CN102071469A - Directional solidification device with traveling-wave magnetic field generator - Google Patents

Abstract

A directional solidification device with a traveling wave magnetic field generator comprises a cooling device, a high frequency induction heating device, a pulling device, a high frequency induction heating power supply, a traveling wave magnetic field generator and a traveling wave magnetic field variable frequency power supply. The traveling wave magnetic field generator, the traveling wave magnetic field coil cooling box in the cooling device and the high frequency induction heating device are all located in the vacuum chamber. The pulling device is located at the center of the bottom of the vacuum chamber. The traveling wave magnetic field generator is located in the cooling box of the traveling wave magnetic field coil. The three traveling wave magnetic field coils are respectively installed on the three-layer coil baffles on the coil frame. The radiation heat insulation baffle in the high frequency induction heating device is located at the center of the gap between the adjacent surfaces of the two traveling wave magnetic field coils under the coil frame. There is a vacuum pump connection port on the side wall of the vacuum chamber; there is an installation hole for the water-cooled crystallizer of the drawing device in the center of the bottom of the vacuum chamber. The invention can feed a large current to study the influence of a stronger magnetic field on the crystal growth process of easily oxidized alloys, higher melting point alloys and even high melting point alloys under vacuum conditions.

Description

A directional solidification device with a traveling wave magnetic field generator

technical field

The invention relates to a magnetic field device, which is mainly used in crystal growth.

Background technique

Electromagnetism is widely used in production and practice, especially in material processing engineering. The reason why electromagnetism can be widely used and developed in the forming process of various materials is that, on the one hand, molten metal is a good conductor of electricity, which can generate electromagnetic force through the action of magnetic field and current, and conduct non-contact to molten metal. Stirring, conveying and shape control can achieve more favorable effects than mechanical means; on the other hand, it can reduce pollution, improve the environment and improve product quality.

A traveling magnetic field (TMF) is a time-varying moving magnetic field produced by a multi-turn coil fed with a three-phase alternating current. The Lorentz force generated by the traveling wave magnetic field directly causes the conductive melt to flow in a symmetrical meridian direction throughout the sample, which is beneficial to control the temperature field and concentration field in the melt. In the past ten years, people's research on traveling wave magnetic field has mainly focused on the stability of traveling wave magnetic field on melt flow, crystal growth interface morphology, solute distribution, casting filling ability and purification effect, etc. The flow stability, solute distribution and growth interface morphology during the crystal growth process are closely related to the solidification structure, and the meridian flow caused by the traveling wave magnetic field may be beneficial to the stability of the melt flow at the front of the solidification interface, the smoothness of the growth interface and the formation of solutes. Uniform distribution may also promote the stable to unstable transition of the melt flow at the front of the solidification interface and affect the unevenness of the growth interface and solute segregation. Therefore, it is very important to study the influence of the traveling wave magnetic field on these aspects during the crystal growth process.

The prerequisite for the experiment of studying the traveling wave magnetic field is to design a traveling wave magnetic field generator. The biggest difficulty in the design of this device is its heat dissipation. It is necessary to rationally design a traveling wave magnetic field generator. At present, there are mainly two types of traveling wave magnetic field generators in the form of flat plate and cylindrical shape at home and abroad. The planar traveling wave magnetic field generator is mainly used in the filling of aluminum alloy, and the cylindrical traveling wave magnetic field generator is mainly used in the crystal growth under vertical gradient solidification (VGF). Among them, the planar traveling-wave magnetic field generator is a linear motor composed of three-phase, 4-level, 24-slot double-layer short-distance non-compensated stacked windings, and the cylindrical traveling-wave magnetic field generator is composed of six-turn coils arranged vertically.

However, the planar traveling wave magnetic field generator is usually used for aluminum alloy filling, the coil current is small, and the service time should not be too long. It is mainly used in an atmospheric environment and requires fan cooling. The current in the coil of the cylindrical traveling wave magnetic field generator is small, and the magnetic field generated is small (B _max ≈ 3.4mT). It is mainly used in the research of extremely low melting point alloys (GaInSn, etc.) in the atmospheric environment.

Contents of the invention

In order to overcome the deficiencies in the research of low generator current, weak magnetic field and extremely low melting point alloys in the atmosphere, the invention proposes a directional solidification device with a traveling wave magnetic field generator.

The invention includes a cooling device, a high-frequency induction heating device, a drawing device, a vacuum pump connection port and a high-frequency induction heating power supply, and is characterized in that it also includes a traveling wave magnetic field generator and a traveling wave magnetic field variable frequency power supply. Wherein, the traveling wave magnetic field generator, the traveling wave magnetic field coil cooling box in the cooling device and the high frequency induction heating device are all located in the vacuum chamber; the pulling device is located at the center of the bottom of the vacuum chamber. The traveling wave magnetic field generator is located in the cooling box of the traveling wave magnetic field coil; the traveling wave magnetic field generator includes three traveling wave magnetic field coils and a coil frame; the three traveling wave magnetic field coils are respectively installed on the three-layer coil baffle on the coil frame, And the distance between adjacent traveling wave magnetic field coils is 54~72mm; the frequency range of traveling wave magnetic field variable frequency power supply is 50~600Hz; the number of turns of each traveling wave magnetic field coil is 30~180 turns; each traveling wave magnetic field coil The cross-sectional shape is square, and the current is 5-60A; the magnetic field strength of the three traveling-wave magnetic field coils is 1-42.5mT. The high-frequency induction heating device is located in the inner hole of the annular traveling wave magnetic field coil cooling box, and is set on the ceramic tube of the drawing device; the radiation heat insulation baffle in the high-frequency induction heating device is located in the two traveling wave At the center of the gap between adjacent surfaces of the field coil. There is a vacuum pump connection port on the side wall of the vacuum chamber; there is an installation hole for the water-cooled crystallizer of the drawing device in the center of the bottom of the vacuum chamber.

The coil frame includes 4 screw rods, 12 coil baffles and 1 annular bottom ring. Wherein, the outer circular surface of the screw rod has threads. There is a connection hole at one end of the coil baffle, and the diameter of the connection hole is equal to the outer diameter of the screw rod. The bottom ring is annular, the outer diameter is smaller than the inner diameter of the outer wall and larger than the outer diameter of the traveling wave magnetic field coil, and the inner diameter is larger than the outer diameter of the inner wall. Four screw mounting holes are evenly and symmetrically distributed on the circumference of the surface edge of the bottom ring, and one end of the 4 screw rods is fixed in the screw mounting holes; 12 coil baffles are divided into three layers, and are uniformly distributed along the axial direction of the screw rods. Distributed and set on each screw rod, and the four coil baffles of each layer are at the same height; the coil baffles are fixed on each screw rod by nuts to form a coil frame.

The cooling device includes a traveling wave magnetic field coil cooling box, a cooling oil tank and a gear oil pump; the traveling wave magnetic field coil cooling box is a circular cylinder, which consists of a circular bottom plate, a circular inner wall, a circular outer wall, an oil inlet pipe, and a traveling wave magnetic field coil. The cooling box cover and the oil outlet pipe are composed; the inner wall and the outer wall are respectively welded on the inner edge and the outer edge of the bottom plate surface to form a ring-shaped cylinder, which is used to place the traveling wave magnetic field generator and the transformer oil for cooling; the ring-shaped The cooling box cover of the traveling wave magnetic field coil is fixed on the flange of the open end of the traveling wave magnetic field coil cooling box; there is an oil outlet pipe on the cooling box cover of the traveling wave magnetic field coil; between the inner wall and the traveling wave magnetic field coil, and between the outer wall and the traveling wave magnetic field coil There is a circulating flow path for transformer oil between them; there is an installation hole for the oil inlet pipe at the bottom of the outer wall; on one side of the outer wall is arranged a via hole for wiring of the traveling wave magnetic field coil.

The cooling oil tank has a sandwich structure with an inner layer and an outer layer; the inner layer of the cooling oil tank is used to hold transformer oil; there are inlets and outlets for transformer oil at both ends of the inner layer of the cooling oil tank; There is a circulating cooling water passage between the inner layer and the outer layer; the circulating cooling water passage between the inner layer and the outer layer of the cooling oil tank is sealed; a cooling water pipe is also arranged in the small box of the cooling oil tank; the two ends of the cooling water pipe are respectively Welded on the through holes on the end plates at both ends of the small box body, the cooling water pipes in the small box body are all communicated with the circulating cooling water passage between the inner layer and the outer layer of the cooling oil tank.

When installing:

Insert the four screw rods into the four round holes of the bottom ring respectively, and fix them with nuts and washers so that the bottom ring is at the bottom of the coil frame. Place the four coil baffles on the screw, close to the bottom ring, the square ends of the coil baffles point to the center of the coil frame, and fix them with nuts and washers, place the first traveling wave on the bottom coil baffle magnetic field coil. Install the second layer of coil baffle and the second traveling wave magnetic field coil and the third layer of coil baffle and the third traveling wave magnetic field coil in the same way on the upper part of the screw to form a traveling wave magnetic field generator, three The traveling wave magnetic field coils are vertically arranged, and the coil spacing d=54mm. The three traveling wave magnetic field coils are connected in a star connection mode and the traveling wave magnetic field generator is installed in the cooling box of the traveling wave magnetic field coil. Connect the 4 wires of the traveling wave magnetic field generator from the 4 adjacent round holes at the height of 9/10 on one side of the outer wall, wrap a layer of insulating tape on the outer skin of the wires at the round holes, and use a ring The epoxy resin fixes and seals the wiring at the 4 round holes. Put the fluorine rubber O-ring seal coated with high vacuum silicone grease into the groove of the cooling box cover of the traveling wave magnetic field coil, the box body and the box cover of the traveling wave magnetic field coil cooling box are connected in the form of flanges, and the oil inlet pipe and The oil pipes are distributed on both sides of the central axis. Put the traveling wave magnetic field coil cooling box equipped with the traveling wave magnetic field generator into the vacuum chamber, and ensure that the radiation heat insulation baffle is in the center of the gap between the two adjacent traveling wave magnetic field coils below, and the coil wiring passes through the round hole on the outer wall It is connected with the terminal post on the wall on one side of the vacuum chamber, and the terminal post is connected with the traveling wave magnetic field frequency conversion power supply outside the vacuum chamber. The oil inlet pipe in the cooling device is connected with the oil outlet of the gear oil pump through a pipeline, and the interface is sealed. The oil inlet pipe of the gear oil pump is connected with the oil outlet of the cooling oil tank through a pipeline, and the oil outlet pipe is connected with the oil inlet of the cooling oil tank 1 through a pipeline, and the interface is sealed.

The radiation heat insulation baffle is placed on the water-cooled crystallizer storing liquid metal for cooling, and the high-frequency induction heating coil is installed so that the lower end surface of the high-frequency induction heating coil is closely attached to the radiation heat insulation baffle. Pass the ceramic tube filled with metal materials through the central hole of the radiation heat insulation baffle and connect it with the pull-down device, place the graphite heating body and the heat preservation cover on the radiation heat insulation baffle, and make the high frequency induction heating coil and heat preservation cover There is a gap between them, there is a gap between the insulation cover and the graphite heating body, and there is a gap between the graphite heating body and the ceramic tube. The cooling box of the traveling wave magnetic field coil, the traveling wave magnetic field generator, the high-frequency induction heating device, the ceramic tube, the water-cooled crystallizer and the pull-down system are coaxial, and the above components are placed together in a vacuum chamber.

The invention arranges three traveling wave magnetic field coils vertically and cools them with circulating transformer oil, and the circulating transformer oil smoothly takes away the heat generated after the traveling wave magnetic field coils are energized and the radiant heat of the graphite heating body. At the same time, the graphite heating body shields the magnetic field of the high-frequency induction heating coil, while the low-frequency traveling wave magnetic field can pass through smoothly. The CT-3 Tesla meter is used to measure the magnetic field. The central part of the device can obtain a traveling wave magnetic field with a B _max of 42.5mT, and this magnetic field has an effect on the directional solidification process of the metal melt in the ceramic tube, and can be studied The effect of strong traveling wave magnetic field under vacuum condition on the crystal growth process of easily oxidized alloys, higher melting point alloys and even high melting point alloys.

Compared with natural convection, which only transports solute in the mushy region, the symmetrical meridian flow caused by the traveling wave magnetic field can make the solute transport throughout the sample. This flow is beneficial to control the distribution of solute and temperature. The direction of the meridian flow is determined by the coil. The phase sequence of the medium current is determined. Using the present invention, a preliminary experiment was carried out on a Sn-0.65Cd alloy with a diameter of 4mm, wherein the temperature gradient G=109k/cm, and the pulling rate V=4μm/s. When B=0mT, as shown in Figure 10(a), the natural convection in the sample leads to uneven distribution of solute and temperature, making the sample interface weakly uneven. When the phase sequence of the current passing into the three coils 4 is b/a/c and B=3.2mT, I=10A, as shown in Figure 10(b), due to the meridian flow and natural convection generated by the traveling wave magnetic field , the solute distribution in the radial direction is uniform, the solute at the front of the interface is less, the solidification interface is a flat interface, and the entire solidification interface is relatively flat. When the phase sequence of the current passing through the three coils 4 is a/b/c and B=3.2mT, I=10A, as shown in Figure 10(c), the meridian flow and phase sequence produced by the traveling wave magnetic field are b The direction of the meridian flow generated during /a/c is opposite. After the meridian flow interacts with natural convection, there are more solutes at the front of the interface, resulting in a cellular interface, and the radial solute distribution is uneven, resulting in uneven solidification interface.

In addition, in order to detect whether the invention can be applied to the research of superalloys, the DZ125 superalloy with a melting point of about 1350° C. is taken as the research object, and a directional solidification experiment is carried out under the present invention. The magnetic field B=10.3mT, I=40A, heating And the draw time is kept at 5 hours. As shown in Figure 11, the maximum temperature of the oil entering the cooling oil tank reaches 57°C, the temperature of the transformer oil pumped out by the gear oil pump after being cooled by the slender cooling oil tank is 36°C, and the flash point of 25# transformer oil is 168°C , so the maximum oil temperature of 57°C is a safe temperature, that is, the present invention can be applied to the research of superalloys.

Description of drawings

Fig. 1 is the structural representation of the directional solidification device with traveling wave magnetic field generator;

Fig. 2 is the front view of traveling wave magnetic field generator;

Fig. 3 is the top view of traveling wave magnetic field generator;

Fig. 4 is a connection diagram of a traveling wave magnetic field coil and a traveling wave magnetic field variable frequency power supply;

Fig. 5 is the front view of the traveling wave magnetic field coil cooling box;

Fig. 6 is the top view of traveling wave magnetic field coil cooling box;

Fig. 7 is the left side view of traveling wave magnetic field coil cooling box;

Figure 8 is a top view of the cooling oil tank;

Fig. 9 is a left side view of the cooling oil tank;

Figure 10 is the macrostructure of the solidification interface under different conditions; wherein: a. natural convection, b.B=3.2mT(b/a/c), c.B=3.2mT(a/b/c);

Fig. 11 is the cooling effect of the present invention (research object is DZ125 superalloy, B=10.3mT)

1. Cooling oil tank 2. Gear oil pump 3. Oil inlet pipe 4. Traveling wave magnetic field coil 5. Screw rod 6. Vacuum pump connection port 7. Sealing ring 8. High frequency induction heating coil 9. Insulation cover 10. Graphite heating body 11. Ceramics Tube 12. Traveling wave magnetic field coil cooling box cover 13. Oil outlet pipe 14. High frequency induction heating power supply 15. Traveling wave magnetic field coil cooling box 16. Coil baffle 17. Vacuum chamber 18. Bottom ring 19. Radiation heat insulation baffle 20 .Liquid metal for cooling 21. Water-cooled crystallizer 22. Pull-down device 23. Outer wall 24. Inner wall 25. Bottom plate 26. Traveling wave magnetic field frequency conversion power supply

Detailed ways

This embodiment relates to a Bridgman directional solidification device with a traveling wave magnetic field generator. The frequency of the high-frequency induction heating power supply 14 of the directional solidification device is 200KHz.

This embodiment includes a traveling wave magnetic field generator, a cooling device, a high frequency induction heating device, a drawing device, a vacuum pump connection port 6 , a high frequency induction heating power supply 14 and a traveling wave magnetic field variable frequency power supply 26 . Wherein, the traveling wave magnetic field generator, the traveling wave magnetic field coil cooling box 15 in the cooling device and the high frequency induction heating device are all located in the vacuum chamber 17 . The traveling wave magnetic field generator comprises three traveling wave magnetic field coils 4 and a coil frame; the three traveling wave magnetic field coils 4 are installed on the three-layer coil baffle plate 16 on the coil frame respectively; Inside box 15. The high-frequency induction heating device is located in the inner hole of the annular traveling-wave magnetic field coil cooling box 15, and is set on the ceramic tube 11 of the drawing device; the radiation heat insulation baffle 19 in the high-frequency induction heating device is located at two The center of the gap between the adjacent surfaces of each traveling wave magnetic field coil 4. The high-frequency induction heating device is connected to the high-frequency induction heating power supply 14 through wires; the wiring between the traveling wave magnetic field coil and the traveling wave magnetic field variable frequency power supply 26 is connected in a star connection. A vacuum pump connection port 6 is arranged on a side wall of the vacuum chamber 17; an installation hole of a water-cooled crystallizer 21 of a drawing device is arranged at the bottom center of the vacuum chamber. The drawing device consisting of the ceramic tube 11 , the water-cooled crystallizer 21 and the drawing device 22 is located at the center of the bottom of the vacuum chamber 17 .

As shown in accompanying drawing 2 and accompanying drawing 3, traveling wave magnetic field generator comprises annular traveling wave magnetic field coil 4 and coil former, there are three traveling wave magnetic field coils 4, all use the acetal enamelled copper flat wire ^of 1.8 * 4mm Winding.

In this embodiment, the adjustment of the magnetic field in the directional solidification device under different parameter conditions is realized by adjusting the parameters of the traveling wave magnetic field generator. The parameters of the traveling wave magnetic field generator in the present embodiment are as shown in the table:

Coil turns Coil current (A) Frequency conversion power supply frequency (Hz) Coil spacing (mm) Magnetic field strength (mT) 30 20 100 72 1 70 20 200 63 1.7 104 10 50 54 3.2 104 40 50 54 10.3

145 5 400 63 1.3 145 10 600 72 1.6 180 60 50 54 42.5

In this embodiment, the distance between the traveling wave magnetic field coils 4 refers to the vertical distance between the height centers of adjacent traveling wave magnetic field coils 4 .

As shown in FIG. 4 , the outer diameter of the traveling wave magnetic field coil 4 is smaller than the inner diameter of the outer wall 23 , and the inner diameter of the traveling wave magnetic field coil 4 is larger than the outer diameter of the inner wall 24 . The total height of the coil device is less than the height of the traveling wave magnetic field coil cooling box 15 . The traveling wave magnetic field coil and the traveling wave magnetic field variable frequency power supply 26 are connected in a star connection manner.

The coil frame includes 4 screw rods 5 , 12 coil baffles 16 and 1 annular bottom ring 18 . Wherein, the outer surface of the screw rod 5 is threaded, and the material is austenitic stainless steel. The coil baffle 16 is rectangular, and one end of the coil baffle 16 is an arc edge, and there is a connecting hole at the arc; the inner diameter of the connecting hole is equal to the outer diameter of the screw mandrel 5 . The bottom ring 18 is annular, the outer diameter is smaller than the inner diameter of the outer wall 23 and larger than the outer diameter of the traveling wave magnetic field coil 4 , and the inner diameter is larger than the outer diameter of the inner wall 24 . The installation holes of four screw rods 5 are uniformly and symmetrically distributed on the circumference of the surface edge of the bottom ring 18, and one end of the four screw rods 5 is fixed in the installation holes, thereby stabilizing the whole coil former. Four screw mandrels 5 are symmetrically distributed and fixed on the outer edge of the bottom ring 18 surface. The heights of the four screw rods 5 are all less than the height of the outer wall 23 . The 12 coil baffles 16 are divided into three layers, uniformly distributed along the axial direction of the screw mandrel 5 and fitted on each screw mandrel 5, and the four coil baffles 16 of each layer are at the same height. The coil baffles 16 are fixed on the screw rods 5 by nuts, forming a coil frame.

The cooling device includes a traveling wave magnetic field coil cooling box 15, a cooling oil tank 1, a gear oil pump 2 and connecting pipes. As shown in accompanying drawing 5, Fig. 6 and Fig. 7, traveling wave magnetic field coil cooling box 15 is the circular cylindrical body that has interlayer, is made up of bottom plate 25, inner wall 24, outer wall 23, oil inlet pipe 3, cooling box cover 12, oil outlet pipe 13 and O type sealing ring 7 forms. The bottom plate 25 is an annular plate, the inner diameter of the bottom plate 25 is equal to the inner diameter of the inner wall 24 , and the outer diameter of the bottom plate 25 is equal to the outer diameter of the outer wall 23 . The inner wall 24 and the outer wall 23 are respectively welded on the inner edge and the outer edge of the surface of the bottom plate 25 to form an interlayer for accommodating the traveling wave magnetic field coil device and the transformer oil for cooling. At the open end of the traveling wave magnetic field coil cooling box 15, there is a flange edge protruding to the outside of the casing wall, by which the annular cooling box cover 12 is fixed on the side of the traveling wave magnetic field coil cooling box 15. on the box. An oil outlet pipe 13 is arranged on the cooling box cover 12 . There is a gap between the inner wall 24 and the traveling wave magnetic field coil 4 , and there is a gap between the outer wall 23 and the traveling wave magnetic field coil 4 , through which the circulation of the transformer oil is facilitated. There is an installation hole for the oil inlet pipe 3 at the bottom of the outer wall 23, and the diameter of the installation hole is equal to the outer diameter of the oil inlet pipe 3. The oil inlet pipe 3 is a round pipe with threads at one end. Four via holes are arranged at a height of 9/10 on one side of the outer wall 23 for passing through the four wires of the traveling wave magnetic field coil 4 . The bottom plate 25, the inner wall 24, the outer wall 23, the round hole at the bottom of the outer wall 23 and the oil inlet pipe 3 are seamlessly connected by argon arc welding. The upper surface of the cooling box cover 12 is a plane, and the lower surface has a boss, and the two sides of the boss cooperate with the inner wall 24 and the outer wall 23 respectively, and are embedded between the inner wall 24 and the outer wall 23 . The inner and outer edges of the boss all have installation grooves for O-rings 7 . An oil outlet pipe 13 is arranged on the cooling box cover 12 . The oil outlet pipe 13 is seamlessly connected with the round hole on the cooling box cover 12 by means of argon arc welding. The cooling box cover 12 is connected with the box body in the form of a flange to form a traveling wave magnetic field coil cooling box 15, and the traveling wave magnetic field coil cooling box 15 is all austenitic stainless steel except the sealing ring.

As shown in accompanying drawings 8 and 9, the cooling oil tank 1 is a rectangular sandwich structure made of antirust aluminum, that is, a large box and a small box are nested to form a structure with an inner layer and an outer layer. sandwich structure. The gap between the inner layer and the outer layer of the cooling oil tank 1 is 30mm. The length of the large box is 1200mm, the width is 1/3 times the length, and the height is 1/2 times the length.

The inner casing of the cooling oil tank 1 is used to hold transformer oil; the two ends of the inner casing of the cooling oil tank 1 are respectively provided with an inlet and an outlet of the transformer oil.

Between the inner layer and the outer layer of the cooling oil tank 1 is a circulating cooling water passage, and the two ends of the outer layer of the cooling oil tank 1 have cooling water inlets and outlets respectively. Laths are welded on the circulating cooling water passage between the inner layer and the outer layer of the cooling oil tank 1 to seal the circulating cooling water passage.

Five cooling water pipes are also arranged in the small box of the cooling oil tank 1; the two ends of the cooling water pipes are respectively welded on the through holes on the end plates at both ends of the small box, so that the five cooling water pipes in the small box are all connected with the cooling water pipes. The circulating cooling water passage between the inner layer and the outer layer of the oil tank 1 is communicated. The arrangement of the 5 cooling water pipes is one in the middle and four around.

In the cooling device, the oil inlet pipe 3 is connected to the oil outlet of the gear oil pump 2 through a pipeline, and the interface is sealed with an O-ring. The oil inlet pipe of the gear oil pump 2 is connected to the oil outlet of the cooling oil tank through a pipeline. The oil inlet of the oil tank 1 is connected by a pipeline, and the interface is sealed with an O-ring.

The high-frequency induction heating device includes a high-frequency induction heating coil 8 , a thermal insulation cover 9 , a graphite heating body 10 and a radiation insulation baffle 19 . The high-frequency induction heating coil 10 has three turns. The inner diameter of the high-frequency induction heating coil is greater than the outer diameter of the heat preservation cover; the inner diameter of the heat preservation cover is greater than the outer diameter of the graphite heater.

When installing:

Insert the four screw rods 5 into the four round holes of the bottom ring 18 respectively, and fix them with nuts and washers so that the bottom ring 18 is at the bottom of the bobbin. Place the four coil baffles 16 on the screw rod 5, close to the bottom ring 18, the square ends of the coil baffles 16 point to the center of the coil frame, fix them with nuts and washers, and place them on the bottom coil baffle 16 The first traveling wave magnetic field coil 4 . Install the second layer of coil baffle 16 and the second traveling wave magnetic field coil 4 and the third layer of coil baffle 16 and the third traveling wave magnetic field coil 4 in the same manner on the upper part of the screw mandrel 5 to form a traveling wave magnetic field In the generator, three traveling wave magnetic field coils 4 are vertically arranged, and the distance between adjacent coils is d=54mm. The three traveling wave magnetic field coils 4 are connected in a star connection mode and the traveling wave magnetic field generator is installed in a cooling box 15 for the traveling wave magnetic field coils. Connect the 4 wires of the traveling wave magnetic field generator from the adjacent 4 round holes at the height of 9/10 on one side of the outer wall 23, wrap a layer of insulating tape on the wire sheath at the round holes, and use Epoxy holds and seals the wiring at the 4 round holes. Put the fluorine rubber O-ring 7 coated with high-vacuum silicone grease into the groove of the cooling box cover 12 of the traveling wave magnetic field coil. And oil outlet pipe 13 is distributed in the both sides of central axis. Put the traveling wave magnetic field coil cooling box equipped with the traveling wave magnetic field generator into the vacuum chamber 17, and ensure that the radiation heat insulation baffle 19 is in the center of the gap between the two adjacent traveling wave magnetic field coils 4 below, and the coil wiring passes through The round hole on the outer wall 23 is connected to the terminal on the wall of one side of the vacuum chamber 17 , and the terminal is connected to the traveling wave magnetic field frequency conversion power supply 26 outside the vacuum chamber 17 . In the cooling device, the oil inlet pipe 3 is connected to the oil outlet of the gear oil pump 2 through a pipeline, and the interface is sealed with an O-ring. The oil inlet pipe of the gear oil pump 2 is connected to the oil outlet of the cooling oil tank through a pipeline. The oil inlet of the oil tank 1 is connected by a pipeline, and the interface is sealed with an O-ring.

Place the radiation heat insulation baffle 19 on the water-cooled crystallizer 21 that stores the liquid metal 20 for cooling, and install the high-frequency induction heating coil 8 so that the lower end surface of the high-frequency induction heating coil 8 is in close contact with the radiation heat insulation baffle 19 . The ceramic tube 13 that is equipped with metal material passes through the central hole of the radiation heat insulation baffle 19 and is connected with the pull-down device 22, and the graphite heating body 10 and the thermal insulation cover 9 are placed on the radiation heat insulation baffle 19, so that the high frequency There is a gap between the induction heating coil 8 and the insulation cover 9 , there is a gap between the insulation cover 9 and the graphite heating body 10 , and there is a gap between the graphite heating body 10 and the ceramic tube 11 . The above traveling wave magnetic field coil cooling box, traveling wave magnetic field generator, high frequency induction heating device, ceramic tube 11, water cooling crystallizer 21 and pull-down device 22 are coaxial, and the above components are placed in the vacuum chamber 17 together.

Claims (5)

1. A directional solidification device with a traveling wave magnetic field generator, comprising a cooling device, a high-frequency induction heating device and a drawing device, is characterized in that, also includes a traveling wave magnetic field generator and a traveling wave magnetic field variable frequency power supply (26); in, a. The traveling wave magnetic field generator, the traveling wave magnetic field coil cooling box (15) in the cooling device and the high frequency induction heating device are all located in the vacuum chamber (17); the pulling device is located at the bottom center of the vacuum chamber (17); b. The traveling wave magnetic field generator is located in the traveling wave magnetic field coil cooling box (15); the traveling wave magnetic field generator includes three traveling wave magnetic field coils (4) and coil holders; the three traveling wave magnetic field coils (4) are installed on-line respectively On the three-layer coil baffle plate (16) on the hoop, and the distance between the adjacent traveling wave magnetic field coils (4) is 54～72mm; the frequency range of the traveling wave magnetic field variable frequency power supply (26) is 50-600Hz; The coils of each traveling-wave magnetic field coil (4) are 30-180 turns; the cross-sectional shape of each traveling-wave magnetic field coil (4) is square, and the current is 5-60A; the magnetic field strength of the three traveling-wave magnetic field coils (4) is 1～42.5mT; c. The high-frequency induction heating device is located in the inner hole of the annular traveling wave magnetic field coil cooling box (15), and is set on the ceramic tube (11) of the drawing device; the radiation heat insulation baffle in the high-frequency induction heating device (19) located at the center of the gap between the adjacent surfaces of the two traveling wave magnetic field coils (4) under the coil frame; d. There is a vacuum pump connection port (6) on the side wall of the vacuum chamber (17); there is an installation hole for the water-cooled crystallizer (21) of the drawing device at the bottom center of the vacuum chamber. 2. a kind of directional solidification device that traveling wave magnetic field generator is arranged as claimed in claim 1, is characterized in that, coil former comprises 4 screw mandrels (5), 12 coil baffles (16) and 1 annular The bottom ring (18) of; wherein, screw mandrel (5) outer circle surface has screw thread; One end of coil baffle plate (16) has connecting hole; The diameter of this connecting hole is equal to the outer diameter of screw mandrel (5); Four screw rod installation holes are evenly and symmetrically distributed on the circumference of the surface edge of the bottom ring (18), and one end of the four screw rods (5) is fixed in the screw rod installation holes; the 12 coil baffles (16) are divided into three layers , evenly distributed along the axial direction of the screw rods (5) and fitted on each screw rod (5), and the four coil baffles (16) of each layer are at the same height; the coil baffles (16) Be fixed on each screw mandrel (5), have formed coil frame. 3. a kind of directional solidification device that traveling wave magnetic field generator is arranged as claimed in claim 1, is characterized in that, cooling device comprises traveling wave magnetic field coil cooling box (15), oil cooling tank (1) and gear oil pump (2); The traveling wave magnetic field coil cooling box (15) is an annular cylinder, consisting of a base plate (25), an inner wall (24), an outer wall (23), an oil inlet pipe (3), a traveling wave magnetic field coil cooling box cover (12) and an outlet oil pipe (13); the inner wall (24) and the outer wall (23) are respectively welded on the inner edge and outer edge of the surface of the bottom plate (25) to form a circular cylinder, which is used to place the traveling wave magnetic field generator and cooling Transformer oil; the annular cooling box cover (12) is fixed on the flange edge of the open end of the traveling wave magnetic field coil cooling box (15); the oil outlet pipe (13) is arranged on the traveling wave magnetic field coil cooling box cover 15; the inner wall ( Between 24) and the traveling wave magnetic field coil (4), between the outer wall (23) and the traveling wave magnetic field coil (4), there is a circulating flow path of transformer oil; the bottom of the outer wall (23) has an installation hole for the oil inlet pipe (3); Vias for connecting the traveling wave magnetic field coil (4) are arranged on one side of the outer wall (23). 4. a kind of directional solidification device that traveling wave magnetic field generator is arranged as claimed in claim 1, is characterized in that, cooling oil tank (1) is the sandwich structure that inner layer and outer layer are arranged; The inner layer box of cooling oil tank (1) The body is used to store transformer oil; there are inlets and outlets for transformer oil at both ends of the inner box of the cooling oil tank (1); there is a circulating cooling water passage between the inner layer and the outer layer of the cooling oil tank (1); The circulating cooling water passage between the inner layer and the outer layer of the cooling oil tank (1) is sealed; cooling water pipes are also arranged in the small box of the cooling oil tank (1); the two ends of the cooling water pipes are respectively welded to the two ends of the small box On the through hole on the end plate, the cooling water pipes in the small box are all communicated with the circulating cooling water passage between the inner layer and the outer layer of the cooling oil tank (1). 5. a kind of directional solidification device that traveling wave magnetic field generator is arranged as claimed in claim 2, is characterized in that, bottom ring (18) is annular, and outer diameter is less than the internal diameter of outer wall (23) and is greater than traveling wave magnetic field coil The outer diameter of (4), inner diameter is greater than the outer diameter of inner wall (24).

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