Anybody know how to braze diamonds to metal?

[davidh]

http://www.boggstool.com/page15.html
this may be an answer for you. . . .

 

[John Hasler]

"Electroplated nickel". My guess is that they have some way to get the diamond to stick to the steel while they electroplate over it?

 

[Ebel440]

I had been thinking about this a few years ago and figured If I ever tried I would try to braze onto the steel wire to tin the whole thing then try to roll diamonds into the brazing somehow then reheat the braze to capture them or add more brazing on top

 

[John Hasler]

Maybe you could roll the diamonds right into the steel: they're hard enough. They might wash off when you try to braze over them, though.

 

[David Kirtley]

I am pretty sure you can do it but since you can buy the diamond coated saw blades already pretty cheaply, I can't see it being cost effective.

Probably the easiest tech to do it at home would be spray welding with the diamond grit mixed in with the metal powder. The waste would be huge though and it would eat up the consumables pretty badly.

 

[savarin]

I've charged copper laps with diamond dust/grit just by using heavy pressure and a steel roller.
The copper is soft enough to trap the diamond.
Isnt the diamond on diamond tools done via a sintering process?
Could the diamond be mixed with silversolder powder (fine file and collect the fillings) and flux, the hot wire rolled in the mix so it sticks then heated to melt the silver solder?
Just thinking out loud there, simple to do a small test to see if it works.

 

[cds4yu]

You can't braze diamonds to steel. When you heat up the diamond, it will revert to graphite. And if there is oxygen, the graphite will burn.

When diamonds are brazed (as in PCD rock bits), the brazing is done at high temperature and high pressure (1 million psi).

Thanks,

Carl

 

[mws]

A lot apples and oranges being commented upon in this thread. Guess I'll add to the confusion.
I learned some time ago that it was a low temperature nickel alloy braze that was used as a base for diamond surfaced abrasives. It is done under zero oxygen (Inert gas) conditions to prevent the destructive oxidation of the carbon in the diamonds when heating the braze. That temp still has to be low enough to prevent the decomposition/decrystalization of the diamond into junk.

Maintaining a low enough vacuum to do this without the inert gas may be a possible method, but having done vacuum deposition for years I wouldn't want to try and hold a vacuum while boiling off flux and risk contaminating my pumps or traps. So I doubt vacuum is a viable method.

Lastly, vacuum deposition is incredibly thin and has little to no bond strength. It literally wipes off most surfaces. Electro-deposition has greater bond strength and thickness but would not likely encapsulate the diamond crystals.

I have embedded diamond grit into brass, bronze and copper to make laps and it works fine.

From the description of what you want to use this diamond cutting wire for I would suggest you look into buying/building a wire EDM machine. It's been done before.

 

[kd4gij]

You can get diamond blades for a scroll saw and do the same thing.