Method and apparatus for the production of directionally solidified castings

Claim 2

Casting apparatus for directionally solidified articles including a cylinder providing an enclosure, means for heating said cylinder to impart heat to a mold in said enclosure, a chill plate located at one end of said cylinder on which the mold is positioned, means for moving said chill plate relative to said cylinder for withdrawing the mold from said cylinder, a radiation shield extending inwardly from the cylinder at the base thereof and overlying the chill plate, said shield extending inwardly substantially to a mold on said chill plate, and stop means for limiting the downward movement of the radiation shield beyond a point substantially coinciding with the base of the cylinder, the outer periphery of the shield being slightly spaced from the cylinder to permit upward movement of the shield within said cylinder.

Claim 3

Casting apparatus for directionally solidified articles including a cylinder providing an enclosure, means for heating said cylinder to impart heat to a mold in said enclosure, a chill plate located at one end of said cylinder on which the mold is positioned, means for moving said chill plate relative to said cylinder for withdrawing the mold from said cylinder, a radiation shield extending inwardly from the cylinder at the base thereof and overlying the chill plate, said shield extending inwardly substantially to a mold on said chill plate, and stop means for limiting the downward movement of the radiation shield beyond a point substantially coinciding with the base of the cylinder, the outer periphery of the shield being slightly spaced from the cylinder to permit upward movement of the shield within said cylinder.

Claim 4

Casting apparatus for directionally solidified articles including a cylinder providing an enclosure, means for heating said cylinder to impart heat to a mold in said enclosure, a chill plate located at one end of said cylinder on which the mold is positioned, means for moving said chill plate relative to said cylinder for withdrawing the mold from said cylinder, a radiation shield extending inwardly from the cylinder at the base thereof and overlying the chill plate, said shield extending inwardly substantially to a mold on said chill plate, and stop means for limiting the downward movement of the radiation shield beyond a point substantially coinciding with the base of the cylinder, the outer periphery of the shield being slightly spaced from the cylinder to permit upward movement of the shield within said cylinder.

Claim 5

Apparatus as in claim 1 in which the inner periphery of the shield conforms closely with the configuration of the mold but slightly spaced therefrom so that the mold may be withdrawn through said shield.

Claim 6

Apparatus as in claim 1 in which the cylinder is a susceptor and the heating means is a surrounding induction coil.

Claim 7

In the casting of the directionally solidified articles, the steps of positioning a shell mold for the article on a chill plate, providing a heating means surrounding said mold for heating said mold to a temperature above the melting point of the alloy to be cast, cooling the end of the mold resting on the chill plate pouring molten alloy into the mold, withdrawing the mold partially from the heating means for more rapid cooling of the mold than is accomplished by the chill plate providing a barrier closely surrounding the mold and movable relative thereto to define, as the mold is withdrawn from the heating means, a dividing line between the cooled and heated portions of the mold, supporting said barrier on said chill plate so that the latter with the mold thereon may be moved upwardly into the heating means, and limiting the downward movement of the barrier to a point adjacent the lower end of the heating means as the mold is withdrawn from the heating means.

Claim 8

In the casting of the directionally solidified articles, the steps of positioning a shell mold for the article on a chill plate, providing a heating means surrounding said mold for heating said mold to a temperature above the melting point of the alloy to be cast, cooling the end of the mold resting on the chill plate pouring molten alloy into the mold, withdrawing the mold partially from the heating means for more rapid cooling of the mold than is accomplished by the chill plate providing a barrier closely surrounding the mold and movable relative thereto to define, as the mold is withdrawn from the heating means, a dividing line between the cooled and heated portions of the mold, supporting said barrier on said chill plate so that the latter with the mold thereon may be moved upwardly into the heating means, and limiting the downward movement of the barrier to a point adjacent the lower end of the heating means as the mold is withdrawn from the heating means.

Claim 9

The process of claim 4 including the step of withdrawing the mold past the barrier substantially at the rate of solidification of the alloy.

Claim 10

The process of claim 4 including the step of withdrawing the mold past the barrier at such a rate as to maintain a liquid-solid interface at a selected distance above the barrier during the solidification of the alloy.

Claim 11

Casting apparatus as in claim 1 in which the radiation shield is a laminated construction with at least one relatively rigid layer, and at least one relatively flexible layer with the inner periphery of the flexible layer extending inwardly beyond the edge of the rigid layer and substantially into contact with the mold surface.