Methods of fabricating polycrystalline ceramic for thermoelectric devices
Provided is a method of fabricating polycrystalline ceramic for thermoelectric devices. The method includes preparing calcined ceramic powders, forming a ceramic sheet by uni-axially pressing the calcined ceramic powders, stacking a plurality of the ceramic sheets in a uni-axial direction, and cofiring the stacked the plurality of the ceramic sheets.
1 . A method of fabricating polycrystalline ceramic for thermoelectric devices, the method comprising:
preparing calcined ceramic powders;
forming a ceramic sheet by uni-axially pressing the calcined ceramic powders;
stacking a plurality of the ceramic sheets in a uni-axial direction; and
cofiring the stacked the plurality of the ceramic sheets.
2 . The method of claim 1 , wherein the calcined ceramic powders have a thin disk-shape.
3 . The method of claim 2 , wherein the ceramic powders comprise a conductive thermoelectric material.
4 . The method of claim 1 , wherein the forming of the ceramic sheet comprises:
providing the calcined ceramic powders to a supporting part of a pressing apparatus; and
pressing the calcined ceramic powders with a pressing part of the pressing apparatus,
wherein the supporting part and the pressing part have a rimless flat surface.
5 . The method of claim 4 , wherein the pressing part presses the calcined ceramic powders with a pressure range of about 30-100 MPa.
6 . The method of claim 1 , wherein the cofiring of the stacked the plurality of the ceramic sheets comprises performing at least one selected from sintering, spark plasma sintering (SPS), or hot pressing.
7 . The method of claim 1 , further comprising:
after the cofiring of the stacked the plurality of the ceramic sheets, performing a reoxidation process.