Method of making copper foam ball
AssigneeCellMo Materials Innovation, Inc.
InventorsHyeji Park, Heeman Choe
Life of this patent
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Abstract
A metal foam ball, several millimeters in diameter, is manufactured to have an open-pore structure to absorb fluid (e.g., gas and liquid) such as water or lubricant. As an example, a copper foam ball is manufactured via a freeze casting method using prepared oxide powder slurry where a spherical silica gel mold is used to freeze the slurry, which is subsequently dried at low temperature in vacuum and then sintered at high temperature. For improved oxidation, copper alloy foam ball or copper foam ball coated with tin can also be manufactured through the same method. For improved strength, steel, copper-nickel alloy, or titanium foam ball can also be manufactured through the same method.
Claims26
A method of manufacturing of a metal-foam ball comprising a three dimensionally connected pore structure with its porosity ranging from about 50 percent to about 90 percent,
- wherein the three dimensionally connected pore structure is formed using water by way of a freeze-casting method comprising
- mixing metal or metal oxide particles in deionized water and a polyvinyl alcohol binder to obtain a slurry,
- injecting the slurry into a spherical mold, the spherical mold having a volume that is about 20 percent to about 170 percent larger than a volume of the metal-foam ball,
- freezing the slurry in the mold at a temperature from about-20 degrees Celsius to about −100 degrees Celsius to obtain a frozen metal or metal oxide ball, and
- freeze drying the frozen metal or metal oxide ball.
A method of manufacturing of a metal-foam ball comprising a three dimensionally connected pore structure with its porosity ranging from about 50 percent to about 90 percent,
- wherein the three dimensionally connected pore structure is formed using water by way of a freeze-casting method comprising
- mixing metal or metal oxide particles in deionized water and a polyvinyl alcohol binder to obtain a slurry,
- injecting the slurry into a spherical mold,
- freezing the slurry in the mold at a first temperature from about −20 degrees Celsius to about −100 degrees Celsius to obtain a frozen metal or metal oxide ball,
- freeze drying the frozen metal or metal oxide ball, and
- sintering the frozen metal or metal oxide ball to obtain a sintered metal-foam ball, wherein a volume of the spherical mold is larger by about 20 percent to about 170 percent than a final desired volume of a sintered metal-foam ball.
Dependencies are inferred from the claim text.