The disclosure relates to automated bi-casting.
Metal casting involves pouring molten metal or alloy into a mold, and allowing the poured molten material to cool and solidify into an object shaped by the mold. The object may be retrieved from the mold, for example, by breaking or disassembling the mold.
In some examples, a system includes a vacuum chamber enclosing a pouring cup and a platform configured to support a casting assembly. In some examples, the casting assembly is configured to hold a plurality of joinable components and a mold defining at least one mating groove configured to join at least two joinable components of the plurality of joinable components when occupied with a metal or an alloy. Each respective mating groove of the at least one mating groove may be fluidically connected to a respective surface opening of a plurality of surface openings defined by the mold. In some examples, the pouring cup and the respective surface opening of the plurality of surface openings are movable relative to each other by moving at least one of the pouring cup or the platform to substantially align the pouring cup with respective surface openings of the plurality of surface openings. In some examples, the pouring cup is configured to pour a respective volume of molten metal or alloy in at least two surface openings of the plurality of surface openings.
In some examples, a technique includes substantially aligning a pouring cup with a first surface opening of a plurality of surface openings defined by a mold by moving at least one of the pouring cup or a platform supporting a casting assembly. In some examples, the casting assembly is configured to hold a plurality of joinable components and the mold, wherein the mold defines at least one mating groove configured to join at least two joinable components of the plurality of joinable components when occupied with a metal or an alloy. In some examples, each mating groove of the at least one mating groove is fluidically connected to a respective surface opening of the plurality of surface openings, and a vacuum chamber encloses the pouring cup, the casting assembly, and the platform. In some examples, the technique includes moving the pouring cup to pour a respective volume of molten metal or alloy in the first surface opening. In some examples, the technique includes substantially aligning the pouring cup with a second surface opening of the plurality of surface openings at least by moving at least one of the pouring cup and the platform. In some examples, the technique includes moving the pouring cup to pour a respective volume of molten metal or alloy in the second surface opening.
In some examples, a computer readable storage medium includes instructions that, when executed, cause at least one processor to control at least one of a cup controller to move a pouring cup and a platform controller to at least move a platform supporting a casting assembly to substantially align the pouring cup with a first surface opening of a plurality of surface openings defined by a mold. In some examples, the casting assembly is configured to hold a plurality of joinable components and the mold, wherein the mold defines at least one mating groove configured to join at least two joinable components of the plurality of joinable components when occupied with a metal or an alloy. In some examples, each mating groove of the at least one mating groove may be fluidically connected to a respective surface opening of the plurality of surface openings. In some examples, a vacuum chamber may enclose the pouring cup, the casting assembly, and the platform. In some examples, the computer readable storage medium further includes instructions that, when executed, cause the at least one processor to control the cup controller to move the pouring cup to pour a respective volume of molten metal or alloy in the first surface opening. In some examples, the computer readable storage medium further includes instructions that, when executed, cause the at least one processor to control at least one of the cup controller to move the pouring cup and the platform controller to move the platform to substantially align the pouring cup with a second surface opening of the plurality of surface openings. In some examples, the computer readable storage medium further includes instructions that, when executed, cause the at least one processor to control the cup controller to move the pouring cup to pour a respective volume of molten metal or alloy in the second surface opening.
The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.
In general, the disclosure describes systems and techniques for bi-casting. In some examples, the systems and techniques described herein may facilitate more efficient use of material in bi-casting, more efficient heating, or both. Bi-casting systems described herein may include a pouring cup and a casting assembly that includes a plurality of surface openings configured to receive molten metal or alloy and direct the molten metal or alloy to a mold. The pouring cup may be movable relative to the surface openings, the casting assembly may be movable relative to the pouring cup, or both, such that the pouring cup may be substantially aligned (e.g., aligned or nearly aligned) with respective surface openings to pour respective charges of molten metal or alloy in the respective surface openings. By pouring respective charges of molten metal or alloy in each of a plurality of surface openings, in some examples, the total amount of molten metal or alloy used in the bi-casting technique may be less than if a single opening is used, e.g., due to shorter pathways from the surface openings to the mold.
As described herein, bi-casting may be used to cast a first metal or alloy (the molten metal or alloy) on or adjacent to a second metal or alloy by pouring a molten volume of the first metal or alloy on or adjacent to the second metal or alloy. In some examples, a joint including the first metal or alloy may be cast to join joinable components including the second metal or alloy. In some examples, the pouring cup and the casting assembly may be enclosed in a vacuum chamber and maintained under vacuum during the pouring process, which may reduce or substantially prevent (e.g., prevent or nearly prevent) air bubbles from forming in the casted joint, reduce or substantially prevent (e.g., prevent or nearly prevent) reaction of atmospheric species with the molten metal or alloy, or both. Further, in some examples, the casting assembly may be supported by a platform, which may move the casting assembly between a heating zone and a cooling zone. Example systems described herein may be used to fabricate articles including a plurality of joinable components joined by at least one casted joint.
In some examples, vacuum chamber 110 encloses pouring cup 120, platform 130, and casting assembly 140 to maintain an appropriate pressure or a substantial vacuum (e.g., a vacuum or nearly a vacuum) during at least one stage of processing, including casting. In some examples, vacuum chamber 110 includes a heating zone 194 and a cooling zone 196.
Heating zone 194 may be a zone or sub-chamber within vacuum chamber 110 that is heated to or maintained at an elevated temperature, for instance, for pre-heating casting assembly 140. In some examples, system 100 includes heating zone controller 195 configured to control heating of heating zone 194. For example, heating zone controller 195 may include a thermostat and a heating source configured to supply heat to heating zone 194 by at least one of conduction, convection, or radiation. In some examples, the temperature to which heating zone 194 is heated may be a temperature at which the metal or alloy to be poured from pouring cup 120 is molten. In some examples, heating zone controller 195 may substantially maintain (e.g., maintain or nearly maintain) heating zone 194 at a predetermined temperature, e.g., a temperature at which the metal or alloy to be poured from pouring cup 120 is molten.
In some examples, casting assembly 140 may be pre-heated externally of system 100, and introduced into vacuum chamber 110 after pre-heating. For example, pre-heated casting assembly may be introduced into heating zone 194 of vacuum chamber 110, and vacuum controller 111 may pull a vacuum within heating zone 194 of chamber 110. In some examples, heating zone controller 195 may control the temperature of heating zone 194 to be substantially equal to the temperature of pre-heated casting assembly 140 introduced into heating zone 194.
In some examples, vacuum chamber 110 also includes a cooling zone 196 for cooling casting assembly 140 after pouring of the molten metal or alloy into at least one mating groove 160. In some examples, system 100 includes cooling zone controller 197 configured to control a temperature of cooling zone 196. For example, cooling zone controller 197 may include a forced convection cooling system and a thermostat, to control the temperature of cooling zone 196. In some examples, cooling zone controller 197 may control the temperature of cooling zone 196 to be a temperature at which the metal or alloy poured from pouring cup 120 is solid. Hence, when platform 130 and casting assembly 140 move to cooling zone 196, the molten metal or alloy in at least one mating groove 160 may cool and solidify. In some examples, cooling zone controller 197 may substantially maintain (e.g., maintain or nearly maintain) cooling zone 196 at a predetermined temperature, e.g., a temperature at which the metal or alloy poured from pouring cup 120 is solid. In some examples, cooling zone controller 197 may control the temperature of cooling zone 196 according to an annealing program by cooling the temperature of cooling zone 196 to various intermediate selected temperatures and holding the respective selected intermediate temperatures for respective predetermined periods of time. For example, cooling zone controller 197 may control the temperature of cooling zone 196 over a period of time to anneal the poured volume of metal or alloy within mating groove 160.
While heating zone 194 may be disposed vertically above cooling zone 196 in some examples, as shown in
While system 100 has been described with reference to vacuum chamber 110 in examples above, in other examples, system 100 may include a chamber that is exposed to the atmosphere, or otherwise does not maintain a vacuum.
In some examples, system 100 includes platform 130 configured to support and move casting assembly 140 and a platform controller 131 configured to control movement of platform 130. Platform 130 may include a base capable of supporting casting assembly 140. Computing device 180 may control platform controller 131 to move platform 130 by at least one of rotating or translating platform 130. For example, platform controller 131 may include a rotary lift configured to raise, lower, and rotate platform 130. In some examples, platform controller 131 may vertically translate platform 130, moving casting assembly 140 between an upper region and a lower region of the vacuum chamber (e.g., heating zone 194 and cooling zone 196). In some examples, platform controller 131 may translate platform 130 horizontally, so that casting assembly 140 is moved horizontally within vacuum chamber 110. In some examples, platform controller 131 may rotate platform 130 about an axis normal to a major surface of platform 130. For example, platform 131 may rotate platform 130 about an axis passing through casting assembly 140. Because platform 130 supports casting assembly 140, computing device 180 may thus control platform controller 131 to locate and orient casting assembly 140 within vacuum chamber 110, for example, relative to pouring cup 120, or between heating zone 194 and cooling zone 196.
Casting assembly 140 is configured to hold a plurality of joinable components 144. Each joinable component of plurality of joinable components 144 may include a metal or alloy. The metal or alloy in each respective joinable component of plurality of joinable components 144 may be the same or may be different. In some examples, the metal or alloy may include alloys such as Fe-based, Ni-based, or Co-based superalloys. For example, the metal or alloy may include CMSX-4 Ni-based superalloy. In some examples, the metal or alloy in each joinable component of plurality of joinable components 144 is different from the molten metal or alloy in pouring cup 120. For example, the molten metal or alloy in pouring cup 120 may include Fe-based, Ni-based, or Co-based superalloy that is different from the metal or alloy in each joinable component of plurality of joinable components 144. In other examples, the metal or alloy in each joinable component of plurality of joinable components 144 may be the same as the molten metal or alloy in pouring cup 120.
Casting assembly 140 may position the plurality of joinable components 144 to define a predetermined shape. In some examples, each joinable component of the plurality of joinable components 144 may define a joint region which, when filled by a solid material, joins the plurality of joinable components 144. In some examples, casting assembly 140 includes a mold 148, which defines a mating groove 160 that, in combination with the joint regions of plurality of joinable components 144, defines the shape of the joint. In some examples, mating groove 160 defines a clip for joining respective joinable components of plurality of joinable components 144. For example, mold 148 may define mating groove 160 as including a semi-circular channel. Mold 148 also defines a plurality of surface openings 162, and at least one channel 164 that fluidically connects a respective mating groove of the at least one mating groove 160 to a respective surface opening of a plurality of surface openings 162.
In some examples, respective surface openings of plurality of surface openings 162 receive a first metal or alloy from cup 120 and the molten metal or alloy flows through respective channels of at least one channel 164 to mating groove 160, around or adjacent each joinable component of plurality of joinable components 144. In some examples, after the first poured metal or alloy cools and solidifies, casting assembly 140 includes at least two joinable components of the plurality of joinable components 144 joined by the first metal or alloy. Plurality of joinable components 144 may include components of a high temperature mechanical system (e.g., a turbine), and casting assembly 140 may position the components in the orientation to be eventually assumed in the final article formed after the poured molten volume of metal or alloy occupies and solidifies within mating groove 160.
In some examples, respective surface openings of plurality of surface openings 162 may be narrow, and it may be difficult to control the stream of molten metal or alloy poured from cup 120 to accurately enter a respective surface opening without spilling. In some examples, casting assembly 140 includes a plurality of pour tubes 170, each pour tube connected to a respective surface opening of plurality of surface openings 162. In some examples, each pour tube of plurality of pour tubes 170 includes an inlet for accepting poured molten metal or alloy from pouring cup 120 and an outlet for directing the molten metal or alloy to a respective surface opening of plurality of surface openings 162. In some examples, the inlet of each pour tube of plurality of pour tubes 170 may at least be wider than a respective surface opening of plurality of surface openings 162, or at least be sufficiently wide to receive the stream of molten metal or alloy poured by pouring cup 120 without spilling outside the respective pour tube of plurality of pour tubes 170. In some examples, each pour tube of plurality of pour tubes 170 includes a funnel for directing the stream of molten metal or alloy poured from pouring cup 120 to a respective surface opening of plurality of surface openings 162.
To allow for uninterrupted passage of molten metal or alloy from plurality of surface openings 162 to groove 160, computing device 180 may control vacuum controller 111 to maintain casting assembly 140 under a vacuum at least while pouring molten metal or alloy from pouring cup 120, to prevent blockage by air (for instance, air bubbles) within casting assembly 140. For example, maintaining a vacuum while pouring molten metal or alloy into casting alloy 140 may prevent blockage plurality of surface openings 162, at least one channel 164, or mating groove 160. Maintaining a vacuum may also provide other advantages, for example, preventing oxidation or other reactions of atmospheric species with the molten metal or alloy.
System 100 includes poring cup 120 for pouring molten metal or alloy into casting assembly 140 and a cup controller 121 that controls motion of poring cup 120. In some examples, computing device 180 may control cup controller 121 to move pouring cup 120 by at least one of rotating around at least one axis or translating along at least one axis. For example, cup controller 121 may translate pouring cup 120 relative to a major surface of platform 130. In some examples, cup controller 121 may rotate pouring cup 120 about a horizontal axis to turn pouring cup 120 between a first configuration in which pouring cup 120 maintains the volume of molten metal or alloy and a second configuration in which pouring cup 120 pours the volume of molten metal or alloy.
Pouring cup 120 may contain a volume of molten metal or alloy to be poured into a casting assembly 140. Pouring cup 120 may include an inlet for charging molten metal or alloy into pouring cup 120. In some examples, pouring cup 120 may include a container in the shape of a cylinder, a cube, or any other shape that may contain the volume of molten metal or alloy. Pouring cup 120 may include at least one of a lip and a spout to direct the stream of poured volume of molten metal or alloy in a desired direction, for example, toward a surface of casting assembly 140. In some examples, pouring cup 120 may be initially or occasionally charged with solid metal or alloy, and may be heated to melt the metal or alloy into a molten volume.
Cup controller 121 may move pouring cup 120 by at least one of translating or rotating, to substantially align (e.g., align or nearly align) pouring cup 120 with regions, portions, or surfaces of casting assembly 140. For example, cup controller 121 may move pouring cup to substantially align (e.g., align or nearly align) pouring cup 120 with a respective surface opening of plurality of surface openings 162 or a respective pour tube of plurality of pour tubes 170. In some examples, cup controller 121 may move pouring cup 120 to turn between the first configuration and the second configuration to pour molten metal or alloy from pouring cup 120 to a respective surface opening of plurality of surface openings 162 or a respective pour tube of plurality of pour tubes 170. In some examples, the degree to which cup controller 121 turns pouring cup 120 affects the rate at which the volume of molten metal or alloy is poured, and affects the flow geometry of the poured stream of molten metal or alloy.
Pouring cup 120 and the respective surface opening of the plurality of surface openings 162 are movable relative to each other. For example, computing device 180 may control cup controller 121 to move pouring cup 120, or platform controller 131 to move platform 130 to move casting assembly 140, or both, to substantially align (e.g., align or nearly align) pouring cup 120 with respective surface openings of the plurality of surface openings 162. In some examples, computing device 180 may control cup controller 121 to move pouring cup 120 to pour a respective volume of molten metal or alloy in at least two respective surface openings of plurality of surface openings 162. For example, computing device 180 may control cup controller 121 to move pouring cup 120 to pour a respective volume of molten metal or alloy in a first surface opening of plurality of surface openings 162; may control cup controller 121, platform controller 131, or both to move pouring cup 120, platform 130, or both to substantially align (e.g., align or nearly align) pouring cup 120 with a second surface opening of plurality of surface openings 162; and control cup controller 121 to move pouring cup 120 to pour a respective volume of molten metal or alloy in the second surface opening of plurality of surface openings 162. In this way, system 100 facilitates pouring of liquid metal or alloy in respective surface openings of plurality of surface openings 162.
Thus, in some examples, system 100 may perform example techniques to fabricate articles including a plurality of joinable components joined by at least one casted joint. For example, system 100 may be used to fabricate a high temperature mechanical component that includes a plurality of joinable components including a first metal or alloy joined by joints including a second metal or alloy. By pouring molten metal or alloy into respective surface openings of plurality of surface openings 162, the system of
In some examples, substantially aligning pouring cup 120 with the first surface opening of plurality of surface openings 162 includes aligning pouring cup 120 with a first pour tube of plurality of pour tubes 170, wherein each respective pour tube of plurality of pour tubes 170 is connected to one surface opening of plurality of surface openings 162. For example, pouring cup 120 may pour molten metal or alloy into respective pour tubes of plurality of pour tubes to accurately direct the poured metal or alloy to surface opening 162 and eventually to mating groove 160 without spilling metal or alloy outside mold 148 or at surfaces of casting assembly 140.
In some examples, the technique of
In some examples, the technique of
In some examples, the technique of
Although the technique of
In some examples, the technique of
In some examples, the example technique of
In various example techniques, vacuum controller 111 may optionally pull vacuum within vacuum chamber 110 at one or more of pre-heating (210), substantially aligning (220, 260), pouring (240, 280), and moving (290). For example, vacuum chamber 110 may maintain substantially a vacuum at least while pouring the respective volume of molten metal or alloy in the first surface opening (240) and while pouring the respective volume of molten metal or alloy in the second surface opening (280), to avoid problems discussed above with reference to
While example techniques described above may be performed substantially in vacuum, in other examples, example techniques may be performed at atmospheric pressure, or otherwise in systems that may not include a vacuum chamber.
Thus, example techniques of
Various examples have been described. These and other examples are within the scope of the following claims.
This application claims the benefit of U.S. Provisional Application No. 62/183,602 filed Jun. 23, 2015, which is incorporated herein by reference in its entirety.
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20160375487 A1 | Dec 2016 | US |
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62183602 | Jun 2015 | US |