Method for preventing powder depletion/contamination during consolidation process

Abstract

A method for preventing powder depletion/contamination during a consolidation process provides a can for holding a powdered material; the can having an interior wall; a protective layer is positioned intermediate the powdered material and the interior wall utilizing a sol-gel process utilizing monodisperse nanopowders; and the protective layer being formed from a material selected from the group consisting of nickel alloys, chrome alloys, and combinations thereof.

Claims

1. A method for preventing powder depletion/contamination during a consolidation process, said method comprising the steps of: providing a can having an inner wall; lining said inner wall of said can with a protective layer formed from a material selected from the group consisting of a nickel alloy, a chrome alloy, and combinations thereof; wherein said lining comprises forming said lining on said inner wall using a sol-gel process utilizing monodisperse nanopowders; placing a powdered nickel based superalloy material in said can so that said powdered nickel based superalloy material is in contact with said protective layer; and subjecting said can with said powdered nickel based superalloy material and said protective layer to a consolidation process.

2. The method of claim 1 wherein said can providing step comprises providing a can formed from a steel material.

3. The method of claim 1, wherein said powdered material placing step comprises placing a powdered nickel based superalloy material in said can.

4. The method of claim 1, wherein said lining step comprises lining said inner wall with a nickel alloy.

5. The method of claim 1, wherein said lining step comprises lining said inner wall with a chrome alloy.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic representation of a container to be used in a consolidation process; and

(2) FIG. 2 is a flow chart illustrating a method for preventing powder depletion/contamination during a consolidation process.

DETAILED DESCRIPTION

(3) The purpose of the system and method described herein is to minimize the formation of the undesirable phases, or depletion of the powdered material from the compositional elements during powder consolidation and extrusion due to the chemical dissimilarity of the can and powder compositional elements.

(4) Referring now to FIG. 1, there is shown a can 10 containing powder compositional elements 12. The can 10 may be formed from any suitable material known in the art, such as steel. The steel forming the can 10 may be a carbon steel. Other exemplary steel alloys which may be used to form the can 10 are 304 stainless steel or 321 stainless steel.

(5) The can 10 may comprise a tube 22 with lids 14 and 16 and a protective layer or liner 18 joined to the tube 22. The tube 22 may be a centrifugally cast tube or a rolled tube formed from a sheet of material and welded along a seam (not shown).

(6) The powder composition elements 12 may be the elements needed to form a nickel based superalloy, a cobalt based superalloy, or another nickel or cobalt based alloy.

(7) The can 10 is provided with the protective layer or lining 18 between an interior wall 20 of the can 10 and the powder compositional elements 12. The protective layer or liner 18 may be formed from a nickel alloy material, such as Nickel 200, IN100, and Inconel 600, or one of a chrome alloy and a commercially pure chromium.

(8) The protective layer or liner 18 may be applied to the inner wall 20 via one of cladding, electroplating, plasma spraying, sol-gel process utilizing monodisperse nanopowders, and a liner made of the nickel alloy.

(9) One of the advantages to using a protective layer or lining 18 is that one can form the can 10 from a lower grade stainless steel if desired, rather than a high grade stainless steel material. For example, one could form the can 10 from a carbon steel.

(10) If desired, the protective layer or lining 18 may be formed by plasma spraying of a NiCr powder onto the inner wall 20.

(11) Using the protective layer or lining 18, one can address the occurrence of LEI in the can 10 and avoid having to machine of layers of contaminated material from every log or billet formed from the powder metallurgy process. The protective layer or lining 18 acts as a means for preventing powder depletion/contamination during the consolidation process.

(12) Referring now to FIG. 2, the method for preventing powder depletion/contamination during a consolidation comprises providing a can 10 having an inner wall 20. Thereafter, the inner wall 20 is lined with a protective layer or lining 18 formed from a material selected from the group consisting of a nickel alloy, a chrome alloy, and combinations thereof. After the protective layer or lining 18 has been formed, the lids 14 and 16 may be attached to the can 10.

(13) Then, the powdered compositional elements 12 are placed in the can 10 by introducing the powdered compositional elements 12 through an opening (not shown) in the can 10. The powdered compositional elements 12 are placed in the can 10 so that they are in contact with the protective layer 18.

(14) Thereafter, the can 10, with the powdered compositional elements 12 therein and the protective layer 18, is subjected to a consolidation process, such as compaction and extrusion at high temperature.

(15) While the system and method described herein have been described in the context of nickel based superalloys or nickel based alloys, the system and method described herein could be applied to any combination of metallic alloy powder and metallic can material that has an issue with depletion or contamination of powder due to diffusion of elements between the alloy powder and can material.

(16) There has been provided a system and method for preventing powder depletion/contamination during a consolidation process. While the system and method for preventing powder depletion/contamination during a consolidation process has been shown in the context of specific embodiments thereof, other unforeseeable modifications, variations, and alternatives may become apparent to those skilled in the art having read the foregoing description. Accordingly, it is intended to embrace those alternatives, modifications, and variations as fall within the broad scope of the appended claims.