BRAZING ALLOY

Abstract

The present invention relates to new brazing alloys containing copper, silver, zinc, manganese, and indium, and a method for their production and their use.

Claims

1. A brazing alloy consisting of 25 to 33 wt % silver, 15 to 25 wt % zinc, 6 wt % to 14 wt % manganese, 0.25 wt % to 4 wt % nickel, 0.5 wt % to 4 wt % indium, 0 to 1.5 wt % tin and/or gallium, 0 to 1 wt % cobalt, 0 to 0.5 wt % germanium, 20 to 53.5 wt % copper, and—as unavoidable contaminants—aluminum in quantities of up to 0.001 wt %, phosphorus, magnesium, or calcium, as well as other alkali and alkaline earth metals, in respective quantities of up to 0.008 wt %, cadmium, selenium, tellurium, tin, antimony, bismuth, and arsenic in respective quantities of up to 0.01 wt %, lead up to 0.025 wt %, sulfur up to 0.03 wt %, silicon up to 0.05 wt %, and iron in quantities of up to 0.15 wt %, wherein the quantity amounts to up to 0.5 wt %, and wherein the quantities of the components add up to 100 wt % in total.

2. Brazing alloy according to claim 1, containing 26 to 30 wt % silver, 17 to 23 wt % zinc, 8 wt % to 12 wt % manganese, 0.25 wt % to 2 wt % nickel, and 1 wt % to 3 wt % indium.

3. Brazing alloy according to claim 1, containing 27 to 29 wt % silver, 18 to 22 wt % zinc, 9 wt % to 11 wt % manganese, 0.5 wt % to 1.5 wt % nickel, and 1.5 wt % to 2.5 wt % indium.

4. Brazing alloy according to claim 1, containing 0.1 to 1.5 wt % tin and/or gallium, and/or 0.1 to 1 wt % cobalt and/or 0.1 to 0.5 wt % germanium.

5. A brazing combination comprising a brazing alloy according to claim 1 and a flux.

6. A method for joining metal components comprising the steps of providing a base material; providing a part that is to be joined to the base material; arranging the base material and the part in contact with one another in a way suitable for brazing; arranging the brazing alloy according to claim 1, in contact with the base material, the part, or both, in a way suitable for brazing; heat treating the arrangement thus obtained at a temperature sufficient to effect brazing, so as to obtain a joined part; cooling the joined part.

7. Method according to claim 6, wherein the temperature sufficient to produce the brazing is 710° C. to 730° C.

8. Method according to claim 6, wherein the base material or the part is a steel alloy.

9. Method according to claim 6, wherein the base material or the part is a carbide or a cermet.

10. A brazed article produced by the method according to claim 6.

11. Brazed article according to claim 10, wherein the brazed article has a braze seam of the brazed article which shows copper-rich phases of nearly circular appearance in a metallographic section.

12. A method for joining metal components comprising the steps of providing a base material; providing a part which is to be connected to the base material, wherein the base material or the part is a steel alloy; arranging the base material and the part in contact with one another in a way suitable for brazing; arranging the brazing alloy according to claim 1 in contact with the base material, the part, or both, in a way suitable for brazing; heat treating the arrangement thus obtained at a temperature of 710° C. to 730° C., in order to obtain a joined part; cooling the joined part.

13. A method for controlling the structure of braze joints, having the steps of providing a parent material; providing a part that is to be connected to the parent material; arranging the parent material and the part in contact with one another in a way suitable for brazing; arranging the brazing alloy according to claim 1 in contact with the base material, the part, or both, in a way suitable for brazing; heat treating the arrangement thus obtained at a temperature sufficient to effect brazing, so as to obtain a joined part; cooling the joined part; production of at least one metallurgical section at least at one position of the braze seam; examination of the structure via inspection of the metallurgical section; if applicable, adaptation of the brazing conditions to a temperature of 710° C. to 730° C., such that the structure of the braze seam of the brazed article shows copper-rich phases of nearly circular appearance in a metallographic section.

Description

EXAMPLES

[0090] The alloys were obtained by melting the corresponding amounts of the alloy constituents in a crucible in an induction furnace and casting them in a graphite mold. These samples were used for the assessment of the alloys. The compositions in the table contain specifications in percentages by weight (wt %).

[0091] The cold working capability (Table: K) was assessed based upon repeated cold rolling. Several cold rolling passes with a thickness reduction of 1 mm per pass were performed without intermediate annealing, until a tearing of the sample occurred. The result is shown in the table.

[0092] The ratings have the following meanings:

[0093] + good workability, ∘ limited workability, − poor workability.

[0094] The shear strength (Table: τ) of a braze joint was determined at room temperature after brazing of a sample body at 720° C., in that a manual device having a maximum load of 40 kN was used to determine the shear strength (Gerling Automation, Solder Strength Testing Device GLFP 800). A cuboid base material made of a 1.2210 (115CrV3) (DIN EN 10027-2) steel having dimensions of 30×8×8 mm was used as a sample body, and an uncoated carbide of type K10 (DIN ISO 513) having dimensions of 8×8×4 mm was used as a carbide, which was brazed to the base material at 720° C. with the solder to be tested.

[0095] The sample body was affixed horizontally in a matching mount above a shearing edge having a clearance of 0.4 mm between steel surface and braze seam. A uniform and planar application of force is ensured in this way.

[0096] The die of the testing device rests upon the carbide; its placement surface has dimensions of 8×4 mm.

[0097] The final arrangement allows a maximization of the ratio of the force in the y-direction and, simultaneously, reduced bending moment in the x-direction. The measured value corresponds to the maximum shear force and may be used to calculate the maximum shear strength.

[0098] The shear strength is obtained in MPa or N/mm.sup.2 by dividing the measurement value (N) by 64 mm.sup.2.

[0099] The ratings have the following meanings:

TABLE-US-00001 Cu Ag Zn Mn In Sn Ni Co T K Examples In 1 39.00 28 20 10 2.00 1.00 + + 2 39.00 28 18 12 2.00 1.00 + + 3 37.00 30 20 10 2.00 1.00 + + 4 39.00 26 22 10 2.00 1.00 + + 5 39.00 30 20 8 2.00 1.00 + + 6 38.75 28 20 10 2.25 1.00 + + 7 39.25 28 20 10 1.75 1.00 + + 8 38.00 28 20 10 2.00 2.00 + + 9 35.00 30 20 10 2.00 3.00 + + 10 39.25 28 20 10 2.00 0.75 + + 11 38.50 28 20 10 2.00 0.50 1.00 + + Comparative examples Ag449 30 16.00 49 23 8 4.50 + + In 31 35.00 28 20 10 6.00 1.00 ◯ − 32 41.00 28 20 10 1.00 ◯ + 33 36.00 28 20 10 6.00 − + 34 31.00 28 20 10 2.00 9.00 − + 35 49.00 28 10 10 2.00 1.00 − + 36 29.00 28 30 10 2.00 1.00 + − 37 46.00 28 20 3 2.00 1.00 − + 38 29.00 28 20 20 2.00 1.00 ◯ − 39 40.00 28 20 10 2.00 ◯ + 40 52.00 15 20 10 2.00 1.00 − + + >=250 MPa; ◯ 150 to <250 MPa; − <150 MPa.