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The Right Flux for Soldering to Nitinol

Eric Bastow recently wrote about using our Indalloy Flux #2 for soldering to Nitinol. He did many tests andwrote an Application Note called Soldering to Nitinol.

Fort Wayne Metals,a leading supplier of medical wire (including Nitinol) also did a test onvarious fluxesasthey relate to break load (maximum load before the joint breaks.

The fluxes tested included:

  • Indalloy Flux #2 and Flux #3
  • Indalloy Flux #5RMA; #5R; #5RA
  • Indalloy Flux #4R
  • Flux #400 (no longer commercially available)

The #5 series and the #4R were found to not be strong enough to clean off the tenacious oxides formed on Nitinol. Therefore, they didn't enable the solder to wet the surface properly.

Flux #2 and Flux#3 gave the best results (of the fluxes testedfor break load) since they removed more of the oxides and allowed for a stronger solder bond.

Want to know more about soldering to this important medical material? You can contact Eric Bastow directly at [email protected] or email us at [email protected].