A single crystal furnace based on liquid metal cooling method

Abstract

The utility model relates to single crystal furnace equipment of liquid metal cooling method especially based on single crystal furnace of liquid metal cooling method. Including smelting chamber, casting room, casting heater, liquid metal cooling device: the smelting chamber is provided with the smelting coil for melting the master alloy in, the casting room with the smelting chamber horizontal parallel arrangement, and the casting room on be provided with the passageway for casting in and out, the smelting chamber with the casting room between be provided with the isolating valve for forming the open and close's vacuum isolation between both, the casting heater set up in the smelting chamber, the liquid metal cooling device set up in the casting heater below, for the forced cooling to the casting that removes from the casting heater. The utility model has the advantages such as big temperature gradient, fast crystal pulling speed etc. compared with traditional HRS method single crystal furnace, especially suitable for the production of aero-engine, gas turbine single crystal blade.

Description

Technical Field

[0001] This utility model relates to a single crystal furnace device based on liquid metal cooling method, and more particularly to a single crystal furnace based on liquid metal cooling method. Background Technology

[0002] A vacuum induction single crystal furnace is a special metallurgical equipment used for precision casting under vacuum or a protective atmosphere. This equipment is mainly used for hot-end single crystal blades in aircraft engines and gas turbines. Traditional single crystal furnaces generally employ the HRS process and are mostly vertical dual-chamber structures, with the mold chamber at the bottom and the melting chamber at the top. The melting chamber is used by the induction generator to remelt the base alloy, and it is equipped with a mold heating system. After the secondary remelting is completed, the molten metal in the crucible is poured into the mold, which moves downwards at a certain speed according to different processes. Once completely removed from the melting chamber, a water-cooled isolation valve seals and separates the two chambers. The mold chamber is then emptied and a new mold is loaded. New alloy is also added to the melting chamber via a feeding mechanism for the next working cycle.

[0003] Traditional vacuum induction single crystal furnaces have the following main drawbacks: a relatively low temperature gradient, typically between 20-40℃ / cm. Furthermore, because the temperature gradient in the HRS method decreases with increasing mold height, traditional single crystal furnaces based on the HRS method are difficult to use for fabricating large-sized blades. Additionally, the pulling speed in traditional HRS-based single crystal furnaces is negatively correlated with the temperature gradient, resulting in a slow pulling speed, typically 1-6 mm / min. Summary of the Invention

[0004] This invention addresses the shortcomings of existing technologies by providing a single crystal furnace based on a liquid metal cooling method. To achieve the above objective, this invention adopts the following technical solution: a single crystal furnace based on a liquid metal cooling method, comprising a melting chamber, a casting chamber, a casting heater, and a liquid metal cooling device; the melting chamber is equipped with a melting coil for melting the master alloy; the casting chamber is arranged horizontally alongside the melting chamber, and the casting chamber has a channel for mold entry and exit; an isolation valve is provided between the melting chamber and the casting chamber to form an openable and closable vacuum isolation between them; the casting heater is located within the melting chamber; the liquid metal cooling device is located below the casting heater for forced cooling of the mold removed from the casting heater.

[0005] Furthermore, the liquid metal cooling device includes a liquid metal pot containing liquid metal coolant, and the bottom of the mold heater has an opening for immersing the mold into the liquid metal pot.

[0006] Furthermore, the melting chamber is provided with a first drive mechanism for moving the mold between the mold heater and the liquid metal cooling device.

[0007] Furthermore, the single crystal furnace is also provided with a second drive mechanism for driving the mold to move between the mold chamber and the melting chamber.

[0008] Furthermore, the melting chamber is connected to a high vacuum system, and the casting chamber is connected to a low vacuum system with a vacuum level lower than that of the high vacuum system.

[0009] Furthermore, the cast heater includes a heater insulation frame, and at least two independently temperature-controlled heating zones are provided within the heater insulation frame.

[0010] Furthermore, the opening area at the bottom of the cast heater accounts for 50% to 85% of its horizontal projected area.

[0011] Furthermore, the isolation valve is a water-cooled isolation valve.

[0012] Furthermore, the first driving mechanism is a mold pulling mechanism, and the second driving mechanism is a mold translation mechanism.

[0013] Furthermore, the at least two heating zones include an upper heating element and a lower heating element.

[0014] Compared with the prior art, this utility model has the following advantages.

[0015] This invention relates to the production of single-crystal blades for power machinery such as aero-engines and gas turbines. It adopts a horizontal layout and continuous design. The melting chamber is mainly used for secondary melting of the master alloy, master alloy feeding and temperature measurement, mold heating, mold pouring, and mold pulling; the mold chamber is mainly used for mold shell entry and exit. To ensure the precision casting process described above, this invention is equipped with necessary devices such as a water-cooled isolation valve, a high-vacuum system, a low-vacuum system, and a liquid metal pot. Compared with the traditional HRS method single-crystal furnace, it has advantages such as a large temperature gradient and fast crystal pulling speed, making it particularly suitable for the production of single-crystal blades for aero-engines and gas turbines.

[0016] The liquid metal cooling method single crystal furnace involved in this invention can achieve a temperature gradient of 70-80℃ / cm, a pulling speed of 10-20mm / min, and the characteristics of being independent of the temperature gradient and blade height, which can solve the shortcomings of the traditional HRS method for preparing single crystal blades. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The scope of protection of the present invention is not limited to the following description.

[0018] Figure 1 This is a simplified structural diagram of a single-crystal furnace based on a liquid metal cooling method.

[0019] Figure 2 This is a front view of a single-crystal furnace casting heater based on a liquid metal cooling method.

[0020] Figure 3 This is a side view of a single-crystal furnace casting heater based on a liquid metal cooling method.

[0021] In the diagram, 1. Melting chamber; 2. Casting chamber; 3. Feeding mechanism; 4. Temperature measuring mechanism; 5. Melting coil; 6. Casting heater; 601. Heater insulation frame; 602. Heater front door; 603. Upper zone heating element; 604. Lower zone heating element; 1101. Mold shell moving support; 1102. Mold shell; 7. Casting mold pulling mechanism; 8. Water-cooled isolation valve; 9. Liquid metal pot; 10. Casting mold translation mechanism; 11. Casting mold; 12. High vacuum system; 13. Low vacuum system; 14. Casting chamber door. Detailed Implementation

[0022] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0023] The terminology used in the embodiments of this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The singular forms “a,” “the,” and “the” as used in the embodiments of this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0024] Depending on the context, words such as “if” or “suppose” used here can be interpreted as “when”, “in response to determination”, or “in response to detection”.

[0025] For ease of understanding, the embodiments of this disclosure will be described in detail first.

[0026] like Figure 1 As shown in the specific embodiment: A single crystal furnace based on liquid metal cooling method includes a melting chamber 1, a casting chamber 2, a casting heater 6, and a liquid metal cooling device: a melting coil 5 for melting the master alloy is provided in the melting chamber 1; the casting chamber 2 is arranged horizontally side by side with the melting chamber 1, and a channel for the entry and exit of the casting mold 11 is provided on the casting chamber 2; an isolation valve is provided between the melting chamber 1 and the casting chamber 2 to form an openable and closable vacuum isolation between the two; and the isolation valve is a water-cooled isolation valve 8.

[0027] The mold heater 6 is located inside the melting chamber 1; the liquid metal cooling device is located below the mold heater 6 and is used to force-cool the mold 11 removed from the mold heater 6.

[0028] Preferably, the liquid metal cooling device includes a liquid metal pot 9 containing liquid metal coolant, and the bottom of the mold heater 6 has an opening for immersing the mold 11 into the liquid metal pot 9.

[0029] Preferably, the melting chamber 1 is provided with a first driving mechanism for moving the mold 11 between the mold heater 6 and the liquid metal cooling device. The single crystal furnace is also provided with a second driving mechanism for moving the mold 11 between the mold chamber 2 and the melting chamber 1. The first driving mechanism is a mold pulling mechanism 7, and the second driving mechanism is a mold translation mechanism 10. The mold pulling mechanism 7 and the mold translation mechanism 10 are conventional structures in the art and are not the inventive point of this utility model, and will not be described in detail here.

[0030] Preferably, the melting chamber 1 is connected to a high vacuum system 12, and the casting chamber 2 is connected to a low vacuum system 13 with a vacuum level lower than that of the high vacuum system 12.

[0031] Preferably, the cast heater 6 includes a heater insulation frame 601, and at least two independently temperature-controlled heating zones are provided within the heater insulation frame 601.

[0032] Preferably, the opening area at the bottom of the cast heater 6 accounts for 50% to 85% of its horizontal projected area.

[0033] Preferably, at least two heating zones include an upper heating element 603 and a lower heating element 604.

[0034] Example 1: The melting chamber 1 is also equipped with a feeding mechanism 3 for adding materials to the melting coil 5 and a temperature measuring mechanism 4 for monitoring the melting temperature.

[0035] Example 2: A casting chamber door 14 is provided on the casting chamber 2 for the entry and exit of the casting mold 11.

[0036] like Figure 2 and Figure 3As shown, the heater consists of a heater insulation frame 601, a heater front door 602, an upper heating element 603, and a lower heating element 604, forming the mold heater. The upper heating element 603 and lower heating element 604 are used to ensure independent temperature control, thus guaranteeing a higher temperature gradient for the mold shell 1102 during the drawing process. The mold shell 1102 is hung on the mold shell moving bracket 1101, together forming the mold 11. The mold shell moving bracket is made of high-temperature resistant material and is a reusable component. The mold shell 1102 is a necessary disposable component in the single-crystal blade casting process. Before the mold 11 enters the heater, the heater front door 602 is opened. This door is also made of insulation material and can be rotated or moved. After the mold 11 enters the heater, the heater front door 602 closes to ensure that the heater 6 does not lose temperature.

[0037] A liquid metal pot 9 is positioned directly below the mold heater 6. The liquid metal pot 9 contains the metal to be heated, typically a low-melting-point metal such as aluminum or tin. The metal in the liquid metal pot 9 is heated through a square opening directly below the mold heater 6, eliminating the need for a separate metal heating mechanism. Since the mold 11 needs to be immersed in the liquid metal during the drawing process, an opening is necessary directly below the mold heater 6. This opening must be slightly larger than the projected dimensions of the mold shell 1102. Based on past experience, the size of this opening is approximately 2 / 3 of the projected area of ​​the mold heater 6. This area will radiate heat from the mold heater 6 into the liquid metal pot 9, thus heating the metal. In summary, the metal in the liquid metal pot 9 can be heated without additional complex mechanisms. The biggest advantage of this structure is its simplification of the liquid metal pot 9's structure, which is highly beneficial to the overall reliability of the equipment.

[0038] The specific working process of this utility model is as follows: 1. The mold shell 11 enters the casting chamber 2 through the casting chamber door 14. At this time, the water-cooled isolation valve 8 is closed, the melting chamber 1 is in a vacuum state, and the casting chamber vacuum system 13 works to pump to the specified vacuum degree (5-10Pa).

[0039] 2. The water-cooled isolation valve 8 is opened, and the mold shell 11 is transferred by the mold pulling mechanism 7 to the mold heater 6 in the melting chamber 1.

[0040] 3. The feeding process of the melting coil 5 is completed by the feeding mechanism 3. After the melting coil 5 melts the metal and the temperature is measured by the temperature measuring mechanism 4, the melting coil 5 pours the mold shell 11 into the casting heater 6.

[0041] 4. After casting is completed, the mold shell 11 is pulled into the liquid metal pot 9 by the casting mold pulling mechanism 7 and the liquid metal cooling (solidification) process is completed.

[0042] 5. During the solidification process of the metal inside the mold shell 11, the mold shell 11 is transferred to the mold heater 6 by the mold pulling mechanism 7, and then the mold shell 11 is transferred to the casting chamber 2 by the mold pulling mechanism 7.

[0043] 6. The water-cooled isolation valve 8 is closed, separating the melting chamber 1 from the casting chamber 2. After the mold shell 11 cools to below the specified temperature, the vacuum in the casting chamber 2 is broken, the casting chamber door 14 is opened, the mold shell 11 is taken out, and one production cycle is completed.

[0044] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "preferred embodiment," "detailed description," or "preferred embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0045] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Therefore, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope defined by the claims of this utility model.

Claims

1. A single crystal furnace based on liquid metal cooling, comprising a melting chamber (1), a casting chamber (2), a casting heater (6), and a liquid metal cooling device: characterized in that, The melting chamber (1) is equipped with a melting coil (5) for melting the master alloy. The casting chamber (2) and the melting chamber (1) are arranged horizontally side by side, and the casting chamber (2) is provided with a channel for the entry and exit of the casting mold (11); an isolation valve is provided between the melting chamber (1) and the casting chamber (2) to form an openable and closable vacuum isolation between the two. The mold heater (6) is located inside the melting chamber (1); The liquid metal cooling device is located below the mold heater (6) and is used to forcibly cool the mold (11) removed from the mold heater (6).

2. The single crystal furnace based on liquid metal cooling method according to claim 1, characterized in that, The liquid metal cooling device includes a liquid metal pot (9) containing liquid metal coolant, and the bottom of the mold heater (6) has an opening for the mold (11) to be immersed in the liquid metal pot (9).

3. A single crystal furnace based on liquid metal cooling method according to claim 1, characterized in that, The melting chamber (1) is provided with a first drive mechanism for driving the mold (11) to move between the mold heater (6) and the liquid metal cooling device.

4. A single crystal furnace based on liquid metal cooling method according to claim 3, characterized in that, The single crystal furnace is also provided with a second driving mechanism for driving the mold (11) to move between the mold chamber (2) and the melting chamber (1).

5. A single crystal furnace based on liquid metal cooling method according to claim 1, characterized in that, The melting chamber (1) is connected to a high vacuum system (12), and the casting chamber (2) is connected to a low vacuum system (13) with a vacuum level lower than that of the high vacuum system (12).

6. A single crystal furnace based on liquid metal cooling method according to claim 1, characterized in that, The cast heater (6) includes a heater insulation frame (601), and at least two independently temperature-controlled heating zones are provided inside the heater insulation frame (601).

7. A single crystal furnace based on liquid metal cooling method according to claim 2, characterized in that, The opening area at the bottom of the cast heater (6) accounts for 50% to 85% of its horizontal projected area.

8. A single crystal furnace based on liquid metal cooling method according to claim 1, characterized in that, The isolation valve is a water-cooled isolation valve (8).

9. A single crystal furnace based on liquid metal cooling method according to claim 4, characterized in that, The first driving mechanism is a mold pulling mechanism (7), and the second driving mechanism is a mold translation mechanism (10).

10. A single crystal furnace based on liquid metal cooling method according to claim 6, characterized in that, The at least two heating zones include an upper heating element (603) and a lower heating element (604).

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