A continuous UHV vertical floating zone melting metal purification system

Abstract

A continuous UHV vertical floating zone melting zone metal purification system can realize the continuous preparation of ultrapure metal and can be applied to industrial production. In particular, by providing an ultra-high vacuum environment for the zone melting, the difference in saturated vapor pressure between the matrix and the impurities can be used to further remove impurities with a higher saturated vapor pressure than the matrix. It is characterized in that it includes a main chamber for performing an ultra-high vacuum zone melting process, a three-dimensional mobile platform is arranged above the main chamber, a multi-axis platform adjustment seat at the lower end of the three-dimensional mobile platform is connected to the upper end clamping assembly of the zone melting metal bar passing through the main chamber cover and entering the main chamber, the right side of the main chamber is connected to the pretreatment chamber through the transmission port flange, the right side of the pretreatment chamber is connected to the magnetic sample feeding rod, the zone melting pre-treatment metal bar clamping claw of the magnetic sample feeding rod is located in the pretreatment chamber, the left side of the main chamber is connected to a cryogenic pump through a plug valve, and the rear side of the main chamber is connected to an induction heating system, and the induction heating system induction coil heats the zone melting metal bar to form a vertical floating zone.

Description

Technical Field

[0001] The invention relates to the technical field of metal purification, in particular to a continuous UHV vertical floating zone melting metal purification system. Background Art

[0002] Zone melting is a method for preparing high-purity materials. It was invented by John Desmond Bernal and further developed by William G. Pfann of Bell Labs. Before zone melting, the raw materials are generally prepared into rod-shaped materials of a certain size, and the raw material rods are fixed vertically in the furnace chamber with two chucks. The raw material rods are partially heated and melted by high-frequency coils, and the molten zone slowly passes through the entire raw material rod from one end to the other to complete the purification. During the entire zone melting process, the molten zone melts the impure solid at its leading edge, and the impurities are concentrated in the melt and moved to one end of the raw material rod, so that the molten zone solidifies after passing through the raw material rod, leaving a purer material. The molten zone is supported by surface tension, so it is often called "suspended zone melting method". This method does not require a crucible, avoids contact between the raw material and the crucible, and the purified material is of high purity. On the other hand, during the zone melting process, the main chamber is evacuated to an ultra-high vacuum state or some gas atmosphere is introduced according to the properties of the purified material to further improve the zone melting effect. In recent years, with the development of technology, some devices have increasingly stringent requirements on the purity of metal materials, especially in the field of semiconductor industry, where the improvement of the purity of raw materials of metal materials often leads to an exponential improvement in device performance. However, the existing regional melting devices have the following disadvantages: lack of a high-precision real-time temperature feedback system, unable to monitor the melting zone temperature and melting zone length of the purified metal sample in the main chamber in real time and dynamically adjust the heating power, which may lead to instability of the melting zone and affect the purification efficiency of the metal; lack of an ultra-high vacuum system, unable to make the air pressure in the main chamber reach an ultra-high vacuum state, and further remove impurities with a saturated vapor pressure higher than that of the matrix by using the saturated vapor pressure difference between the matrix and the impurities; lack of a residual gas analyzer, unable to accurately measure the gas composition in the main chamber, and unable to accurately control the melting atmosphere during regional melting and purification, resulting in unsatisfactory purification effects. Therefore, the present invention provides a continuous UHV vertical floating zone melting metal purification system (UHV, ultra-high vacuum, ultra-high vacuum), which realizes a continuous preparation of ultra-pure metals and can be applied to industrial production. Summary of the invention

[0003] In view of the defects or shortcomings in the prior art, the present invention provides a continuous UHV vertical floating zone melting metal purification system, which can realize the continuous preparation of ultra-pure metals and can be applied to industrial production. In particular, by providing an ultra-high vacuum environment for zone melting, the difference in saturated vapor pressure between the matrix and the impurities can be utilized to further remove impurities with a higher saturated vapor pressure than the matrix.

[0004] The technical solution of the present invention is as follows:

[0005] A continuous UHV vertical floating zone melting zone metal purification system, characterized in that it includes a main chamber for performing an ultra-high vacuum zone melting process, a three-dimensional movable platform is arranged above the main chamber, a multi-axis platform adjustment seat at the lower end of the three-dimensional movable platform is connected to the upper end clamping assembly of the zone melting metal bar, the upper end clamping assembly of the zone melting metal bar passes through the main chamber cover into the main chamber, the right side of the main chamber is connected to the pretreatment chamber through a transmission port flange, the right side of the pretreatment chamber is connected to a magnetic sample feeding rod, the zone melting pre-treatment metal bar claw of the magnetic sample feeding rod is located in the pretreatment chamber, the left side of the main chamber is connected to a low temperature pump through a gate valve, and the rear side of the main chamber is connected to an induction heating system, and the induction heating system heats the zone melting metal bar through an induction coil located in the middle waist of the main chamber to form a vertical floating zone.

[0006] A control button and a control panel are arranged on the front side of the induction heating system, and a cooling port is arranged on the top surface of the induction heating system.

[0007] The cryopump is provided with a cryopump heating wire, and the cryopump is connected to a cryopump transformer.

[0008] A micro-leak valve and a residual gas analyzer interface are arranged on the right side surface of the main chamber, and the residual gas analyzer interface is connected to the residual gas analyzer.

[0009] The main chamber and the pretreatment chamber are respectively connected to a vacuum system, and the vacuum system includes a combination of a mechanical pump and a molecular pump. The vacuum system provides a maximum of 9×10 -5 Pa vacuum, the vacuum system provides the main chamber with a maximum vacuum of 9×10 -8 Pa vacuum, the vacuum system includes a vacuum pump control panel and a molecular pump control panel, the vacuum pump control panel and the molecular pump control panel are both located below the table supporting the pretreatment chamber, and a central controller is arranged on the table.

[0010] The side of the main cavity cover is connected to the main cavity cover lifting device.

[0011] An annular groove formed by the support of a spring sheet is arranged between the upper and lower combined structures of the clamping assembly at the upper end of the zone melting sample, so as to release the thermal expansion caused by the zone melting sample.

[0012] The clamping claw structure of the clamping assembly at the upper end of the zone melting sample comprises a spring sheet device to eliminate the stress acting on the zone melting sample during the process of clamping the zone melting sample up and down.

[0013] The multi-axis platform adjustment seat is respectively connected to the X-axis drive motor, the Z-axis drive motor, the Y-axis drive motor and the rotation drive motor.

[0014] The pretreatment chamber is provided with a high-voltage arc discharge device to perform plasma cleaning on the surface of the metal rod to be melted in the vacuum zone.

[0015] The technical effects of the present invention are as follows: A continuous UHV vertical floating zone melting metal purification system of the present invention can achieve continuous preparation of ultra-pure metals through a combination of an ultra-high vacuum main chamber, a high vacuum pretreatment chamber, a three-dimensional mobile platform, a clamping assembly, an induction heating system and a cryogenic pump, and can be applied to industrial production. In particular, by providing an ultra-high vacuum environment for zone melting, the difference in saturated vapor pressure between the matrix and the impurities can be utilized to further remove impurities with a higher saturated vapor pressure than the matrix. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a continuous UHV vertical floating zone melting metal purification system for implementing the present invention.

[0017] Figure 2 yes Figure 1 Schematic diagram of the three-dimensional mobile platform structure.

[0018] Figure 3 yes Figure 1 Schematic diagram of the magnetic sample feeding rod structure.

[0019] Figure 4 yes Figure 1 Schematic diagram of the main chamber structure.

[0020] Figure 5 yes Figure 2 Schematic diagram of the structure of the upper end clamping assembly of the zone melting metal rod.

[0021] Figure 6 yes Figure 1 Schematic diagram of the vertical floating zone state formed by the induction heating system heating the zone melting iron rod through the induction coil located in the middle waist of the main chamber.

[0022] The accompanying drawings are marked as follows: 1-central controller (display screen); 2-magnetic sample delivery rod; 3-table; 4-baffle; 5-first metal panel; 6-vacuum pump control panel; 7-second metal panel; 8-third metal panel; 9-film thickness control panel; 10-molecular pump control panel; 11-fourth metal panel; 12-fifth metal panel; 13-sixth metal panel; 14-cover plate; 15-cryogenic pump transformer; 16-induction heating system; 17-first control button; 18-second control button; 19-third control button; 20-fourth control button; 21-first control panel; 22-second control panel; 23-first cooling port; 24-second cooling port; 25-cryogenic pump; 26-cryogenic pump heating wire; 27-gate valve; 28-main chamber cover lifting device; 29-support plate; 30-three-dimensional moving platform; 31-main chamber (i.e., ultra-high vacuum zone melting process chamber or UHV zone melting process chamber, UHV, ultra-high vacuum, ultra-high vacuum); 32-reversing rod; 33-micro-leakage valve; 34-pretreatment chamber; 35-rotation drive motor; 36-Z-axis drive motor; 37-X-axis drive motor; 38-Y-axis drive motor; 39-transmission device; 40-zone melting metal rod upper end clamping assembly; 41-zone melting pre-treatment metal rod clamping claw; 42-residual gas analyzer interface; 43-claw structure; 44-annular groove; 45-multi-axis platform adjustment seat. DETAILED DESCRIPTION

[0023] Below is a combination of the embodiments and the accompanying drawings ( Figure 1-Figure 6 ) to illustrate the present invention.

[0024] Figure 1 It is a structural schematic diagram of a continuous UHV vertical floating zone melting metal purification system for implementing the present invention. Figure 2 yes Figure 1 Schematic diagram of the three-dimensional mobile platform structure. Figure 3 yes Figure 1 Schematic diagram of the magnetic sample feeding rod structure. Figure 4 yes Figure 1 Schematic diagram of the main chamber structure. Figure 5 yes Figure 2 Schematic diagram of the structure of the upper end clamping assembly of the zone melting metal rod. Figure 6 yes Figure 1 Schematic diagram of the vertical floating zone formed by the induction heating system using the induction coil located in the middle of the main chamber to heat the zone melting iron rod. Figures 1 to 6As shown, a continuous UHV vertical floating zone melting zone metal purification system includes a main chamber 31 for performing an ultra-high vacuum zone melting process, a three-dimensional movable platform 30 is arranged above the main chamber 31, a multi-axis platform adjustment seat 45 at the lower end of the three-dimensional movable platform 30 is connected to the upper end clamping assembly 40 of the zone melting metal bar, the upper end clamping assembly 40 of the zone melting metal bar passes through the main chamber cover and enters the main chamber 31, the right side of the main chamber 31 is connected to the pretreatment chamber 34 through the transmission port flange, the right side of the pretreatment chamber 34 is connected to the magnetic sample feeding rod 2, the zone melting pre-treatment metal bar claw 41 of the magnetic sample feeding rod 2 is located in the pretreatment chamber 34, the left side of the main chamber 31 is connected to the cryogenic pump 25 through the gate valve 27, and the rear side of the main chamber 31 is connected to the induction heating system 16, and the induction heating system 16 heats the zone melting metal bar through the induction coil located in the middle waist of the main chamber 31 to form a vertical floating zone.

[0025] The front side of the induction heating system 16 is provided with control buttons and a control panel (including a first control button 17, a second control button 18, a third control button 19, a fourth control button 20, a first control panel 21, a second control panel 22, etc.), and the top surface of the induction heating system 16 is provided with cooling ports (including a first cooling port 23, a second cooling port 24, etc.). The cryopump 25 is provided with a cryopump heating wire 26, and the cryopump 25 is connected to the cryopump transformer 15. The right side of the main chamber 31 is provided with a micro-leakage valve 33 and a residual gas analyzer interface 42, and the residual gas analyzer interface 42 is connected to the residual gas analyzer.

[0026] The main chamber 31 and the pretreatment chamber 34 are respectively connected to a vacuum system, and the vacuum system includes a combination of a mechanical pump and a molecular pump. The vacuum system provides a vacuum of up to 9×10 -5 Pa vacuum, the vacuum system provides the main chamber 31 with a maximum vacuum of 9×10 -8Pa vacuum, the vacuum system includes a vacuum pump control panel 6 and a molecular pump control panel 10, the vacuum pump control panel 6 and the molecular pump control panel 10 are both located below the table 3 supporting the pretreatment chamber 34, and the table is provided with a central controller 1. The side of the main chamber cover is connected to the main chamber cover lifting device 28. An annular groove 44 formed by a spring sheet support is provided between the upper and lower combined structures of the upper end clamping assembly 40 of the zone melting metal bar, which is used to release the thermal expansion caused by the zone melting sample. The claw structure of the upper end clamping assembly 40 of the zone melting metal bar includes a spring sheet device to eliminate the stress acting on the zone melting sample during the upper and lower clamping of the zone melting sample. The multi-axis platform adjustment seat 45 is respectively connected to the X-axis drive motor 37, the Z-axis drive motor 36, the Y-axis drive motor 38 and the rotation drive motor 35. A high-voltage arc discharge device is provided in the pretreatment chamber 34 to perform plasma cleaning on the surface of the zone melting metal bar to be vacuumed.

[0027] A continuous UHV vertical floating zone melting metal purification system. The system includes: a clamping assembly, the clamping assembly is used to clamp the raw material rod in the main chamber; a sample delivery assembly, the sample delivery assembly is used to transfer the rod-shaped material from the pre-evacuated high vacuum chamber to the designated position in the ultra-high vacuum process chamber; an induction heating system, the induction heating system includes an induction heating power supply and an induction heating coil, and the induction coil is internally circulated with cooling water; an ultra-high vacuum system, the ultra-high vacuum system is composed of a cryogenic pump, a molecular pump and a mechanical pump; a residual gas analyzer, the residual gas analyzer is arranged in the main chamber; and a central control system, the central control system is electrically connected to the clamping assembly, the induction heating system, the ultra-high vacuum system and the residual gas detector. The ultra-high purity metal prepared by the system is characterized by high purity, controllable process, simple steps and continuous operation, and can be used in industrial production.

[0028] A continuous UHV vertical floating zone melting metal purification system, the system comprises a machine box, the inside of the machine box comprises a vacuum process chamber, a pre-vacuum chamber, a vacuum system, a three-dimensional motion platform, a fixed rod, a magnetic sample delivery rod, an induction heating system, and a central controller, the inside of the vacuum process chamber comprises a clamping assembly, a temperature detection system, and a residual gas analyzer. The three-dimensional motion platform is used to lift the fixed rod, and the clamping assembly is used to clamp rod-shaped materials.

[0029] The vacuum system is a combination of a mechanical pump and a cryogenic pump, which can make the highest vacuum degree in the vacuum process chamber reach 9×10 -8 Pa.

[0030] The vacuum system in the pre-vacuum chamber is a combination of a mechanical pump and a cryogenic pump, and its maximum vacuum degree can reach 9×10 -5 Pa, the pre-vacuum chamber can perform plasma cleaning on the rod-shaped material.

[0031] The clamping assembly comprises a spring sheet device, which can eliminate the stress exerted on the rod-shaped material by the upper and lower clamping devices during the process of clamping the rod-shaped material.

[0032] The fixing rod is located inside the chassis, and both ends of the fixing rod are fixedly connected with the three-dimensional motion platform and the clamping assembly.

[0033] The magnetic sample sending rod is respectively located in the pre-vacuum chamber and the vacuum process chamber. The magnetic sample sending rod in the pre-vacuum chamber can send the rod-shaped material into the vacuum process chamber; the magnetic sample sending rod in the vacuum process chamber can adjust the rod-shaped material from a horizontal state to a vertical state for clamping.

[0034] The temperature detection system is mainly composed of a film thickness meter. The crystal oscillator probe is connected to the film thickness meter and is located in the vacuum process chamber. The crystal oscillator probe is used to measure the deposition rate of the rod-shaped material when it is melted. After multiple experiments to determine the deposition rate when it is melted, the purpose of detecting the temperature can be achieved.

[0035] The induction heating system includes a water cooling circulation system, which is connected to a central controller to circulate cooling water into the interior of the heating coil. The cooling water temperature is controlled and set by the central controller to ensure the stability of the output power of the induction heating coil.

[0036] The three-dimensional motion platform includes a slider, a motor, a bellows and a bearing; the bellows is arranged in the chassis along the vertical direction, the motor is arranged in the chassis, and the bearing is fixed on the inner wall of the vacuum process chamber; the motor transmits power through the output shaft to connect one end of the bellows, and the other end of the bellows is connected to the bearing; a nut is sleeved on the bellows, the nut is fixedly connected to a nut seat, the slider is fixedly connected to the nut seat, and the fixing rod is fixedly connected to the slider.

[0037] Various gas tanks are also provided outside the chassis, and the gas tanks are connected to the vacuum process chamber through air pipes. According to the properties of the rod-shaped material, different gases can be selected to be introduced through the input parameters of the central controller to improve the purification effect.

[0038] The mechanical pump and cryogenic pump of the vacuum system are arranged outside the chassis and are connected to the vacuum process chamber through a vacuum pump; a vent is opened on the inner wall of the vacuum process chamber, and the vent is switched on and off by a plug valve.

[0039] An observation window is provided above the vacuum process chamber.

[0040] The induction heating system is composed of an induction coil and an induction heating host power supply.

[0041] The induction coil extends into the vacuum process chamber to heat the rod-shaped material.

[0042] The induction heating host power supply is used to control the induction heating current and power.

[0043] The residual gas analyzer can detect the gas composition in the vacuum process chamber.

[0044] The central controller is arranged inside the chassis, and the central controller is electrically connected to the three-dimensional motion platform, the temperature detection system, the vacuum system, the supporting component, the induction heating system, the current detection system, and the residual gas analyzer.

[0045] The residual gas analyzer is electrically connected to a computer.

[0046] After the residual gas analyzer detects the gas composition in the vacuum process chamber, the data is fed back to the computer.

[0047] As a further improvement of the continuous UHV vertical floating zone melting metal purification system of the present invention, the three-dimensional motion platform is divided into an upper part and a lower part, which can be displaced in three-dimensional directions respectively for rapid positioning and precise displacement.

[0048] Compared with the prior art, the system of the present invention has the following beneficial effects:

[0049] (1) The film thickness meter probe provided in the main chamber of the vertical zone melting furnace of the present invention can provide feedback on the real-time deposition rate of the rod-shaped material and judge the temperature of the melting zone by the rate, thereby adjusting the power of the induction coil and providing conditions for achieving stability of the melting zone during the zone melting process.

[0050] (2) The ultra-high vacuum system of the vertical zone melting furnace of the present invention makes the pressure in the main chamber reach an ultra-high vacuum state (9×10 -8 Pa), and with minimal substrate loss, the difference in saturated vapor pressure between the substrate and the impurities is used to further remove impurities with higher saturated vapor pressure than the substrate, thereby improving the purification effect.

[0051] (3) The residual gas analyzer of the vertical zone furnace described in the present invention can accurately measure the gas composition in the main chamber, and accurately control the atmosphere during metal rod purification through feedback data, so as to achieve the purpose of removing specific impurities by using a specific gas atmosphere, thereby further improving the purification effect.

[0052] (4) The various systems in the vertical zone furnace of the present invention can adjust parameters to achieve the best purification effect and the highest purification efficiency, with a wide range of applications, strong flexibility, high working efficiency, simple methods, and easy industrialization.

[0053] (5) The ultrapure metal preparation of the present invention adopts the above-mentioned purification device, which can realize vertical zone melting purification of refractory metals and greatly improve the purity of refractory metal samples.

[0054] like Figure 1 As shown, the central controller 1 (display screen): can control the gas valve, air valve, mechanical pump, and vacuum pump. The magnetic sample delivery rod 2: is used to transport the molten sample between the pretreatment chamber and the main chamber. The table 3: is used to place the pretreatment chamber. The baffle 4: is used for decoration. The first metal panel 5: is used for decoration. The vacuum pump control panel 6: controls the parameters of the vacuum pump. The second metal panel 7: is used for decoration. The third metal panel 8: is used for decoration. The film thickness control panel 9: is used to control the film thickness monitoring. The molecular pump control panel 10: is used to control the parameters of the molecular pump. The fourth metal panel 11: is used for decoration. The fifth metal panel 12: is used for decoration. The sixth metal panel 13: is used for decoration. The cover plate 14: is used for decoration. The cryopump transformer 15: is used for the cryopump power supply control. The induction heating system 16: is used to control the current and frequency of the coil. The first control button 17, the second control button 18, the third control button 19, the fourth control button 20, the first control panel 21, and the second control panel 22 are all used for control. The first cooling port 23 and the second cooling port 24 are both used to cool the molten sample fixture. Cryogenic pump 25: used to extract gas from the main chamber. Cryogenic pump heating wire 26: used to restore pump activity. Plug valve 27: controls the switch of the cryogenic pump and the main chamber. Main chamber cover lifting device 28: used to control the lifting and lowering of the main chamber cover. Support plate 29: with bellows inside. Three-dimensional moving platform 30: controls the movement of the molten sample in the main chamber. Main chamber 31 (i.e., ultra-high vacuum zone melting process chamber or UHV zone melting process chamber, UHV, ultra-high vacuum): used for zone melting treatment of the molten sample machine. Reversing rod 32 (located on the front side of the main chamber 31): used to exchange the molten sample with the sample feeding rod in the pretreatment chamber. Micro-leakage valve 33: can control the gas entering the main chamber. 34-Pretreatment chamber: used for pretreatment of molten sample.

[0055] The present invention discloses a continuous UHV vertical floating zone melting metal purification system, which is applied to the purification of 4N grade iron rods. The process includes opening a pretreatment chamber 34 (i.e., a pre-vacuum chamber), placing the 4N grade iron rods in the pretreatment chamber 34, turning on the bias power supply, and cleaning the surface of the 4N grade iron rods by a high-voltage arc. The vacuum system is turned on by the central controller 1, and the gate valve 27 is opened to make the vacuum degree of the pretreatment chamber 34 reach 10 -5 Pa, the sample delivery assembly delivers the 4N grade iron rod to the specified position of the main chamber 31, and the vacuum degree of the main chamber 31 is 10 -5 Pa. The sample delivery assembly in the main chamber 31 clamps the 4N grade iron rod and performs a turn and transposition. The 4N grade iron rod is fixed by the clamping assembly, the gate valve is closed, the vacuum system is turned on, and the vacuum degree of the main chamber 31 is waited to reach 9×10 -8Pa. The induction heating system 16 sets the current range to 40-140A, and sets the vertical moving speed of the three-dimensional mobile platform 30 to 0.1-200mm / min, and the rotation speed to 1-25r / min. Input parameters to manipulate the three-dimensional mobile platform 30 to move the 4N-grade iron rod from the initial position to the set position, repeat the above process according to the set parameters, and perform n vertical zone melting purification in sequence according to different process parameters, where n is a positive integer, for example, n=7. After repeating the above steps n times, the induction heating system 30 is powered off, and after the iron rod after zone melting purification is cooled to room temperature, it is taken out to the pretreatment chamber 34 using the sample delivery assembly, the gate valve is closed, and a protective atmosphere is introduced. After the internal and external air pressures are consistent, the rod-shaped material is taken out, and new rod-shaped material can be loaded for continuous production. The upper and lower preset parts (5% to 15%) of the purified iron rod are cut off, and the remaining part in the middle is the purified product, that is, 5N (iron content 99.995 to 99.9994wt%) or higher N iron rod.

[0056] The contents not described in detail in this specification belong to the prior art known to the professional and technical personnel in this field. It is pointed out here that the above description helps those skilled in the art to understand the invention, but does not limit the protection scope of the invention. Any equivalent replacement, modification and / or simplification of the above description without departing from the essence of the invention falls within the protection scope of the invention.

Claims

1. A continuous UHV vertical floating zone melting metal purification system, characterized in that: It comprises a main chamber for performing an ultra-high vacuum zone melting process, wherein a three-dimensional moving platform is arranged above the main chamber, a multi-axis platform adjustment seat at the lower end of the three-dimensional moving platform is connected to an upper clamping assembly of a zone melting metal bar, the upper clamping assembly of the zone melting metal bar passes through a main chamber cover and enters into the main chamber, the right side of the main chamber is connected to a pretreatment chamber through a transmission port flange, the right side of the pretreatment chamber is connected to a magnetic sample delivery rod, a zone melting pretreatment metal bar clamping claw of the magnetic sample delivery rod is located in the pretreatment chamber, the left side of the main chamber is connected to a cryogenic pump through a plug valve, and the rear side of the main chamber is connected to an induction heating system, and the induction heating system heats the zone melting metal bar through an induction coil located in the middle of the main chamber to form a vertical floating zone; The main chamber and the pretreatment chamber are respectively connected to a vacuum system, and the vacuum system includes a combination of a mechanical pump and a molecular pump. The vacuum system provides a maximum of 9×10 -5 Pa vacuum, the vacuum system provides the main chamber with a maximum vacuum of 9×10 -8 Pa of vacuum.

2. The continuous UHV vertical floating zone melting metal purification system according to claim 1, characterized in that: A control button and a control panel are arranged on the front side of the induction heating system, and a cooling port is arranged on the top surface of the induction heating system.

3. The continuous UHV vertical floating zone melting metal purification system according to claim 1, characterized in that: The cryopump is provided with a cryopump heating wire, and the cryopump is connected to a cryopump transformer.

4. The continuous UHV vertical floating zone melting metal purification system according to claim 1, characterized in that: A micro-leak valve and a residual gas analyzer interface are arranged on the right side surface of the main chamber, and the residual gas analyzer interface is connected to the residual gas analyzer.

5. The continuous UHV vertical floating zone melting metal purification system according to claim 1, characterized in that: The vacuum system comprises a vacuum pump control panel and a molecular pump control panel, both of which are located below a table that carries the pretreatment chamber, and a central controller is arranged on the table.

6. The continuous UHV vertical floating zone melting metal purification system according to claim 1, characterized in that: The side of the main cavity cover is connected to the main cavity cover lifting device.

7. The continuous UHV vertical floating zone melting metal purification system according to claim 1, characterized in that: An annular groove formed by the support of a spring sheet is arranged between the upper and lower combined structures of the zone melting metal bar upper end clamping assembly to release the thermal expansion caused by the zone melting sample.

8. The continuous UHV vertical floating zone melting metal purification system according to claim 1, characterized in that: The clamping claw structure of the upper end clamping assembly of the zone melting metal bar includes a spring sheet device to eliminate the stress acting on the zone melting sample during the process of clamping the zone melting sample up and down.

9. The continuous UHV vertical floating zone melting metal purification system according to claim 1, characterized in that: The multi-axis platform adjustment seat is respectively connected to the X-axis drive motor, the Z-axis drive motor, the Y-axis drive motor and the rotation drive motor.

10. The continuous UHV vertical floating zone melting metal purification system according to claim 1, characterized in that: The pretreatment chamber is provided with a high-voltage arc discharge device to perform plasma cleaning on the surface of the metal rod to be melted in the vacuum zone.

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