stainless to silver solder high temp application

[rhinelander]

Im am pressing 2 .125" dia tubes into a block of pure silver
(99.9%)pure. the block is 1x1x1/4 inch
The tube wall is .020" thk. Press in about .187 "

This assembly is a heating element that exceeds 600 deg C.

I need to seal the tube joints so it dosent leak.
Normal silver solder is not high temp enough.
Im trying Silver wire but the stainless seams to oxidize
by the time I reach a high enough temp to get the silver wire to flow.

Any one help me?

 

[tomwalz]

Do you want a higher temp silver braze alloy, e.g. 700C ?

tom

 

[JimMetalsCeramics]

I would recommend that you silver plate the stainless on the inside and outside right where the bonding is to occur. Then insert it like you are doing. You may want to heat the assembly. To avoid oxidation, you should have it heated a a commercial heat treat house, in nitrogen or hydrogen.