Carfbide Brazing Help Please

I want to braze a small piece of carbide onto a piece of steel to keep the end from dulling so fast, are there any tricks or tips I should know about or does one do it just like steel to steel ?

Those store bought carbide lathe tools that have carbide brazed onto the is very close to what I wnat to do but I need my own shape

TIA

Hi Rick,

I have tried to silver solder tungsten carbide onto steel. I used uncoated carbide and used a dry diamond hone on the underside of the carbide piece and cleaned and fluxed before heating. The carbide piece is still firmly attached to the steel.

Regards

Thor

Hi Rick,

Use silver solder in foil form. Suggest 55% silver cadmium free alloy about 0.125mm thick.

Make into L-shaped preform to achieve contact on two faces.

Carbide and foil should be thoroughly degreased prior to assembly.

Use longlife flux eg HT5 mixed into a paste and applied to the carbide before assembly.

Heat the joint in such a manner that the joint is brought upto temperature evenly. A propane flame is better than oxy-acetylene.

When the solder has melted move the carbide on its seat, say 3-4mm, three or 4 times to ensure there are no gas or flux pockets. Press the carbide firmly into place.

Allow to cool naturally in air. Do not quench.

Any subsequent dressing of the carbide should be done with liberal quantities of coolant to prevent build up of any thermal stresses that would cause the carbide to crack.

All products are readily available.

regards

keith

Hi,

Read "Popular mechanics oct 1952"

http://books.google.fr/books?id=jdwDAAAAMBAJ&pg=PA211&lpg=PA81&ots=KUR9lUj5EQ&dq=popular+mechanics+oct+1952&hl=fr

pierre

An excellent "find" Pierre !

MichaelG.

Hi Rick

Here is a toolbit for a boring bar, with a brazed carbide tip.

The carbide was from a scrap masonry drill, and is 1 mm thick. It is silver soldered to a 6mm diameter piece of silver steel rod. The solder was a small flake flattened from silver solder wire.

The carbide was tied on with steel wire after cleaning & fluxing. This stops it from moving as the flux is heated. The wire is removed when grinding to shape with a diamond wheel. You can just about see the solder line, surface tension pulls the carbide onto the steel stock. The assembly was allowed to cool slowly as noted by Keith (CuP) above.

I used this when line-boring sintered bronze camshaft bushes in a vintage car engine. For some reason sintered bronze "oilite" is quite abrasive and HSS bits tended to wear. I used similar bits when boring iron castings for a Quorn. This bit did not need re-sharpening during the job.

regards

Jim

I was going to suggest foil, and then say i have no idea where you get it - I think Keith has probably solved that for you!

Neil