Arc heating method and device

Abstract

The present invention relates to the field of electric arc heating technology, and in particular, to an electric arc heating method and device for heating a substrate formed by pressing and / or sintering powder. The electric arc heating method comprises: configuring a metal electrode to be in contact with the substrate, the melting point of the metal electrode being higher than the target heating temperature; in a vacuum environment, bombarding the side of the metal electrode away from the substrate by electric arc bombardment to heat the metal electrode; and heating the substrate by heat conduction through the metal electrode. The electric arc heating method and device for a substrate formed by pressing and / or sintering powder of the present invention utilizes the high-density and high-temperature-resistant characteristics of the cathode of the arc generator to enable it to be heated by electric arc. Under the bombardment of large current, the metal electrode will not be cracked or damaged, and the high temperature generated can be indirectly heated to the substrate formed by pressing or sintering powder by contact conduction, thereby ensuring the service life of the heated substrate.

Description

Technical Field

[0001] The present invention relates to the technical field of electric arc heating, and in particular to an electric arc heating method and device for heating a matrix formed by pressing and / or sintering powder. Background Art

[0002] Heating refers to the process of transferring heat energy from a heat source to a colder object to make it hot. It is a common operation method in life and production. Heating methods can generally be divided into two categories: direct heating and indirect heating. The existing heating methods mainly include arc discharge heating, current direct heating and microwave heating. Among them, the current direct heating method has low heat energy conversion efficiency, the microwave heating structure is too complicated, and the microwave equipment is easily damaged at high temperatures. Therefore, the arc discharge heating method is more popular.

[0003] Many existing heated objects are manufactured by pressing or sintering powder or granular materials. Although the internal porosity is reduced after pressing or sintering, forming a dense structure with high mechanical energy, for such heated objects, it is found in actual operation that heating by arc heating, under the bombardment of high-energy arc, is likely to cause the matrix formed by pressing and / or sintering powder to be damaged, causing the matrix to crack, break into fragments or particles, resulting in a shortened service life of the heated object. In particular, for such heated objects of larger size, the phenomenon of damage caused by high-energy arc heating is more serious. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an arc heating method and device for a substrate formed by pressing and / or sintering powder.

[0005] A first aspect of the present invention provides an arc heating method.

[0006] According to an embodiment of the present invention, an arc heating method for heating a substrate formed by pressing and / or sintering powders comprises:

[0007] configuring a metal electrode to be in contact with the substrate, wherein the melting point of the metal electrode is higher than the target heating temperature;

[0008] In a vacuum environment, bombarding the side of the metal electrode away from the substrate by electric arc bombardment to heat the metal electrode;

[0009] The substrate is heated by heat conduction through the metal electrodes.

[0010] Furthermore, the matrix includes a matrix sintered from boride powder.

[0011] Furthermore, the boride includes lanthanum hexaboride.

[0012] Furthermore, the material of the metal electrode is tungsten or tungsten alloy.

[0013] Furthermore, the substrate is a rod, the metal electrode is a tube, and the substrate is matched and inserted into the metal electrode.

[0014] A second aspect of the embodiments of the present application provides an arc heating device having a base formed by pressing and / or sintering powder.

[0015] According to an embodiment of the present invention, an arc heating device for heating a substrate formed by pressing and / or sintering powder comprises an arc generator and a vacuum chamber, wherein the anode and cathode of the arc generator are both located in the vacuum chamber, and the cathode is configured to provide thermal energy to the substrate in a heat conduction manner.

[0016] Furthermore, the cathode is attached to the surface of the substrate, and the anode is arranged on a side of the cathode away from the substrate.

[0017] Furthermore, the cathode covers the substrate.

[0018] Furthermore, the substrate is a rod, the cathode is a tube, and the substrate is matched and inserted into the cathode.

[0019] Furthermore, the substrate is a substrate sintered from lanthanum hexaboride powder, and the cathode is made of metal tungsten.

[0020] The arc heating method and device of the present invention for a substrate formed by pressing and / or sintering powder utilizes the high-density and high-temperature-resistant characteristics of the arc generator cathode to enable it to be heated by the arc. Under the bombardment of large current, the metal electrode will not crack or be damaged, and the high temperature generated can be indirectly heated to the substrate formed by pressing or sintering powder through contact conduction, thereby ensuring the service life of the heated substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention, so that other features, purposes and advantages of the present invention become more obvious. The accompanying drawings of the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 A schematic flow diagram of an arc heating method for a substrate formed by pressing and / or sintering powder;

[0023] Figure 2 A schematic diagram of the structure of an arc heating device for a substrate formed by pressing and / or sintering powder;

[0024] Figure 3A connection method between the cathode and the substrate is schematically given;

[0025] Figure 4 Another connection method between the cathode and the substrate is schematically shown;

[0026] Figure 5 Another connection method between the cathode and the substrate is schematically given;

[0027] Figure 6 Another connection method between the cathode and the substrate is schematically given;

[0028] Figure 7 A schematic diagram of the connection relationship between the cathode and the anode is given;

[0029] Figure 8 Another connection relationship diagram between the cathode and the anode is schematically provided; and

[0030] Fig. 9 Another connection relationship diagram between the cathode and the anode is schematically given.

[0031] In the figure:

[0032] 1. Arc generator; 2. Vacuum chamber; 3. Substrate; 4. Anode; 5. Cathode; 6. Vacuum pump; 7. Power supply. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0034] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a system, product or device comprising a series of units is not necessarily limited to those units explicitly listed, but may include units that are not explicitly listed or inherent to these products or devices.

[0035] In the present invention, the directions or positional relationships indicated by the terms "upper", "lower", "inner", "middle", "outer", etc. are based on the directions or positional relationships shown in the drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction.

[0036] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0037] In addition, the terms "disposed", "connected" and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0039] Example 1

[0040] The present application provides an arc heating method, which is suitable for heating a substrate formed by directly pressing powder, a substrate formed by directly sintering powder, or a product formed by pressing and sintering powder, such as Figure 1 As shown, the arc heating method includes the following steps: first, a metal electrode is configured to be in contact with the substrate, and the melting point of the metal electrode is configured to be higher than the target heating temperature; then, in a vacuum environment, the metal electrode is bombarded by an arc on the side away from the substrate to heat the metal electrode; finally, the substrate is heated by the arc-heated metal electrode by heat conduction. The metal electrode has high density and high temperature resistance, so under the bombardment of large current, the metal electrode will not be cracked or damaged, and the high temperature generated by the arc bombardment can be indirectly heated to the substrate by contact conduction to heat it to the temperature required in production and life, avoiding direct heating of the substrate by arc heating, and will not cause damage to the heated substrate, thereby ensuring the service life of the substrate.

[0041] The matrix in the above embodiment is preferably a matrix formed by pressing and sintering powders, and the powders used to form the matrix include but are not limited to oxides, borides, metals and clay minerals, etc. Among them, borides include but are not limited to boron trioxide, boron nitride and lanthanum hexaboride.

[0042] The matrix in the embodiment of the present application is preferably a lanthanum hexaboride matrix. Lanthanum hexaboride LaB6 has been successfully applied to more than 20 military and high-tech fields such as radar, aerospace, electronics industry, instrumentation, medical equipment, home appliances, metallurgy and environmental protection. Lanthanum hexaboride is the best material for making high-power electronic light, magnetron, electron beam and accelerator cathode. Lanthanum hexaboride can be heated, and electrons will escape at high temperature, which can be used. The lanthanum hexaboride matrix in the embodiment of the present application refers to a ceramic with lanthanum boride as the main crystal phase, cubic crystal, purple color, density of 4.76g / cubic centimeter, melting point of 2530℃, linear expansion coefficient of 6.4*10 -6 ℃ -1 , elastic modulus 460GPa, microhardness 2.76MPa, acid and alkali resistance, and excellent thermal radiation. The preparation method of the lanthanum hexaboride matrix can be: lanthanum trioxide and carbon tetraboride are synthesized into lanthanum hexaboride powder at high temperature in an inert atmosphere or a reducing atmosphere; and then the lanthanum hexaboride is sintered into a lanthanum hexaboride matrix under nitrogen protection according to a ceramic process. A metal electrode is configured to contact and connect with the above-mentioned lanthanum hexaboride matrix, and then, in a vacuum environment, the side of the metal electrode away from the lanthanum hexaboride matrix is ​​bombarded by electric arc bombardment, and the lanthanum hexaboride matrix is ​​heated by heat conduction through the metal electrode heated by the electric arc, and electrons will escape from the lanthanum hexaboride matrix at high temperature.

[0043] The material of the metal electrode used in the above arc heating method is preferably a metal or alloy with high density and high temperature resistance, including but not limited to copper, tungsten and tungsten alloy, etc. In some embodiments, the material of the metal electrode is selected to be metal tungsten, which has a melting point of 3410°C and generally does not crack under arc bombardment, and is an ideal metal electrode material in the embodiments of the present application.

[0044] In some embodiments, in the above arc heating method, the substrate is designed as a rod, the metal electrode is designed as a tube, and the substrate is matched and inserted into the metal electrode, that is, the rod is matched and inserted into the tube. Through the matching connection of the rod and the tube, on the one hand, a larger contact area can be obtained, thereby improving the heat conduction efficiency between the lanthanum hexaboride substrate and the metal tungsten; on the other hand, when the tube is placed horizontally, it can play a fixing role for the internally inserted rod, and only the rod needs to be inserted, without other fixing structures.

[0045] In the above embodiment, the vacuum degree range of the vacuum environment where the arc bombards and heats the metal tungsten is not greater than 10. -4 -10 -2 Pa, ultimately can ensure the effective implementation of the arc heating method.

[0046] When metal tungsten is used as a metal electrode to heat the lanthanum hexaboride substrate, in order to achieve the purpose of escaping more electrons during the heating process, the inventors have determined through multiple experiments that the appropriate heating temperature is 1200°C to 1800°C, that is, by controlling the heating temperature range of 1200°C to 1800°C during the heating of the lanthanum hexaboride substrate by metal tungsten, more escaped electrons can be obtained. Most preferably, when the vacuum degree is 10 -3 In the case of Pa, the heating temperature is controlled to be 1600°C during the heating process of the lanthanum hexaboride substrate by metal tungsten.

[0047] Example 2

[0048] In order to implement the arc heating method provided in Example 1 for heating a substrate formed by pressing and / or sintering powder, an embodiment of the present application provides an arc heating device for heating a substrate formed by pressing and / or sintering powder.

[0049] like Figure 2 As shown, the arc heating device comprises an arc generator 1, a vacuum chamber 2 and a substrate 3. The substrate 3 and the positive cathode of the arc generator 1 are both located in the vacuum chamber 2. The anode 4 and cathode 5 of the arc generator 1 are both made of metal. The cathode 5 is configured to provide heat energy to the substrate 3 in a heat conduction manner. The anode is arranged on the side of the cathode 5 away from the substrate 3. The specific working process of the arc heating device provided in the above embodiment can be: evacuating the vacuum chamber 2 to keep it at a certain vacuum degree, turning on the power supply 7 to make the arc generator 1 work, the two electrodes for generating the arc provided on the arc generator 1 are arranged oppositely, located on the same horizontal plane, and the ends are kept not in contact, when the arc generator 1 is powered on, a discharge arc is generated between the anode 4 and the cathode 5, a large current bombards the metal as the cathode 5 to generate heat, and the cathode 5 transfers the heat to the substrate 3 connected thereto in a heat conduction manner, thereby heating the substrate 3. In the arc heating device, since the cathode 5 made of metal has the properties of high density and high temperature resistance, the cathode will not crack or be damaged under the bombardment of large current, and the high temperature generated by the arc bombardment can be indirectly heated to the substrate 3 through contact conduction, thereby avoiding direct heating of the substrate 3 by arc heating, and will not cause damage to the heated substrate 3, thereby ensuring the service life of the substrate 3.

[0050] The cathode 5 in the above embodiment is used to receive the bombardment of high-energy arc, and after generating heat, the heat is transferred to the substrate 3 in the form of heat conduction. The contact connection between the two is used to achieve heat conduction. The specific connection method between the cathode 5 and the substrate 3 can be in various forms.

[0051] Optional, such as Figure 3As shown, the cathode 5 and the substrate 3 are mutually attached, that is, the cathode 5 covers the surface of the substrate 3, and the anode 4 is arranged on the side of the cathode 5 away from the substrate 3, so that the arc generated between the anode 4 and the cathode 5 will not bombard the substrate 3. Preferably, as Figure 4 As shown, the cathode 5 includes a first segment 501 and a second segment 502 which are arranged perpendicular to each other, wherein one end of the second segment 502 is connected to the middle of the first segment 501, forming Figure 4 The cross-section shown is a T-shaped cathode structure, in which the first section 501 of the cathode 5 faces the anode 4 with one side facing away from the second section 502, and the right angle where the first section 501 and the second section 502 are connected is used to fix the substrate 3. As shown in the figure, two substrates 3 can be provided at this time, and each substrate 3 is respectively attached to the first section 501 and the second section 502, which can increase the heating area of ​​the substrate 3.

[0052] Optionally, the cathode 5 is configured to cover the substrate 3, which increases the contact area and improves the heat transfer efficiency. At the same time, the substrate 3 can be fixed by the cathode 5, and the fixing structure can be reduced in the overall structure. As an optional embodiment, Figure 5 As shown, the cross-sectional shape of the cathode 5 is U-shaped, and the substrate 3 is arranged inside the U-shaped cathode 5, and the cathode 5 is used to cover the substrate 3 in three directions; as an optional embodiment, as Figure 2 and 6 As shown, the cross-sectional shape of the cathode 5 is a closed figure, the substrate 3 is arranged inside the cathode 5, and the cathode 5 is used to cover the substrate 3 in four directions. Figure 2 and 6 The cathodes shown are all designed as tubes, and the substrate 3 is designed as rods. Figure 2 The middle cathode is a round tube design, and the base 3 is a cylindrical design that can match the inserted cathode; Figure 6 The middle cathode is designed as a square tube, and the base body 3 is designed as a rectangular parallelepiped that can match the inserted cathode.

[0053] Optional, such as Figure 7 As shown, multiple groups of anodes 4 and cathodes 5 are arranged in the vacuum chamber 2, and multiple cathodes 5 are evenly arranged in a circular array, and multiple anodes 4 are arranged inside the circular array composed of cathodes 5. The above arrangement can make full use of the space inside the vacuum chamber 2, allowing multiple groups of anodes 4 and cathodes 5 to work simultaneously, and multiple substrates 3 can be heated simultaneously.

[0054] Optional, such as Figure 8As shown, a plurality of anodes 4 are arranged in the vacuum chamber, and the figures of this embodiment show three anodes 4, and a cathode 5 is arranged in the vacuum chamber 2, and the cross section of the cathode 5 is annular, surrounding the periphery of the plurality of anodes 4. The above arrangement can make full use of the space inside the vacuum chamber 2, allowing arc discharge to be generated between a plurality of anodes 4 and a cathode 5 at the same time, and the annular cathode 5 can obtain a larger surface area for heating the substrate.

[0055] Optional, such as Fig. 9 As shown, one anode 4 is provided in the vacuum chamber, and the anode 4 shown in the drawings of this embodiment is cylindrical, and multiple cathodes 5 are provided in the vacuum chamber 2, and the number of cathodes 5 shown in the drawings of this embodiment is 4, and the 4 cathodes 5 are evenly arranged in a circular array, and the anode 4 is provided inside the circular array composed of the cathodes 5. The above-mentioned arrangement can make full use of the space inside the vacuum chamber 2, allowing one anode 4 to discharge arcs to multiple cathodes 5 at the same time, and multiple substrates 3 can be heated by multiple cathodes 5 at the same time.

[0056] It should be noted that the arc heating device of this embodiment is to implement the arc heating method provided in Example 1 for heating a substrate pressed and / or sintered by powder. Therefore, all technical solutions in Example 1 are applicable to this embodiment. For example, the substrate 3 can be a substrate sintered by lanthanum hexaboride powder, and the material of the cathode can be metal tungsten, etc., which will not be repeated here.

[0057] In the above embodiment, the vacuum chamber 2 can be set in the workshop and is the main body of the arc heating equipment. The role of the vacuum chamber is to provide the necessary vacuum environment for realizing the generation of arcs between the electrodes of the arc generator. It can provide the vacuum degree required for the arc generation, the vacuum pump 6 and the detection function component. Among them, the vacuum degree refers to the use of the vacuum pumping system during the arc generation process to make the gas in a certain space reach a certain vacuum degree, and this vacuum degree can just meet the vacuum degree required for the arc generation. It can be reasonably set according to specific needs. From another perspective, the setting of the vacuum degree is conducive to preventing the metal electrode from oxidizing at high temperature and plays a role in protecting the electrode; the vacuum pump 6 is used to maintain the required vacuum conditions and pressure values ​​for the vacuum chamber 2, which includes but is not limited to mechanical pumps, dry pumps, Roots pumps, molecular pumps and cold pumps. Of course, vacuum valves and control circuits for controlling vacuum pumps can also be set, which are applicable to the prior art and will not be repeated here; the detection function component refers to providing real-time monitoring of the pressure, temperature, etc. in the vacuum chamber 2. Commonly used tools include but are not limited to RGA, vacuum gauge, spectrometer, etc., which do not belong to the vacuum chamber but can be attached to the vacuum chamber 2. It should be noted that for the convenience of display, the attached application Figure 2 The figure only schematically shows an optional structure of the vacuum chamber, and the vacuum chamber 2 for forming the vacuum condition is not limited to the structure and shape shown in the figure.

[0058] The power supply 7 in the above embodiment is used to provide electric power to the entire system including the arc generator 1. The voltage of the power supply 7 can be set to a DC voltage ranging from several volts to several thousand volts, and the current can be set from several amperes to several hundred amperes. During use, it can be specifically set according to the size of the heated lanthanum hexaboride substrate and the required temperature. The anode 4 of the arc generator 1 is preferably made of high-temperature resistant metal tungsten, and its shape includes but is not limited to a cylinder and a torus.

[0059] When metal tungsten is used as the cathode 5 and the lanthanum hexaboride matrix is ​​heated, in order to achieve the purpose of escaping more electrons during the heating process, the optimal heating temperature is 1600°C. In order to obtain more precise temperature control, when the specific dimensions of the cathode 5 and the lanthanum hexaboride matrix are determined, the heating temperature can be achieved by adjusting the output power of the power supply 7 to the arc generator 1.

[0060] Optionally, the material of the anode 4 and the cathode 5 are both selected to be metal tungsten, and the shape of the cathode 5 is processed as follows: Figure 2 The tungsten tube shown in the figure has specific size parameters: inner diameter of 150 mm, outer diameter of 185 mm, and length of 350 mm; the substrate 3 is selected as a lanthanum hexaboride substrate, and the substrate 3 is processed into a shape as shown in FIG. Figure 2 The rod shown has the following dimensional parameters: diameter 149 mm, length 350 mm; the distance between the anode 4 and the cathode 5 is 10 mm; the vacuum degree in the vacuum chamber 2 is maintained at 10 -3 Pa, when no arc occurs, the power output parameters of the arc generator are: voltage 1150V. After about 10-12s, a stable plasma flow is formed, so that a stable arc is generated between the anode and cathode, and the voltage drops below 70V. At this time, the temperature of the lanthanum hexaboride matrix can be maintained at 1600℃.

[0061] Optionally, the material of the anode 4 and the cathode 5 are both selected to be tungsten-rhenium alloy, and the shape of the cathode 5 is processed as follows: Figure 5 The tungsten tube shown in the figure has specific size parameters as follows: the outer square ring size of the cross section is 20mm×20mm, the inner square ring size is 17mm×17mm, and the length of the tungsten tube is 300mm; the substrate 3 is selected as a lanthanum hexaboride substrate, and the substrate 3 is processed into a shape as shown in the figure. Figure 5 The bar shown in the figure has the following dimensional parameters: the cross-sectional dimension is 16.8 mm × 16.8 mm, the length is 300 mm; the distance between the anode 4 and the cathode 5 is 12 mm; the vacuum degree in the vacuum chamber 2 is maintained at 10 -4Pa, when no arc occurs, the power supply parameters output by the arc generator are: voltage 1000V. After about 8s, a stable plasma flow is formed, so that a stable arc is generated between the anode and cathode, and the voltage drops below 110V. At this time, the temperature of the lanthanum hexaboride matrix can be maintained at 1600℃.

[0062] Some embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referenced to each other.

[0063] The above is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features invented herein.

Claims

1. An arc heating method for heating a matrix formed by pressing and / or sintering powder, characterized in that: include: configuring a metal electrode to be in contact with the substrate, wherein the melting point of the metal electrode is higher than the target heating temperature; In a vacuum environment, bombarding the side of the metal electrode away from the substrate by electric arc bombardment to heat the metal electrode; heating the substrate by heat conduction through the metal electrode; The connection between the cathode and the substrate is as follows: the cathode and the substrate are bonded to each other, and the anode is arranged on the side of the cathode away from the substrate; The cathode includes a first section and a second section arranged perpendicularly to each other, wherein one end of the second section is connected to the middle of the first section to form a cathode structure with a T-shaped cross-section, and the first section of the cathode faces the anode with one side away from the second section. The right angle where the first section and the second section are connected is used to fix the substrate, and two substrates are provided, each of which is respectively attached to the first section and the second section.

2. The arc heating method according to claim 1, characterized in that: The matrix includes a matrix formed by sintering boride powder.

3. The arc heating method according to claim 2, characterized in that: The boride includes lanthanum hexaboride.

4. The arc heating method according to claim 1, characterized in that: The material of the metal electrode is tungsten or tungsten alloy.

5. The arc heating method according to claim 1, characterized in that: The substrate is a rod, the metal electrode is a tube, and the substrate is matched and inserted into the metal electrode.

6. An arc heating device for heating a matrix (3) formed by pressing and / or sintering powder using a method according to any one of claims 1 to 5, characterized in that: The invention comprises an arc generator (1) and a vacuum chamber (2). The anode (4) and cathode (5) of the arc generator (1) are both located in the vacuum chamber (2). The cathode (5) is configured to provide thermal energy to the substrate (3) in a heat conduction manner.

7. The arc heating device according to claim 6, characterized in that: The cathode (5) is attached to the surface of the substrate (3), and the anode (4) is arranged on a side of the cathode (5) facing away from the substrate (3).

8. The arc heating device according to claim 6, characterized in that: The cathode (5) covers the substrate (3).

9. The arc heating device according to claim 8, characterized in that: The substrate (3) is a rod, the cathode (5) is a tube, and the substrate (3) is matched and inserted into the cathode (5).

10. The arc heating device according to claim 6, characterized in that: The substrate is a substrate formed by sintering lanthanum hexaboride powder, and the cathode is made of metal tungsten.

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