Process for producing metal foam and metal body produced using this process
View Patent ↗The invention relates to a process for producing metal foam and to a metal body produced using this process. The object is achieved by a process for producing metal foam by adding a blowing agent to a metal melt, wherein the metal melt is introduced into the die cavity of a metal die-casting machine and is foamed using a blowing agent which releases gases and is solid at room temperature.
1. A process for producing an aluminum or an aluminum alloy metal foam in a die-casting machine comprising a shot-sleeve and a die cavity which comprises:
a die-casting step comprising
(a) introducing at high pressure an aluminum or an aluminum alloy metal melt into the shot sleeve and transferring said melt to the die cavity; and
(b) mixing magnesium hydride as a blowing agent with the aluminium or aluminium alloy metal melt wherein the magnesium hydride is introduced with the aluminium or aluminium alloy metal into the shot sleeve or is introduced directly into the die cavity; and
(ii) wherein foaming of the mixture of the aluminium or aluminium alloy metal and magnesium hydride takes place in the die cavity.
2. The process according to claim 1 , wherein the mixture comprising the aluminum or an aluminum alloy metal melt and the blowing agent is formed by introducing the aluminum or an aluminum alloy metal melt and the blowing agent into the die cavity at the same time.
3. The process according to claim 1 , wherein the mixture comprising the aluminum or an aluminum alloy metal melt and the blowing agent is formed before introducing the mixture to the die cavity.
4. The process according to claim 3 , wherein the mixture comprising the aluminum or an aluminum alloy metal melt and the blowing agent is formed in the shot-sleeve and is then introduced to the die cavity.
5. The process according to claim 1 , wherein the die cavity is filled with the mixture comprising the aluminum or an aluminum alloy metal melt and the blowing agent before foaming said mixture.
6. The process according to claim 1 , wherein the die cavity is underfilled by a defined volume.
7. The process according to claim 1 , wherein the process is a cold-chamber process.
8. The process according to claim 1 , wherein the process is a hot-chamber process.
9. The process according to claim 1 wherein, the amount of magnesium hydride used is from about 0.01 to about 10% by weight, based on the aluminum or an aluminum alloy metal melt.
10. The process according to claim 9 , wherein the amount of blowing agent is from 0.01 to 10% by weight, based upon metal melt.
11. The process according to claim 9 , wherein the amount of blowing agent is from about 0.1 to about 10% by weight based upon metal melt.
12. The process according to claim 1 , wherein the magnesium hydride is autocatalytically produced.
13. A process for producing an aluminum or an aluminum alloy metal foam in a die-casting machine comprising a shot-sleeve and a die cavity which comprises foaming a mixture comprising an aluminum or an aluminum alloy metal melt and magnesium hydride as a blowing agent in the die cavity at a pressure at or greater than approximately 10 7 Pa.
14. The process according to claim 13 wherein the pressure is between 10 7 Pa to 10 8 Pa.