Soldering to Kanthal-A or Alloy-875 Resistance Wire

[Erro11]

My application does not involve elevated temperatures.
I would like to process the termination ends of Kanthal or Alloy-875 resistance wire to make it solderable with standard electronic solders.

I understand that Nichrome wire can be tinned using Steel solder flux with standard
solder provided that the acid flux is removed after tinning.
Nichrome-A – 80% Ni, 20% Cr
Nichrome-C - 61% Ni, 15% Cr, balance Fe

I would like to do something similar with Kanthal or Alloy-875 if possible.
Alloy 875 - 22.5% Cr, 5.5% Al, 5% Si, 1% C, balance Fe
Kanthal-A – 22.5% Cr, 5.3% Al, 0.7% Si, 0.08% C, 0.5% Mn Balance F3


Does anyone have application experience along these lines that they could share?

Thank you,
Erro11

 

[btrueblood]

I've tinned fairly large pieces of 304 stainless using a torch to heat the metal, then brushing on zinc chloride/zinc fluoride flux. As you say, follow this with a good washing in an alkaline cleaner, rinse, maybe a little work with a Scotchbrite pad. Should work for any chrome/nickel alloy.

 

[roydm]

How about a tinning with silver solder, after that regular solder would stick.

 

[btrueblood]

Before silver solder will "stick" to the chrome-containing alloys, you will still need to use a fairly agressive, acid flux. Something with fluorides, or fluoro-borate compounds, that will etch the chrome oxide.

For wire, a quick method is to heat the wire and dip into the flux bottle. But it's also a good way to crud up your flux.

You may find you need to do several heat/flux/wash/buff cycles before you get a smooth, evenly tinned surface.