Silver brazing titanium nitride covered parts.

[waterlaz]

I've been asked to braze stainless steel plates covered with titanium nitride on the dropouts and I have some doubts about it.

1) Does silver stick to titanium nitride or do I have to strip it off the back side of the plates.

2) AFAIU titanium nitride handles silver brazing temperatures with no problem but what happens when the flux is applied?
I am afraid that it might get dissolved by the flux or react with some components of the flux and change colour.
Since most of the fluxes are proprietary I don't even really know the contents of them to google for possible chemical reactions.

Has anyone brazed something like that?

[Eric Estlund]

Contact your flux and filler supplier and ask them for advice.

[czernysz]

Definitely do some research. I was asked to silver braze goldplated parts once, I asked lots of people in the welding industry
And the answers I got was mostly "good luck with that and let me know how it goes". I did come across some data about brazing over chrome and Nickle plated parts (not much) and some soldering of gold plated parts. Basically bonding is only as good as the plating bond itself. What I ended up doing was lots of silver brazing tests of gold plated scrap parts.
Fortunately the request for that job went away.
How about silver brazing some TiN drill bits as a test and see what happens? There is a good chance that the TiN will get diffused into the silver braze alloy itself even though the melting temps are vastly different. This happens with gold plated parts, even with soldering. As to the coating on the outside? "good luck with that and let me know how it goes".
That's all I got. Sorry.

[czernysz]

Here is a link to a Flickr album is anyone's interested.
Flickr

[waterlaz]

Thank you.
I think I'll just pass on this one.