and produces cleaner joints on copper alloys than matched-composition filler. Wire diameter of 0.8mm or 1.0mm is appropriate for most handheld copper applications.

Copper laser welding is common in: plumbing and refrigeration copper pipe fittings (particularly food-grade and pharmaceutical applications requiring clean, contamination-free joints); electrical component fabrication including bus bars, terminal connections, and battery cell assemblies; custom lighting and decorative copperwork including furniture, fixtures, and art installations; HVAC copper evaporator and condenser coil fabrication; and emerging applications in EV battery manufacturing where copper busbar welding to dissimilar metals (aluminum, nickel) is a growing requirement. For any application where joint cleanliness and conductivity preservation at the weld are critical, laser welding outperforms TIG or soldering on copper.

Yes — laser welding is particularly capable at dissimilar metal joining that traditional welding cannot achieve reliably. Common copper dissimilar metal welds include: copper to stainless steel (common in heat exchangers and industrial fittings); copper to aluminum (critical in EV battery manufacturing for busbar connections); copper to brass; and copper to nickel alloys. These combinations require careful parameter control and sometimes specific filler materials to manage the intermetallic compounds that form at the joint — the tight energy control of a fiber laser welder is what makes these joints feasible at all. Contact our team for specific guidance on dissimilar copper welding for your application.