Low cost brazes for titanium
A braze material and method of brazing titanium metals. The material may consist of Ti, Ni, Cu Zr, PM and M where PM is a precious metal and M may be Fe, V, Cr, Co, Mo, Nb, Mn, Si, Sn, Al, B, Gd, Ge or combinations thereof, with the (Cu+PM)/Ni ratio around 0.9. Optionally, a second brazing may be performed to rebraze any braze joint that did not braze successfully. The second brazing material has a lower braze temperature than the first and may consist of a mixture of Ti, Ni, Cu, Zr PM and M with from 1-20 wt % more Zr, PM, M or combinations thereof than the first braze. The braze material may be placed on a base material, in a vacuum furnace, and heated to form a braze joint between the braze and base material. The heating step may occur from about 800-975° C. and over 3 to 15 minutes.
1. A brazing material for joining titanium metals comprising;
a first powder for a first braze on a base material;
a second powder for a second braze on the first brazed base material:
the first powder comprising 54-76% by weight Ti, 12-24% by weight Ni, 12-22% by weight Cu, and a precious metal (PM) wherein the (Cu+PM)/Ni ratio is between 0.5 and 1.0;
the second powder comprising Ti, Ni, Cu and PM;
the second powder comprising 1-20 wt % more of PM than said first powder; and
wherein the second powder has a brazing temperature lower than a brazing temperature of the first powder.
2. A brazing material as in claim 1 , wherein said Ti, Ni, and Cu are in powder form with a particle size less than 60 microns.
3. A brazing material for joining titanium metals as in claim 1 :
wherein the second powder further comprises Zr;
wherein the second powder comprises 0.5-12% by wt. Zr., 42-76 wt % Ti, 12-22% by weight Cu+PM; and
wherein the (Cu+PM)/Ni ratio is between 0.5 and 1.0.
4. A braze material as in claim 3 , wherein said Ti, Ni, Cu, PM and Zr are in particle form with a particle size of less than 60 microns.
5. A brazing material for joining titanium metals comprising:
a first powder for a first braze on a base material;
a second powder for a second braze on the first brazed base material:
the first powder comprising 30-80 wt % Ti, 10-30 wt % Ni, 10-30 wt % Cu, and 1-20 wt % M, wherein M is selected from the group consisting of Fe, V, Cr, Co, Mo, Nb, Mn, Si, Sn, Al, B, Gd, and Ge and any combinations thereof;
the second powder comprising Ti, Ni, Cu and M;
the second powder comprising 1-20 wt % more of M than said first powder; and
wherein said Ti, Ni, Cu and M are in powder form and have a particle size no greater than 20 microns.
6. A brazing material for joining titanium metals comprising:
a first powder for a first braze on a base material;
a second powder for a second braze on the first brazed base material:
the first powder comprising 30-80 wt % Ti, 10-30 wt % Ni, 10- 30 wt % Cu+PM, and 1-20 wt % M, wherein the (Cu+PM)/Ni ratio is between 0.8 and 1.0, and M is selected from the group consisting of Fe, V, Cr, Co, Mo, Nb, Mn, Si, Sn, Al, B, Gd and Ge or any combinations thereof;
the second powder comprising Ti, Ni, Cu, Zr and PM; and
the second powder comprising 1-20 wt % more of (PM+Zr) than said first powder.
7. A brazing material as in claim 6 , wherein said Ti, Ni, Cu, PM and M of the first powder are in powder form and have a particle size less than 60 microns.
8. A brazing material as in claim 6 :
wherein the second powder comprises 0.5-12 % by wt. (PM+Zr).
9. A braze material as in claim 8 wherein said Ti, Ni, Cu, PM, M, and Zr of the second powder are in powder form and have a particle size less than 60 microns.