Fluxless brazing process

Claim 2

A process for brazing parts in a chamber without the use of flux comprising the steps of, forming an assembly of the parts and of a brazing material located at the areas of the parts to be joined, evacuating the chamber with the assembly therein to a high order of vacuum to establish a predetermined negative pressure within the chamber, heating the assembly within the evacuated chamber in the presence of a sacrificial metal capable of vaporizing at said pressure and at a temperature below the brazing temperature of said material, increasing the pressure in said chamber after commencing heating of said assembly and before reaching said brazing temperature thereby to retard vaporization of said sacrificial metal, decreasing the pressure in the chamber as the brazing temperature is approached thereby to vaporize said sacrificial metal, heating the assembly to the brazing temperature cooling the chamber, increasing the pressure therein, and thereafter removing the brazed assembly from the chamber.

Claim 3

A process as defined in claim 3 in which said assembly and said sacrificial metal are heated concurrently and are increased in temperature at substantially the same rate.