Trouble with silver solder, carbide , and 17-4 stainless 2

[Durkee]

We have been having trouble with soldering carbide tips to a 17-4 stainless body. We have not had trouble with any other mat'l. It seems that the solder doesn't stick to the carbide, which doesn't make sense to me since the solder sticks to the carbide okay when soldered to other materials. Can anyone help me on this?

Keith Durkee

http://www.toolgrinder.com

 

[funnelguy]

Give Brownells a look. They carry pastes specifically for difficult to join materials like stainless and carbide. The pastes are very convenient. I'm sure your local industrial or welding supply house will be helpful, also.

http://www.brownells.com

 

[Durkee]

Thanks. I'll give it a look. And no the local industrial house is no help. They no nothing exc what they can read in a catalog. I can do that.

Keith Durkee

http://www.toolgrinder.com

 

[hacksaw]

ultrasonically assisted soldering/brazing is the usual method for soldering to ceramics and other difficult to wet materials

 

[tomwalz]

Try

http://www.carbideprocessors.com

for info on brazing carbide

Does the copper in the 17-4 cause it to wet so well it sucks all the solder away from the carbide?

Does the same carbide braze well to other materials? E.G/ Does the same identical piece that won’t stick to 17-4 stick to something else? 2 pieces of carbide can come out of the same box and 1 will work and 1 won’t.

Do you have some pictures you can send for analysis?

Tom

P.S. Hacksaw is right as usual but this doesn’t sound like it should be that difficult to do and you need the chemical bonding evidenced by good wetting to get the strength levels you need for tool use.

 

[Durkee]

"Does the copper in the 17-4 cause it to wet so well it sucks all the solder away from the carbide?"

YES. I believe that is exactly what is happening. The first ime I did these, Inoticed that the solder stuck very well to the stainless, but not to the carbide. And when I knock a piece of the carbide off, the solder has a red tint to it.

The carbide I am using is a c-2 from Valenite. I have never had ant trouble soldering this carbide to any other mat'l we use.

How do we get around this problem?

I too believe hacksaw is right, but we only make 10 of these cutters a year. They are a 3.5" x 1" x 1 1/4" 12 tooth plastic chopping mill.

I can take a dig pic, but am unfamiliar with how to post it here.

Thanks!

Keith



Keith Durkee

http://www.toolgrinder.com

 

[TVP]

Keith,

Check out the Process TGML box under Step 2 Options box for info on images.

 

[tomwalz]

Are you using a trimetal material? Would the copper be the copper layer in the middle?

Are you heating through the carbide into the braze alloy and then the steel? All three parts (carbide, braze alloy, steel holder) have to be at the flow point (NASA figures 50F over the liquidus which seems to work pretty well) of the braze alloy. Sometimes the tool holder can suck so much heat away that the joint is cold on the carbide side.

You can send the pic as a jpeg attachment to me at president@carbideprocessors.com

tom

 

[tomwalz]

Try Lucas Milhaupt
5656 S. Pennsylvania Ave.
Cudahy, WI 53110
800 558-7006

or Prince & Izant
Cincinnati, OH 45624
800 634-0437

both sell braze alloy and both have really good technical help

 

[Durkee]

We have kind of figured this one out. What I normally do with a cutter of this size is pre-heat the arbor, (which by the way, I neck down to about 3/8" before it goes into my indexer to reduce heat loss)then pre-heat most of the cutter w/o getting too much heat near the pockets. I use a .05" round stock for my soldering. Then I lay in the solder and carbide and heat mostly from the cutter side to avoid burning the flux on the insert. As the pocket reaches temp, I move around to the insert and heat both until the solder flows.

What I did with these due to Tom's statement about the copper is this. I didn't pre-heat anything except the area immediately below the pocket on the back side. Then I went around to the insert and heated until the solder flowed. Then I moved the heat around the whole pocket/insert area uuntil the flow looked even. I had to concentrate the heat mmore on the insert or you could tell just by looking at it that the solder was being pulled away from the insert. The last two cutters were 100% on the carbide sticking. We could not knock them off with out breaking the carbide.

Does this sound like we did the right thing?

Couldn't have done it without you Tom. Thanks!!

If we get another failure, I'll definitely send you a pic, but right now all the pockets are filled with inserts. We still have 6 cutters to go though. Any other observations or suggestions are welcomed.

Keith Durkee

http://www.toolgrinder.com

 

[metman]

Keith,
I gave you star because we don't often get good feedback like this. Very clearly stated.

Jesus is THE life,
Leonard