Methods for forming alkali halide ingots into rectangular plates
AssigneeSiemens Medical Solutions USA, Inc.
InventorsOlexy V. Radkevich, Efim Toutchinskii, Yuriy Yakovlev, Robert S. Zwolinski
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Abstract
The present disclosure provides methods for forging cylindrical alkali halide melt-grown single-crystal-type ingots into rectangular blocks. The resulting rectangular blocks are devoid of peripheral cracks and fissures, and possess uniform properties and reduced levels of impurities.
Claims20
A method of forging a generally cylindrical alkali halide single-crystal ingot of a crystal material having a face-centered lattice crystallographic structure, the ingot having an axis generally coinciding with the crystallographic direction, comprising:
- placing the ingot upon a lower platen of a press having parallel upper and lower platens each covered with a metal foil so that the ingot is between two parallel, planar, vertically extending barriers located between and perpendicular to said upper and lower platens;
- orienting the ingot so that its axis is vertical, the ingot is mid-way between the barriers, and one of the ingot's crystallographic planes is parallel to the barriers;
- heating the ingot to a temperature below the melting point of the alkali halide;
- compressing the ingot along its axis by moving at least one of the upper and lower platens toward the other platen and compressing the ingot therebetween;
- and
- maintaining the barriers in fixed relation to each other.
A method of forging a generally cylindrical alkali halide single-crystal ingot of a crystal material having a body-centered lattice crystallographic structure, the ingot having an axis generally coinciding with the crystallographic direction, comprising:
- placing the ingot upon a lower platen of a press having parallel upper and lower platens each covered with a metal foil so that the ingot is between two parallel, planar, vertically extending barriers located between and perpendicular to said upper and lower platens;
- orienting the ingot so that its axis is vertical, the ingot is mid-way between the barriers, and one of the ingot's crystallographic planes is parallel to the barriers;
- heating the ingot to a temperature below the melting point of the alkali halide;
- compressing the ingot along its axis by moving at least one of the upper and lower platens toward the other platen and compressing the ingot therebetween;
- and
- maintaining the barriers in fixed relation to each other.
A method of forging a generally cylindrical alkali halide single-crystal ingot of a crystal material having a crystallographic structure selected from the group consisting of a face-centered lattice crystallographic structure and a body-centered lattice crystallographic structure, the ingot having an axis generally coinciding with the crystallographic direction, comprising:
- placing the ingot upon a lower platen of a press having parallel upper and lower platens each covered with a metal foil selected from the group consisting of aluminum, stainless still, nickel, and combinations thereof so that the ingot is between two parallel, planar, vertically extending barriers located between and perpendicular to said upper and lower platens;
- orienting the ingot so that its axis is vertical, so that the ingot is mid-way between the barriers and one of the ingot's crystallographic planes is parallel to the barriers;
- heating the ingot to a temperature below the melting point of the alkali halide for a period of time of about 4 days;
- compressing the ingot along its axis by moving at least one of the upper and lower platens toward the other platen and compressing the ingot therebetween for a period of time of about 5 hours;
- maintaining the barriers in fixed relation to each other;
- and
- cooling the ingot to room temperature for a period of time of about 4 days.
Dependencies are inferred from the claim text.