Electric spark electrode examination test device and test method thereof

Abstract

The invention provides an electric spark electrode examination and test device and a test method thereof, which can realize batch high-efficiency discharge test of multiple types of electrodes, quantitative examination of loss behavior and service life, and multi-dimensional evaluation of processing and drilling quality. And electrode material rapid screening, multi-scale research of discharge ablation behaviors and comprehensive evaluation of electrode service performance are carried out. The electric spark electrode examination test device and the matched test method can quickly evaluate the comprehensive service performance of the electrode and perform iterative optimization, have the advantages of wide adaptive electrode configuration, agile and efficient test, sound evaluation system, high reliability and the like, and are particularly suitable for quick iteration and shaping of new materials and new structure electrodes; and the development and application of the electrode are effectively promoted.

Description

Technical Field

[0001] This invention relates to an electrical discharge electrode testing device and its testing method, belonging to the field of machining technology. Background Technology

[0002] Electrical discharge machining (EDM), as a specialized machining technology, is widely used in the aerospace field due to its suitability for precision machining of workpieces with high hardness and complex shapes. The electrode, as the core component of EDM hole-making equipment, directly affects machining efficiency, hole-making accuracy, and surface quality. During the discharge process, the electrode ignites a high-temperature electric arc plasma with the workpiece surface to complete the hole-making process, enduring temperatures of 3000–8000 K and 10 K / m² during continuous feed. 4 A / m 2 The arc root current density. Metal electrodes, subjected to high-temperature arc erosion, thermal stress impact, and cutting fluid erosion in extreme machining environments, often melt, oxidize, and burn rapidly. Especially under high-frequency pulse and high-current conditions, electrode wear intensifies, exhibiting characteristics such as ablation pits and splashing ablation, deteriorating machining quality, thickening the ablation damage layer on the workpiece surface, and even leading to through-hole defects. Therefore, the electrode is a key component determining the efficiency and quality of EDM hole making, and its comprehensive service performance determines the continuous machining capability of EDM hole making. With the trend towards integrated development of aerospace components, component sizes are gradually increasing, and the number of through holes is also increasing, requiring EDM equipment to have long-term continuous machining capabilities. However, existing electrodes have poor ablation resistance, and the electrode development stage suffers from problems such as low testing efficiency, limited service process observation, and a lack of evaluation dimensions, failing to promptly respond to the needs of improving the quality and efficiency of EDM equipment. Therefore, developing a testing and evaluation device that can comprehensively assess electrode ablation and wear behavior and efficiently and agilely evaluate service life and machining quality is of great significance for the development of new electrode materials.

[0003] Most existing electrode testing devices focus on a single electrode in each test. The testing process is based on a real electrode ablation damage environment, and the discharge mode is either cyclic opening and closing or continuous discharge of the contact electrode. Taking the contact electrode testing device as an example, after fixing the electrode spacing in an air atmosphere, a constant or periodic pulse current is applied. The arc is ignited and extinguished cyclically according to the test plan. Reaching a certain number of times is considered as completing the testing of a single electrode. The electrode performance is evaluated by observing the electrode ablation morphology and combining it with the mass damage before and after discharge. For electrodes operating in specific environments, such as arc heater electrodes and track armatures, the testing devices emphasize the simulation of the ablation process. When the arc of the heater electrode is working, it migrates directionally in a specific area on the electrode surface. Corresponding testing devices mostly control the arc root movement behavior by applying an external magnetic field or airflow to achieve the ablation test of the electrode under the action of the moving arc root. The track armature is subjected to compressive stress while under load current and moves relative to the guide rail. Its ablation testing device focuses more on the friction and wear behavior of the electrode under current-carrying conditions. Current electrode discharge testing devices evaluate the performance of electrodes primarily based on indicators such as ablation rate, cut-off value, and ablation morphology.

[0004] While existing electrode testing devices can assess the service performance of electrode materials under specific operating conditions, they still suffer from problems such as low testing efficiency, limited testing dimensions, insufficient process observation methods, and inadequate comprehensive evaluation methods. Cyclic switching devices, such as contact points, can only ablate one pair of electrodes at a time, requiring electrode replacement only after a preset number of cycles, resulting in excessively long parallel testing times for a single material. Furthermore, common testing devices mostly evaluate electrode wear rates and ablation behavior based solely on mass ablation rate indicators, lacking dimensions such as discharge uniformity, cathode spot migration rate, machining edge integrity, and surface quality. This lack of evaluation dimensions leads to incomplete assessment of electrode service performance. Moreover, current EDM electrode ablation testing devices are limited by the intense arc radiation brightness at the electrode tip and the liquid environment, making real-time analysis of electrode discharge behavior and machining quality difficult, resulting in unclear electrode ablation damage mechanisms. Therefore, current electrode testing devices fail to meet the demands for improved quality and efficiency in EDM equipment, necessitating the development of high-performance, high-efficiency EDM electrode testing devices. Summary of the Invention

[0005] The purpose of this invention is to provide an electrical discharge electrode testing device and method, capable of performing high-efficiency batch discharge tests on various types of electrodes, quantitatively assessing wear behavior and service life, and multi-dimensionally evaluating the quality of machining and hole making. The testing method comprises the following steps: test plan development – ​​electrode clamping and environmental preparation – discharge testing and process monitoring – multi-dimensional analysis of discharge and hole making quality – comprehensive service performance evaluation. Using this testing device and method, the comprehensive service performance of electrodes can be rapidly evaluated and iteratively optimized, offering advantages such as wide adaptability to electrode configurations, agile and efficient testing, and a sound and reliable evaluation system.

[0006] According to one aspect of this application, an electrical spark electrode testing device is provided, comprising an integrated control system 1, a filter and in-situ observation module 2, a sealed test chamber 3, a clamping control module 4, a processing module 5, an atmosphere control module 6, and a power supply module 7.

[0007] The integrated control system 1 performs data acquisition and automatic analysis, provides operators with test command input ports and parameter monitoring, and is the core module of the electrode testing device, completing the functions of data acquisition, automatic analysis, test command input, and parameter monitoring;

[0008] The integrated control system 1 has parameter monitoring function. When abnormal data is detected, such as burns, splashes, or electrode melting on the processed surface, it automatically generates a log and suspends the test assessment.

[0009] The filter and in-situ observation module 2 is coupled from the discharge monitoring high-speed camera 12, the hole-making monitoring high-speed camera 13, and the feature recognition camera 14. It also includes a visual recognition data processing system, which is responsible for recording the electrode ablation process and observing the processing quality.

[0010] The sealed test chamber 3 provides a sealed processing area, which also provides conditions for in-situ observation and electrode ablation rate calculation.

[0011] The clamping control module 4 is responsible for fixing and feeding the electrode 8, and includes a clamping base, a motor and a lead screw;

[0012] The processing module 5 adopts a grid design and is composed of grid walls 10. The grid walls 10 are insulating and heat-resistant adhesive layers and are filled with grid filler 11. The grid filler 11 is at least one of titanium alloy and aluminum alloy.

[0013] The atmosphere control module 6 simulates actual working conditions and completes the stable control and rapid switching of the atmosphere in the sealed test chamber 3.

[0014] The power module 7 controls the current and voltage of multiple electrodes 8 during parallel testing, enabling the ignition and stabilization of DC, AC, and pulsed arcs within a specific current range.

[0015] The discharge monitoring high-speed camera 12 and the hole-making monitoring high-speed camera 13 work alternately according to monitoring needs. The discharge monitoring high-speed camera 12 mainly works during the discharge process and monitors it in the dark field by filtering. The hole-making monitoring high-speed camera 13 mainly monitors it in the bright field when the arc is extinguished.

[0016] Using the upper surface of the processing module 5 as a horizontal reference plane, tilt upwards at 15°, 30° and 45° respectively, and arrange a high-speed discharge monitoring camera 12 at each angle, with the focus point being the discharge processing area at the lower end of the electrode 8, and the field of view being 4mm×4mm.

[0017] Using the upper surface of the processing module 5 as a horizontal reference plane, a high-speed camera 13 for hole making monitoring is set at an upward tilt of 75°, focusing on the surface of the mesh filler 11 to monitor the shape integrity and edge quality of the hole making process.

[0018] When the discharge monitoring high-speed camera 12 and the hole-making monitoring high-speed camera 13 are working, the frame rate is maintained at 4000 to 6000 fps.

[0019] The visual recognition data processing system can monitor the discharge and hole-making process of electrode 8 in real time. When abnormal discharge and damage phenomena are recorded, a log file is generated and submitted to the centralized control system 1.

[0020] The lower part of the sealed test chamber 3 contains the processing fluid, and the upper part is made of filter glass to filter out the excessive arc radiation during the electric spark discharge process, so as to meet the observation requirements of the discharge process. The sealed test chamber 3 is equipped with feature recognition cameras 14 around its perimeter to perform ablation length recognition and calculation.

[0021] The base bottom clamps and fixes multiple electrodes 8. The top of the clamping control module 4 is connected to the lead screw via a universal thread assembly. The lead screw is connected to the motor, which is fixed to the inner top of the sealed test chamber 3. The bottom of the clamping base has multiple clamping positions. Each clamping position is quickly fastened to the electrode 8 by a transverse fastening bolt 9, which is suitable for electrodes 8 with various cross-sections such as round, rectangular, rhomboid, and elliptical. Each clamping position is independent of the others, with a spacing of more than 3 cm, and is powered by a separate wiring harness. The power supply wiring harness of each clamping position runs from bottom to top through the clamping base and is connected to the power module 7 via a bus.

[0022] Each of the grid walls 10 and the electrode 8 has a one-to-one correspondence. During processing, a single electrode 8 can only perform electrical spark discharge on a specific grid wall 10. Each grid filler 11 is connected to a wire harness on its back. Multiple wire harnesses are combined into a bus and then connected to the power module 7 to form a closed loop.

[0023] The atmosphere control module 6 connects the gas storage source to the sealed test chamber 3 through multiple pipelines, and relies on the high-pressure gas source to achieve stable control and rapid switching of specific atmospheres (air, nitrogen, argon, etc.) within the sealed test chamber 3.

[0024] The power module 7 is equipped with an isolation transformer at its output terminal. This avoids electrical signal interference between multiple electrodes 8 and mitigates the impact of drastic voltage changes caused by frequent arc ignition and extinguishing on the integrated control system 1.

[0025] According to another aspect of this application, a test method for testing electrical spark electrodes is provided, which uses the above-mentioned electrical spark electrode testing device.

[0026] Includes the following steps:

[0027] Step 1: Test plan development; Based on the electrode material, structure, service environment, performance requirements, etc., develop a test plan, including the number of test electrodes, current value, voltage value, feed speed, hole depth, etc., and input the quantifiable test parameters into the integrated control system 1.

[0028] Step 2: Electrode clamping and environmental preparation; Assemble multiple electrodes 8 one by one into the clamping positions at the bottom of the clamping base, and tighten them with horizontal fastening bolts 9. Adjust the height of the electrodes 8 protruding from the platform to a near-horizontal level, and turn on the atmosphere control module 6 to prepare the environment inside the sealed test chamber 3.

[0029] Step 3: Discharge assessment and process monitoring; Power module 7 is started, and multiple electrodes 8 are individually controlled by their respective wire harnesses to feed towards the mesh filler of the opposite processing module 5. When the limit gap is reached, breakdown discharge occurs, igniting the arc for discharge processing; Under the constraints of the test plan, clamping control module 4 repeats the processing; During the discharge process, a high-speed camera monitors the discharge ablation behavior of the electrode ends in real time, and at the same time monitors the shape integrity and edge quality of the hole making process.

[0030] Step 4: Multi-dimensional analysis of discharge-induced borehole quality; Based on the filtering and in-situ observation module, the focus is on capturing the discharge process at the electrode tip, evaluating electrode performance from multiple dimensions such as discharge continuity, uniformity, presence or absence of sputtering particles, edge integrity, cathode spot aggregation morphology, and spot brightness. Simultaneously, based on in-situ observation of the borehole edge, the focus is on monitoring the borehole edge integrity, sputtering particles, ablation-reconstituted layer, and borehole shape under bright-field conditions during the arc extinction gap, providing a comprehensive evaluation of the borehole quality.

[0031] Step 5: Comprehensive service performance evaluation; After completing the electrode test according to the test plan, use a feature recognition camera to calculate the degree of electrode burn-off, obtain the average ablation rate, and then combine the electrode discharge uniformity, hole making quality, electrode cost, processing efficiency and other dimensions to quickly evaluate the comprehensive performance of the electrode material.

[0032] During the test plan development phase, based on the visual panel, the operator inputs the test plan, and the integrated control system 1 automatically converts it into instructions to perform parallel testing on the electrodes;

[0033] During the experiment, the integrated control system 1 was able to identify, analyze and process the current and voltage signals involved in the electrode discharge processing and the filtered capture segments returned by the in-situ observation module in real time.

[0034] After any electrode 8 reaches the preset spatial position, it breaks down the liquid gap between the electrode 8 and the grid filler 11 with high-frequency oscillation to ignite the electric arc plasma. According to the program settings, the arc ignition-arc stabilization-arc extinguishing actions are continuously completed during the electrode feeding-maintenance-exit process, and the current and voltage are adjusted according to the test plan.

[0035] Four feature recognition cameras 14 are distributed around the sealed test chamber 3. Before the test begins, the initial length d1 of the electrode 8 is recorded. After the test, the remaining length d2 of the electrode 8 is recorded. The difference between d1 and d2 can be used to obtain the electrode ablation length and rate.

[0036] Feature recognition cameras, which capture electrode length, can significantly improve the efficiency of characterizing electrode ablation rate performance. Four cameras record the remaining electrode length in their respective quadrants, and calculate the electrode wear rate by subtracting the remaining length from the initial length and taking the average. The above process can be achieved by the camera's built-in algorithm, eliminating the need for the conventional step of removing and measuring each test electrode one by one, thus improving the agility of the evaluation test process.

[0037] This invention's device is also suitable for the rapid and efficient evaluation of electrode materials in arc discharge scenarios such as argon arc welding, arc heaters, and arc plasma torches. When used for argon arc welding, the atmosphere is switched to argon to remove the processing fluid. When used for arc heaters, the atmosphere is switched to air for continuous arc discharge. When used for arc plasma torches, an air atmosphere is maintained, and the corresponding current and voltage characteristics are matched.

[0038] The present invention has the following advantages:

[0039] 1) Wide adaptability to electrode configurations. The electrode testing device of this invention, equipped with a dedicated clamping base and clamping positions, can accommodate single-rod electrodes with various cross-sections such as circular, rhomboid, elliptical, and rectangular without frequent base replacements. Furthermore, the transverse bolt fastening method is also suitable for array-type electrodes.

[0040] 2) Agile and efficient testing. Compared with existing testing devices, this invention can test multiple electrodes simultaneously and in batches, achieving the effect of "single test, multiple performance results". In addition, the testing process relies on a feature recognition camera to quickly identify and calculate the remaining length of the electrode, thereby obtaining the average ablation rate of the electrode. This eliminates the need for disassembling the electrodes one by one and the load-bearing testing environment required by conventional testing, greatly improving the efficiency of electrode performance testing.

[0041] 3) The evaluation system is comprehensive, reliable, and highly reliable. Utilizing high-speed filtering and capture technology during the discharge process, combined with characterization of the electrodes before and after discharge, a multi-dimensional evaluation system for electrode performance is established, encompassing burn-off rate, discharge continuity, uniformity, spatter particles, edge integrity, cathode spot aggregation morphology, and spot brightness. Simultaneously, the quality of the borehole formation is assessed based on edge integrity, sputtered particles, ablation and resolidification layer, and borehole shape. Therefore, this set of testing equipment and methods possesses a comprehensive evaluation system and high reliability. Attached Figure Description

[0042] Figure 1 This is a structural diagram of a modular electrical discharge electrode testing device.

[0043] Figure 2 This is a schematic diagram showing the correspondence between the electrode clamping base and the processing module, where a is the clamping base and b is the processing module.

[0044] Figure 3 This is a schematic diagram of in-situ monitoring of electrode end discharge and hole-making process under dark field and bright field conditions, where a is dark field and b is bright field.

[0045] Figure 4 This is a schematic diagram of a feature recognition camera identifying and recording the electrode length before and after an electrode assessment test, where a represents the length before the test and b represents the length after the test.

[0046] Figure 5 a and b are multiple segments of electrode discharge behavior captured by a high-speed filter camera under dark conditions.

[0047] In the figure: 1 Integrated control system, 2 Filtering and in-situ observation module, 3 Sealed test chamber, 4 Clamping control module, 5 Machining module, 6 Atmosphere control module, 7 Power supply module, 8 Electrode, 9 Lateral fastening bolt, 10 Grid wall, 11 Grid filler, 12 Discharge monitoring high-speed camera, 13 Hole making monitoring high-speed camera, 14 Feature recognition camera. Detailed Implementation

[0048] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0049] Example 1

[0050] The present invention relates to an electrical discharge electrode testing apparatus, such as... Figure 1As shown, the device comprises an integrated control system 1, a filtering and in-situ observation module 2, a sealed test chamber 3, a clamping control module 4, a processing module 5, an atmosphere control module 6, and a power supply module 7, adopting a highly modular design. Based on this EDM electrode evaluation and testing device and its supporting test methods, the comprehensive service performance of EDM electrodes can be quickly evaluated and iteratively optimized. It has advantages such as wide adaptability to electrode configurations, agile and efficient testing, and a sound and reliable evaluation system. It is particularly suitable for the rapid iteration and finalization of new material electrodes, effectively promoting the research and application of electrodes.

[0051] The power module controls the current and voltage required for parallel testing of multiple electrodes. The control process involves using high-frequency oscillation to break down the liquid gap between the electrode and the workpiece after any electrode reaches a preset spatial position, igniting an electric arc plasma. Then, according to the programmed sequence, the module continuously performs arc ignition, arc stabilization, and arc extinguishing actions during the electrode feed-holding-retreat process, adjusting the current and voltage according to the test plan. Simultaneously, considering the circuit contamination caused by high-frequency arc ignition, an isolation transformer is equipped at the power module output. This avoids electrical signal interference between multiple electrodes and mitigates the impact of frequent arc ignition and extinguishing on the control system.

[0052] The clamping control module is responsible for fixing and feeding the electrodes, and includes a clamping base, motor, and lead screw. During operation, as... Figure 1 As shown, multiple electrodes 8 are clamped and fixed to the bottom of the base, and the top of the base is connected to the lead screw and motor. The top of the base adopts a universal threaded assembly method, which can be flexibly replaced as needed. Multiple clamping positions are arrayed at the bottom of the clamping base. Each clamping position is quickly and securely connected to the electrode rod by a transverse bolt 9, accommodating electrodes with various cross-sections such as round, rectangular, and rhomboid. Each clamping position is independent of the others, with a spacing of more than 3cm, and is controlled and powered by a separate wiring harness. The power supply wiring harnesses for each clamping position run from bottom to top through the clamping base, converging into a bus and connecting to the power module.

[0053] The distribution of multiple electrodes on the surface of the clamping base and the matching positions of the opposite side processing modules are as follows: Figure 2 As shown in a and 2b, the surface of the clamping base is divided into four quadrants in a clockwise direction for marking and electrode classification.

[0054] The processing module corresponds to the material to be processed and adopts a grid design. The grid wall 10 is an insulating and heat-resistant adhesive layer, and the grid filler 11 is titanium alloy, aluminum alloy, or other metals to be processed. Each grid has a one-to-one correspondence with an electrode, and during processing, a single electrode can only perform electrical discharge within a specific grid. A wiring harness is connected to the back of each filler, and multiple harnesses converge into a bus that connects to the power module, thus forming a closed loop between the power supply, electrode, and workpiece.

[0055] The sealed test chamber serves to seal the processing area and provides conditions for in-situ observation and electrode ablation rate calculation. The lower part of the chamber holds the processing fluid, while the upper part is entirely made of filter glass to filter out excessive arc radiation during the electrical discharge process. Feature recognition cameras are installed around the perimeter of the chamber. Figure 2 As shown in Figure a, four feature recognition cameras (A, B, C, and D) are symmetrically distributed around the middle of the outer wall of the sealed box, focusing on the electrode ends at their initial positions. The electrodes at the bottom of the clamping base are divided into groups 1 to 4 according to their quadrant distribution. Each of the four cameras (A, B, C, and D) is responsible for recording the electrodes in its respective group (1, 2, 3, and 4), recording the remaining length of the electrode within its respective quadrant, and calculating the electrode wear rate by subtracting the remaining length from the initial length and taking the average.

[0056] The atmosphere control module simulates actual working conditions, achieving stable control and rapid switching of the atmosphere within the enclosure. Multiple pipelines connect the gas storage source to the sealed enclosure, utilizing a high-pressure gas source to achieve stable control of specific atmospheres (air, nitrogen, argon, etc.) within the sealed enclosure. Simultaneously, by adjusting the opening degree of multiple pipeline valves, the introduction of specific component gas mixtures can be achieved.

[0057] The filtering and in-situ observation module consists of multiple coupled cameras and includes a visual recognition data processing system responsible for recording the electrode ablation process and observing the processing quality. High-speed cameras focusing on the discharge area at the electrode tip and the edge of the borehole operate in an alternating manner according to monitoring requirements. The high-speed camera 12 focusing on the electrode discharge primarily operates during the discharge process, such as... Figure 3 As shown in Figure a, monitoring is performed using a filtering method under dark conditions; correspondingly, a high-speed camera 13, focusing on the edge of the aperture, is used, as shown in Figure a. Figure 3 As shown in b, monitoring is primarily conducted during the bright field when the arc is extinguished. For electrode discharge monitoring, the upper surface of the processing module is used as a horizontal reference plane, tilted upwards at 15°, 30°, and 45° respectively, with high-speed cameras a, b, and c positioned at each angle. The focus point is the discharge processing area at the lower end of the electrode, with a field of view of 4mm × 4mm. For hole-making monitoring, a high-speed camera d is positioned at a 75° upward tilt, focusing on the metal surface to be processed, monitoring the shape integrity and edge quality during the hole-making process. The frame rate of the high-speed cameras is maintained between 4000 and 6000 fps. The visual recognition data processing system can monitor electrode discharge and the hole-making process in real time. When abnormal discharge or damage phenomena are recorded, a log file is generated and submitted to the centralized control system, which includes keyframe photos, anomaly points, and time information.

[0058] The identification and calculation of electrode ablation rates mainly rely on four feature recognition cameras, such as... Figure 4 As shown, four feature recognition cameras, A, B, C, and D, are distributed around the sealed test chamber. Taking feature recognition camera A as an example

[14] , as... Figure 4a. Before the start of the assessment test, it records the initial length d1 of the electrodes within its assigned group. Correspondingly, after the electrode discharge test is completed, as follows: Figure 4 As shown in b, the feature recognition camera records the remaining length d2 of the electrode. The electrode ablation length and rate can be obtained by subtracting d1-d2 from the initial length and the remaining length.

[0059] The integrated control system performs data acquisition and automatic analysis, providing operators with test command input ports and parameter monitoring. During the test plan development phase, operators input the test plan via a visual panel, which is automatically converted into commands to perform parallel tests on the electrodes. Throughout the testing process, the integrated control system can identify, analyze, and process the current and voltage signals involved in the electrode discharge processing, as well as the filtered capture segments transmitted back by the in-situ observation module, in real time. Simultaneously, the integrated control system has parameter monitoring capabilities; when abnormal data is detected, such as burns, spatter, or electrode melting on the processed surface, it automatically generates a log and suspends the test.

[0060] The test method using the electric spark electrode testing device of the present invention comprises the following steps: test plan development, electrode clamping and environmental preparation, discharge testing and process monitoring, multi-dimensional analysis of discharge hole quality, and comprehensive service performance evaluation, as described in detail below:

[0061] Step 1: Test Plan Development. Based on the electrode material, structure, service environment, and performance requirements, develop a test plan, including the number of test electrodes, current value, voltage value, feed rate, and hole depth. Input the quantifiable test parameters into the integrated control system.

[0062] Step Two: Electrode Clamping and Environmental Preparation. Assemble multiple electrodes one by one into the clamping positions at the bottom of the clamping base, securing them with horizontal bolts. Adjust the height of the electrodes protruding from the platform to approximately the same level. Activate the atmosphere control module to prepare the environment within the sealed chamber.

[0063] Step 3: Discharge Assessment and Process Monitoring. The power module is activated, and multiple electrodes are individually controlled by their respective wiring harnesses, feeding towards the mesh filler of the opposite processing module. When the limit gap is reached, breakdown discharge occurs, igniting an arc for discharge machining. Under the constraints of the test plan, the clamping base is repeatedly processed. During the discharge process, a high-speed camera monitors the discharge ablation behavior at the electrode ends in real time, while simultaneously monitoring the shape integrity and edge quality of the hole-making process.

[0064] Step 4: Multi-dimensional analysis of discharge-induced borehole quality. Based on the filtering and in-situ observation module, the focus is on capturing the discharge process at the electrode tip. Electrode performance is evaluated from multiple dimensions, including discharge continuity, uniformity, presence or absence of sputtering particles, edge integrity, cathode spot aggregation morphology, and spot brightness. Simultaneously, based on in-situ observation of the borehole edge, the focus is on monitoring the borehole edge integrity, sputtering particles, ablation-reconstituted layer, and borehole shape under bright-field conditions during the arc extinction gap, providing a comprehensive evaluation of the borehole quality.

[0065] Step 5: Comprehensive Service Performance Evaluation. After completing the electrode assessment according to the test plan, a feature recognition camera is used to calculate the degree of electrode burn-off, obtain the average ablation rate, and then combine the electrode discharge uniformity, hole-making quality, electrode cost, processing efficiency, and other dimensions to quickly evaluate the comprehensive performance of the electrode material.

[0066] In this embodiment, the electrical discharge machining (EDM) equipment is mainly used for machining circular through holes on the surface of titanium alloy parts. Due to the poor ablation resistance of copper electrodes, a new type of electrode needs to be tested. The new electrode material system is a CuMo alloy. Based on this, it is necessary to systematically evaluate three types of electrodes: CuMo5, CuMo25, and CuMo40. Each electrode has a rod-shaped structure with a circular cross-section of 4 mm in diameter and a length of 15 cm. The experimental requirements are to clarify the ablation rate, discharge uniformity, cathode spot aggregation morphology, and corresponding hole structure integrity, resolidification layer, and hole shape deviation of the three electrode materials under specific conditions (current 40 A, pulse width 60 μs, pulse gap 20 μs, and tool lift-off speed 2).

[0067] Using the electrical discharge electrode testing device of this invention, a test plan was formulated according to requirements, setting the processing conditions as follows: current 40A, pulse width 60μs, pulse gap 20μs, and tool lift speed 2. Processing fluid was injected into the sealed cavity, and the discharge atmosphere was set to air. According to the test requirements, the testing of three types of electrodes—CuMo5, CuMo25, and CuMo40—was completed in three batches sequentially. Each electrode had 16 parallel groups, and the first, second, and third rounds of electrode testing were conducted in the order of CuMo5, CuMo25, and CuMo40. Each round tested only the discharge and hole-making quality of a single material. During the CuMo5 electrode test, four electrodes were grouped together, and the 16 electrodes were clamped in quadrants 1, 2, 3, and 4 of the clamping base. The electrode protrusion heights at each clamping position were adjusted to be approximately horizontal, and the atmosphere control module was activated, setting the atmosphere to air.

[0068] After completing the experimental design and preparing the clamping environment, a discharge test was conducted. The 16 electrodes fixed to the clamping base were continuously fed and discharged according to the preset program under the electrode actuation. The high-speed camera and the feature recognition camera monitored the electrode discharge behavior and electrode length under the conditions of arc burning (dark field) and arc extinguishing (bright field), respectively. At the same time, the high-speed camera continuously monitored and recorded the integrity of the hole shape and edge quality.

[0069] After completing the CuMo5 electrode evaluation test, a multi-dimensional analysis was conducted on the electrode discharge behavior and hole formation quality. The former focused on discharge continuity, uniformity, presence or absence of spatter particles, edge integrity, cathode spot aggregation morphology, and spot brightness, such as... Figure 5 As shown; the latter focuses on the integrity of the aperture edge, sputtered particles, ablation resolidification layer, aperture shape, etc. Furthermore, the overall performance of the CuMo5 electrode was evaluated by combining its discharge drilling performance with the electrode ablation rate. The average discharge ablation rate of CuMo5 under the corresponding conditions was 65.2 μg / s. Abnormal discharge phenomena caused by cathode spots occurred during the electrode discharge process, but the overall discharge performance met the requirements of the new EDM electrode. Similarly, the EDM testing of CuMo25 and CuMo40 electrodes was completed, and the overall electrode performance was evaluated.

[0070] The evaluation tests, focusing on three types of electrode materials, lasted a total of 75 minutes. The testing process was highly automated, with sufficient experimental groups, high data reliability, and a sound performance evaluation system, effectively achieving efficient and agile testing of novel electrode materials.

[0071] Comparative Example 1

[0072] In this comparative example, the electrode material type and electrical discharge machining (EDM) conditions for the testing were consistent with those in the previous example. The electrode materials were CuMo5, CuMo25, and CuMo40, and the EDM conditions were a current of 40 A, a pulse width of 60 μs, a pulse gap of 20 μs, and a tool lift-off speed of 2. Sixteen parallel groups were set up for each electrode, and the new electrode tests were conducted on actual EDM machines. Due to the limitations of the machining platform structure, only a single electrode could be processed at a time. During the actual electrode EDM process, no high-speed filtering or other monitoring methods were applied; only the electrode length was measured before and after the test.

[0073] After sequentially completing the discharge of the three types of electrodes, a total of 48 single-bar electrode tests were conducted, taking 240 minutes. The testing was time-consuming, and the electrode service performance was evaluated solely based on the electrode ablation rate and hole quality. The testing was time-consuming and inefficient, with frequent electrode changes and limited automation, making it impossible to achieve efficient testing of various new types of electrodes.

[0074] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions made by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A testing device for electrical discharge electrodes, characterized in that, It consists of an integrated control system (1), a filter and in-situ observation module (2), a sealed test chamber (3), a clamping control module (4), a processing module (5), an atmosphere control module (6), and a power supply module (7); The integrated control system (1) performs data acquisition and automatic analysis, provides test command input ports and parameter monitoring for operators, and is the core module of the electrode testing device, completing the functions of data acquisition, automatic analysis, test command input, and parameter monitoring; The filter and in-situ observation module (2) is formed by coupling a discharge monitoring high-speed camera (12), a hole-making monitoring high-speed camera (13), and a feature recognition camera (14), and also includes a visual recognition data processing system responsible for recording the electrode ablation process and observing the processing quality. The sealed test chamber (3) seals the processing area, and at the same time provides conditions for in-situ observation and electrode ablation rate calculation; The clamping control module (4) is responsible for fixing and feeding the electrode (8), and includes a clamping base, a motor and a lead screw; The processing module (5) adopts a grid design and is composed of grid walls (10). The grid walls (10) are insulating and heat-resistant adhesive layers. The grid walls (10) are filled with grid filler (11), which is at least one of titanium alloy and aluminum alloy. The atmosphere control module (6) simulates actual working conditions and completes the stable control and rapid switching of the atmosphere in the sealed test chamber (3); The power module (7) controls the current and voltage of multiple electrodes (8) during the parallel testing process, thereby achieving the ignition and stabilization of DC, AC, and pulse arcs within a specific current range.

2. The electrical discharge electrode testing device according to claim 1, characterized in that, The discharge monitoring high-speed camera (12) and the hole-making monitoring high-speed camera (13) work alternately according to monitoring needs. The discharge monitoring high-speed camera (12) mainly works during the discharge process and monitors the discharge in a dark field using a filtering method. The hole-making monitoring high-speed camera (13) mainly monitors the discharge in a bright field when the arc is extinguished. Using the upper surface of the processing module (5) as a horizontal reference plane, tilt it upwards by 15°, 30° and 45° in sequence, and arrange a high-speed discharge monitoring camera (12) at each angle. The focus is on the discharge processing area at the lower end of the electrode (8), and the field of view is 4mm×4mm. Using the upper surface of the processing module (5) as a horizontal reference plane, a high-speed camera (13) for hole making monitoring is set at an upward tilt of 75°, focusing on the surface of the mesh filler (11) to monitor the shape integrity and edge quality of the hole making process; When the discharge monitoring high-speed camera (12) and the hole-making monitoring high-speed camera (13) are working, the frame rate is maintained at 4000 to 6000 fps; The visual recognition data processing system can monitor the discharge and hole-making process of the electrode (8) in real time. When abnormal discharge and damage phenomena are recorded, a log file will be generated and submitted to the centralized control system (1).

3. The electrical discharge electrode testing device according to claim 1, characterized in that, The lower part of the sealed test chamber (3) is filled with processing fluid, and the upper part is made of filter glass to filter out the excessive arc radiation during the electric spark discharge process, so as to meet the observation requirements of the discharge process. The sealed test chamber (3) is equipped with a feature recognition camera (14) around its perimeter to perform ablation length recognition calculation.

4. The electrical discharge electrode testing device according to claim 1, characterized in that, The base bottom is used to clamp and fix multiple electrodes (8). The top of the clamping control module (4) is connected to the lead screw by a universal thread assembly. The lead screw is connected to the motor, and the motor is fixed on the inner side of the top of the sealed test box (3). The bottom of the clamping base has multiple clamping positions. Each clamping position is quickly fastened to the electrode (8) by a transverse fastening bolt (9). It is suitable for electrodes (8) with various cross-sections such as round, rectangular, rhomboid, and elliptical. Each clamping position is independent of each other, with a spacing of more than 3cm, and is powered by a separate wire harness. The power supply wire harness of each clamping position runs through the clamping base from bottom to top and is connected to the power module (7) by a bus.

5. The electrical discharge electrode testing device according to claim 1, characterized in that, Each of the grid walls (10) and the electrode (8) has a one-to-one correspondence. During processing, a single electrode (8) can only perform electrical spark discharge on a specific grid wall (10). Each grid filler (11) is connected to a wire harness on its back. Multiple wire harnesses are combined into a bus and then connected to the power module (7) to form a closed loop.

6. The electrical discharge electrode testing device according to claim 1, characterized in that, The atmosphere control module (6) connects the gas storage source to the sealed test chamber (3) through multiple pipelines, and relies on the high-pressure gas source to achieve stable control and rapid switching of the specific atmosphere in the sealed test chamber (3).

7. The electrical discharge electrode testing device according to claim 1, characterized in that, The power module (7) is equipped with an isolation transformer at its output terminal. On the one hand, it avoids electrical signal interference between multiple electrodes (8), and on the other hand, it reduces the impact of drastic voltage changes caused by frequent arc ignition and extinguishing on the integrated control system (1).

8. A test method for evaluating and testing electrical discharge electrodes, characterized in that, The electric spark electrode testing device according to any one of claims 1 to 7 is used; Includes the following steps: Step 1: Test plan formulation; Combine the electrode material, structure, service environment, performance requirements, etc., formulate the test plan, including the number of test electrodes, current value, voltage value, feed speed, hole depth, etc., and input the quantifiable test parameters into the integrated control system (1). Step 2: Electrode clamping and environmental preparation; Assemble multiple electrodes (8) one by one into the clamping position at the bottom of the clamping base, and tighten them with the horizontal fastening bolts (9). Adjust the height of the electrodes (8) protruding from the platform to a similar level, and turn on the atmosphere control module (6) to prepare the environment inside the sealed test chamber (3). Step 3: Discharge assessment and process monitoring; Start the power module (7), and multiple electrodes (8) are individually controlled by their respective wire harnesses to feed into the mesh filler of the opposite side processing module (5). When the limit gap is reached, breakdown discharge occurs, and an electric arc is ignited for discharge processing; Under the constraints of the test plan, the clamping control module (4) repeats the processing; During the discharge process, the high-speed camera monitors the discharge ablation behavior of the electrode ends in real time, and at the same time monitors the shape integrity and edge quality of the hole making process; Step 4: Multi-dimensional analysis of discharge-induced hole quality; Based on the filter and in-situ observation module, the discharge process at the electrode end is captured in the key area. The electrode performance is evaluated from multiple dimensions such as discharge continuity, uniformity, presence or absence of sputtering particles, edge integrity, cathode spot aggregation morphology, and spot brightness. At the same time, based on in-situ observation of the hole edge, the integrity of the hole edge, sputtering particles, ablation resolidification layer, and hole shape are monitored under bright field conditions during the arc extinction gap to comprehensively evaluate the hole quality. Step 5: Comprehensive service performance evaluation; After completing the electrode test according to the test plan, use a feature recognition camera to calculate the degree of electrode burn-off, obtain the average ablation rate, and then combine the electrode discharge uniformity, hole making quality, electrode cost, processing efficiency and other dimensions to quickly evaluate the comprehensive performance of the electrode material.

9. The test method according to claim 8, characterized in that, During the test plan development stage, based on the visualization panel, the operator inputs the test plan, and the integrated control system (1) automatically converts it into instructions to perform parallel testing on the electrodes; During the experiment, the integrated control system (1) was able to identify, analyze and process the current and voltage signals involved in the electrode discharge processing and the filter capture segments returned by the in-situ observation module in real time; After any electrode (8) reaches the preset spatial position, the liquid gap between the electrode (8) and the grid filler (11) is broken down by high-frequency oscillation to ignite the electric arc plasma. According to the program settings, the arc ignition-arc stabilization-arc extinguishing actions are continuously completed during the electrode feeding-maintenance-exit process, and the current and voltage are adjusted according to the test plan.

10. The test method according to claim 8, characterized in that, Four feature recognition cameras (14) are distributed around the sealed test chamber (3). Before the test begins, the initial length d1 of the electrode (8) is recorded. After the test, the remaining length d2 of the electrode (8) is recorded. The difference (d1-d2) can be used to obtain the electrode ablation length and rate.

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