Aluminum casting alloy

Abstract

An aluminum casting alloy contains the following alloy components: Si: 3.0 to 3.8 wt.-%, Mg: 0.3 to 0.6 wt.-%, Cr: 0.05 to <0.25 wt.-%, Fe: <0.18 wt.-%, Mn: <0.06 wt.-%, Ti: <0.16 wt.-%, Cu: <0.006 wt.-%, Sr: 0.010 to 0.030 wt.-%, Zr: <0.006 wt.-%, Zn: <0.006 wt.-%, Contaminants: <0.1 wt.-%, and is supplemented to 100 wt.-% with Al, in each instance.

Claims

1. An Al casting alloy that contains the following alloy components Si: 3.0 to 3.8 wt.-%, Mg: 0.5 to 0.6 wt.-%, Cr: 0.05 to <0.25 wt.-%, Fe: 0.01 to 0.15 wt.-%, Mn: 0.01 to 0.05 wt.-%, Ti: <0.16 wt.-%, Cu: <0.006 wt.-% Sr: 0.010 to 0.030 wt.-%, Zr: <0.006 wt.-%, Zn: <0.006 wt.-%, Contaminants: <0.1 wt.-%, and is supplemented to 100 wt.-% with Al, in each instance.

2. The Al casting alloy according to claim 1, wherein Si is contained at a content of more than 3.1 to less than 3.7 wt.-%.

3. The Al casting alloy according to claim 1, wherein Cr is contained at a content of 0.10 to less than 0.20 wt.-%.

4. The Al casting alloy according to claim 1, wherein Cr is contained at a content of 0.12 to 0.17 wt.-%.

5. The Al casting alloy according to claim 1, wherein Ti is contained at a content of 0.05 to 0.15 wt.-%.

6. The Al casting alloy according to claim 1, wherein Cu is contained at a content of 0.001 to 0.005 wt.-%.

7. The Al casting alloy according to claim 1, wherein Sr is contained at a content of 0.015 to 0.025 wt.-%.

8. The Al casting alloy according to claim 1, wherein Zr is contained at a content of 0.001 to 0.005 wt.-%.

9. The Al casting alloy according to claim 1, wherein Zn is contained at a content of 0.001 to 0.005 wt.-%.

10. The Al casting alloy according to claim 1, wherein contaminants are contained at a content of <0.05 wt.-%.

11. The Al casting alloy according to claim 1, wherein contaminants are contained at a content of <0.005 wt.-%.

12. The Al casting alloy according to claim 1, wherein the Al casting alloy is a low-pressure Al casting alloy.

13. The Al casting alloy according to claim 1, wherein the Al casting alloy is a counter-pressure (CPC) Al casting alloy.

14. A method for the production of a cast component composed of an Al casting alloy according to claim 1, in which the low-pressure casting method is used.

15. A method for the production of a cast component composed of an Al casting alloy according to claim 1, in which the counter-pressure (CPC) casting method is used.

16. A method for the production of a cast component composed of an Al casting alloy according to claim 1, in which squeeze casting, gravity chill casting or die-casting is used.

17. A method for the production of a cast component composed of an Al casting alloy according to claim 1, in which the low-pressure casting method is used and the cast component is subjected to two-stage heat treatment after the casting process, namely solution annealing and subsequent hot aging.

18. The method according to claim 17, wherein the cast component is quenched in water between the two heat treatment stages.

19. The method according to claim 14, wherein the cast component, after the casting process, is solution-annealed between 530 C. and 550 C. for 6 to 10 h.

20. The method according to claim 14, wherein the cast component, after the casting process, is tempered between 180 C. and 210 C. for 1 to 8 h.

21. A method for producing a chassis part of a motor vehicle, comprising: providing the Al casting alloy according to claim 1; and producing the chassis part from the Al casting alloy.

22. A cast component, produced from an Al casting alloy according to claim 1, wherein the cast component, after heat treatment, has a tensile yield strength R.sub.p0.2 of 300 to 325 MPa, and/or an elongation to rupture A5 of 4 to 10%, and/or a tensile strength R.sub.m of 350-375 MPa.

Description

EXAMPLE

(1) To determine the mechanical properties of the alloy AlSi3Mg0.5Cr0.15, what is called a French test rod is removed, according to DIN 50125, from a pivot bearing produced by means of a counter-pressure chill casting method (CPC method), wherein the pivot bearing previously received a heat treatment (solution annealing 540 C. for 8 h, quenching in water, hot aging 180 C. for 6.5 h). Casting of comparison samples (AlSi3Mg0.5 and AlSi3Mg0.5Cr0.3) and the subsequent heat treatment take place under the same conditions. The alloys to be compared differ only in terms of their chromium content. The sample rod is taken at the same location of the pivot bearing. The mechanical properties of tensile strength R.sub.m, tensile yield strength R.sub.p0.2, and elongation to rupture A5 are determined according to DIN 10002.

(2) TABLE-US-00001 R.sub.m [MPa] R.sub.p0.2 [MPa] A5 [%] AlSi3Mg0.5 327 263 9.3 AlSi3Mg0.5Cr0.15 356 305 8.2 AlSi3Mg0.5Cr0.3 358 308 6.9

(3) Against the background of DE 10 2008 055 928 A1 and the lower limit value for chromium of 0.3 wt.-% that was indicated as being critical with regard to the mechanical characteristic values, it could not be expected that the mechanical characteristic values indicated above for AlSi3Mg0.5Cr0.15 could be reached.

(4) It can furthermore be advantageous if the chassis part, preferably the damper stilt or the wheel support, is produced by means of low-pressure sand casting or preferably by means of counter-pressure chill casting (CPC). Use of the casting apparatus disclosed in DE 10 2010 026 480 A1 and of the method disclosed there has proven to be particularly advantageous. The disclosure content of DE 10 2010 026 480 A1 and its content are being explicitly incorporated or integrated into the present application, by explicit reference, as belonging to the object of the present application.