High temperature experimental furnace to which a magnetic field can be applied

Abstract

The application relates to the technical field of material performance test, in particular to an experimental device suitable for testing the mechanical properties of materials under high-temperature and magnetic field environments. The device comprises a furnace body, a furnace cavity arranged in the furnace body, a test piece and a Hopkinson pressure bar arranged in the furnace cavity; the device further comprises a heating part, a magnetic field loading part and a control part; the heating part is arranged in the furnace body; a water cooling circulation part is arranged on the annular outer side of the furnace body; the magnetic field loading part is arranged on the outer side of the water cooling circulation part; and the control part is connected with the heating part, the water cooling circulation part and the magnetic field loading part respectively. The device can apply a stable and uniform magnetic field to a sample under a high-temperature environment, can be effectively integrated with a Hopkinson pressure bar and other dynamic mechanical test equipment, and can realize accurate evaluation of the dynamic mechanical properties of materials under the coupling action of high temperature and a magnetic field, thereby providing an efficient and reliable experimental platform for in-depth research on the influence of the coupling action of a magnetic field and high temperature on the properties of materials, especially the response under high strain rate.

Description

Technical Field

[0001] This invention relates to the field of materials performance testing technology, and in particular to an experimental apparatus suitable for testing the mechanical properties of materials under high temperature and magnetic field environments. Background Technology

[0002] In materials science and engineering, studying the deformation behavior of materials at high strain rates is crucial for understanding their mechanical properties. High strain rate typically refers to loading conditions with a strain rate greater than 1 / s, under which the deformation behavior of materials differs significantly from that under static loading. During cutting, materials undergo a typical form of plastic deformation, characterized by large strain and extremely high strain rate. Under this high strain rate, the flow stress of the material increases significantly because the movement velocity of dislocations within the material is restricted, leading to dislocation accumulation and enhanced interactions. Furthermore, the dynamic hardening phenomenon of materials is more pronounced at high strain rates due to changes in the dislocation structure during plastic deformation.

[0003] High temperatures are common extreme environmental factors, and magnetic fields can also affect material properties. Many engineering materials exhibit different mechanical properties under high-temperature magnetic field coupling compared to those under normal temperature and magnetic field conditions. Therefore, developing experimental devices capable of testing material properties under high-temperature and magnetic field environments has significant scientific and engineering application value.

[0004] Currently, the testing technology for the mechanical properties of materials under high-temperature environments is relatively mature, and there are various types of high-temperature experimental furnaces, such as resistance furnaces and induction furnaces. These experimental furnaces can provide a high-temperature environment for materials and, in conjunction with corresponding mechanical testing equipment (such as tensile testing machines, compression testing machines, creep testing machines, etc.), perform mechanical property testing on the materials.

[0005] Meanwhile, magnetic fields, as an important physical field, influence the magnetic, electrical, and mechanical properties of materials. To study the effects of magnetic fields on material properties, various magnetic field application devices have been developed, such as permanent magnets, electromagnets, and superconducting magnets. These devices can provide static or dynamic magnetic field environments for materials. However, combining high-temperature and magnetic field environments to achieve performance testing of materials under the coupled effects of high-temperature magnetic fields still faces many technical challenges.

[0006] (1) It is difficult to guarantee the uniformity of the magnetic field;

[0007] (2) Insufficient high-temperature tolerance of electromagnetic coils: As the core component for magnetic field loading, electromagnetic coils need to operate stably in high-temperature environments. However, traditional electromagnetic coils mostly use copper wire and ordinary iron core materials, which are prone to magnetic field strength fluctuations or even magnetic field failure in high-temperature environments, seriously affecting the stability and controllability of the experiment. Summary of the Invention

[0008] The purpose of this invention is to overcome the above-mentioned defects in the existing technology and propose a high-temperature experimental furnace that can apply a magnetic field. It can apply a stable and uniform magnetic field to the sample in a high-temperature environment and can be effectively integrated with dynamic mechanical testing equipment such as the Hopkinson pressure bar. This enables accurate evaluation of the dynamic mechanical properties of materials under the coupling effect of high-temperature magnetic field, and provides an efficient and reliable experimental platform for in-depth research on the influence of magnetic field and high temperature coupling on material properties, especially the response under high strain rate.

[0009] The technical solution of the present invention is: a high-temperature experimental furnace capable of applying a magnetic field, comprising a furnace body, wherein a furnace cavity is provided inside the furnace body, and a test piece and a Hopkinson pressure bar are provided inside the furnace cavity;

[0010] It also includes a heating section, a magnetic field loading section, and a control section. The heating section is located inside the furnace body. A water-cooling circulation section is provided on the outer ring of the furnace body. A magnetic field loading section is provided on the outer side of the water-cooling circulation section. The control section is connected to the heating section, the water-cooling circulation section, and the magnetic field loading section respectively.

[0011] In this invention, the furnace body is horizontally arranged, and the axial direction of the furnace body is arranged in the horizontal direction.

[0012] The furnace body includes a furnace body;

[0013] Flanges are fixed on both ends of the furnace body. Through holes are provided at the axial center of the flanges and the furnace body. The through holes are connected in sequence to form the furnace cavity.

[0014] Water cooling pipes are installed on the outer ring of the furnace body.

[0015] The furnace cavity has a ring-shaped outer side and a wire groove inside the furnace body. The resistance wire heating element is set in the resistance wire groove, and the power supply wire of the resistance wire heating element, as well as the thermocouple and Hall sensor wire, are set in the wire groove.

[0016] The water-cooled circulation section includes a spiral water-cooled pipe and a cooling water tank. The spiral water-cooled pipe is located on the outer ring of the furnace body, and the cooling water tank is connected to the spiral water-cooled pipe. The cold water in the cooling water tank is continuously injected into the spiral water-cooled pipe by a water pump.

[0017] The magnetic field loading part includes an iron core, an inner conductor, and an outer conductor. The iron core is located on the outer ring of the spiral water-cooling pipe. The inner conductor is wound around the outer ring of the iron core, and the outer conductor is located on the outer side of the inner conductor.

[0018] The control unit includes a K-type thermocouple and a temperature controller. The K-type thermocouple is installed inside the furnace cavity, and the temperature controller is connected to the K-type thermocouple.

[0019] The control unit also includes a power control module for controlling the magnitude of the electromagnetic coil current.

[0020] The control unit includes a Hall sensor, which is installed inside the furnace cavity.

[0021] The beneficial effects of this invention are:

[0022] (1) Integration and multifunctionality: Existing high-temperature experimental furnaces usually focus on providing a high-temperature environment, while the equipment for applying magnetic fields and the Hopkinson bar system for dynamic mechanical testing are often separate; This application integrates the ability to heat at high temperatures, apply a stable and uniform magnetic field and provide an experimental environment for dynamic mechanical testing of Hopkinson bars into one, eliminating the need to transfer samples between different devices, which greatly improves experimental efficiency and convenience.

[0023] (2) Controllable and uniform magnetic field environment: Although the magnetic field loading part in this application includes an inner spiral main coil and an outer spiral auxiliary coil, the inner main coil is wound in a spiral manner and is mainly responsible for generating the magnetic field strength required for the experiment; the outer auxiliary coil is arranged outside the main coil, with a denser number of turns and a spiral direction opposite to that of the inner main coil; the auxiliary coil does not directly enhance the magnetic field strength, but is used to adjust the magnetic field distribution, suppress the magnetic field gradient and edge effect generated by the main coil, and play a role in stabilizing the magnetic field and improving uniformity. Combined with a precise control system, it can provide a stable and uniform magnetic field environment for the sample in the high-temperature furnace cavity, providing reliable experimental conditions for studying the material behavior under the coupling effect of magnetic field and high temperature.

[0024] (3) Precise temperature control: This invention uses resistance wire heating combined with K-type thermocouples for temperature detection and feedback control, which can achieve precise control of the temperature inside the furnace cavity, ensuring the accuracy and stability of the experimental temperature, which is crucial for studying temperature-dependent material behavior.

[0025] (4) Excellent heat dissipation performance: A closed water cooling circulation device is installed on the outside of the furnace body, which effectively reduces heat loss, improves heating efficiency, reduces energy consumption, and also protects external components from high temperature, ensuring long-term stable operation of the equipment; at the same time, the water cooling circulation device can also prevent the heat generated by the furnace body from being transferred to the magnetic field loading part to a certain extent, so as to minimize the working environment of the magnetic field loading part and provide a stable and uniform magnetic field environment for the sample. Attached Figure Description

[0026] Figure 1 This is a three-dimensional structural diagram of the present invention when used in conjunction with a Hopkinson pressure bar;

[0027] Figure 2 This is a cross-sectional view of the present invention when used in conjunction with a Hopkinson pressure bar;

[0028] Figure 3 This is a schematic diagram of the main structure of the present invention;

[0029] Figure 4 This is a schematic diagram of a portion of the internal structure of the furnace.

[0030] In the diagram: 1. Water pump; 2. Cooling water tank; 3. Support base; 4. Hopkinson pressure bar; 5. Front flange; 6. Spiral water-cooled pipe; 7. Iron core; 8. Inner wire; 9. Rear flange; 10. K-type thermocouple; 11. Hall sensor; 12. Ceramic guide sleeve; 13. Resistance wire groove; 14. Furnace cavity; 15. Furnace body; 16. Specimen; 17. Outer wire; 18. Wire groove; 19. Temperature controller. Detailed Implementation

[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0032] Specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0033] The high-temperature experimental furnace capable of applying a magnetic field described in this invention needs to be used in conjunction with a Hopkinson pressure bar to perform dynamic performance testing on the sample under high strain rates. Therefore, the integration of the Hopkinson pressure bar needs to be considered in the structural design of the high-temperature experimental furnace described in this application.

[0034] like Figure 1 and Figure 2 As shown, the high-temperature experimental furnace capable of applying a magnetic field according to the present invention includes a furnace body, a heating section, a magnetic field loading section, a control section, and a water-cooling circulation section. The furnace body is cylindrical and horizontally arranged, meaning its axial direction is horizontal. A furnace cavity 14 is located at the axial center of the furnace body, through which a Hopkinson pressure rod 4 passes to perform dynamic mechanical testing on the specimen 16 located at the center of the furnace cavity.

[0035] The furnace body is equipped with a heating section to heat the interior of the furnace cavity, thereby achieving a high-temperature environment. An external water-cooling circulation section is located on the furnace body to reduce heat loss from the furnace cavity, improve heating efficiency, and maintain a relatively low temperature on the outer shell of the experimental furnace. A magnetic field loading section is located outside the water-cooling circulation section. The magnetic field generated by the magnetic field loading section acts on the specimen 16 inside the furnace cavity, placing the specimen within the magnetic field environment. A control unit is connected to the heating section, the magnetic field loading section, and the water-cooling circulation section, respectively. The control unit can accurately control the heating temperature of the heating section, the cooling temperature of the water-cooling circulation section, and the magnetic field strength generated by the magnetic field loading section.

[0036] like Figures 1 to 2As shown, the furnace body in this embodiment is cylindrical and includes a furnace body 15. The furnace body 15 is horizontally positioned, meaning its axial direction is horizontal. One end face of the furnace body 15 is fixedly connected to the front flange 5, and the other end face of the furnace body 15 is fixedly connected to the rear flange 9. Through holes are provided at the axial center of the front flange 5, the furnace body 15, and the rear flange 9, and these through holes are interconnected, thereby forming a furnace cavity 2 horizontally positioned at the axial center of the furnace body.

[0037] Furnace cavity 2 is the internal experimental space of the experimental furnace, used to place the specimen 16 to be tested. In order to conduct mechanical tests at high temperatures, the furnace cavity can also accommodate Hopkinson bars 4. The specimen 16 is located between the Hopkinson bars 4 on both sides, and a high strain rate load is directly applied to the specimen through the Hopkinson bars 4.

[0038] In this embodiment, the front flange 5 and the rear flange 9 are respectively bolted to the two end faces of the furnace body 15. Ceramic guide sleeves 12 are provided at both ends of the furnace cavity through-hole, and the ceramic guide sleeves 12 are fixed in the furnace cavity. In this embodiment, the ceramic guide sleeves are fixedly connected to the furnace wall by high-temperature resistant metal flanges. The Hopkinson pressure rod 4 passes through the ceramic guide sleeve 12, and the Hopkinson pressure rod 4 and the ceramic guide sleeve 12 are in a sliding seal connection, allowing the Hopkinson pressure rod to move freely in a high-temperature environment while ensuring the airtightness of the furnace cavity. The ceramic guide sleeve 12 is used to seal the furnace cavity and maintain the temperature uniformity inside the furnace cavity.

[0039] like Figure 2 As shown, a resistance wire groove 13 is provided outside the annular cavity 2 and inside the furnace body 15, and the resistance wire heating element is located inside the resistance wire groove 13. When the resistance wire heating element is energized, it generates heat to heat the interior of the furnace cavity, thereby creating a high-temperature environment within the furnace cavity 2, placing the test specimen 16 in this high-temperature environment. In this embodiment, since the resistance wire heating element is spiral-shaped, the resistance wire groove 13 is also correspondingly spiral-shaped, arranged along the axial direction of the furnace cavity 2. By setting the resistance wire groove 13, the resistance wire heating element is effectively isolated from the furnace cavity 2, ensuring experimental safety.

[0040] Meanwhile, the furnace body 15 is also equipped with a wire groove 18, in which the power supply wires of the resistance wire heating element are arranged to ensure the neatness and safety of the wiring.

[0041] The water-cooled circulation section includes a spiral water-cooled pipe 6, a water pump 1, and a cooling water tank 2. The spiral water-cooled pipe 6 is located on the annular outer side of the furnace body 15. The spiral water-cooled pipe 6 is used to reduce heat loss from the furnace cavity, improve heating efficiency, and maintain a relatively low temperature on the outer shell of the experimental furnace. The spiral water-cooled pipe 6 is connected to the cooling water tank 2 via a pipe, and the water pump 1 provides a constant flow of water to the spiral water-cooled pipe 6. The spiral water-cooled pipe 6 effectively blocks heat conduction and heat convection.

[0042] The magnetic field loading section is located on the annular outer side of the spiral water-cooled pipe 6. The magnetic field loading section includes an iron core 7, an inner conductor 8, and an outer conductor 17. The iron core 7 is located on the annular outer side of the spiral water-cooled pipe 6, and the inner conductor 8 is wound around the annular outer side of the iron core 7, providing the main magnetic field strength. The outer conductor 17 is wound around the outer side of the inner conductor 8, providing stability to the magnetic field. The iron core 7, the inner conductor 8, and the outer conductor 17 form an electromagnetic coil, which is the core of the magnetic field loading section.

[0043] When current flows through the inner conductor 8, the iron core 7 generates a magnetic field. The outer conductor 17, through its reverse winding design, generates a magnetic field component that can counteract the uneven magnetic field generated by the main coil in the edge region, reducing the magnetic field gradient. This magnetic field acts on the specimen 16 inside the furnace cavity 2, placing the specimen 16 in a magnetic field environment. The strength of the magnetic field can be controlled by adjusting the current. In this embodiment, the electromagnetic coil can be powered by an external power source.

[0044] The control unit includes a temperature controller 19 and a K-type thermocouple 10. The K-type thermocouple 10 is installed inside the furnace cavity 2. It is used to detect the temperature near the specimen in the furnace cavity 2 in real time and feeds the temperature signal back to the temperature controller 19. The K-type thermocouple 10 has advantages such as a wide measurement range and high accuracy, making it suitable for temperature measurement in high-temperature environments. The temperature controller 19 receives the temperature signal from the K-type thermocouple 10 and adjusts the power supply of the resistance wire according to the set target temperature, thereby precisely controlling the temperature inside the furnace cavity 2.

[0045] The control unit also includes a Hall sensor 11, which is also located inside the furnace chamber 2. The Hall sensor 11 is used to detect the magnetic field strength near the specimen inside the furnace chamber 2 in real time.

[0046] The control unit also includes a power control module for controlling the magnitude of the electromagnetic coil current. This power control module can also control the magnitude of the electromagnetic coil current to adjust the magnetic field strength applied to the specimen 16.

[0047] In this embodiment, the furnace body should be made of non-magnetic, high-temperature resistant material to avoid the influence of magnetic field on the furnace body itself and to ensure the stability of the structure at high temperatures.

[0048] When conducting experiments using the high-temperature experimental furnace described in this application, the specimen 16 is first fixed to the incident rod, ensuring that the Hopkinson pressure bar 4 passes through the furnace cavity 2 and is aligned with the specimen. Then, the target temperature is set via the temperature controller 19, and the resistance wire heating element begins heating. Simultaneously, according to experimental requirements, the current of the electromagnetic coil is adjusted via the power control module in the control unit to apply a magnetic field of the required strength. Once the temperature and magnetic field stabilize, the dynamic mechanical testing of the Hopkinson pressure bar on the specimen 16 within the furnace cavity 2 can be performed.

[0049] During the experiment, one end of the Hopkinson pressure rod 4 was located inside the furnace cavity 2, and the other end of the Hopkinson pressure rod 4 was located outside the furnace cavity 2. The support seat 13 supported the Hopkinson pressure rod 4, keeping it in a horizontal position during operation.

[0050] The high-temperature experimental furnace capable of applying a magnetic field provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention. The above description of the disclosed embodiments enables those skilled in the art to implement or use this invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this invention. Therefore, this invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-temperature experimental furnace capable of applying a magnetic field, comprising a furnace body, characterized in that, The furnace body is provided with a furnace cavity, and the furnace cavity contains a specimen and a Hopkinson pressure bar. The specimen is located between the two Hopkinson pressure bars on both sides. It also includes a heating section, a magnetic field loading section, a water cooling circulation section, and a control section. The heating section is located inside the furnace body. A water cooling circulation section is located on the outer ring of the furnace body. A magnetic field loading section is located on the outer side of the water cooling circulation section. The control section is connected to the heating section, the water cooling circulation section, and the magnetic field loading section respectively. The furnace body is horizontally arranged, and its axis is set along the horizontal direction; The furnace body includes a furnace body; Flanges are fixed on both ends of the furnace body. Through holes are provided at the axial center of the flanges and the furnace body. The through holes are connected in sequence to form the furnace cavity. Water cooling pipes are installed on the outer ring of the furnace body; The furnace cavity has a ring-shaped outer side and a wire groove inside the furnace body. The resistance wire heating element is set in the resistance wire groove, and the power supply wire of the resistance wire heating element, as well as the thermocouple and Hall sensor wires, are set in the wire groove. The water-cooled circulation section includes a spiral water-cooled pipe and a cooling water tank. The spiral water-cooled pipe is located on the outer ring of the furnace body, and the cooling water tank is connected to the spiral water-cooled pipe. The cold water in the cooling water tank is continuously injected into the spiral water-cooled pipe by a water pump. The magnetic field loading part includes an iron core, an inner conductor, and an outer conductor. The iron core is located on the outer ring of the spiral water-cooling pipe. The inner conductor is wound around the outer ring of the iron core, and the outer conductor is located on the outer side of the inner conductor.

2. The high-temperature experimental furnace capable of applying a magnetic field according to claim 1, characterized in that, The control unit includes a K-type thermocouple and a temperature controller. The K-type thermocouple is installed inside the furnace cavity, and the temperature controller is connected to the K-type thermocouple.

3. The high-temperature experimental furnace capable of applying a magnetic field according to claim 2, characterized in that, The control unit also includes a power control module for controlling the magnitude of the electromagnetic coil current.

4. The high-temperature experimental furnace capable of applying a magnetic field according to claim 2, characterized in that, The control unit includes a Hall sensor, which is installed inside the furnace cavity.

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