Method and apparatus for casting directionally solidified articles
AssigneeGeneral Electric Company
InventorThomas F. Sawyer
Life of this patent
Estimating the term…
Abstract
The invention relates to an improved method of casting superalloy articles and more particularly to an apparatus for directionally solidifying eutectic superalloy compositions to produce a composite structure of a superalloy matrix reinforced with aligned carbide fibers. The improvement includes positioning a movable bed of a ceramic insulation around the mold such that as the mold is lowered the bed forms a continuous heat insulating barrier around the sides of the mold to prevent lateral heat transfer.
Claims10
An apparatus for producing a directionally solidified article from a eutectic superalloy composition comprising:
- a. a mold within a heating zone, said mold having a lower portion and being attached at its bottom to a chill plate;
- b. a retaining means for a ceramic insulation around the heating zone and said lower portion of the mold, said retaining means being attached at its bottom to said chill plate;
- c. a substantially spherical ceramic insulation disposed in said retaining means and in contact with said lower portion of the mold;
- and
- d. a means for lowering said mold out of said heating zone and to permit the insulation to form a continuous heat barrier around the portion of the mold descending out of the heating zone.
In the casting of superalloys wherein molten alloy is introduced into a movable mold extending into a heating zone and gradually lowering the mold and simultaneously chilling the lower end of the mold to achieve directional solidification, the improvement comprising disposing a plurality of hollow ceramic bodies around the mold such that as the mold is lowered, the bodies conform to and form a contacting insulating layer around the outside surface of the mold as it is exposed below the heating zone whereby lateral heat transfer is prevented.
Dependencies are inferred from the claim text.