HOT ISOSTATIC PRESSING CONTAINER WITH ENHANCED DIRECTIONAL CONSOLIDATION

Abstract

The present application provides a container for use in manufacturing a metal billet from a metal powder in a hot isostatic pressing process. The container may include a top, a bottom, a wall extending between the top and the bottom, an enhanced directional consolidation feature in the wall, and a sleeve positioned about the enhanced directional consolidation feature.

Claims

1. A container for use in manufacturing a metal billet from a metal powder in a hot isostatic pressing process, comprising: a top; a bottom; a wall extending between the top and the bottom; the wall comprising an enhanced directional consolidation feature; and a sleeve positioned about the enhanced directional consolidation feature.

2. The container of claim 1, wherein the enhanced directional consolidation feature comprises a bellows.

3. The container of claim 2, wherein the bellows comprises a plurality of crest portions and a plurality of root portions separated by flank portions.

4. The container of claim 2, wherein the sleeve comprises one or more sleeves positioned about the bellows.

5. The container of claim 4, wherein the one or more sleeves comprise one or more internal sleeves.

6. The container of claim 5, wherein the one or more internal sleeves comprises an upper internal sleeve and a lower internal sleeve.

7. The container of claim 6, wherein the upper internal sleeve and the lower internal sleeve overlap.

8. The container of claim 2, wherein the bellows is disposed between an upper wall portion and a lower wall portion of the wall.

9. The container of claim 8, wherein the bellows is attached to the wall at a middle wall portion of the lower wall portion.

10. The container of claim 8, wherein the sleeve comprises an internal sleeve positioned about the bellows.

11. The container of claim 10, wherein the internal sleeve overlaps the lower wall portion.

12. The container of claim 4, wherein the one or more sleeves comprise one or more external sleeves.

13. The container of claim 12, wherein the one or more external sleeves comprise an upper external sleeve and a lower external sleeve.

14. The container of claim 13, wherein the upper external sleeve and the lower external sleeve overlap.

15. A method of manufacturing a metal billet from a nanostructured ferritic alloy powder in a hot isostatic pressing process, comprising: providing an enhanced directional consolidation feature in a wall of a container; filling the container with the nanostructured ferritic alloy powder; subjecting the container to the hot isostatic pressing process to form the metal billet; deforming the container along the enhanced directional consolidation feature; and removing the metal billet from the container.

16. A container for use in manufacturing a metal billet from a metal powder in a hot isostatic pressing process, comprising: a top; a bottom; a wall extending between the top and the bottom; the wall comprising a bellows; and one or more sleeves positioned about the bellows.

17. The container of claim 16, wherein the bellows is disposed between an upper wall portion and a lower wall portion of the wall.

18. The container of claim 16, wherein the one or more sleeves comprise one or more internal sleeves.

19. The container of claim 16, wherein the one or more sleeves comprise one or more external sleeves.

20. The container of claim 16, wherein the one or more sleeves overlap.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a schematic cross-section of a container before undergoing a hot isostatic pressing process.

[0013] FIG. 2 is a schematic cross-section of the container of FIG. 1 after undergoing the hot isostatic pressing process.

[0014] FIG. 3 is a plan view of a container with an enhanced directional consolidation feature as may be described herein before undergoing the hot isostatic pressing process.

[0015] FIG. 4 is a plan view of the container with the enhanced directional consolidation feature of FIG. 3 after undergoing the hot isostatic pressing process.

[0016] FIG. 5 is schematic cross-section of an alternative embodiment of a portion of a container with an enhanced directional consolidation feature.

[0017] FIG. 6 is schematic cross-section of an alternative embodiment of a portion of a container with an enhanced directional consolidation feature.

[0018] FIG. 7 is schematic cross-section of an alternative embodiment of a portion of container with an enhanced directional consolidation feature.

DETAILED DESCRIPTION

[0019] Referring again to the drawings, in which like numerals refer to like elements throughout the several views, FIGS. 3 and 4 show plan views of an exemplary container 100 as may be described therein. In a manner similar to FIGS. 1 and 2, the container 100 includes one or more walls 20 extending between the top 25 and the bottom 30. The container 100 also may be filled with the powder mixture 15. As described above, the container 100 may be manufactured from low carbon steel, authentic stainless steel such as 304SS, and the like. Other types of materials may be used herein. The container 100 may have any suitable size, shape, and configuration. Likewise, many different types of powders and mixtures thereof may be used herein.

[0020] The container 100 may include an enhanced directional consolidation feature 110 formed therein. The enhanced directional consolidation feature 110 may allow the container 100 to deform in a preferential manner and direction. The enhanced directional consolidation feature 110 generally may be any structure that allows for such substantially axial deformation and shrinkage. In this example, the enhanced directional consolidation feature 110 may be in the form of a bellows 120 provided in the wall or walls 20 of the container 10. As is known, a bellows 120 may include any number of alternating crest portions 130 and root portions 140 separated by flank portions 150 in a generally sinusoidal manner. The distance between respective crest portions 130 may be described as a pitch 160. The alternating crest portions 130 and root portions 140 allow the bellows 120 to mechanically expand and/or contract. The bellows 120 may have any suitable size, shape, or configuration. The bellows 120 may be manufactured out of the same or different materials as the container 100. The bellows 120 may be formed in the walls 20 of the container 100 or the bellows 120 may be a separate structure that is attached thereto. The bellows 120 is one example of shaped features that are generally weak structures with preferential deformation in one direction, i.e., substantially axial deformation and shrinkage. The container 100 may include a feature for evacuation and/or sealing of various designs.

[0021] FIG. 3 shows the container 100 before undergoing the hot isostatic pressing process while FIG. 4 shows the container 100 after undergoing the hot isostatic pressing process. As compared to the container 10 of FIGS. 1 and 2, the reduction in the outer diameter of the containers 10, 100 may be similar but the reduction in height for the container 100 of FIGS. 3 and 4 may be almost double that of the container 10 of FIGS. 1 and 2. By providing more shrinkage along the length of the container 100 with a substantially uniform diameter, overall material waste after machining the container 100 may be significantly reduced.

[0022] FIGS. 5-7 show several alternative embodiments of the container 100. In these embodiments, the enhanced directional consolidation feature 110 may include the bellows 120 and one or more sleeves 170. The sleeves 170 may be manufactured out of the same or similar materials as the container 100 and the bellows 120. For example, FIG. 5 shows the container 100 with the bellows 120 attached to the outer wall 20. Specifically, the bellow 120 may be attached via welding or other types of joining means to an upper portion 180 and a lower portion 190 of the wall 20. The enhanced directional consolidation feature 110 also may include a number of internal sleeves 200. Specifically, an upper internal sleeve 210 and a lower internal sleeve 220 may be positioned inside the container 100 in an overlapping fashion adjacent to the bellows 120. Upon deformation and shrinkage, the internal sleeves 210, 220 overlap for straightening or to prevent non-axial deformation, i.e., buckling. The sleeves 210, 220 also may prevent the powder mixture 15 from flowing into the crest portions 130 of the bellows 120 so as to reduce further the need for any subsequent machining and, hence, overall reduced material waste in the final billet 35. A metallic mesh and the like also may be used. Other components and other configurations may be used herein.

[0023] FIG. 6 shows a further embodiment of the container 100 with an internal sleeve 200. Here, the bellows 120 may be attached to the upper portion 180 of the wall 20 but to a middle portion 230 of the lower portion 190 of the wall 20. A single internal sleeve 200 may be positioned inside the container 100 about the bellows 120. In this case, the internal sleeve 200 overlaps with the lower wall portion 190 for straightening or to prevent non-axial deformation, i.e., buckling. The internal sleeve 200 and the middle portion 230 may be thick and rigid or made in a strong material at the HIP temperature to resist any non-axial deformation. Other components and other configurations may be used herein.

[0024] FIG. 7 shows a further embodiment of the container 100, in this case with an external sleeve 240. Specifically, an overlapping upper external sleeve 250 and a lower external sleeve 260 may be positioned outside the container 100 about the bellows 120. The use of the external sleeves 240 may provide for a more uniform deformation and shrinkage of the bellows 120 by reducing any outward expansion of the bellows 120 and/or the wall or walls 20 along the length of the container 100 as a whole. The external sleeve 240 may be a standard feature of the hot isostatic pressing process. The external sleeve 240 thus may be a reusable component. Specifically, the external sleeve 240 may be a removable/separate structure (fixturing). One or more internal sleeves 200 also may be used with the external sleeves 240. Other components and other configurations may be used herein.

[0025] The container 100 with the enhanced directional consolidation feature 110 thus uses a structural feature such as the bellows 120 to provide significant deformation in a preferential direction during hot iso static pressing processing. Specifically, the structural features of the bellows 120 and the like are designed to deform in a particular fashion/direction. The flexible nature of the bellows 120 allows deformation at lower stresses. The bellows 120 thus allow the container 100 to collapse more easily in the axial direction versus the radial direction. Such a controlled deformation should reduce powder waste, save cost, and add overall shape control. Moreover, a container 100 with this enhanced directional consolidation feature 110 could be hot or cold pre-compressed axially before hot isostatic pressing to improve further starting density uniformity and final shape. Other applications may allow the use of otherwise poor packing materials (ceramics or composite type materials).

[0026] The nature of the powder material 15 may vary herein. In this example, the powder material 15 may be a nanostructured ferritic alloy powder and the like. Specifically, any low packing density powder (mechanically alloyed or not) or expensive powder with normal packing density. Such a material may offer superior creep and cyclic fatigue resistance for an overall longer component life. Because of the mechanically alloying process to incorporate nanoscale oxides into the steel powder, the costs of such a material may be significantly more than typical gas atomized powders. The powders used herein may have a loading/packing density of about 40 to about 70 percent. The density may increase to about 97 to about 100 percent after the hot isostatic pressing process. The resulting billet 35 may be tube like in shape and serve as, for example, a dissimilar metal weld in high temperature applications such as a heat recovery steam generator and/or other types of turbine equipment. Many other applications may be provided herein.

[0027] Further aspects of this invention are provided by the subject matter of the following clauses: a container for use in manufacturing a metal billet from a metal powder in a hot isostatic pressing process, comprising: a top; a bottom; a wall extending between the top and the bottom; the wall comprising an enhanced directional consolidation feature; and a sleeve positioned about the enhanced directional consolidation feature.

[0028] The container of any preceding clause, wherein the enhanced directional consolidation feature comprises a bellows.

[0029] The container of any preceding clause, wherein the bellows comprises a plurality of crest portions and a plurality of root portions separated by flank portions.

[0030] The container of any preceding clause, wherein the sleeve comprises one or more sleeves positioned about the bellows.

[0031] The container of any preceding clause, wherein the one or more sleeves comprise one or more internal sleeves.

[0032] The container of any preceding clause, wherein the one or more internal sleeves comprises an upper internal sleeve and a lower internal sleeve.

[0033] The container of any preceding clause, wherein the upper internal sleeve and the lower internal sleeve overlap.

[0034] The container of any preceding clause, wherein the bellows is disposed between an upper wall portion and a lower wall portion of the wall.

[0035] The container of any preceding clause, wherein the bellows is attached to the wall at a middle wall portion of the lower wall portion.

[0036] The container of any preceding clause, wherein the sleeve comprises an internal sleeve positioned about the bellows.

[0037] The container of any preceding clause, wherein the internal sleeve overlaps the lower wall portion.

[0038] The container of any preceding clause, wherein the one or more sleeves comprise one or more external sleeves.

[0039] The container of any preceding clause, wherein the one or more external sleeves comprise an upper external sleeve and a lower external sleeve.

[0040] The container of any preceding clause, wherein the upper external sleeve and the lower external sleeve overlap.

[0041] A method of manufacturing a metal billet from a metal powder in a hot isostatic pressing process, comprising: providing an enhanced directional consolidation feature in a wall of a container; filling the container with the metal powder; subjecting the container to the hot isostatic pressing process to form the metal billet; deforming the container along the enhanced directional consolidation feature; and removing the metal billet from the container.

[0042] A container for use in manufacturing a metal billet from a metal powder in a hot isostatic pressing process, comprising: a top; a bottom; a wall extending between the top and the bottom; the wall comprising a bellows; and one or more sleeves positioned about the bellows.

[0043] The container of any preceding clause, wherein the bellows is disposed between an upper wall portion and a lower wall portion of the wall.

[0044] The container of any preceding clause, wherein the one or more sleeves comprise one or more internal sleeves.

[0045] The container of any preceding clause, wherein the one or more sleeves comprise one or more external sleeves.

[0046] The container of any preceding clause, wherein the one or more sleeves overlap.

[0047] It should be apparent that the foregoing relates only to certain embodiments of this application and resultant patent. Numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the invention as defined by the following claims and the equivalents thereof.