US 5,207,776 A · Bi-metallic extrusion billet preforms and method and apparatus for producing same

Abstract

A bi-metallic extrusion billet perform is produced in a single casting. An inner core made of a desired material is placed in the center of a crucible or mold as a prepared bar. Molten cladding material is cast into an annular area between the outside surface of the inner core and an inner surface of the crucible or mold. Bottom pouring is enabled through the center of the inner core, which has been appropriately provided with a hole of a size that is consistent with the extrusion press and the required extruded hollow size involved in later manufacturing steps. The entire operation, including the melting of the cladding material, is advantageously performed under a vacuum to eliminate the risk of trapping air at an interface between the inner core and the cladding material cost therearound.

Claims24

Dependent claims

A method for producing a bi-metallic extrusion billet preform in a single casting, comprising the steps of:

providing a mold for said preform;
providing a bottom pouring distribution manifold on a bottom surface of said mold;
providing a metal core having a bore which extends along an entire length of said core;
placing said core into said mold so that said manifold supports said core, leaving an annular area between an outside surface of said core and an inner surface of said mold;
delivering a molten cladding metal into a bottom of said mold via a bottom pouring tube positioned within said bore so that the molten cladding metal is delivered directly to said manifold in a bottom pouring operation, filling said annular area with said molten cladding metal;
and
allowing said molten cladding metal to solidify around said core to produce said extrusion billet preform.

4 more elements

Dependencies are inferred from the claim text.

Bi-metallic extrusion billet preforms and method and apparatus for producing same

Life of this patent

Bi-metallic extrusion billet preforms and method and apparatus for producing same

Life of this patent

Abstract

Claims24