Insights
May 27, 2026 · 2 min read · Materials
Lab data · 5 tested schedules
- Wire diameter
- .010"–.040"
- Actuator velocity
- 48–93 V
- Weld voltage
- 40–70 V
- Delay time
- 1.00–2.00 ms
Starting points from our lab experiments, not guaranteed settings. Validate on your own parts.
Chapter 01 / 05
Copper to Aluminum Welding
Copper-to-aluminum is a difficult dissimilar metal joint. Conventional fusion processes tend to produce brittle intermetallic compounds that can fracture under thermal cycling or vibration.
Copper melts at a higher temperature than aluminum, and the two metals have different thermal conductivities. They also have a large galvanic potential difference, which accelerates corrosion at any exposed interface.
When copper and aluminum are held at elevated temperatures, they form hard, brittle intermetallic compounds. In service, thermal cycling creates stress at the intermetallic layer, and cracks can propagate through the joint.
How Percussion Welding Addresses Intermetallics
In percussion welding, the arc melts the facing surfaces of both wires and the molten surfaces are driven together within milliseconds, which leaves little time at temperature for intermetallic compounds to grow.
The result is a direct metallic bond. In pull tests the wire often breaks before the weld. There is no filler metal and no flux.
Verified Weld Parameters: Copper to Aluminum
| Wire Dia. | Velocity (V) | Delay time (ms) | Cap | Weld voltage (V) | Pulse |
|---|---|---|---|---|---|
| 0.010" | 62V | 1.00 | Cap2 | 45V | Short |
| 0.020" | 62V | 1.00 | Cap3 | 40V | Short |
| 0.030" | 48V | 1.50 | Cap3 | 45V | Short |
Verified Weld Parameters: Aluminum to Copper
With aluminum listed first, the lab parameters are:
| Wire Dia. | Velocity (V) | Delay time (ms) | Cap | Weld voltage (V) | Pulse |
|---|---|---|---|---|---|
| 0.025" | 62V | 2.00 | Cap3 | 55V | Long |
| 0.040" | 93V | 2.00 | Cap3 | 70V | Long |
Applications
- EV Battery Busbars: Connecting copper cell tabs to aluminum bus conductors.
- Aerospace Wiring: Weight reduction by transitioning from copper to aluminum conductors at terminal points.
Related Resources
View the complete parameter database at Weld Schedules. Check any material pair instantly with our Material Compatibility Checker.
Chapter 02 / 05
How to read and use these settings
Each lab schedule lists the wire diameter and the 858 settings used to make a good weld in our lab:
- Actuator velocity (V): the voltage applied to the actuator, which sets how fast it drives the moving wire holder. The 858 actuator speed is 0–33 inches per second across 0–150 V.
- Delay time (ms): the timing delay setting on the 858.
- Cap: the capacitor bank setting: 1, 2 and 3 are the regular banks and 1HD, 2HD and 3HD are the heavy-duty banks.
- Voltage (V): the weld-energy (bank) voltage.
- Pulse: the pulse width, long or short.
Treat them as starting points. Actual alloys and the masses of the materials vary, so your final schedule comes from small adjustments. We strongly recommend varying a single parameter at a time and testing the result: that makes patterns easier to see and gets the best strength and appearance faster. Always run test welds and validate joint strength on your own parts before production.
Want to see it on your parts?
Send samples and we'll run test welds before you commit.
Chapter 03 / 05
Surface preparation
Clean and degrease both materials and remove oxides, oils and contamination from the weld area. Material notes from our process team:
- Copper: Remove surface oxidation and tarnish. Clean until bright metal shows.
- Aluminum: Remove the oxide layer before welding to ensure proper fusion.
Chapter 05 / 05
Test your own samples
Send us your copper and aluminum parts. Free applications tests of your materials are available, and we can run live, in-person tests at our lab in Denver. Tell us your weld challenge or call 303-536-7838.
FAQ
What are starting settings for copper to aluminum welding?
Our lab has 5 schedules for Copper and Aluminum. For example, .010" wire: 62 V actuator velocity, 45 V weld voltage, 1.00 ms delay, capacitance setting 2, short pulse.
These are starting points, not guarantees. Change one setting at a time and test.
Which wire diameters have lab schedules for copper to aluminum?
.010", .020", .025", .030", .040". If your wire size is different, send samples and we will develop and verify a schedule.
Does copper to aluminum percussion welding need filler, solder or flux?
No. Percussion welding joins the two base metals directly, with no filler material, solder or flux and a minimal heat-affected zone.
Can you test my copper and aluminum samples?
Yes. Free applications tests of your materials are available, and we can run live, in-person tests at our lab in Denver. Call 303-536-7838 or send your weld challenge.
Still have a question? Tell us your weld challenge and an engineer will reply.
Start here
Free applications tests of your materials are available. Tell us what you are joining.
Prefer to talk? Book a demo or call 303-536-7838