CAST COMPONENT AND METHODS OF MANUFACTURING WITH COLD SPRAYING

Abstract

A cast component includes a cast structure having a primary geometry formed by a mold. Also included is a structural deposit formed by cold spraying one or more layers of powdered material on an outer surface of the cast structure, the structural deposit defining at least one feature of the overall outer geometry of the cast component in addition to the primary geometry. Also provided are methods of manufacturing the cast component.

Description

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to cast components and, more particularly, to a cast component manufactured with cold spray deposition, as well as methods of manufacturing such components.

Mold assemblies are employed in casting processes to form components in a wide range of industries. An example of an industry that benefits from a casting process is the aerospace industry, which requires intricate features on various components. Typically, a single mold is required to form components, but such a mold is often costly as increasingly intricate features are formed therein. In some cases, a rather generic mold is employed to form similar components, which are then machined to form a final component with the desired intricate features. Therefore, investing in a large number of castings with the desired intricate features or machining a generic component leads to time and cost inefficiencies. Additionally, component design requirements often change over time and such changes require modifications to the mold or a change in the machining process to produce the final component, again leading to undesirable time and cost impacts.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect of the invention, a cast component includes a cast structure having a primary geometry formed by a mold. Also included is a structural deposit formed by cold spraying one or more layers of powdered material on an outer surface of the cast structure, the structural deposit defining at least one feature of the overall outer geometry of the cast component in addition to the primary geometry.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the cast component comprises at least one of an aluminum alloy, a titanium alloy, a steel alloy, and a magnesium alloy.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the cast component comprises a component for an aircraft.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the cast structure is a sand cast structure.

According to another aspect of the invention, a method of manufacturing a component is provided. The method includes casting a structure having a primary geometry with a mold. The method also includes depositing a structural deposit by cold spraying one or more layers of powdered material on an outer surface of the cast structure with a cold spray nozzle to define at least one feature of the overall outer geometry of the component in addition to the primary geometry.

In addition to one or more of the features described above, or as an alternative, further embodiments may include post-processing at least one of the primary geometry and the at least one feature of the structure.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that casting the structure comprises casting with a sand casting mold.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that depositing the structural deposit comprises moving the structure.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that depositing the structural deposit comprises moving the cold spray nozzle.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that depositing the structural deposit comprises coupling a cold spray nozzle to a numerically controlled machine, wherein a deposition path is automated.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that depositing the structural deposit comprises coupling the structure to a numerically controlled machine, wherein a deposition path is automated.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the powdered material comprises at least one of an aluminum alloy, a titanium alloy, a steel alloy, and a magnesium alloy.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that cold spraying comprises accelerating powder particles with a gas comprising at least one of helium and nitrogen.

In addition to one or more of the features described above, or as an alternative, further embodiments may include that the component comprises a component for an aircraft.

According to yet another aspect of the invention, a method of manufacturing a component is provided. The method includes forming a mold for casting a structure, the mold having a primary geometry. The method also includes depositing a structural deposit by cold spraying one or more layers of powdered material on a surface of the mold to define at least one feature of the overall geometry of the structure in addition to the primary geometry. The method further includes casting the structure within the mold.

These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a cold spray deposition assembly for depositing a structural deposit on a substrate;

FIG. 2 is a structure having a primary geometry;

FIG. 3 illustrates a cold spray deposition of a deposit on the structure;

FIG. 4 is a cast component having a deposit thereon to form an overall geometry;

FIG. 5 is a mold cavity having a primary geometry;

FIG. 6 illustrates a cold spray deposition of a deposit on a surface of the mold cavity; and

FIG. 7 is the mold cavity with a deposit thereon to form an overall mold geometry.

The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a manufacturing set-up 10 is illustrated. The manufacturing set-up 10 illustrates various components and systems used in a method to form a component 12. The component 12 is generically referred to based on the fact that the component 12 may be employed in a wide variety of application related to numerous industries. The component 12 is formed in a casting process and includes an overall geometry that includes detailed or intricate features.

One industry that particularly benefits from cast components is the aerospace industry, for example. A helicopter is an example of an application that employs the component 12 that is additively manufactured by the methods described herein. Numerous systems and structural assemblies of a helicopter may employ the structure 10 described herein. Although the aerospace industry has been provided as an example, as noted above it is to be appreciated that any industry that requires cast components having features that complicate the exterior geometry would benefit from the embodiments described herein. Furthermore, although the exemplary embodiments described herein are in the form of originally manufactured components, it is to be understood that the methods described herein may be applied to repair and salvage of existing components. The functionality of the components and systems of the manufacturing set-up 10 will be described in more detail below.

Referring to FIGS. 2-4, the cast component 12 is illustrated in greater detail and is shown at multiple stages of a manufacturing process. The geometries illustrated and described herein are merely illustrative and it is to be understood that any overall geometry may be formed from the processes described. FIG. 2 illustrates a cast structure 14 after having been formed by a casting process in a mold assembly (not illustrated). Any suitable molding assembly and casting process, such as a sand casting process, may be employed to form the cast structure 14 into a primary geometry 16 that is illustrated in FIG. 2. As shown, a relatively simple geometry is provided as the primary geometry 16, but it is noted that the cast structure 14 may include cored internal passages. Casting the cast structure 14 may be done with a mold assembly having a relatively simple geometry, thereby avoiding the need for assembling a mold with intricate geometric features. In this manner, a single mold assembly may be employed to form cast structures of a single geometry, but which are available to be further modified by the methods described herein. Consequently, manufacturing costs are reduced due to the need for fewer specifically designed mold assemblies for each part that is to be cast. Additionally, improvement in casting yield as compared with more complex casting geometries can be achieved as a result of a casting with a mold having comparatively less intricate geometric features.

Subsequent to forming the cast structure 14, the cast structure 14 is subjected to a cold spray deposition process with the manufacturing set-up 10 illustrated in FIG. 1, as shown in FIG. 3. Reference to FIGS. 1 and 3 is made, which illustrates a structural deposit 20 being formed on the cast structure 14 to provide at least one structural feature 21 on the cast structure 14. The at least one structural feature 21 refers to additional intricate features that are to be added to the primary geometry 16 of the cast structure 14 to form an overall outer geometry of the cast component 12. The cast structure 14 may also be formed with one or more relatively simple surface features 27 (FIG. 2) that are designed to facilitate the deposition of the structural deposit 20 to provide the at least one structural feature 21 on the cast structure 14. Exemplary surface features 27 include recesses, dimples, bosses, channels, saddles, and the like.

The structural deposit 20 may be formed from any suitable powdered material known in the art, such as aluminum, titanium, steel or magnesium alloys, for example. The material employed to form the structural deposit 20 may be the same or different than the material used to form the primary geometry 16 of the cast structure 14. Such variation in material allows for designing into the component 12 desired characteristics such as for example, corrosion resistance and a high strength-to-weight ratio. The structural deposit 20 is formed by applying one or more layers of powdered material to an area 22 of a surface 24 of the cast structure 14. The one or more layers of powdered material used to form the structural deposit 20 are more substantial than a coating and are configured to share a load applied over the surface 24. The layers of powdered material used to form the structural deposit 20 are generally applied through a deposition process that provides sufficient energy to accelerate the particles to a high enough velocity such that the particles plastically deform and bond to the area upon impact. The particles of the powered material are accelerated through a converging/diverging nozzle 30 of a spray gun 32 to supersonic velocities using a pressurized or compressed gas, such as helium, nitrogen, other inert gases, or mixtures thereof (FIG. 1). The deposition process does not metallurgically transform the particles from their solid state, but does affect metallurgical bonding. Various techniques may be used to achieve this type of particle deposition, including but not limited to, cold spray deposition, kinetic metallization, electromagnetic particle acceleration, modified high velocity air fuel spraying, or high velocity impact fusion (HVIF) for example.

The nozzle 30 and spray gun 32 are operably coupled to a numerically controlled machine 34 configured to automate the deposition path of the structural deposit 20. The numerically controlled machine 34 is operated by precisely programmed commands encoded on a storage medium, such as a computer in a computer numerical control (CNC) machine, for example. During deposition of the powdered material, the cast structure 14 may be held stationary or may be articulated or translated by any suitable means (not shown). Alternatively, the nozzle 30 of the spray gun 32 may be held stationary or may be articulated or translated. In some instances, both the cast structure 14 and the nozzle 30 may be manipulated, either sequentially or simultaneously. It is to be appreciated that either the cast structure 14 or the nozzle 30 may be coupled to the numerically controlled machine 34 to facilitate automation of the deposition path.

Subsequent to deposition of the structural deposit 20, the cast component 12 is formed, as shown in FIG. 4. The cast component 12 includes the primary geometry 16 and the at least one feature 21 that have been added to the primary geometry 16 to form the final outer geometry of the cast component 12 with the cold spray deposition process. Although the phrase “at least one feature” generally refers to a singular type of feature, it is to be understood that countless distinct features may be formed. In other words, the phrase generically refers to a geometry or feature that is different and in addition to the primary geometry 16. Therefore, different types of features may be formed on the cast structure 14.

One or more post-processing techniques may be employed to further define the primary geometry 16 and/or the at least one feature 21. For example, the primary geometry 16 and/or the at least one feature 21 may be machined subsequent to the cold spraying process.

Referring now to FIGS. 5-7, with continued reference to FIG. 1, an additional embodiment of the method for manufacturing the cast component 12 is illustrated. In the illustrated embodiment, a mold assembly 40 is subjected to the cold spray deposition process rather than the cast structure 14. As shown, the mold assembly 40 comprises the primary geometry 16, which as described above is relatively simple, thereby avoiding the need for expensive, complicated and time-consuming assembly of intricately-shaped mold geometries.

The mold assembly 40 is used to produce associated cast components that may be assembled to form an overall cast component, which will be described in greater detail below. As shown in FIG. 5, the mold assembly 40 is first formed into a first mold condition 42 having the primary geometry 16. This condition is formed by any mold assembly process known in the art. The primary geometry 16 of the mold assembly 40 has a geometry that is common to one or more cast components. The primary geometry 16 is defined by a cavity region 48 including a surface 44. The nozzle 30 and spray gun 32 are then used to deposit a structural deposit on the surface 44 of the mold assembly 40, as shown in FIG. 6. The deposit is made with the cold spray deposit process that is described in detail above. This process is employed to deposit at least one feature 46 on the surface 44 of the mold assembly 40 to provide additional detail that is desired for the final cast component 12 (FIG. 7).

It can be seen that the final cast component 12 includes intricate features that are substantially more detailed than the primary geometry 16. As the time and cost associated with forming more intricate features increases with the level of detail, it is advantageous to avoid requiring the formation of a new primary mold structure having the desired detail for every potential cast component. Accordingly, the cold spray deposition process provides the ability to more cheaply and easily provide detail to cast components formed by the mold assembly 40 by simply forming the additional mold structures.

While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

Claims

1. A cast component comprising: a cast structure having a primary geometry formed by a mold; anda structural deposit formed by cold spraying one or more layers of powdered material on an outer surface of the cast structure, the structural deposit defining at least one feature of the overall outer geometry of the cast component in addition to the primary geometry.

2. The cast component of claim 1, wherein the cast component comprises at least one of an aluminum alloy, a titanium alloy, a steel alloy, and a magnesium alloy.

3. The cast component of claim 1, wherein the cast component comprises a component for an aircraft.

4. The cast component of claim 1, wherein the cast structure is a sand cast structure.

5. A method of manufacturing a component comprising: casting a structure having a primary geometry with a mold; anddepositing a structural deposit by cold spraying one or more layers of powdered material on an outer surface of the cast structure with a cold spray nozzle to define at least one feature of the overall outer geometry of the component in addition to the primary geometry.

6. The method of claim 5, further comprising post-processing at least one of the primary geometry and the at least one feature of the structure.

7. The method of claim 5, wherein casting the structure comprises casting with a sand casting mold.

8. The method of claim 5, wherein depositing the structural deposit comprises moving the structure.

9. The method of claim 5, wherein depositing the structural deposit comprises moving the cold spray nozzle.

10. The method of claim 5, wherein depositing the structural deposit comprises coupling the cold spray nozzle to a numerically controlled machine, wherein a deposition path is automated.

11. The method of claim 5, wherein depositing the structural deposit comprises coupling the structure to a numerically controlled machine, wherein a deposition path is automated.

12. The method of claim 5, wherein the powdered material comprises at least one of an aluminum alloy, a titanium alloy, a steel alloy, and a magnesium alloy.

13. The method of claim 5, wherein cold spraying comprises accelerating powder particles with a gas comprising at least one of helium and nitrogen.

14. The method of claim 5, wherein the component comprises a component for an aircraft.

15. A method of manufacturing a component comprising: forming a mold for casting a structure, the mold having a primary geometry;depositing a structural deposit by cold spraying one or more layers of powdered material on a surface of the mold to define at least one feature of the overall geometry of the structure in addition to the primary geometry; andcasting the structure within the mold.