ALUMINUM ALLOY, WIRE AND CONNECTING ELEMENT MADE OF THE ALUMINUM ALLOY

Abstract

An aluminum alloy for manufacturing wire for cold forming, in particular for manufacturing connecting elements, includes an alloy content of aluminum greater than 88 mass % and an alloy content of copper greater than or equal to 5 mass % as main alloy elements. The aluminum alloy contains no boron. Nickel and silicon are additional alloy elements, with an alloy content of nickel greater than or equal to 0.15 mass %, and an alloy content of silicon less than or equal to 1.0 mass %. A wire for manufacturing connecting elements or screws and a connecting element or screw made of the aluminum alloy are also provided.

Claims

1. An aluminum alloy for manufacturing wire for cold forming or for manufacturing connecting elements, the aluminum alloy comprising: an aluminum alloy having an aluminum content of greater than 88 mass % and a copper content of greater than or equal to 5 mass % as main alloy elements; said aluminum alloy containing no boron; an additional nickel alloy having a nickel content of greater than or equal to 0.15 mass %; and an additional silicon alloy having a silicon content of less than or equal to 1.0 mass %.

2. The aluminum alloy according to claim 1, wherein said aluminum content of said aluminum alloy is between 88 mass % and 90 mass % or greater than 90 mass %.

3. The aluminum alloy according to claim 1, wherein said nickel content is between 0.15 mass % and 1.0 mass %.

4. The aluminum alloy according to claim 1, wherein said silicon content is between 0.4 mass % and 1.0 mass %.

5. The aluminum alloy according to claim 1, wherein said copper content is between 5.0 mass % and 6.1 mass %.

6. The aluminum alloy according to claim 1, which further comprises an additional magnesium alloy content of between 1.5 mass % and 2.2 mass %.

7. The aluminum alloy according to claim 1, which further comprises an additional alloy content of at least one of manganese or titanium.

8. The aluminum alloy according to claim 1, which further comprises: TABLE-US-00003 5.0 to 6.1 mass % Copper 0.15 to 1.0 mass % Nickel, 0.4 to 1.0 mass % Silicon 0 to 0.2 mass % Iron 0 to 0.2 mass % Manganese, 1.5 to 2.2 mass % Magnesium, 0 to 0.2 mass % Chromium 0 to 0.3 mass % Zinc 0 to 0.25 mass % Titanium, 0 to 0.15 mass % admixtures and a remainder aluminum.

9. A wire for manufacturing connecting elements or screws, the wire comprising the aluminum alloy according to claim 1.

10. A connecting element or screw, comprising the aluminum alloy according to claim 1.

11. The connecting element according to claim 10, wherein the connecting element has a tensile strength greater than 570 MPa at room temperature.

12. The connecting element according to claim 10, which further comprises a heat resistance provided by at least one of: a remaining tensile strength of greater than 0.8 times a tensile strength at room temperature, or a remaining tensile strength of greater than 400 MPa after undergoing a temperature load of 200° C. for 24 hours.

13. The connecting element according claim 12, wherein the remaining tensile strength is greater than 450 MPa after undergoing a temperature load of 200° C. for 24 hours.

14. The connecting element according to claim 11, which further comprises a heat resistance provided by at least one of: a remaining tensile strength of greater than 0.8 times said tensile strength at room temperature, or a remaining tensile strength of greater than 400 MPa after undergoing a temperature load of 200° C. for 24 hours.

15. The connecting element according claim 14, wherein the remaining tensile strength is greater than 450 MPa after undergoing a temperature load of 200° C. for 24 hours.

16. The connecting element according claim 10, which further comprises a heat resistance to a temperature at least intermittently above 180° C. in a thermally stressed area or in a motor vehicle.

17. The connecting element according to claim 10, wherein the screw is an engine screw of an internal combustion engine.

18. The connecting element according to claim 10, wherein the connecting element or screw is a contact element or a pole terminal or a screw for a pole terminal of an accumulator.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0034] FIG. 1 is a simplified comparison diagram comparing the heat resistance of different aluminum alloys; and

[0035] FIG. 2 is a diagrammatic, partly broken-away, side-elevational view of a screw.

DETAILED DESCRIPTION OF THE INVENTION

[0036] Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a diagram which shows the tensile strength (given in MPa) over time (aging time) for elements (screws) made of different alloys. The elements were heated to 200° C. and kept at this temperature for a total of 24 hours.

[0037] The different alloys are two comparison alloys V1, V2 and an alloy L according to the invention (dashed line). Comparison alloy V1 is the alloy according to EN AW-6056 (solid line) and comparison alloy V2 is a 7xxx alloy (dotted line).

[0038] It is clear from the diagram that the alloy L according to the invention has a significantly higher tensile strength than the comparison alloy V1. Over the entire aging time, the tensile strength is more than 100 MPa above the tensile strength of the comparison alloy V1.

[0039] As compared to the comparison alloy V2, the alloy L according to the invention has a lower tensile strength at the start of the aging period, but is distinguished by a notably better heat resistance, so that the tensile strength remains high even at longer aging times. In addition, even after just a few hours, it has a higher tensile strength than the comparison alloy V2.

[0040] Due to these properties, the alloy L according to the invention is particularly suitable for, and indeed is used in, applications in fields with high thermal stress. In particular, the alloy is used for manufacturing connecting elements such as screws.

[0041] FIG. 2 shows an exemplary side view of such a screw 2. The screw 2 extends along a central longitudinal axis, starting from a head 4 to which a shank 6 is attached. One portion of the shank 6 is provided with a thread 8. The screw 2 shown in the drawing is an engine screw, specifically a cylinder head screw. These screws typically have a length ranging from several centimeters up to 10 or 15 cm and are constructed for example as M8, M10, M11 or M12 screws.