US 11,654,504 B1
Solid state diffusion bonding of refractory metals and their alloys
Robert E. Hardesty, Orinda, CA (US)
Assigned to Peregrine Falcon Corporation, Pleasanton, CA (US)
Filed by Peregrine Falcon Corporation, Pleasanton, CA (US)
Filed on Sep. 10, 2021, as Appl. No. 17/472,438.
Claims priority of provisional application 63/221,810, filed on Jul. 14, 2021.
Int. Cl. B23K 20/00 (2006.01); B23K 20/02 (2006.01); C22C 27/02 (2006.01); B23K 103/08 (2006.01)
CPC B23K 20/023 (2013.01) [C22C 27/02 (2013.01); B23K 2103/08 (2018.08)] 10 Claims
OG exemplary drawing
 
1. A solid-state bonding method, comprising:
sandwiching an intermediate nickel layer between a pair of refractory metal members to form a composite bonding assembly, the intermediate nickel layer being substantially uniform of at most 75 μm thickness, the refractory metal members and the intermediate nickel layer being mutually soluble and diffusive; and
applying compressive pressure to and heating to a specified elevated temperature the composite bonding assembly, the pressure being less than 3400 kPa (500 psi) and the elevated temperature being at least 1280° C., the applied pressure and elevated temperature being maintained for at least a minimum time in excess of 15 minutes until the intermediate nickel layer has dissolved surface oxides and asperities in the refractory metal members and has completely diffused into the refractory metal to create a seamless refractory metal bond.