US 11,738,414 B2
Method for joining metal parts
Per Sjödin, Lund (SE); Kristian Walter, Genarp (SE); and Axel Knutsson, Lund (SE)
Assigned to ALFA LAVAL CORPORATE AB, Lund (SE)
Appl. No. 17/606,566
Filed by Alfa Laval Corporate AB, Lund (SE)
PCT Filed May 8, 2020, PCT No. PCT/EP2020/062864
§ 371(c)(1), (2) Date Oct. 26, 2021,
PCT Pub. No. WO2020/239395, PCT Pub. Date Dec. 3, 2020.
Claims priority of application No. 1950640-1 (SE), filed on May 29, 2019.
Prior Publication US 2022/0212295 A1, Jul. 7, 2022
Int. Cl. B23K 1/00 (2006.01); B23K 35/36 (2006.01); B23K 1/20 (2006.01); B23K 35/02 (2006.01); B23K 35/30 (2006.01); B23K 103/04 (2006.01)
CPC B23K 35/3606 (2013.01) [B23K 1/20 (2013.01); B23K 35/025 (2013.01); B23K 35/3086 (2013.01); B23K 2103/05 (2018.08)] 20 Claims
OG exemplary drawing
 
1. A method for joining a first metal part with a second metal part, the metal parts having a solidus temperature above 1100° C., the method comprising:
applying a melting depressant composition at least on a surface of the first metal part, the melting depressant composition comprising:
a melting depressant component comprising at least 25 wt % boron and silicon in total for decreasing a melting temperature of the first metal part; and
optionally, a binder component for facilitating the applying of the melting depressant composition on the surface;
bringing the second metal part into contact with the melting depressant composition at a contact point on said surface;
heating the first and second metal parts to a temperature above 1100° C., said surface of the first metal part thereby melting such that a surface layer of the first metal part melts and, together with the melting depressant component, forms a molten metal layer that is in contact with the second metal part at the contact point; and
allowing the molten metal layer to solidify, such that a joint is obtained at the contact point,
wherein a source of the boron comprises a boron compound selected from any of the following compounds: titanium diboride, boron nitride and/or combinations thereof.