High temperature stable nanocrystalline SiGe thermoelectric material
View Patent ↗A method of forming a nanocomposite thermoelectric material having microstructural stability at temperatures greater than 1,000° C. The method includes creating nanocrystalline powder by cryomilling. The method is particularly useful in forming SiGe alloy powder.
1. A method of forming a thermoelectric component comprising:
creating a powder of thermoelectric material by cryomilling the thermoelectric material in a mixture of liquid nitrogen and nitrogen gas; and
hot pressing the powder to form a thermoelectric component.
2. The method of claim 1 wherein the cryomilling is performed in a high energy ball mill with the balls and powder submersed in liquid nitrogen in a closed container.
3. The method of claim 1 wherein the cryomilling is performed in an attritor mill with the balls and powder submersed in liquid nitrogen in a closed container.
4. The method of claim 1 wherein the powder has a particle size less than 1 micron.
5. The method of claim 1 wherein the powder has a particle size less than 0.1 micron.
6. The method of claim 1 wherein the hot pressing is at a temperature greater than about 1,000° C.
7. The method of claim 1 and further comprising:
annealing the thermoelectric component.
8. The method of claim 6 wherein the annealing is at a temperature less than about 1,000° C.
9. The method of claim 1 wherein the thermoelectric material is a SiGe alloy.
10. A method comprising:
creating a powder of thermoelectric material by cryomilling the thermoelectric material in a mixture of liquid nitrogen and nitrogen gas; and
hot pressing the powder to form a high temperature thermoelectric component with microstructural stability at temperatures exceeding 1,000° C.
11. The method of claim 10 and further comprising:
annealing the thermoelectric component.
12. The method of claim 10 wherein the cryomilling is performed in a high energy ball mill or an attritor mill.