Patent EA-003035-B1 (EA)
Title: Method for plugging a hole and a cooling element manufactured by said method
Inventor: POLVI VEIKKO
IPC: B23K35/28
Filed: 2000-06-20
Abstract: 1. A method for plugging a hole, particularly a hole in a cooling element, in which method in a hole (9) formed in a piece essentially made of mainly copper, for instance in the housing element (2) of a cooling element (1), there is arranged a plug (8) mainly made of copper, characterized in that between the side surface (11) of the plug (8) and the inner surface (13) of the hole, there is arranged brazing agent (10) with a melting temperature lower than that of the pieces to be joined together, on the surface of the brazing agent (10) and/or in at least one of the surfaces (11, 13) to be joined, there is brought a layer of tin (Sn) and that the junction area between the plug (8) and the piece, such as the housing element (2) of a cooling element is heated at least up to the melting temperature of the brazing agent or to the vicinity thereof, where after the junction area is cooled off. 2. A method according to claim 1, characterized in that the brazing agent (10) is brought to the hole (9) provided in the housing element (2) and/or to the junction surface (11) of the plug (8) prior to inserting the plug in the hole. 3. A method according to claim 1 or 2, characterized in that the brazing agent (10) is in the form of foil. 4. A method according to any of the preceding claims 1 - 3, characterized in that the brazing agent (10) is chosen from a group containing the combinations Ag+Cu, Al+Cu, Sn+Cu and Sb+Cu. 5. A method according to any of the preceding claims 1 - 4, characterized in that the brazing agent (10) has, with a given alloy composition, an eutectic composition with copper. 6. A method according to any of the preceding claims 1 - 3, characterized in that the brazing agent (10) is essentially Ag. 7. A method according to any of the preceding claims 1 - 3, characterized in that the brazing agent (10) is essentially Al. 8. A method according to any of the preceding claims 1 - 7 characterized in that the thickness of the brazing agent foil is 10 - 500 μm, advantageously 20 to 100 μm. 9. A method according to claim 8, characterized in that the thickness of the foil in the middle section is 10-100 μm and in the surface layers 1-20 μm. 10. A method according to any of the preceding claims 1 - 9, characterized in that in addition to brazing, the plug (8) is welded to the housing element (2). 11. A cooling element for furnaces, said element comprising a housing element (2) mainly made of copper, and channels (3, 4, 5) formed in the housing element for cooling agent circulation; when said channels (3, 4, 5) were manufactured, in the housing element (2) there were formed holes opening to the surface of said element, at least part of said holes being plugged, characterized in that the junction of the plug (8) and the housing element (2) is a tin (Sn) containing diffusion joint. 12. A cooling element according to claim 11, characterized in that the junction surfaces are mainly formed of the plug side surface (11) and the hole inner surface (13). 13. A cooling element according to claim 11 or 12, characterized in that the plug comprises a threaded part (12) and a conical junction part (11). 14. A cooling element according to any of the preceding claims 12 - 14, characterized in that the junction is formed by using a brazing agent foil (10) arranged between the junction surfaces (11, 13). 15. A cooling element according to any of the preceding claims 11 - 14, characterized in that the junction part (11) of the plug (8) is formed to be self-centering.