MAGNESIUM-ALUMINUM BASED ALLOY

• US 20120195789A1
• Filed: 01/18/2012
• Published: 08/02/2012
• Est. Priority Date: 02/01/2011
• Status: Abandoned Application

• Current Assignee: Helmholtz-Zentrum Geesthacht Zentrum FüR Material- und Kã¼Stenforschung GmbH
• Original Assignee: Helmholtz-Zentrum Geesthacht Zentrum Fur Material-Und Kustenforschung GmbH
• Inventors: Hort, Norbert, Kainer, Karl U., Huang, Yuanding, Peng, Qiuming
• Application Number:
  US13/352,632
• Publication Number:
  US 20120195789A1
• Time in Patent Office: Days
• US Class Current: 420/546
• CPC Class Codes: B22D 27/20 Measures not previously mentioned for influencing the grain structure or texture; Selection of compositions therefor
• CPC Class Codes: C22C 1/03 using master alloys
• CPC Class Codes: C22C 23/02 with aluminium as the next major constituent

Abstract

The present invention relates magnesium-aluminum based alloys having a small grain size and to a method of their production. The alloys are particularly useful in casting applications. The alloys comprise a grain refiner, the grain refiner having the chemical formula:

Mg_100-x-y-zAl_xC_yR_z

wherein R is an element selected from the group consisting of silicon, calcium, strontium or a rare earth element, x is from 10 to 60 At. %, y is from 5 to 50 At. %, and z is from 0 to 20 At. %, provided that x+y+z is less than 100 At. %.

Claims

1. A magnesium-aluminum alloy comprising a grain refiner, the grain refiner having the chemical formula:

Mg_100-x-y-zAl_xC_yR_z

wherein R is an element selected from the group consisting of silicon, calcium, strontium or a rare earth element, x is from 10 to 60 At. %, y is from 5 to 50 At. %, and z is from 0 to 20 At. %, provided that x+y+z is less than 100 At. %.

2. The magnesium-aluminum alloy according to claim 1, which comprises the grain refiner in an added amount of 0.1 to 2% by weight of the initial weight of the alloy.

3. The magnesium-aluminum alloy according to claim 1, wherein the rare earth element is selected from the group consisting of lanthanum, cerium, neodymium, samarium, europium and rare earth mischmetal.

4. The magnesium-aluminum alloy according to claim 1, wherein the magnesium-aluminum alloy is selected from the group consisting of magnesium-aluminum-zinc alloys and magnesium-aluminum-manganese alloys.

5. The magnesium-aluminum alloy according to claim 4, wherein the alloy is selected from the group consisting of AM50, AM60, AM201, AZ10, AZ31, AZ63, AZ80, AZ91, AE44, AE42, AJ53, AS41 and AS42.

6. A method for producing a magnesium-aluminum alloy having fine grain, which comprises melting an alloy comprising magnesium and aluminum under a protective gas atmosphere, adding to the molten magnesium-aluminum alloy a grain refiner according to claim 1, and allowing the alloy to solidify.

7. The method of claim 6, wherein the molten magnesium-aluminum alloy comprising the grain refiner is cast prior to allowing the alloy to solidify.

8. The method of claim 6, wherein the protective gas comprises argon.

9. The method of claim 6, wherein the protective gas further comprises SF6.

10. The method according to claim 6, wherein the grain refiner is used in the form of a milled powder having a particle size of less than 50 nm.

11. The method according to claim 6, wherein the molten magnesium-aluminum alloy is stirred between 10 minutes and 60 minutes after adding the grain refiner.

12. The method of claim 6, wherein the protective gas comprises argon.

13. The method according to claim 7, wherein the grain refiner is used in the form of a milled powder having a particle size of less than 50 nm.

14. The method according to claim 8, wherein the grain refiner is used in the form of a milled powder having a particle size of less than 50 nm.

15. The method according to claim 9, wherein the grain refiner is used in the form of a milled powder having a particle size of less than 50 nm.

16. The magnesium-aluminum alloy according to claim 2, wherein the rare earth element is selected from the group consisting of lanthanum, cerium, neodymium, samarium, europium and rare earth mischmetal.

17. The magnesium-aluminum alloy according to claim 2, wherein the magnesium-aluminum alloy is selected from the group consisting of magnesium-aluminum-zinc alloys and magnesium-aluminum-manganese alloys.

18. The magnesium-aluminum alloy according to claim 3, wherein the magnesium-aluminum alloy is selected from the group consisting of magnesium-aluminum-zinc alloys and magnesium-aluminum-manganese alloys.

19. The method of claim 6, wherein the grain refiner is added in an amount of 0.1 to 2% by weight of the initial weight of the alloy.

20. The method of claim 6, wherein the rare earth element is selected from the group consisting of lanthanum, cerium, neodymium, samarium, europium and rare earth mischmetal.