Carbon fibers in ceramic cores for investment casting
AssigneeGeneral Electric Company
InventorsTao Li, Xi Yang
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Abstract
A method of producing a ceramic core for investment casting is provided. The method includes injecting a slurry into a disposable die. The slurry includes ceramic particles, a binder, and carbon fibers. The method also includes a first heating to eliminate the disposable die, leaving a cured ceramic core comprising the ceramic particles, binder, and carbon fibers.
Claims19
A method of producing a ceramic core comprising:
- injecting an Al2O3-siloxane based slurry into a disposable die, the slurry comprising ceramic particles, binders, and carbon fibers, the carbon fibers aligned in a direction of slurry flow upon injection;
- converting silicon in the siloxane based slurry to amorphous silica in a first firing step at a first temperature and a first length of time;
- and
- removing the carbon fibers and converting the amorphous silica and excess Al2O3 to mullite in a second firing step at a second temperature and a second length of time, wherein the second temperature is higher than the first temperature.
A method of producing a ceramic core for investment casting, the method comprising:
- forming aligned voids in a cured composition formed from a Al2O3-siloxane based slurry of ceramic particles, binders, and carbon fibers by heating a disposable die comprising the cured composition, the heating of the disposable die oxidizing and substantially removing the carbon fibers from the cured composition leaving the aligned voids.
The method of claim 17, wherein the heating of the disposable die further converts amorphous silica and excess Al2O3 in the cured composition to mullite.
The method of claim 17, wherein the aligned voids are formed at a temperature between 1050° C. and 1700° C.
The method of claim 17, wherein the heating of the disposable die is for one hour to 24 hours at a temperature between 1050° C. and 1700° C.
Dependencies are inferred from the claim text.