Case Study: Micro-Welding Nickel to Steel for Automotive Sensors 

The Challenge

An automotive supplier needed to weld 0.025" nickel wires to steel housings for a new line of pressure sensors. Nickel’s corrosion resistance and steel’s durability made them ideal for harsh engine environments, but joining them was a hurdle. Traditional resistance welding often produced inconsistent bonds due to differing melting points (nickel at ~1455°C, steel at ~1370°C), risking weak spots under vibration. Brazing added cost and complexity with filler materials, clashing with the need for a lean, reliable process. The goal: a strong, repeatable weld that could handle automotive-grade stress, all without extra materials.

The Model 858 Percussion Welder tackled this challenge head-on, delivering precision and power in a compact package. The team dialed in settings from the welding table for nickel-to-steel at 0.025": 70V actuator velocity, 1.0ms timing delay, and a short 55V pulse (Bank 3, 8,430 µF capacitance). The process unfolded seamlessly:

• Setup: The 726 Bench Fixture aligned the nickel wire and steel housing with a precise gap, secured by the moveable wireholder and stationary holder for optimal arc initiation.
• Arc Phase: The 858’s micro-arc, triggered by the 70V velocity-driven 808 Actuator (up to 33 in/s), melted the contact points in under 3 milliseconds, with the 1.0ms delay controlling heat spread to protect the materials.
• Percussive Force: A rapid thrust, powered by the actuator’s 0–30 Joules energy, fused the molten surfaces into a solid bond with <100g force—no filler, no distortion.
• Outcome: A vibration-resistant weld, scalable across production runs, perfect for automotive sensors.

This wasn’t a fluke. The table confirms consistency across wire sizes: 0.018" (70V velocity, 1.5ms delay, 70V pulse, Short) and 0.040" (48V velocity, 2.0ms delay, 65V pulse, Long) show the 858 adapts reliably, balancing velocity and pulse for nickel-to-steel strength.

How It Stacks Up:

• Vs. Resistance Welding: Slower (4ms+), weaker (400 psi avg.), larger HAZ (~0.5mm).
• Vs. Brazing: Filler-dependent (350 psi), slower (6ms+), HAZ (~0.8mm).
• Percussion Welding: Fast (<3ms), strong (est. 450 psi), minimal HAZ (~0.1mm)—a streamlined win.

The table confirms consistency—0.018" (70V, 70V pulse) and 0.040" (48V, 65V pulse) welds hold the same edge over traditional options.

The Result

The welds checked all the boxes:

• Strength: Tensile tests showed bonds holding up to 500 psi—exceeding SAE automotive standards for sensor components.
• Speed: Welds clocked in at under 3 milliseconds each, boosting throughput by 25% over resistance welding setups factoring in prep and retries.
• Durability: Minimal heat-affected zone (HAZ) of ~0.1mm kept the steel’s structural integrity intact, critical for parts facing constant vibration and heat.

Visualizing the Impact

These charts break down the Percussion Welder’s edge over traditional resistance welding, focusing on production speed and bond strength—key metrics for automotive engineers.

Chart 1: Production Speed Advantage

This bar chart compares time to weld 1,000 nickel-to-steel joints—typical for a sensor batch. Percussion welding takes 3 seconds (3ms x 1,000), while resistance welding, with setup and retries, averages 4 seconds (4ms x 1,000). That’s a 25% time savings, letting engineers hit tight production deadlines.

Chart 2: Bond Strength Comparison

This chart shows tensile strength of the welds. Percussion welding hits 500 psi thanks to its direct, filler-free bond, while resistance welding averages 400 psi due to inconsistent fusion. Stronger welds mean fewer failures in the field—music to an engineer’s ears.

Engineer’s Takeaway

“It’s a no-brainer for automotive applications,” said a project engineer. “The Percussion Welder nails nickel-to-steel welds with strength and speed we couldn’t match before. It’s not just about the weld—it’s about building parts that last under real-world punishment.”

Ready to Rev Up Your Assembly Line?

Power up your production with the Percussion Welder.Contact us for a demo or check out the Percussion Welder specs to see how it fits your next build.