Current-carrying friction and wear detection system and detection method

Abstract

The present application relates to the technical field of current-carrying friction and wear detection and analysis technology, and particularly relates to a current-carrying friction and wear detection system and a detection method.The present application provides a current-carrying friction and wear detection system and a detection method.The system comprises a base and a box arranged on the base;the top of the box is provided with a movable upper grinding head;the box is provided with a lower grinding head;the upper grinding head and the lower grinding head can be close to or away from each other;when the upper grinding head and the lower grinding head are in contact, the contact is surface contact;the lower part of the lower grinding head is provided with a tapered tip;the tapered tip is detachably arranged on the box.The present application aims to solve the technical problem that there is no test machine in the prior art that can truly reflect the change of the physicochemical properties of materials caused by friction and related factors during the real electromagnetic emission process.

Description

Technical Field

[0001] This invention relates to the technical field of current-carrying friction and wear detection and analysis technology, and particularly to a current-carrying friction and wear detection system and detection method. Background Technology

[0002] Electromagnetic launch technology uses electromagnetic fields to generate electromagnetic force, converting electrical energy into kinetic energy. It can be used in spacecraft launches, high-speed train acceleration, and industrial testing, offering advantages such as rapid acceleration, high energy conversion efficiency, and low cost, making it a highly promising new technology. An electromagnetic launch system typically consists of a high-power power supply, two parallel rails, and an armature. During electromagnetic launch, the current output from the power supply flows from one rail through the armature to the other. The current flowing through the armature interacts with a strong magnetic field, propelling the armature with an extremely high Ampere force until it leaves the rail. Because the rail surface must withstand extremely high current density, extremely high local temperatures, and high-intensity mechanical friction during electromagnetic launch, the rail surface material is highly susceptible to melting, ablation, and peeling damage. In severe cases, this can lead to rail structure failure, affecting launch reliability and safety. Therefore, studying the wear failure mechanism of electromagnetic rails and its countermeasures has become a research hotspot in the field. To accurately simulate real-world conditions, using a friction and wear testing machine to test the rail structure, rail and coating material properties is a common practice. However, there is currently no dedicated friction and wear testing equipment for electromagnetic launch orbits. Researchers generally use general-purpose friction and wear testing machines, simplifying the test conditions for related experiments and tests. Friction and wear tests using general-purpose friction and wear testing machines differ significantly from the actual friction and wear process during electromagnetic launch, and the data obtained cannot reflect the wear of the orbital materials during electromagnetic launch. This is mainly reflected in the following aspects:

[0003] (1) Differences in test parameters: The electromagnetic launch process involves high-speed friction between the track surface and the armature, with a maximum speed of several thousand meters per second, while the maximum speed of a general-purpose friction and wear testing machine is far below this level. When the armature slides on the track surface, the friction and wear mechanisms between the two are completely different at low and high speeds. In the actual electromagnetic launch process, the armature is accelerated by electromagnetic force, and its running speed accelerates from 0 to a super-high speed of several thousand meters per second in a short period of time, while the general-purpose friction and wear testing machine maintains a uniform speed for most of its running path, which does not match the actual motion state. Although a general-purpose friction and wear testing machine with current-carrying friction and wear testing function can apply voltage between the upper and lower grinding heads, and when the two contact and begin to slide relative to each other, the current flows through the two in sequence, which can be used for current-carrying friction and wear testing of materials. However, the general-purpose friction and wear testing machine is a laboratory device, and the power of the external power supply used to generate the current is usually small, and its output voltage is often less than 10 V. During electromagnetic launch, the current between the armature and the track surface can reach up to millions of amperes. When such a current passes through the guide rail surface, the friction and wear between the guide rail and the armature, as well as the arc erosion mechanism between them, are completely different from the current-carrying friction and wear between the upper and lower grinding heads achieved using a general-purpose friction and wear testing machine.

[0004] (2) Differences in contact form: In the design of electromagnetic track and armature structure, in order to reduce local peak current and avoid track surface damage caused by current ablation, the cross-section at the top of the track is usually designed as an arc, and the top of the cross-section on the side of the armature that contacts the track is correspondingly designed as an arc coupled to the top of the track. During electromagnetic launch, the arc surfaces between the armature and the track come into contact with each other and generate friction, and the contact form between the two is surface contact. However, when a general-purpose testing machine uses standard samples for testing, due to the limitations of equipment size and fixtures, the armature material is usually made into a spherical or cylindrical shape of a specific size as the upper grinding head for friction and wear testing, and the track material is made into a block or plate of a specific size as the lower grinding head for friction and wear testing. The contact form between the two in the test is point contact or micro-area surface contact. Since different contact forms affect the key influencing factors of friction and wear performance such as current, temperature and force on the sample surface, the general-purpose testing machine is not suitable for friction and wear testing to simulate electromagnetic launch.

[0005] (3) Difference in heat accumulation: During electromagnetic emission, the armature is accelerated by electromagnetic force and slides at high speed along the track. The contact point between the armature and the guide rail surface generates instantaneous high temperature, which gradually decreases as the armature moves away. However, in general-purpose testing machines, the upper grinding head often generates reciprocating friction with the lower grinding head along a short (<25 cm) straight or circular path. Due to the limitations of sample size and testing machine size, the relative sliding path length of the friction pair is limited. Therefore, the heat generated by friction continuously accumulates in the upper and lower grinding heads. To ensure safety, the testing machine is usually installed in a closed chamber, which further slows down heat dissipation and seriously affects the accuracy of the test results. In addition, in high-temperature friction and wear tests, the sample and the chamber are in a high-temperature state after the test, making it impossible to take samples in time, which seriously affects the test efficiency.

[0006] Research on electromagnetic launch technology still faces the challenge of a lack of testing equipment for friction and wear performance. Furthermore, due to this lack of equipment, there is no suitable method for detecting and evaluating friction and wear on the surface of electromagnetic tracks during electromagnetic launch. Based on this situation, it is necessary to propose a testing machine that can accurately reflect the changes in the physicochemical properties of materials caused by friction and related factors during actual electromagnetic launch, and to develop a method for detecting and evaluating current-carrying friction and wear on the surface of electromagnetic tracks based on this testing machine. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a current-carrying friction and wear detection system and method, which aims to solve the technical problem that there is no testing machine in the prior art that can truly reflect the changes in the physical and chemical properties of materials due to friction and related factors during real electromagnetic emission.

[0008] To achieve the above objectives, in a first aspect, the present invention proposes a current-carrying friction and wear detection system, comprising a base and a housing disposed on the base; a movable upper grinding head is disposed on the top of the housing, and a lower grinding head is disposed inside the housing, wherein the upper grinding head and the lower grinding head can move closer to or further away from each other, and the upper grinding head and the lower grinding head are in surface contact when in contact; a conical tip is disposed below the lower grinding head, and the conical tip is detachably disposed on the housing.

[0009] Preferably, the outer wall of the box is made of thermal insulation material, and the inner wall of the box is made of a metal material with good thermal conductivity; a circulating water channel is provided inside the box, and the circulating water in the first water circulation system flows through the circulating water channel to achieve heat exchange with the box.

[0010] Preferably, the tip of the cone is coated with an ultra-low surface energy coating; the upper grinding head is mounted on an upper grinding head fixture, the upper grinding head fixture is mounted on a motion device, and the motion device is equipped with an ultra-high speed motor that can drive the upper grinding head fixture to move and lift in a plane.

[0011] Preferably, the upper grinding head is provided with an array of through holes and a temperature sensor is installed thereon. When the upper grinding head contacts the lower grinding head, the temperature sensor is close to the surface of the lower grinding head.

[0012] Preferably, an electric heater is installed inside the enclosure and connected to the control system via a data cable; a temperature sensor is installed on the inner wall of the enclosure; and an aviation connector is installed on the enclosure, through which the data cable transmits signals.

[0013] Secondly, the present invention proposes a method for detecting current-carrying friction and wear, which uses the aforementioned current-carrying friction and wear detection system and includes the following steps:

[0014] S1. Weigh the upper grinding head and the lower grinding head respectively. Apply a thermally conductive and electrically conductive grease coating to the lower surface of the lower grinding head. Fix the upper grinding head and the lower grinding head to the upper grinding head fixture and the lower grinding head fixture respectively.

[0015] S2. Power on the current-carrying friction and wear detection system.

[0016] S3. Parameter settings: Set the material-related information, test parameters, and environmental parameters of the upper and lower grinding heads according to the test requirements.

[0017] S4. Parameter conversion and correction: The control system corrects the ambient temperature and upper grinding head pressure test parameters based on the electromagnetic emission process simulated in the test through a temperature conversion model.

[0018] S5. During the non-contact stage between the upper and lower grinding heads, the temperature inside the chamber is adjusted, and a set voltage is applied between the upper and lower grinding heads.

[0019] S6. During the wear stage of the upper and lower grinding heads, the upper grinding head moves along the set path and speed and begins to rub against the lower grinding head, keeping the upper and lower grinding heads and the ambient temperature consistent with the temperature calculated by the temperature conversion model.

[0020] S7. The upper grinding head and the lower grinding head disengage from each other;

[0021] S8. Sampling: Remove the upper grinding head, lower grinding head, and the tip of the cone.

[0022] S9. Analysis.

[0023] As a preferred option, the material-related information, test parameters, and environmental parameters in S3 include material physicochemical information, test parameters, environmental parameters, and parameters related to actual electromagnetic emission.

[0024] Preferably, the parameter transformation and correction in S4 includes the following steps:

[0025] S4.1. Based on the input real electromagnetic launch parameters, determine the change in track temperature over time during the simulated electromagnetic launch process;

[0026] S4.2. Using a temperature conversion model, the actual temperature is converted into the required inter-sample temperature in the experiment;

[0027] S4.3. The range of temperature control for the sample and environment during the entire experiment is obtained through model calculation.

[0028] Preferably, in S8, the upper and lower grinding heads are cleaned with an organic solvent and dried, and the conical part under the housing is removed to collect the grinding debris accumulated therein.

[0029] As a preferred option, the analysis method in S9 is:

[0030] S9.1 Weigh the upper and lower grinding heads separately and compare them with their original weights before wear to obtain the wear amount;

[0031] S9.2 Perform a macroscopic inspection on the surfaces of the upper and lower grinding heads, and check for macroscopic defects on the surfaces by visual inspection or by using a magnifying glass tool;

[0032] S9.3 Observe the microscopic morphology of the upper and lower grinding head surfaces after wear using scanning electron microscopy, laser confocal microscopy and atomic force microscopy.

[0033] S9.4. Use the control system to analyze the friction coefficient and friction force data to obtain average friction coefficient information;

[0034] S9.5 Conduct a comprehensive analysis of friction and wear, analyze the wear type, and evaluate the degree of wear and the wear resistance of the material.

[0035] Compared with the prior art, the beneficial effects of the current-carrying friction and wear detection system and method provided by the present invention are as follows:

[0036] This system overcomes the limitations of general-purpose friction and wear testing machines in reflecting the friction during actual electromagnetic launch, and addresses the current lack of detection devices for the friction and wear process in electromagnetic launch. This method enables a realistic and effective evaluation of friction and wear during electromagnetic launch, and is of great significance for the study of the friction and wear mechanisms of materials during electromagnetic launch.

[0037] The features and advantages of the present invention will be described in detail through embodiments and in conjunction with the accompanying drawings. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of a friction and wear detection system.

[0039] Figure 2 This is a flowchart of a friction and wear detection method.

[0040] Figure 3 This is a structural diagram of the upper grinding head fixture, the upper grinding head, and the lower grinding head.

[0041] Figure 4 This is a schematic diagram of the conical section at the bottom of the box.

[0042] Figure 5 This is a schematic diagram of the conical tip section at the bottom of the box.

[0043] Figure 6 This is a schematic diagram of the through-hole array of the upper grinding head.

[0044] Figure 7 This is a temperature change curve from Comparative Example 2.

[0045] In the diagram: 1. Base; 2. Housing; 3. Motion device; 4. Control system; 5. First water circulation system; 6. Solenoid valve; 7. Cone tip; 8. Heater; 9. Data cable; 10. Temperature sensor; 11. Aviation connector; 12. Pipe; 13. Upper grinding head; 14. Lower grinding head; 15. Upper grinding head clamp; 16. Lower grinding head clamp; 17. Second water circulation system; 18. Vacuum pump or gas cylinder; 19. Air compressor. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0047] In the description of this invention, it should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to or indirectly connected to the other element.

[0048] In the description of this invention, it should be noted that the terms "center," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0049] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0050] See Figure 1 , Figures 3-6 This invention provides a system for detecting friction and wear on the surface of an arc-shaped track to simulate real electromagnetic emission, including a base 1, a housing 2, a water circulation system, a high-voltage power supply and transformer, a motion device 3, a fixture and a control system 4, etc.

[0051] The chamber 2 is mounted on the base 1, and the two are stably connected by threads. The base 1 ensures the stability of the entire test apparatus, especially when there is ultra-high-speed relative motion between the upper and lower grinding heads inside the apparatus, thus ensuring the accuracy of the test results. The outer wall of the chamber 2 is made of thermal insulation material to slow down heat dissipation; the inner wall of the chamber 2 is made of a metal material with good thermal conductivity to achieve rapid heat exchange; the chamber 2 has a circulating water channel, and the circulating water with precise temperature control through the first water circulation system 5 continuously flows through the water channel inside the chamber to achieve heat exchange with the space inside the chamber 2, and to achieve rapid and precise adjustment of the ambient temperature inside the space; a solenoid valve 6 is installed on the outer wall of the chamber 2 to connect the circulating water channel inside the chamber to the first water circulation system 5; the lower part of the chamber 2 has a conical tip 7 to collect the grinding debris generated by the friction between the upper and lower grinding heads. The surface of the conical tip 7 is coated with an ultra-low surface energy coating to facilitate the sliding or rolling of grinding debris to the tip position. The cone tip 7 can be removed from the chamber to transfer grinding debris. An electric heater 8 is installed inside the chamber 2 to heat the interior and connects to the control system 4 via a data cable 9. Multiple temperature sensors 10 are installed on the inner wall of the chamber 2 to measure the temperature distribution in real time. An aviation connector 11 is installed in the chamber 2, and the data cables 9 inside and outside the chamber 2 transmit signals through the connector. The first water circulation system 5 is connected to the solenoid valve 6 on the chamber 2 via a pipe 12 and consists of a water temperature controller and a water pump. The water temperature controller is used to quickly and accurately adjust the circulating water temperature; the water pump is used to precisely control the circulating water flow rate. A high-voltage power supply and transformer provide power to the motion device 3, upper grinding head 13, lower grinding head 14, and sensors within the test system. The motion device 3 is installed at the top inside the chamber 2, and its core component is an ultra-high-speed motor that drives the upper grinding head clamp 15 and can apply pressure vertically downwards. The upper grinding head clamp 15 is installed below the motion device 3 to stably fix the upper grinding head 13. A force sensor inside the upper grinding head clamp 15 is used to measure the magnitude of the vertical and horizontal forces between the upper and lower grinding heads. The upper grinding head 13, used to simulate the armature in the electromagnetic emission process, is fixed to the lower part of the upper grinding head clamp 15. During the friction and wear test, its lower surface contacts the material of the lower grinding head, and under the control of the motion device 3, a certain pressure is applied downwards. Driven by the motion device 3, it moves and rubs against the lower grinding head 14. The upper grinding head 13 has an array of through holes for installing temperature sensors 10. Temperature sensors 10 are installed within the array of through holes in the upper grinding head 13. When the upper grinding head 13 contacts the lower grinding head 14, the temperature sensors 10 are close to the surface of the lower grinding head 14. Each sensor can accurately obtain the local temperature of the lower grinding head 14. Through continuous measurement by the array of temperature sensors 10, real-time monitoring of the temperature distribution of the lower grinding head 14 can be achieved.The lower grinding head clamp 16 is fixed to the bottom of the housing 2 by a support structure, located directly above the tip 7 of the cone. The lower grinding head 14 is stably fixed above it. During the test, the grinding debris generated by friction will fall from the surface of the lower grinding head 14 to the bottom of the housing 2, and roll or slide along the conical surface into the tip 7 of the cone. The lower grinding head clamp 16 is made of a material with good thermal conductivity and has a circulating water channel inside to regulate the sample temperature. It is connected to the second water circulation system 17 through the pipe 12.

[0052] In the friction and wear test of the electromagnetic track, the lower grinding head 14 is used to simulate the electromagnetic track in electromagnetic launch. Its surface shape is consistent with the shape of the track to be tested. The surface can be a plane, or a regular or irregular curved surface. The control system 4 is used to control the entire test system. Before the test starts, parameters such as speed, pressure, voltage or current, and ambient temperature need to be input into the control system. After the test starts: ① The control system 4 controls the movement path, movement speed, and pressure of the upper grinding head 13; ② It controls the temperature and flow rate of the circulating water in the chamber 2 and the lower grinding head fixture 16 by controlling the opening of the two water circulation systems and the solenoid valve 6; ③ It receives the force value information between the upper and lower grinding heads, records and analyzes the continuous change of force value in different directions, and obtains data such as the friction coefficient-time curve; ④ It receives the temperature information measured by the temperature sensor 10 in the inner wall of the chamber 2 and the upper grinding head 13, analyzes the temperature distribution inside the chamber 2 and between the upper and lower grinding heads, and feeds it back to the electric heater 8 in the chamber 2 and the two water circulation systems in real time for temperature adjustment.

[0053] See Figure 2 A method for detecting current-carrying friction and wear, using the aforementioned current-carrying friction and wear detection system, includes the following steps:

[0054] S1. Weigh the upper grinding head 13 and the lower grinding head 14 respectively. Apply a thermally conductive and electrically conductive grease coating to the lower surface of the lower grinding head 14. Open the hatch on the side of the box 2. Then fix the sample (fix the upper grinding head 13 and the lower grinding head 14 to the upper grinding head clamp 15 and the lower grinding head clamp 16 respectively). Finally, close the hatch.

[0055] S2. Power on the current-carrying friction and wear detection system. Before powering on, install the housing 2 on the base 1 and secure it with threads; turn on the high-voltage power supply and transformer to power the entire detection system, and turn on the switches of the control system 4, motion device 3, and two water circulation systems. Wait 30 minutes for the water circulation system to stabilize.

[0056] S3. Parameter settings: Set the material information, test parameters and environmental parameters of the upper grinding head 13 and the lower grinding head 14 according to the test requirements.

[0057] S3 contains material-related information, test parameters, and environmental parameters, including material physicochemical information, test parameters, environmental parameters, and actual electromagnetic emission parameters. This mainly includes, but is not limited to, the following information:

[0058] ① Material physicochemical information: electrical conductivity, thermal conductivity, density, hardness, etc. of the materials of the electromagnetic track (i.e., lower grinding head 14) and armature (i.e., upper grinding head 13);

[0059] ② Test parameters: path and stroke of the upper grinding head 13, speed, pressure, voltage or current between the upper and lower grinding heads, etc.;

[0060] ③ Environmental parameters: air pressure, vacuum level, temperature, etc.;

[0061] ④ Parameters related to real electromagnetic launch: Input the relevant parameters of the simulated real electromagnetic launch process, such as electromagnetic track length, speed, pressure, ambient temperature, etc.

[0062] The physical and chemical information of the material needs to be determined or measured before the experiment. The test parameters and environmental parameters can be determined according to the needs of the experiment. In order to simulate the real electromagnetic emission process, the relevant parameters of the simulated real electromagnetic emission need to be determined before the experiment.

[0063] S4. Parameter Conversion and Correction: The control system corrects the ambient temperature and upper grinding head pressure test parameters based on the electromagnetic emission process simulated in the experiment using a temperature conversion model.

[0064] The parameter transformation and correction in S4 includes the following steps:

[0065] S4.1. Based on the input real electromagnetic launch parameters, determine the change in track temperature over time during the simulated electromagnetic launch process;

[0066] S4.2. Using a temperature conversion model, the actual temperature is converted into the required inter-sample temperature in the experiment;

[0067] S4.3. The range of temperature control for the sample and environment during the entire experiment is obtained through model calculation.

[0068] Based on the actual electromagnetic launch parameters input, the change in orbital temperature over time during the simulated electromagnetic launch process can be determined:

[0069]

[0070] Among them, T RThe average temperature of the contact area between the armature and the track during a real electromagnetic launch process is a function of time t. T0 is the ambient temperature during a real electromagnetic launch process (i.e., the temperature of the armature before launch). e1 and e2 are the heat absorption coefficients of the armature and the track, respectively. The heat absorption coefficient e is a parameter used to reflect the thermal conductivity between the materials of the upper and lower grinding heads. Where e is the heat absorption coefficient, C is the specific heat capacity of the material, ρ is the density of the material, and λ is the thermal conductivity of the material. e reflects the material's ability to exchange heat with the surroundings; the larger the value, the stronger the exchange capacity. In friction tests, the surfaces of the upper and lower grinding heads (track and armature) come into contact with each other, generating heat exchange. The larger the value of e, the stronger the heat exchange capacity, and the more heat is transferred from one side to the other, or from the other side to itself. Before testing, the value of e needs to be determined by consulting the relevant material parameters (specific heat capacity, density, or thermal conductivity, etc.) or by measuring these parameters.

[0071] q r Heat flux density, a parameter reflecting the heat exchange between the armature and the track during friction and wear, specifically represents the thermal power on the contact surface when the upper and lower grinding heads are in contact, i.e., the heat transferred per unit time and per unit contact area. It includes both heat generated by the current and heat generated by friction. It is determined by the current I between the upper and lower grinding heads, the contact resistance R, the contact area A, the coefficient of friction μ, the normal force F, and the armature speed v.

[0072]

[0073] The actual temperature T can be converted using a temperature conversion model. R (t) is converted to the required inter-sample temperature T in the experiment. S (t) to ensure that the test results reflect the actual launch process:

[0074] ;

[0075] in, The ambient temperature during the actual electromagnetic launch process (i.e., the armature temperature before launch). and These are the heat absorption coefficients of the upper and lower grinding heads, respectively. The duration of the friction and wear test. , , All are constants.

[0076] Where e1dt and e2dt are the temperature accumulation factors of the upper grinding head 13 and the lower grinding head 14 respectively during the experiment, which are determined by the material properties of the upper and lower grinding heads, the operating characteristics of the upper grinding head during the experiment, and the temperature measured by the temperature sensor 10. s The heat flux density between the upper and lower grinding heads during the experiment is q.r Similar to the same calculation formula, it characterizes the thermal power on the contact surface of the upper and lower grinding heads in the friction and wear test. It is determined by the current I between the upper and lower grinding heads, the contact resistance R, the contact area A, the friction coefficient μ, the normal force F and the armature speed v, and K1, K2 and K0 are constants.

[0077] The model calculations determined the range of temperature control required for both the sample and the environment throughout the experiment.

[0078] S5, the non-contact stage between the upper grinding head 13 and the lower grinding head 14, adjusts the temperature inside the housing 2, and applies a set voltage between the upper grinding head 13 and the lower grinding head 14.

[0079] Specifically, a distance is maintained between the upper grinding head 13 and the lower grinding head 14. Under the control of the control system 4, the heater 8 begins to heat up, and the circulating water circuit 2 of the chamber and the water circuit of the lower grinding head begin to flow, so that the temperature of the chamber 2 and the temperature of the lower grinding head 14 are stabilized at the set temperature. Under the control of the control system 4, the solenoid valve 6, vacuum pump or gas cylinder 18, air compressor 19, etc., adjust the atmosphere in the chamber 2 to the set state. A set voltage is applied between the upper and lower grinding heads.

[0080] S6, the wear stage of upper grinding head 13 and lower grinding head 14: the upper grinding head moves along the set path and speed and begins to rub against the lower grinding head 14, keeping the upper grinding head 13 and lower grinding head 14 and the ambient temperature consistent with the temperature calculated by the temperature conversion model.

[0081] Specifically, the upper grinding head 13 slowly approaches the lower grinding head 14. When the surfaces of the upper and lower grinding heads come into contact, the control system 4 controls the upper grinding head to move along a set path and speed to begin friction with the lower grinding head 14. During this period, the temperature sensor 10 detects the temperature between the upper and lower grinding heads and their surroundings in real time. The control system 4 adjusts the temperature in real time through the first water circulation system 5 and the second water circulation system 17 based on the measured temperature, so that the sample and ambient temperature are consistent with the temperature calculated by the temperature conversion model.

[0082] S7. The upper grinding head 13 and the lower grinding head 14 disengage from each other.

[0083] Specifically, after the friction and wear test is completed according to the program settings, the voltage between the upper and lower grinding heads is removed under the control of the control system 4, the heater 8 stops heating, and the circulating water flows into the water path in the chamber 2 and the lower grinding head clamp 16. According to the control program of the control system 4, the temperature inside the chamber and the sample drops rapidly.

[0084] S8. Sampling: Remove the upper grinding head 13, the lower grinding head 14, and the tip of the cone 7. In S8, the upper grinding head 13 and the lower grinding head 14 are cleaned with an organic solvent and dried. The cone-shaped part below the housing 2 is removed, and the grinding debris accumulated therein is collected.

[0085] Specifically, the air compressor 19 operates, blowing compressed air at high speed through the solenoid valve 6 to the lower grinding head clamp 16, blowing the friction-generated grinding debris into the conical part below the housing 2; the housing 2 door is opened, the upper grinding head 13 and the lower grinding head 14 are removed, the upper grinding head 13 and the lower grinding head 14 are cleaned with organic solvent and dried, the conical part below the housing 2 is removed, and the grinding debris accumulated therein is collected.

[0086] S9. Analysis. The analysis method in S9 is as follows:

[0087] S9.1 Weigh the upper grinding head 13 and the lower grinding head 14 respectively, and compare them with the mass before wear to obtain the wear amount;

[0088] S9.2 Perform a macroscopic inspection on the surfaces of the upper grinding head 13 and the lower grinding head 14, checking for macroscopic defects by visual inspection or using a magnifying glass. Specifically, check the surfaces for macroscopic defects such as pits, grooves, furrows, or coating peeling by visual inspection or using tools such as a magnifying glass.

[0089] S9.3. The microstructure of the upper grinding head 13 and lower grinding head 14 after wear was observed using scanning electron microscope, laser confocal microscope and atomic force microscope.

[0090] S9.4. Use control system 4 to analyze the friction coefficient and friction force data to obtain average friction coefficient information;

[0091] S9.5 Conduct a comprehensive analysis of friction and wear, analyze the wear type, and evaluate the degree of wear and the wear resistance of the material.

[0092] Example 1:

[0093] The wear performance of the armature and track materials used in a certain electromagnetic launch device was tested through specific experiments using the above-described system and methods.

[0094] The armature material used is a nickel-copper alloy, and the track substrate material is a copper-chromium alloy. The track surface is coated with an approximately 1.2cm thick aluminum oxide laser cladding coating. The top shape of the track cross-section is curved. After accurately measuring its dimensions and curvature, upper and lower grinding heads made of the same materials as the armature and track, respectively, are machined. The bottom shape of the upper grinding head cross-section and the top shape of the lower grinding head cross-section are consistent with the top shape of the actual track cross-section during launch. Upper and lower grinding head clamps suitable for holding the upper and lower grinding heads are then machined.

[0095] S1. Install the housing on the base and secure it with threads; turn on the high-voltage power supply and transformer to power the entire detection system, turn on the switches of the control system, motion device and two water circulation systems, and wait 45 minutes for the water circulation system to stabilize.

[0096] S2. First, the clean upper and lower grinding heads were measured to be approximately 875.37 g and 1426.33 g, respectively. The upper and lower grinding head fixtures were installed in the housing, and the upper and lower grinding heads were mounted on their respective fixtures. A thermally and electrically conductive coating was evenly applied to the lower surface of the lower grinding head, and it was then fixed to the lower grinding head fixture.

[0097] S3, Parameter Settings:

[0098] ① Physicochemical information of the upper grinding head material: electrical conductivity 86% IACS, thermal conductivity 255W / m K, density 8.7g / cm3, hardness 140HV;

[0099] ② Physicochemical information of the lower grinding head material: electrical conductivity 65% ​​IACS, thermal conductivity 210W / m K, density 8.8g / cm3, hardness 80HV;

[0100] ③ Test parameters: upper grinding head stroke 500 mm, speed 1500 mm / s, contact pressure 1.2 MPa, current 300 A;

[0101] ④ Environmental information: room temperature, normal pressure, humidity 40%;

[0102] ⑤Relevant parameters of actual electromagnetic launch: track length 22 m, maximum armature speed 1400 m / s, contact pressure 1.2 MPa, current 300 A;

[0103] ⑥ Environmental information for actual electromagnetic emission: room temperature, normal pressure, humidity 40%.

[0104] S4. Parameter Conversion and Correction: The control system corrects the test parameters such as ambient temperature and upper grinding head pressure based on the electromagnetic emission process simulated in the experiment through a temperature conversion model.

[0105] S5. At the start of the experiment, the upper grinding head slowly approaches the lower grinding head. When the surfaces of the upper and lower grinding heads contact, the motion system controls the upper grinding head to move along a set path and speed to begin friction with the lower grinding head. During this period, the temperature probe monitors the temperature between the upper and lower grinding heads and their surroundings in real time. Based on the measured temperature, the control system adjusts the temperature in real time through the first and second water circulation systems to ensure that the sample and ambient temperatures are consistent with the temperatures calculated by the temperature conversion model. After the experiment, under the control of the control system, the voltage between the upper and lower grinding heads is removed, the heater stops heating, and circulating water flows into the water channels inside the chamber and the lower grinding head fixture, achieving a rapid decrease in the temperature inside the chamber and on the sample according to the control program of the control system.

[0106] S6. Sampling: The air compressor operates, blowing compressed air at high speed through the solenoid valve to the lower grinding head, blowing the friction-generated shavings into the conical part below the housing 2; open the door of housing 2, remove the upper and lower grinding heads, clean the upper and lower grinding heads with organic solvent and dry them, remove the conical part below the housing 2, and collect the shavings accumulated therein. The mass of the shavings is approximately 75.45 g.

[0107] S7. Analysis: ① First, the masses of the upper and lower grinding heads after cleaning were measured to be 864.12 g and 1315.91 g, respectively. Calculations showed that the wear amounts of the upper and lower grinding heads were 11.21 g and 110.42 g, with wear rates of 1.28% and 7.74%, respectively. ② Macroscopic inspection of the surfaces of the upper and lower grinding heads revealed relatively uniform wear marks. ③ Observation of the microstructure of the lower grinding head surface after wear using an atomic force microscope revealed micron-level grooves caused by wear, with nano-level pits and protrusions distributed within the grooves. The surface roughness (Ra) after wear was approximately 220.74 nm. ④ The average friction coefficient was calculated to be 0.475 using the control system. ⑤ Subsequent comprehensive analysis of the friction and wear conditions was conducted to explore the wear process and mechanism of the material, and the wear performance was systematically studied.

[0108] Example 2:

[0109] Reference Figure 2 This embodiment conducted a friction and wear test under a low vacuum environment. The test used the detection system and method proposed in this invention. The other methods and steps of the test were exactly the same as in Embodiment 1. Before step S5, the following steps were added: close the door of chamber 2 and check the sealing condition. Under the control of control system 4, the vacuum pump started to evacuate the chamber, stabilizing the air pressure inside chamber 2 at about 900 Pa.

[0110] The current-carrying tribological wear performance of a copper-nickel alloy upper grinding head and a copper-chromium alloy lower grinding head under low vacuum was tested. This invention presents a testing system and method capable of conducting tribological wear performance tests under vacuum and specific atmospheric environments.

[0111] Comparative Example 1:

[0112] This comparative example compares the friction and wear testing performed using the detection system and method proposed in this invention in Example 1 with a general friction and wear testing machine.

[0113] General-purpose friction and wear testing machines typically cannot achieve the current and speed levels required for a real electromagnetic emission process;

[0114] The general friction and wear testing machine has strict restrictions on the shape and size of the upper and lower grinding heads. The upper grinding head is usually spherical and the lower grinding head is usually cuboid. This results in the contact form between the upper and lower grinding heads in the test being mostly electrical contact.

[0115] The size, particle size distribution, and surface micromorphology of wear debris are important bases for studying the wear resistance of materials, but general-purpose friction and wear testing machines do not have the function of collecting wear debris;

[0116] The relative motion between the upper and lower grinding heads in a general-purpose friction and wear testing machine is a reciprocating linear motion or a circular motion. The heat between the upper and lower grinding heads accumulates continuously with the motion, resulting in a wear mechanism and process of the sample in the test that is completely different from that of real electromagnetic emission.

[0117] In conclusion, general-purpose friction and wear testing machines cannot simulate the actual electromagnetic emission process, and the results obtained through general-purpose testing machines have low reference value for the research of materials used in actual electromagnetic emission.

[0118] Comparative Example 2:

[0119] This comparative example compares the cooling capacity of a traditional general-purpose friction and wear testing machine with the testing system and method proposed in this invention in high-temperature friction and wear testing.

[0120] Two different testing machines or systems were used to conduct high-temperature friction and wear tests at 650℃ with the same parameters. After the tests, the temperature changes within each testing machine were recorded. Figure 7 As shown, traditional general-purpose testing machines cool down slowly after the test, decreasing from 653.3℃ to 55.9℃ after 90 minutes, with an average cooling rate of approximately 6.63℃ / min. The testing system proposed in this invention, however, cools down from 648.2℃ to 38.9℃ in just 20 minutes, with an average cooling rate of approximately 30.47℃ / min.

[0121] The experimental system proposed in this invention can effectively improve the cooling rate and increase the experimental efficiency due to the circulating water circuit design inside the chamber and in the lower grinding head fixture.

[0122] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for detecting current-carrying friction and wear, characterized in that: Includes the following steps: S1. Weigh the upper grinding head (13) and the lower grinding head (14) respectively. Apply a thermally conductive and electrically conductive grease coating to the lower surface of the lower grinding head (14). Fix the upper grinding head (13) and the lower grinding head (14) to the upper grinding head fixture (15) and the lower grinding head fixture (16) respectively. S2. Power on the current-carrying friction and wear detection system. S3. Parameter settings: Set the material information, test parameters and environmental parameters of the upper grinding head (13) and lower grinding head (14) according to the test requirements; S4. Parameter conversion and correction: The control system corrects the ambient temperature and upper grinding head pressure test parameters based on the electromagnetic emission process simulated in the test through a temperature conversion model. S5. During the non-contact stage between the upper grinding head (13) and the lower grinding head (14), the temperature inside the housing (2) is adjusted, and a set voltage is applied between the upper grinding head (13) and the lower grinding head (14). S6, the wear stage of the upper grinding head (13) and the lower grinding head (14): the upper grinding head moves along the set path and speed and begins to rub against the lower grinding head (14), keeping the upper grinding head (13) and the lower grinding head (14) and the ambient temperature consistent with the temperature calculated by the temperature conversion model; S7. The upper grinding head (13) and the lower grinding head (14) are disengaged from each other; S8. Take a sample and remove the upper grinding head (13), the lower grinding head (14), and the tip of the cone (7). S9. Analysis; The parameter transformation and correction in S4 includes the following steps: S4.

1. Based on the input real electromagnetic launch parameters, determine the change in track temperature over time during the simulated electromagnetic launch process; S4.

2. Using a temperature conversion model, the actual temperature is converted into the required inter-sample temperature in the experiment; S4.

3. The range of temperature control for the sample and environment during the entire experiment is obtained through model calculation; Based on the input actual electromagnetic launch parameters, determine the change in orbital temperature over time during the simulated electromagnetic launch process: ;T R Let T0 be the average temperature of the contact area between the armature and the track during a real electromagnetic launch process, which is a function of time t. Let T0 be the ambient temperature during the real electromagnetic launch process, and e1 and e2 be the heat absorption coefficients of the armature and the track, respectively. Where e is the heat absorption coefficient, C is the specific heat capacity of the material, ρ is the density of the material, and λ is the thermal conductivity of the material; q r The heat flux density is determined by the current I between the upper and lower grinding heads, the contact resistance R, the contact area A, the coefficient of friction μ, the normal force F, and the armature speed v. Temperature conversion model is , This represents the ambient temperature during a real electromagnetic emission process. The duration of the friction and wear test. , , All are constants.

2. The method for detecting current-carrying friction and wear as described in claim 1, characterized in that: The material-related information, test parameters, and environmental parameters in S3 include material physicochemical information, test parameters, environmental parameters, and parameters related to actual electromagnetic emission.

3. The current-carrying friction and wear detection method as described in claim 1, characterized in that: In S8, the upper grinding head (13) and lower grinding head (14) are cleaned with organic solvent and dried. The conical part below the housing (2) is removed and the grinding debris collected therein is collected.

4. The current-carrying friction and wear detection method as described in claim 1, characterized in that: The analysis method in S9 is as follows: S9.1 Weigh the upper grinding head (13) and the lower grinding head (14) respectively, and compare them with the mass before wear to obtain the wear amount; S9.

2. Perform a macroscopic inspection on the surfaces of the upper grinding head (13) and the lower grinding head (14), and check for macroscopic defects on the surfaces by visual inspection or by using a magnifying glass tool. S9.

3. The microstructure of the upper grinding head (13) and lower grinding head (14) after wear was observed using scanning electron microscope, laser confocal microscope and atomic force microscope. S9.

4. Use the control system (4) to analyze the friction coefficient and friction force data to obtain the average friction coefficient information; S9.5 Conduct a comprehensive analysis of friction and wear, analyze the wear type, and evaluate the degree of wear and the wear resistance of the material.

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