DIFFUSION BONDING OF SUPERALLOY MEMBERS

• US 3,632,319 A
• Filed: 07/11/1969
• Issued: 01/04/1972
• Est. Priority Date: 07/11/1969
• Status: Expired due to Term

• Current Assignee: George S. Hoppin, James F. Barker, Reed E. Yount, Thomas F. Berry
• Original Assignee: George S. Hoppin, James F. Barker, Reed E. Yount, Thomas F. Berry
• Inventors: Hoppin, George S., Yount, Reed E., Berry, Thomas F., Barker, James F.
• Primary Examiner(s): Campbell, John F.
• Assistant Examiner(s): Shore, Ronald J.
• Application Number:
  US04/841,093
• Time in Patent Office: 907 Days
• Field of Search: 29/487,494,497,498,501,504
• US Class Current: 228/194
• CPC Class Codes: B23K 35/004 at least one of the workpieces being of a metal of the iron group
• CPC Class Codes: B23K 35/304 with Cr as the next major constituent

Abstract

An improved diffusion-bonded, age hardenable joint between superalloy members results from a method which combines the benefits of vacuum high-temperature brazing and pressure solidstate diffusion bonding through use of an age hardenable bonding powder related to the superalloy and including temperature depressants selected from B, Si, Mn, Cb, Ta and their mixtures. The method avoids the need for pressure during the diffusion bonding portion.

Claims

2. In a method as described in claim 1 in which, after homogenization, the joint portion is heated at a third temperature less than the first temperature for a time sufficient to age harden the joint portion.

3. In a method as described in claim 1 for bonding a plurality of age hardenable superalloy members, the superalloy based on an element selected from the group consisting of Fe, Co, and Ni, in which:

the age hardenable bonding material consists essentially of, by weight, up to about 0.3% C, up to about 25% Cr, up to about 17% of elements selected from the group consisting of Mo and W, 0.3-7% A1, 0.5-6% Ti, up to about 2% V, up to about 0.2% Zr, greater than 1 up to about 15 weight percent of the total composition of elements selected from the group consisting of B, Si, Mn, Cb, Ta, and their mixtures, with the balance except for incidental impurities selected from the group consisting of Fe, Co, and Ni.

4. In a method as described in claim 3 for bonding superalloy members based on nickel in which:

the high vacuum is no more than about 10 3 mm. Hg pressure;

the joint gap is in the range of 0.001-0.005 inch;

the bonding material consists essentially of an age hardenable powder consisting essentially of, by weight, 0.02-0.3% C;

8-25% Cr;

5-20% Co;

2-12% Mo;

0.3-7% A1;

0.5-6% Ti;

up to about 5%W;

up to about 2% V;

up to about 0.2% Zr;

up to about 25% Fe;

with the balance nickel and incidental impurities and greater than 1 percent up to about 15 percent of elements selected from the group consisting of B, Si, Mn, Cb, Ta, and their mixtures;

the powder having a liquidus temperature below about 2,250* F.;

the first temperature is in the range of about 1,950*-2,250* F.; and

the second temperature is in the range of about 1,600*-2,100* F.

5. In a method as described in claim 4 in which, after homogenization, the joint portion is heated at a third temperature less than the first temperature and in the range of about 1,300*-2,000* F. for a time sufficient to age the joint portion.