Titanium Nitride on dissimilar metals

[kneelingatlas]

Here's my situation: I have an Open build in the white with a stainless steel comp.  I'm planning to send the frame and slide to H&M for black nitride and since H&M says they can't do the black nitride on stainless I'm thinking I'll send the comp and barrel to Titanium Gun for titanium nitride, but my gunsmith installed a set screw in the comp so what I'd like to do is use that hole to pin and weld the comp to the barrel, but I worry about doing the TiN coating on a barrel/comp which is half stainless, half carbon.  Does anyone have experience with this situation?  Of the smith hadn't used a set screw I'd just coat the pieces separately, then use Loctite.

[ACree]

Did I misread your post? Stainless can be finished with black nitride. H&M has done stainless parts for me and they turned out great.

Edited June 14, 2018 by CCG

[kneelingatlas]

Was it 4130?

 

This is what I read:

"H&M Blacknitride+™, or Ferritic Nitrocarburizing, is the thermochemical that simultaneously diffuses nitrogen and carbon into the surface of ferrous metals. "

 

The stainless used in my comp is non-ferrous.

[ACree]

Stainless steel is a ferrous metal. You will be fine in having it treated by H&M. I am looking at a stainless steel gun that I sent to them to have finished and it turned out great. Non-ferrous metals are metals that do not contain iron in any appreciable amounts like aluminum, copper, lead, brass, etc.

 

You sure that your comp is stainless steel and not titanium?

[mike cyrwus]

Ha

[ltdmstr]

They can do titanium too.  

[zzt]

 

On 6/15/2018 at 3:29 PM, ltdmstr said:

They can do titanium too.  

 

I'm not sure about that.  H&M told me the Black Nitride process would eat up any Ti.  They specifically asked me to remove any Ti parts and make sure I didn't send them down.  They have no problem with carbon or stainless steel.

Edited June 17, 2018 by zzt

[ltdmstr]

They can do it.  I've seen samples in person at SHOT Show and talked to them about it because I have a PT titanium grip.  But it's a specialized process and probably the only way they'll do it for you is if they're running a batch for someone. 

[DRCNC]

We do nitride finishes on stainless guns that we build or refinish for customers all the time.  One thing to be aware of is a nitride finish can make it difficult to get the gun back together if the fit was tight to begin with.  Nitride finishes are in the 20-50 micron range (~.0008"-.002").

Titanium and aluminum we only coat with DLC or one of the many PVD, e.g. TiN, coatings available, depending on the part and customers' color preference.  Titanium generally isn't an issue with these coatings.  The aluminum parts have to be good quality aluminum, otherwise they'll vaporize in the chamber and cause a big cleanup headache.  We mostly do frames, triggers, MSH, and the occasional grip in DLC/PVD on Aluminum.

[PaladinPrecision]

The dissimilar metals can cause a corrosion and galling issue if done with improper surface finish and also clearance. However, in the corrosion department the PVD, salt bath carburizing etc coatings that make the parts corrosion resistant will help alot with that department. However mixing the parts you will want to factor in the average coating buildup. ie there is a pretty large range of coatings and thicknesses. Titanium nitride for example varies quite a bit depending on the process... it can be from (memory tells me) half a micron to about 10 microns, and i forget what black nitride thickness is. Some of the PVD coatings have a smaller range. The "in" coating seems to be black nitride, they have been in business since the 1980's and they seem to have dialed in their production throughput to be a decent price and excellent performance coating.

Bottom line, I would suggest getting the thickness information and having your smith build in clearances for the expected coating thickness.