Aluminum alloy foam and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-10913990-B2
Application number	US-201916690352-A
Country	US
Kind code	B2
Filing date	Nov 21, 2019
Priority date	Nov 27, 2018
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

Provided is aluminum (Al) alloy foam including an Al alloy matrix containing magnesium (Mg), and hollow ceramic spheres dispersed in the Al alloy matrix, wherein a reaction layer including a Mg—Al composite oxide is formed at an interface where the Al alloy matrix is in contact with the hollow ceramic spheres, and wherein a density of the Al alloy foam may be higher at a surface region of the Al alloy foam compared to a middle region of the Al alloy foam.

First claim

What is claimed is:

1. Aluminum (Al) alloy foam comprising:
an Al alloy matrix containing magnesium (Mg); and
hollow ceramic spheres dispersed in the Al alloy matrix,
wherein a reaction layer comprising a Mg—Al composite oxide is formed at an interface where the Al alloy matrix is in contact with the hollow ceramic spheres.

2. The Al alloy foam of claim 1 , wherein a density of the Al alloy foam is higher at a surface region of the Al alloy foam compared to a middle region of the Al alloy foam.

3. The Al alloy foam of claim 1 , wherein a hardness of the Al alloy foam is higher at a surface region of the Al alloy foam compared to a middle region of the Al alloy foam.

4. The Al alloy foam of claim 1 , wherein an aspect ratio between a major width and a minor width of the hollow ceramic spheres is greater at a surface region of the Al alloy foam compared to a middle region of the Al alloy foam.

5. The Al alloy foam of claim 1 , wherein a content of Mg is 2.0 wt % to 8.0 wt %.

6. The Al alloy foam of claim 1 , wherein the hollow ceramic spheres have a particle size ranging from 125 μm to 500 μm, and
wherein a content of the hollow ceramic spheres is 20 Vol. % to 50 Vol. %.

7. The Al alloy foam of claim 1 , wherein the Al alloy matrix further contains silicon (Si), and
wherein a content of Si in the Al alloy matrix is less than 1.0 wt %.

8. The Al alloy foam of claim 1 , wherein a dispersion uniformity (%) of the hollow ceramic spheres dispersed in the Al alloy matrix is defined as shown in Equation 1 and is 82% to 96%.
Dispersion uniformity (%)={1−(Standard deviation of fraction of hollow ceramic spheres/Average fraction of hollow ceramic spheres)}×100  [Equation 1]

9. A method of manufacturing aluminum (Al) alloy foam, the method comprising:
providing first Al alloy foam comprising an Al alloy matrix containing magnesium (Mg), and hollow ceramic spheres dispersed in the Al alloy matrix, wherein a reaction layer comprising a Mg—Al composite oxide is formed at an interface where the Al alloy matrix is in contact with the hollow ceramic spheres; and
forming second Al alloy foam by rolling the first Al alloy foam while the first Al alloy foam is being heated in such a manner that a surface region of the first Al alloy foam is higher in temperature than a middle region of the first Al alloy foam.

10. The method of claim 9 , wherein the forming of the second Al alloy foam comprises rolling the first Al alloy foam while the first Al alloy foam is being heated to a solid-liquid coexistence temperature of the Al alloy matrix.

11. The method of claim 9 , wherein the first Al alloy foam comprises Mg: 2.0 wt % to 8.0 wt %, silicon (Si): 0 wt % to 1 wt %, and Al: the remainder, and
wherein the forming of the second Al alloy foam comprises rolling the first Al alloy foam while the first Al alloy foam is being heated in a range of 530° C. to 630° C.

12. The method of claim 9 , wherein the forming of the second Al alloy foam comprises rolling the first Al alloy foam to a reduction ratio of 5% to 25%.

13. A method of manufacturing aluminum (Al) alloy foam, the method comprising:
adding magnesium (Mg) to molten aluminum (Al) to form a molten Al alloy; and
adding hollow ceramic spheres to the molten Al alloy by forming a vortex in the molten Al alloy by using a stirrer.

14. The method of claim 13 , wherein the forming of the vortex comprises stirring the molten Al alloy by rotating the stirrer at a rotation speed ranging from 500 rpm to 1,200 rpm.

15. The method of claim 14 , wherein the stirring of the molten Al alloy comprises stirring the molten Al alloy at a temperature ranging from 750° C. to 850° C.

16. The method of claim 13 , further comprising preheating the hollow ceramic spheres to a temperature ranging from 100° C. to 180° C., before the adding of the hollow ceramic spheres.

17. The method of claim 13 , wherein a content of Mg is 2.0 wt % to 8.0 wt %.

18. The method of claim 13 , wherein the hollow ceramic spheres have a particle size ranging from 125 μm to 500 μm, and
wherein a content of the hollow ceramic spheres is 20 Vol. % to 50 Vol. %.

Assignees

• Korea Inst Mach & Materials

Inventors

• Kim Su-Hyeon
• Lim Cha-Yong
• Jung Jeki
• Lee Yun-Soo

Classifications

• C22C1/1047

  by mixing and casting liquid metal matrix composites · CPC title

• C22C1/1021

  the preform being ceramic · CPC title

• C22C1/1094

  comprising an after-treatment · CPC title

• C22C21/08

  with silicon · CPC title

• C22C1/08 Primary

  Alloys with open or closed pores · CPC title