Patent ID: 7559454

Claim:
A method of brazing a titanium metal within a heat exchanger comprising the steps of: coating a first braze material onto a multitude of portions of a base material, said first braze material being a mixture comprising 20-80 wt % Ti, 10-30 wt % Cu, 10-30 wt % Ni, 0-20 wt % PM, 0-20 wt % M and having a Ni/(Cu+PM) ratio between 0.77-0.93, wherein the amount of Zr present in said first braze material is from 0 to not more than 12 wt %; placing said base material with said first braze material in a vacuum furnace; performing a first heating on said first braze material and said base material for ten minutes to achieve thermal stability between said braze material and said base material; forming a multitude of braze joints between said first braze material and said base material; examining said multitude of braze joints to determine whether a second brazing is desirable; optionally performing a second brazing, wherein said second brazing comprises the steps of; coating a multitude of selected portions of said base material with a second braze material, wherein said second braze material is a mixture of Ti, Ni, Cu, PM, Zr and M powders comprising 1-20 wt % more of PM, Zr, M or combinations thereof than said first braze; placing said base material with said second braze material in a vacuum furnace; performing a second heating on said second braze material and said base material for a given braze time of between 8 and 12 minutes to achieve thermal stability between said second braze material and base material, said heating being up to a temperature that is 10 to 100° C. lower than first heating temperature of said second braze material; and forming a braze joint between said second braze material and said base material.