In-situ heating temperature control method under high rotation speed and high temperature

Abstract

The application discloses an in-situ heating temperature control method under high-speed and high-temperature action. When the main shaft of a centrifuge rotates, a temperature load is applied to a test sample by an induction heating system while the main shaft of the centrifuge rotates. The temperature load includes applying a constant and uniform temperature field according to a uniform heating mode, applying a periodically changing alternating temperature field according to a periodically changing alternating temperature heating mode, and applying a temperature field with gradient change in a fixed range according to a temperature gradient heating mode. The application solves the limitation that radiation heating under high-speed can only heat the whole sample, and can test different temperatures and different centrifugal forces on one sample. The application solves the limitation that the temperature of radiation heating under high-speed cannot exceed 800 DEG C, and solves the technical limitation that radiation heating under high-speed cannot realize rapid temperature alternation.

Description

Technical Field

[0001] This invention relates to a centrifuge heating and temperature control method in the field of in-situ heating of metallic materials, and more particularly to a centrifuge in-situ heating and temperature control method for metallic materials under high speed and high temperature conditions. Background Technology

[0002] National standards GB / T 38822-2020 "Metallic Materials Creep-Fatigue Test Methods" and GB / T 6825.1-2008 "Inspection of Static Uniaxial Testing Machines Part 1: Inspection and Calibration of Force Measuring Systems for Tensile and / or Compressive Testing Machines" both specify test methods for the mechanical properties of metallic materials. However, the test environment specified in these standards is 1G (G = 9.8 m / s²), which is sufficient for the study of the mechanical properties of metallic materials themselves. However, in turbine propulsion systems, key components such as compressor blades, fan blades, and turbine blades in power systems like aero-engines, space engines, industrial and marine gas turbines, and automotive and train turbochargers are all in a high-speed rotating state during normal operation; that is, the service environment is typically a centrifugal hypergravity environment.

[0003] A turbine propulsion system is typically a turbine power unit that converts the thermal energy from fuel combustion into mechanical energy by using guide vanes to drive a turbine through thermal expansion. A turbocharger, for example, utilizes the exhaust gases from a diesel (gasoline) engine to convert engine waste heat into mechanical energy through thermal expansion on a turbine. During service, the turbine blades of these power units rotate at high speed around the engine axis. Their function is to convert the potential and thermal energy of the combustion gases into mechanical work for the rotor through combustion gas expansion. Therefore, the turbine blades bear loads including aerodynamic forces, centrifugal forces, and thermal loads. Centrifugal force, generated by high-speed rotation, is a volume force that primarily causes radial tensile stress on the blades. For blades with torsional structures, it also generates torsional stress. If the blade's overlap line and radial line are not perfectly aligned, the centrifugal force also causes bending stress. The thermal stress generated by the thermal load is closely related to the blade's temperature gradient and geometric constraints; the greater the temperature gradient, the greater the thermal stress. However, the key material mechanical property data currently used for designing turbine blades in turbine propulsion systems all come from testing standard specimens under static, uniaxial stress states using 1G-based endurance, creep, and fatigue testing machines. While the mechanical property data from standard specimens can provide a design basis for the strength design of turbine blades in turbine propulsion systems to some extent, the complex geometry of the blades and their complex stress states differ from those of standard specimens. The material mechanical property data obtained from standard specimens do not consider the impact of high speeds and blade geometry on structural reliability and cannot be directly used to assess the lifespan of turbine blades. Summary of the Invention

[0004] To address the shortcomings of current static mechanical property testing of metallic materials at 1G speeds, and the lack of suitable in-situ heating devices and intelligent temperature control technologies for mechanical property testing of metallic materials under high rotational speed and high temperature conditions, this invention provides a method for applying in-situ heating and temperature control to metallic materials in a high-speed rotational environment, solving the key challenges of in-situ heating and temperature control in the mechanical property testing of metallic materials under high rotational speed and high temperature conditions.

[0005] The in-situ heating of metal materials under high rotation speed environment described in this invention refers to the process in which the test material or component rotating at high speed is always in an in-situ heating state until the test is completed.

[0006] The high temperature mentioned in this invention refers to a heating temperature of not less than 500°C applied to a designated area of ​​the sample during the experiment, and the duration of in-situ heating is not less than the test time.

[0007] The high speed mentioned in this invention refers to the centrifuge's maximum speed during the experiment being no less than 5000 rpm.

[0008] The technical solution adopted in this invention is as follows:

[0009] When the centrifuge spindle is rotating, the present invention applies a temperature load to the test sample through an induction heating system. The application of the temperature load includes applying a constant and uniform temperature field according to a uniform temperature heating mode, applying a periodically changing alternating temperature field according to a periodically changing alternating temperature heating mode, and applying a temperature field with a fixed range and a gradient according to a temperature gradient heating mode.

[0010] The uniform heating mode is as follows: the distance h between the standard segment of the test sample and the upper and lower induction coils is kept the same, and the current power and current alternation frequency of the upper and lower induction coils remain unchanged within time t, thereby applying a constant and uniform temperature field to the standard segment.

[0011] The periodically changing alternating temperature heating mode is as follows: the distance h between the standard segment of the test sample and the upper and lower induction coils is kept the same. The alternating frequency of the current in the upper and lower induction coils remains unchanged, but the current power of the upper and lower induction coils is periodically changed within time t, thereby giving the standard segment a continuously periodically repeating alternating temperature field composed of temperature T1 applied within time t1 and temperature T2 applied within time t2.

[0012] The heating mode of the temperature gradient is specifically as follows: the standard segment of the test sample is processed into an arc with a radius of R. The lowest point of the arc of the standard segment is kept at the same distance h between the upper induction coil and the lower induction coil, and the current power and current alternation frequency of the upper and lower induction coils remain unchanged within time t; thereby implementing a temperature gradient temperature field on the standard segment of the test sample.

[0013] The method employs an in-situ heating and temperature control device, which includes a sample chuck, an induction heating system, a circulating water cooling system, and a temperature control system. The sample chuck is coaxially mounted on the main shaft of a centrifuge and rotates synchronously with the main shaft. The test sample is mounted on the sample chuck. The induction heating system is coaxially mounted on the centrifuge and does not rotate with the main shaft. The induction heating system and the circulating water cooling system are connected. The temperature control system is connected to both the circulating water cooling system and the test sample.

[0014] The sample chuck includes a chuck body, slots, and flanges. Flanges are coaxially mounted at both ends of the center of the chuck body. The chuck body is coaxially fixedly connected to the main shaft of the centrifuge through the flanges. Multiple slots are circumferentially arranged around the chuck body, and each slot is used to install a test sample.

[0015] The test specimen is strip-shaped and includes a mass block, a gauge section, a load-bearing section, and an assembly tenon connected in sequence. The mass block, gauge section, load-bearing section, and assembly tenon are arranged sequentially along the strip shape of the test specimen, and the assembly tenon is fitted into the slot of the sample chuck.

[0016] The induction heating system includes an upper induction coil, an upper fixing plate, a lower induction coil, and a lower fixing plate; the upper fixing plate and the lower fixing plate are fixedly arranged parallel to each other at intervals, and a sample chuck is arranged in the interval between the upper fixing plate and the lower fixing plate; the annular upper induction coil and the lower induction coil are fixed to the bottom surface of the upper fixing plate and the top surface of the lower fixing plate through the upper induction coil insulation layer and the lower induction coil insulation layer, respectively.

[0017] The circulating water cooling system includes a piping assembly installed in the induction heating system, as well as a flow inlet pipe, a flow outlet pipe, a positive electrode, an inner insulating sleeve, a metal sleeve, a negative electrode, a copper pipe, an insulating sleeve, a fixed flange, an insulating sleeve, a clamping nut, a seal, an electrode insulating sleeve, an external outlet pipe, an external positive electrode plate, an external inlet pipe, and an external negative electrode plate. An insulating sleeve for insulation between the copper pipe and the metal sleeve is fitted over the copper pipe, and a metal sleeve is fitted over the insulating sleeve. The middle of the metal sleeve is sealed in the center hole of the fixed flange by the insulating sleeve and a shaft sealing ring. The fixed flange is fixed to the experimental chamber cover of the centrifuge. The two ends of the copper pipe, the insulating sleeve, and the metal sleeve are fixed and sealed by the inner insulating sleeve and the seal, respectively. One end of the copper pipe passes through the inner insulating sleeve and is coaxially connected to the flow outlet pipe, and the copper pipe also passes through the inner insulating sleeve at one end. A positive electrode is installed at the rear end; the external positive electrode plate is electrically connected to the copper tube through the electrode insulating sleeve, so that the positive electrode is directly connected to the external positive electrode plate after passing through the copper tube; the other end of the copper tube is connected to the external water outlet pipe, so that the water outlet pipe flows directly through the copper tube and the external water outlet pipe; there is an annular pipe gap between the insulating sleeve and the metal sleeve to serve as a water inlet channel, one end of the water inlet channel is connected to the water inlet pipe through the metal pipe, and a negative electrode is installed near the end of the water inlet pipe; the external negative electrode plate is electrically connected to the metal sleeve through the clamping round nut, so that the negative electrode is connected to the external negative electrode plate after passing through the metal pipe and the metal sleeve in sequence; a through groove is opened in the pipe wall at one end of the metal sleeve that connects to the sealing element, and the through groove is connected to the external water inlet pipe, so that the water inlet pipe flows through the metal pipe, the water inlet channel, and the through groove in sequence before flowing through the external water inlet pipe;

[0018] The pipeline assembly includes a heating inlet pipe, an inlet pipe sealing sleeve, a heating outlet pipe, and an outlet pipe sealing sleeve. One end of the heating inlet pipe and the heating outlet pipe are connected to the inlet pipe sealing sleeve and the outlet pipe sealing sleeve, respectively, and to the flow inlet pipe and the flow outlet pipe. The other end of the heating inlet pipe and the heating outlet pipe are respectively connected to the inner cavity environment where the upper induction coil and the lower induction coil are located in the induction heating system. The inner cavity environments where the upper induction coil and the lower induction coil are located are interconnected.

[0019] The temperature control system includes thermocouples, thermocouple extension lines, high-speed slip rings, a data acquisition module, a data conversion and transmission module, and a high-frequency AC power supply cabinet. Thermocouples are fixed on the test sample surfaces corresponding to the upper and lower induction coils of the induction heating system. Thermocouples are connected via thermocouple extension lines, high-speed slip rings, and the data acquisition module. The data acquisition module is communicatively connected to the high-frequency AC power supply cabinet via the data conversion and transmission module. The high-frequency AC power supply cabinet is electrically connected to the external positive electrode plate and external negative electrode plate of the circulating water cooling system.

[0020] The beneficial effects of this invention are:

[0021] (1) This invention solves the limitation that radiation heating at high speed can only heat the whole sample. By changing the diameter of the inductive coil, the present invention can heat a specific area or position of the sample at high speed.

[0022] (2) By changing the diameter of the inductive coil, the present invention heats a specified area or position of the sample at high speed, thereby applying a temperature gradient to the sample along the hypergravity direction and providing test conditions under different temperatures and centrifugal forces on a single sample.

[0023] (3) This invention solves the current limitation that the radiation heating temperature cannot exceed 800°C at high speed. It can increase the local heating temperature of the test component to 1200°C at high speed.

[0024] (4) This invention solves the technical limitation that radiation heating at high speed cannot achieve rapid temperature alternation. It can apply a constant or alternating temperature load to the test component by controlling the induction heating power through a program at high speed. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the sample chuck 1.

[0026] Figure 2 This is a schematic diagram of the structure of test sample 1.1;

[0027] Figure 3 This is a schematic diagram of the structure of induction heating system 2;

[0028] Figure 4 This is a schematic diagram of the circulating water cooling system 3;

[0029] Figure 5 This is a schematic diagram of temperature control system 4;

[0030] Figure 6 This is a schematic diagram of the structure of test sample 1.1;

[0031] Figure 7 This is a schematic diagram of the structure of test sample 1.1;

[0032] Figure 8 This is a schematic diagram of the structure of test sample 1.1;

[0033] Figure 9 This is a schematic diagram of the installation of sample chuck 1 and induction heating system 2 on a centrifuge;

[0034] Figure 10 This is a process route diagram for the specific implementation of heating;

[0035] Figure 11 This is the process route diagram for heating implementation two;

[0036] Figure 12 This is the process route diagram for the third specific implementation of heating.

[0037] In the picture:

[0038] Sample chuck 1: Test specimen 1.1, chuck slot 1.2, flange 1.3;

[0039] Mass block 1.1.1, gauge section 1.1.2, load-bearing section 1.1.3, assembly tenon 1.1.4;

[0040] Induction heating system 2: 2.1 Upper induction coil, 2.2 Upper induction coil insulation layer, 2.3 Upper fixing plate, 2.4 Upper fixing screw, 2.5 Lower induction coil, 2.6 Lower induction coil insulation layer, 2.7 Lower fixing plate, 2.8 Lower fixing screw, 2.9 Connecting rod, 2.10 Nut, 2.11 Heating water inlet pipe, 2.12 Water inlet pipe sealing sleeve, 2.13 Heating water outlet pipe, 2.14 Water outlet pipe sealing sleeve;

[0041] Circulating water cooling system 3: Flow inlet pipe 3.1, connecting nut 3.2, flow outlet pipe 3.3, connecting nut 3.4, positive electrode 3.5, inner insulating sleeve 3.6, negative electrode 3.8, copper pipe 3.9, insulating sleeve 3.10, fixing flange 3.11, fixing screw 3.12, shaft sealing ring 3.13, insulating sleeve 3.14, clamping round nut 3.15, tightening nut 3.16, insulating component 3.17, sealing component 3.18, electrode insulating sleeve 3.19, sealing nut 3.20, external outlet pipe 3.21, external positive electrode plate 3.22, external inlet pipe 3.23, and external negative electrode plate 3.24;

[0042] Temperature control system 4: thermocouple 4.1, thermocouple extension cable 4.2, high-speed slip ring 4.3, data acquisition module 4.4, control software 4.5, data conversion and transmission module 4.6, high-frequency AC power supply cabinet 4.7. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0044] like Figure 9 As shown, an in-situ heating and temperature control device was designed in the specific implementation. The device includes a sample chuck 1, an induction heating system 2, a circulating water cooling system 3, and a temperature control system 4. The sample chuck 1 is coaxially mounted on the main shaft of the centrifuge and rotates synchronously with the main shaft of the centrifuge. The test sample 1.1 is mounted on the sample chuck 1. The induction heating system 2 is coaxially mounted on the centrifuge and remains fixed without rotating with the main shaft of the centrifuge. The induction heating system 2 is connected to the circulating water cooling system 3. The temperature control system 4 is connected to the circulating water cooling system 3 and the test sample 1.1 respectively.

[0045] The centrifuge is a supergravity centrifuge.

[0046] like Figure 1 As shown, the sample chuck 1 is used to install test samples and is connected to the centrifuge via the main shaft. It includes a chuck body, slots 1.2 and flanges 1.3. The flanges 1.3 are coaxially fixed at both ends of the center of the chuck body. The chuck body is coaxially fixedly connected to the main shaft of the centrifuge via the flanges 1.3. Multiple slots 1.2 are circumferentially arranged around the chuck body. The multiple slots 1.2 are spaced apart circumferentially. Each slot 1.2 is used to install one test sample 1.1.

[0047] Flange 1.3 is used to connect sample chuck 1 to centrifuge spindle. During the experiment, the high-speed rotation of centrifuge spindle drives sample chuck 1 to rotate, thereby applying centrifugal load to test sample 1.1.

[0048] The slot 1.2 is mainly used to fix the high-speed rotating test specimen 1.1. The mounting tenon 1.1.4 of the test specimen 1.1 is installed in the slot 1.2, so that the sample chuck 1 drives the test specimen 1.1 to rotate together when it rotates.

[0049] like Figure 2 As shown, the test specimen 1.1 is made of a metal material used for testing performance and is strip-shaped. It includes a mass block 1.1.1, a reference segment 1.1.2, a load-bearing segment 1.1.3, and an assembly tenon 1.1.4 connected in sequence. The mass block 1.1.1, reference segment 1.1.2, load-bearing segment 1.1.3, and assembly tenon 1.1.4 are all arranged sequentially along the strip shape of the test specimen 1.1. Specifically, the mass block 1.1.1, reference segment 1.1.2, load-bearing segment 1.1.3, and assembly tenon 1.1.4 are arranged radially outward from the slot 1.2 of the sample chuck 1, and the assembly tenon 1.1.4 is fitted into the slot 1.2 of the sample chuck 1.

[0050] In the specific implementation, the width of the tenon 1.1.4 and the groove width of the chuck 1.2 of the sample chuck 1 are both greater than the width of the mass block 1.1.1, the gauge section 1.1.2 and the load-bearing section 1.1.3, so that the test specimen 1.1 can be stably embedded and positioned when it is driven to rotate at high speed by the sample chuck 1.

[0051] Mass block 1.1.1 is used to apply a centrifugal stress to the standard moment section 1.1.3 through the centrifugal force generated by its own weight at high speeds. The mass of mass block 1.1.1 is m, its effective radius is r, and its rotational speed is ω. Therefore, the centrifugal force F generated by mass block 1.1.1 is F = mrω. 2 The weight m of mass block 1.1.1 depends on the fracture strength of the material under experimental conditions.

[0052] Gauge segment 1.1.2 is connected to mass block 1.1.1 and is used to bear the centrifugal stress and thermal stress loads applied by mass block 1.1.1 under high-speed rotation and high temperature. The shape of gauge segment 1.1.2 can be changed according to actual needs.

[0053] The load-bearing section 1.1.3 is used to connect the gauge section 1.1.2 and the assembly tenon 1.1.4.

[0054] According to experimental requirements, test sample 1.1 can be designed as follows: Figure 2 , Figures 6-8 The structure.

[0055] The center of the gauge length 1.1.2 of the test specimen 1.1 is provided with one or both of a thermocouple and a strain gauge.

[0056] like Figure 3 As shown, the induction heating system 2 is used to heat the high-speed rotating sample in situ, applying a temperature load to a designated area of ​​the test sample 1.1. It includes an upper induction coil 2.1, an upper fixing plate 2.3, a lower induction coil 2.5, and a lower fixing plate 2.7. The upper fixing plate 2.3 and the lower fixing plate 2.7 are fixedly arranged parallel to each other at intervals. In practice, the centrifuge spindle rotatably passes through the upper fixing plate 2.3. A sample chuck 1 is arranged in the gap between the upper fixing plate 2.3 and the lower fixing plate 2.7. The upper fixing plate 2.3 and the lower fixing plate 2.7 are supported and fixed by a connecting rod 2.9, with a nut 2.10 installed at the outer end of the connecting rod 2.9. The annular upper induction coil 2.1 and lower induction coil 2.5 are fixed to the bottom surface of the upper fixing plate 2.3 and the top surface of the lower fixing plate 2.7 by the upper induction coil insulation layer 2.2 and the lower induction coil insulation layer 2.6, respectively.

[0057] Both the upper fixing plate 2.3 and the lower fixing plate 2.7 are annular plates, and both the upper induction coil 2.1 and the lower induction coil 2.5 are integral annular coils.

[0058] Specifically, the upper induction coil 2.1 and the lower induction coil 2.5 are respectively encased in the inner cavities of the upper induction coil insulation layer 2.2 and the lower induction coil insulation layer 2.6. The inner cavities of the upper induction coil insulation layer 2.2 and the lower induction coil insulation layer 2.6 are connected by a pipe. The upper induction coil insulation layer 2.2 and the lower induction coil insulation layer 2.6 are respectively fixed to the bottom surface of the upper fixing plate 2.3 and the top surface of the lower fixing plate 2.7 by the upper fixing screw 2.4 and the lower fixing screw 2.8.

[0059] The upper induction coil 2.1 is wrapped inside the upper induction coil insulation layer 2.2 to prevent conductivity and for insulation purposes. Then, the upper induction coil 2.1 with the insulation layer is fixed to the upper fixing plate 2.3 by the upper fixing screw 2.4 to form the upper induction coil. The lower induction coil 2.5 is wrapped inside the lower induction coil insulation layer 2.6 and is also fixed to the lower fixing plate 2.7 by the lower fixing screw 2.8 to form the lower induction coil. Subsequently, the upper fixing plate 2.3 and the lower fixing plate 2.7 are assembled together by the connecting rod 2.9 and the nut 2.10.

[0060] When an alternating current is applied, the metal material placed between the upper induction coil 2.1 and the lower induction coil 2.5 generates an induced current I or eddy current under the action of the alternating magnetic field. The eddy current generates heat through a resistive conductor, and then heats the metal material through thermal conduction. The Joule heat Q generated by the induced current I is I. 2 RtR is the resistance of the metallic material, and t is time. During induction heating, the heating temperature is controlled by adjusting the AC frequency f, the distance between the sample and the upper induction coil 2.1 and the lower induction coil 2.5, and the heating power.

[0061] like Figure 4 As shown, the function of the circulating water cooling system 3 is to cool the copper tubes in the upper induction coil 2.1 and the lower induction coil 2.5 in the induction heating system 2. It includes pipe assemblies installed in the induction heating system 2, as well as a flow inlet pipe 3.1, a flow outlet pipe 3.3, a positive electrode 3.5, an inner insulating sleeve 3.6, a metal sleeve 3.7, a negative electrode 3.8, a copper tube 3.9, an insulating pressure sleeve 3.10, a fixed flange 3.11, an insulating pressure sleeve 3.14, a clamping round nut 3.15, a seal 3.18, an electrode insulating pressure sleeve 3.19, an external outlet pipe 3.21, an external positive electrode plate 3.22, an external inlet pipe 3.23, and an external negative electrode plate 3.24.

[0062] An insulating sleeve 3.10 and a metal sleeve 3.7 are coaxially fitted from the outer radial direction of the copper tube 3.9. An insulating sleeve 3.10 for insulation with the metal sleeve 3.7 is fixedly and coaxially fitted outside the copper tube 3.9. The metal sleeve 3.7 is coaxially fitted outside the insulating sleeve 3.10, thus maintaining insulation between the copper tube 3.9 and the metal sleeve 3.7. The middle part of the metal sleeve 3.7 is sealed in the center hole of the fixed flange 3.11 through the insulating sleeve 3.14 and the shaft sealing ring 3.13. The fixed flange 3.11 is fixed to the experimental chamber cover of the centrifuge by the fixing screw 3.12. The two ends of the copper tube 3.9, the insulating sleeve 3.10 and the metal sleeve 3.7 are fixed and sealed by the inner insulating sleeve 3.6 and the sealing element 3.18, respectively, which provide insulation and prevent water leakage.

[0063] One end of the copper pipe 3.9 passes through the inner insulating sleeve 3.6 and is coaxially connected to the water outlet pipe 3.3. A positive electrode 3.5 is installed at the end of the copper pipe 3.9 after passing through the inner insulating sleeve 3.6. An external positive electrode plate 3.22 is electrically connected to the copper pipe 3.9 through multiple electrode insulating sleeves 3.19. Specifically, at least two electrode insulating sleeves 3.19 are threaded onto the external threads of the copper pipe 3.9. An external positive electrode plate 3.22 is pressed between two adjacent electrode insulating sleeves 3.19. The external positive electrode plate 3.22 passes through the gap between two adjacent electrode insulating sleeves 3.19 and is electrically connected to the external positive electrode plate 3.22. This allows the positive electrode 3.5 to be directly electrically connected to the external positive electrode plate 3.22 via the copper pipe 3.9.

[0064] The other end of the copper pipe 3.9 is connected to the external water outlet pipe 3.21 via the sealing nut 3.20, so that the water outlet pipe 3.3 can flow directly through the copper pipe 3.9 and the external water outlet pipe 3.21;

[0065] An annular pipe gap exists between the insulating sleeve 3.10 and the metal sleeve 3.7 to serve as a water inlet channel. The water inlet channel is connected to a flow-through water inlet pipe 3.1 at one end near the inner insulating sleeve 3.6 via a metal pipe. A negative electrode 3.8 is positioned near the end of the flow-through water inlet pipe 3.1. An external negative electrode plate 3.24 is electrically connected to the metal sleeve 3.7 via multiple clamping round nuts 3.15. Specifically, at least two clamping round nuts 3.15 are threaded onto the external threads of the metal sleeve 3.7. An external negative electrode plate 3.24 is clamped between adjacent clamping round nuts 3.15, and the external negative electrode plate 3.24 passes through the gap between adjacent clamping round nuts 3.15 to maintain electrical connection. This allows the negative electrode 3.8 to be electrically connected to the external negative electrode plate 3.24 after sequentially passing through the metal pipe and the metal sleeve 3.7.

[0066] The metal sleeve 3.7 has a through groove on the end wall between the external positive electrode plate 3.22 and the external negative electrode plate 3.24 connected to the sealing element 3.18. The through groove is connected to the external water inlet pipe 3.23. Specifically, an insulating element 3.17 is fitted on the metal sleeve 3.7 around the through groove by a tightening nut 3.16. The external water inlet pipe 3.23 passes through the through hole and the through groove on the insulating element 3.17. This allows the water inlet pipe 3.1 to flow through the metal pipe, the water inlet channel, the through groove, and then to the external water inlet pipe 3.23.

[0067] More specifically, copper tube 3.9 is a hollow long copper tube with an insulating sleeve 3.10 installed on its outer circumference for insulation, and a sealing ring is installed to prevent air leakage from the experimental chamber.

[0068] The inlet pipe 3.1 is connected to the heating inlet pipe 2.11 of the induction heating system 2 via the connecting nut 3.2; the outlet pipe 3.3 is connected to the heating outlet pipe 2.13 of the induction heating system 2 via the connecting nut 3.4; the positive electrode 3.5 is installed on the outer periphery of the outlet pipe 3.3 to ensure that the cooling water can cool the positive electrode 3.5; the negative electrode 3.8 is installed on the outer periphery of the inlet pipe 3.1 to ensure that the cooling water can cool the negative electrode 3.8.

[0069] The metal sleeve 3.7 is installed on the chamber cover of the experimental chamber via a flange 3.11 using six fixing screws 3.12. A axial sealing ring 3.13 prevents air leakage, and an insulating sleeve 3.14 provides insulation to prevent electrical leakage. An external negative electrode plate 3.24 is fixedly installed on the insulating sleeve 3.14 using three clamping round nuts 3.15. An external water inlet pipe 3.23 is connected to the through groove of the copper pipe 3.9 via a tightening nut 3.16 and an insulating component 3.17. The tightening nut 3.16 facilitates replacement or maintenance of the external water inlet pipe 3.23, while the insulating component 3.17 prevents motor leakage. An external positive electrode plate 3.22 is fixed on the sealing component 3.18 via an electrode insulating sleeve 3.19. An external water outlet pipe 3.21 is connected to the copper pipe of the flowing water outlet pipe 3.3 via a sealing nut 3.20 on the electrode insulating sleeve 3.19.

[0070] The piping assembly includes a heating inlet pipe 2.11, an inlet pipe sealing sleeve 2.12, a heating outlet pipe 2.13, and an outlet pipe sealing sleeve 2.14. One end of the heating inlet pipe 2.11 and the heating outlet pipe 2.13 are connected to the inlet pipe sealing sleeve 2.12 and the outlet pipe sealing sleeve 2.14, and the flow inlet pipe 3.1 and the flow outlet pipe 3.3, respectively. The other end of the heating inlet pipe 2.11 and the heating outlet pipe 2.13 are connected to the inner cavity environment where the upper induction coil 2.1 and the lower induction coil 2.5 are located in the induction heating system 2, respectively. The inner cavity environments where the upper induction coil 2.1 and the lower induction coil 2.5 are located are interconnected.

[0071] Specifically, the other end of the heating water inlet pipe 2.11 is connected via the water inlet pipe sealing sleeve 2.12, the connecting nut 3.2 and the flow water inlet pipe 3.1, respectively, and the other end of the heating water outlet pipe 2.13 is connected via the water outlet pipe sealing sleeve 2.14, the connecting nut 3.4 and the flow water outlet pipe 3.3, respectively.

[0072] External outlet pipe 3.21 and external inlet pipe 3.23 are connected to the inlet and outlet of the circulating water machine, respectively. In practice, external outlet pipe 3.21 is connected to the inlet pipe of the circulating water machine, and external inlet pipe 3.23 is connected to the outlet pipe of the circulating water machine, forming a closed circulating water cooling system to cool the induction heating system 2.

[0073] Positive electrode 3.5 and negative electrode 3.8 are electrically connected to the upper induction coil 2.1 and the lower induction coil 2.5, respectively. External positive electrode plate 3.22 and external negative electrode plate 3.24 are connected to the positive and negative terminals of an external power supply, respectively. In a specific implementation, external positive electrode plate 3.22 is connected to the positive terminal of the high-frequency AC power supply cabinet 4.7, which serves as the AC power supply, and external negative electrode plate 3.24 is connected to the negative terminal of the high-frequency AC power supply cabinet 4.7, forming a closed-loop circuit to provide power to the induction heating system 2.

[0074] The inner cavity containing the upper induction coil 2.1 is connected to the heating water inlet pipe 2.11, which is connected to the circulating water inlet pipe 3.1 of the circulating water cooling system 3 via the water inlet pipe sealing sleeve 2.12. The inner cavity containing the lower induction coil 2.5 is connected to the heating water outlet pipe 2.13, which is connected to the circulating water outlet pipe 3.3 of the circulating water cooling system 3 via the water outlet pipe sealing sleeve 2.14. The cooling water provided by the cooling system 3 cools the copper pipe.

[0075] like Figure 5 As shown, the function of the temperature control system 4 is to ensure that the test sample 1.1 is heated to a predetermined temperature and maintained at that temperature until the end of the experiment by controlling the heating power of the induction power supply. The system includes thermocouples 4.1, thermocouple extension lines 4.2, high-speed slip rings 4.3, data acquisition modules 4.4, data conversion and transmission modules 4.6, and a high-frequency AC power supply cabinet 4.7. Thermocouples 4.1 are fixedly mounted on the surface of the test sample 1.1 corresponding to the upper induction coil 2.1 and lower induction coil 2.5 of the induction heating system 2. Thermocouples 4.1 are connected via thermocouple extension lines 4.2, high-speed slip rings 4.3, and data acquisition modules 4.4. Thermocouple extension lines 4.2 pass through the sample chuck 1 and the centrifuge spindle before being electrically connected to the high-speed slip ring 4.3, which is positioned on the centrifuge spindle. The data acquisition module 4.4 is communicatively connected to the high-frequency AC power supply cabinet 4.7 via the data conversion and transmission modules 4.6. The high-frequency AC power supply cabinet 4.7 is electrically connected to the circulating water machine, the external positive electrode plate 3.22, and the external negative electrode plate 3.24 of the circulating water cooling system 3.

[0076] In the specific implementation, control software 4.5 is also set up, which is connected to data acquisition module 4.4 and data conversion and transmission module 4.6 respectively.

[0077] During the experiment, thermocouple 4.1 was welded to the center of the upper induction coil 2.1 and the lower induction coil 2.5 corresponding to the test sample 1.1. Then, thermocouple 4.1 was connected to the high-speed slip ring 4.3 through the hollow spindle of the centrifuge via thermocouple extension wire 4.2. It was then connected to the data acquisition module 4.4, control software 4.5, and data conversion and transmission module 4.6 via wires. Finally, the control signal line was connected to the high-frequency AC power supply cabinet 4.7 to form a temperature control system.

[0078] The present invention also designs different specimens to better test the mechanical properties of the metal materials in the specimens.

[0079] The structure of the first test specimen 1.1 is shown below. Figure 2 , for grooved specimens and related similar structures;

[0080] The structure of the second type of test specimen 1.1 is shown below. Figure 6 , for flat plate specimens and related similar structures;

[0081] The structure of the third type of test specimen 1.1 is shown below. Figure 7 , for round bar specimens and related similar structures;

[0082] The structure of the fourth test specimen 1.1 is shown below. Figure 8 , structural gradient specimens and related similar structures.

[0083] The in-situ heating and temperature control method of the present invention is as follows:

[0084] While the centrifuge spindle is rotating, a temperature load is applied to the test sample 1.1 by the induction heating system 2. The application of the temperature load includes applying a constant and uniform temperature field according to the uniform temperature heating mode, applying a periodically changing alternating temperature field according to the periodically changing alternating temperature heating mode, and applying a temperature field with a fixed range and a gradually changing gradient according to the temperature gradient heating mode.

[0085] This invention provides various in-situ heating modes for high-speed environments, offering new experimental conditions for material performance testing under different temperatures and speeds. The heating modes of this invention include, but are not limited to, the following:

[0086] Heating Mode 1: A uniform temperature heating mode is applied to the standard section 1.1.2 of the test sample 1.1 at high speed. Figure 10 .

[0087] The experimental materials are of the same type. During the experiment, the distance h between the standard segment 1.1.2 and the upper induction coil 2.1 and the lower induction coil 2.5 remains the same, and the heating power and heating frequency remain unchanged within time t. A constant and uniform temperature field is applied to the standard segment 1.1.2.

[0088] Heating Mode Two: A periodic alternating temperature heating mode is applied to the standard section 1.1.2 of the test sample 1.1 at high speed. Figure 11 .

[0089] The experimental materials are of the same type. During the experiment, the distance h between the standard segment 1.1.2 and the upper induction coil 2.1 and the lower induction coil 2.5 remains the same. The heating frequency remains unchanged, but the heating power is periodically changed within time t. An alternating temperature field of T1 is applied to the standard segment 1.1.2 within time t1 and T2 within time t2.

[0090] Heating Mode 3: A temperature gradient heating mode that applies constant temperature to the standard section 1.1.2 of the test sample 1.1 at high speed. Figure 12 .

[0091] Using the same type of experimental materials, the standard segment 1.1.2 of test specimen 1.1 was machined into an arc with radius R. During the experiment, the distance h between the lowest point of the arc of standard segment 1.1.2 and the upper induction coil 2.1 and the lower induction coil 2.5 remained constant, and the heating power and heating frequency remained constant within time t. Since the distance from the arc-shaped standard segment 1.1.2 to the induction coils 2.1 and 2.5 changes continuously, according to the principle of induction heating, under the same power and frequency conditions, the sample heating temperature is inversely proportional to its distance from the induction coil. Therefore, a constant temperature gradient was applied to the standard segment 1.1.2 of test specimen 1.1.

[0092] The material property testing process under high-speed-high-temperature coupling using the method of this invention is as follows:

[0093] Step 1: Determine the centrifuge speed and disc radius based on the experimental conditions;

[0094] Step 2: Determine the dimensions and weight of mass block 1.1.1;

[0095] Step 3: Determine the dimensions and geometric center of gauge length segment 1.1.2;

[0096] Step 4: Determine the experimental temperature and the centrifugal stress applied at the geometric center of gauge length 1.1.2;

[0097] Step 5: Install the test specimen 1.1 onto the sample chuck 1 using the tenon 1.1.4, and determine the distance between the geometric center of the gauge length section 1.1.2 and the center of the rotating shaft;

[0098] Step 6: Determine the rotational speed corresponding to the centrifugal stress value at the geometric center of gauge length segment 1.1.2 through finite element analysis;

[0099] Step 7: Weld the temperature control thermocouple 4.1 to the geometric center of the gauge length section 1.1.2 of the sample, and connect the temperature extension wire 4.2 of the temperature control thermocouple to the temperature control system 4 through the centrifuge spindle;

[0100] Step 8: If testing strain, weld a strain gauge at the geometric center of the gauge length section 1.1.2 of the specimen, and connect the strain gauge extension wire to the data acquisition module 4.4 through the centrifuge spindle to realize real-time acquisition of strain signals;

[0101] Step 9: Start heating system 2 to apply a temperature load to the sample. Hold the sample at the predetermined temperature for 30 minutes.

[0102] During the temperature control process, the power and frequency of the induced current are adjusted by the temperature control system 4 according to the temperature set in the experiment. Different temperatures are applied in this experiment 1.1.

[0103] Step 10: Start the centrifuge and bring the rotation speed up to the speed corresponding to the centrifugal stress value;

[0104] Step 11: Maintain constant temperature and rotation speed until the sample breaks;

[0105] Step 12: After the sample breaks, the heating and temperature control system is powered off, the centrifuge is powered off, and the sample is air-cooled to room temperature.

Claims

1. A method for in-situ heating and temperature control under high rotation speed and high temperature, characterized in that: While the centrifuge spindle is rotating, a temperature load is applied to the test sample (1.1) by the induction heating system (2) at the same time. The application of the temperature load includes applying a constant and uniform temperature field according to the uniform temperature heating mode, applying a periodically changing alternating temperature field according to the periodically changing alternating temperature heating mode, and applying a temperature field with a fixed range and a gradient change according to the temperature gradient heating mode. The method employs an in-situ heating and temperature control device, which includes a sample chuck (1), an induction heating system (2), a circulating water cooling system (3), and a temperature control system (4). The sample chuck (1) is coaxially mounted on the main shaft of the centrifuge and rotates synchronously with the main shaft of the centrifuge. The test sample (1.1) is mounted on the sample chuck (1). The induction heating system (2) is coaxially mounted on the centrifuge and does not rotate with the main shaft of the centrifuge. The induction heating system (2) is connected to the circulating water cooling system (3). The temperature control system (4) is connected to the circulating water cooling system (3) and the test sample (1.1) respectively. The circulating water cooling system (3) includes a pipe assembly installed in the induction heating system (2), a flow inlet pipe (3.1), a flow outlet pipe (3.3), a positive electrode (3.5), an inner insulating sleeve (3.6), a metal sleeve (3.7), a negative electrode (3.8), a copper pipe (3.9), an insulating sleeve (3.10), a fixed flange (3.11), an insulating sleeve (3.14), a clamping round nut (3.15), a seal (3.18), an electrode insulating sleeve (3.19), an external outlet pipe (3.21), an external positive electrode plate (3.22), an external inlet pipe (3.23), and an external negative electrode plate (3.24); copper pipe (3.24). 9) An insulating sleeve (3.10) is fitted on the outside for insulation with the metal sleeve (3.7), and the metal sleeve (3.7) is fitted on the outside of the insulating sleeve (3.10); the middle part of the metal sleeve (3.7) is sealed in the center hole of the fixed flange (3.11) through the insulating sleeve (3.14) and the shaft sealing ring (3.13), and the fixed flange (3.11) is fixed on the experimental chamber cover of the centrifuge. The two ends of the copper tube (3.9), the insulating sleeve (3.10) and the metal sleeve (3.7) are fixed and sealed by the inner insulating sleeve (3.6) and the sealing element (3.18) respectively; one end of the copper tube (3.9) passes through the inner insulating sleeve (3.6) and then flows into the water outlet pipe (3.18). 3) Coaxial connection, with a positive electrode (3.5) installed at the end of the copper tube (3.9) after passing through the inner insulating sleeve (3.6); the external positive electrode plate (3.22) is electrically connected to the copper tube (3.9) through the electrode insulating sleeve (3.19), so that the positive electrode (3.5) is directly connected to the external positive electrode plate (3.22) through the copper tube (3.9); the other end of the copper tube (3.9) is connected to the external water outlet pipe (3.21), so that the water outlet pipe (3.3) flows directly through the copper tube (3.9) and the external water outlet pipe (3.21); there is an annular pipe gap between the insulating sleeve (3.10) and the metal sleeve (3.7) to serve as a water inlet channel, the water inlet channel one The end is connected to the metal pipe and the water inlet pipe (3.1). The water inlet pipe (3.1) has a negative electrode (3.8) near its end. The external negative electrode plate (3.24) is electrically connected to the metal sleeve (3.7) through the tightening round nut (3.15), so that the negative electrode (3.8) is electrically connected to the external negative electrode plate (3.24) after passing through the metal pipe and the metal sleeve (3.7) in sequence. The metal sleeve (3.7) has a through groove on the pipe wall at one end of the connecting seal (3.18). The through groove is connected to the external water inlet pipe (3.23) in a flow-through manner, so that the water inlet pipe (3.1) is connected to the external water inlet pipe (3.23) after passing through the metal pipe, the water inlet channel, and the through groove in sequence. The pipeline assembly includes a heating inlet pipe (2.11), an inlet pipe sealing sleeve (2.12), a heating outlet pipe (2.13), and an outlet pipe sealing sleeve (2.14). One end of the heating inlet pipe (2.11) and the heating outlet pipe (2.13) are connected to the inlet pipe sealing sleeve (2.12), the outlet pipe sealing sleeve (2.14), the flow inlet pipe (3.1), and the flow outlet pipe (3.3), respectively. The other end of the heating inlet pipe (2.11) and the heating outlet pipe (2.13) are connected to the inner cavity environment where the upper induction coil (2.1) and the lower induction coil (2.5) are located in the induction heating system (2). The inner cavity environments where the upper induction coil (2.1) and the lower induction coil (2.5) are located are interconnected.

2. The in-situ heating and temperature control method under high rotation speed and high temperature as described in claim 1, characterized in that: The uniform heating mode is as follows: the distance h between the standard segment (1.1.2) of the test sample (1.1) and the upper induction coil (2.1) and the lower induction coil (2.5) is kept the same, and the current power and current alternation frequency of the upper induction coil (2.1) and the lower induction coil (2.5) remain unchanged within time t, thereby applying a constant and uniform temperature field to the standard segment (1.1.2).

3. The in-situ heating and temperature control method under high rotation speed and high temperature as described in claim 1, characterized in that: The periodic alternating temperature heating mode is as follows: the distance h between the standard segment (1.1.2) of the test sample (1.1) and the upper induction coil (2.1) and the lower induction coil (2.5) is kept the same. The alternating frequency of the current of the upper induction coil (2.1) and the lower induction coil (2.5) remains unchanged, but the current power of the upper induction coil (2.1) and the lower induction coil (2.5) is periodically changed within time t, thereby giving the standard segment (1.1.2) a continuously periodically repeating alternating temperature field composed of the temperature T1 applied within time t1 and the temperature T2 applied within time t2.

4. The in-situ heating and temperature control method under high rotation speed and high temperature as described in claim 1, characterized in that: The heating mode of the temperature gradient is as follows: the standard segment (1.1.2) of the test sample (1.1) is processed into an arc with a radius of R. The lowest point of the arc of the standard segment (1.1.2) is kept at the same distance h between the upper induction coil (2.1) and the lower induction coil (2.5), and the current power and current alternation frequency of the upper induction coil (2.1) and the lower induction coil (2.5) remain unchanged within time t; thereby implementing a temperature gradient temperature field on the standard segment (1.1.2) of the test sample (1.1).

5. The in-situ heating and temperature control method under high rotation speed and high temperature as described in claim 1, characterized in that: The sample chuck (1) includes a chuck body, a chuck groove (1.2) and a flange (1.3). The flange (1.3) is coaxially installed at both ends of the center of the chuck body. The chuck body is coaxially fixedly connected to the main shaft of the centrifuge through the flange (1.3). Multiple chuck grooves (1.2) are opened around the circumference of the chuck body. The multiple chuck grooves (1.2) are arranged at intervals along the circumference. Each chuck groove (1.2) is used to install a test sample (1.1).

6. The in-situ heating and temperature control method under high rotation speed and high temperature as described in claim 1, characterized in that: The test specimen (1.1) is strip-shaped and includes a mass block (1.1.1), a standard section (1.1.2), a load-bearing section (1.1.3), and an assembly tenon (1.1.4) connected in sequence. The mass block (1.1.1), the standard section (1.1.2), the load-bearing section (1.1.3), and the assembly tenon (1.1.4) are all arranged in sequence along the strip shape of the test specimen (1.1). The assembly tenon (1.1.4) is fitted into the slot (1.2) of the sample chuck (1).

7. The in-situ heating and temperature control method under high rotation speed and high temperature as described in claim 1, characterized in that: The induction heating system (2) includes an upper induction coil (2.1), an upper fixing plate (2.3), a lower induction coil (2.5), and a lower fixing plate (2.7). The upper fixing plate (2.3) and the lower fixing plate (2.7) are fixedly arranged parallel to each other at intervals. A sample chuck (1) is arranged in the interval between the upper fixing plate (2.3) and the lower fixing plate (2.7). The annular upper induction coil (2.1) and the lower induction coil (2.5) are fixed to the bottom surface of the upper fixing plate (2.3) and the top surface of the lower fixing plate (2.7) through the upper induction coil insulation layer (2.2) and the lower induction coil insulation layer (2.6), respectively.

8. The in-situ heating and temperature control method under high rotation speed and high temperature as described in claim 1, characterized in that: The temperature control system (4) includes a thermocouple (4.1), a thermocouple extension line (4.2), a high-speed slip ring (4.3), a data acquisition module (4.4), a data conversion and transmission module (4.6), and a high-frequency AC power supply cabinet (4.7). Thermocouples (4.1) are fixed on the test sample (1.1) corresponding to the upper induction coil (2.1) and the lower induction coil (2.5) of the induction heating system (2). Thermocouples (4.1) are connected via thermocouple extension line (4.2), high-speed slip ring (4.3), and data acquisition module (4.4). Data acquisition module (4.4) is connected to high-frequency AC power supply cabinet (4.7) via data conversion and transmission module (4.6). High-frequency AC power supply cabinet (4.7) is electrically connected to external positive electrode plate (3.22) and external negative electrode plate (3.24) of circulating water cooling system (3).

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