Residual stress composite detection device and method based on pulsed eddy current and nanoindentation

Abstract

The invention discloses a residual stress composite detection device and method based on pulsed eddy current and nanoindentation, and relates to the technical field of nondestructive testing. A clamp module is installed in the middle of the upper end of a supporting module and used for clamping a detected workpiece; the motion scanning module is installed at the upper end of the supporting module, the output end of the motion scanning module is connected with the nanoindentation loading and detecting module, the motion scanning module can drive the nanoindentation loading and detecting module to move in multiple directions, and the output end of the nanoindentation loading and detecting module is connected with the pulsed eddy current nondestructive testing module. The pulsed eddy current nondestructive testing module is located above a detected workpiece and used for detecting residual stress in the detected workpiece, the parallel detection control module is used for controlling the pulsed eddy current nondestructive testing module to adjust the distance between the pulsed eddy current nondestructive testing module and the surface of the detected workpiece, and the parallel detection control module is further used for controlling the motion scanning module to act. According to the invention, synchronous and same-position testing of residual stress of metal materials on the processing surface and the subsurface of the tested workpiece can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of non-destructive testing, and particularly to a composite residual stress detection device and method based on pulsed eddy current and nanoindentation. Background Art

[0002] The distribution of residual stress formed in the manufacturing processes such as machining, surface modification, and heat treatment of metal materials will directly affect the reliability and durability of the materials and their products during service. The research on the online detection technology of residual stress in metal materials during the manufacturing process has received great attention.

[0003] Compared with traditional destructive residual stress testing technologies such as the blind hole method and the stripping method, methods based on X-ray / neutron diffraction, eddy current / ultrasonic detection, nanoindentation, etc. can perform micro-destructive / non-destructive testing on the material to be tested without damaging the integrity of the structural member. However, traditional single detection methods usually can only obtain the stress state of a single dimension on the surface / subsurface, and it is difficult to evaluate the distribution law of normal residual stress. Moreover, they have high requirements for instrument equipment and testing costs, and it is difficult to achieve high-throughput online detection during the manufacturing process. Although ultrasonic detection can evaluate the internal residual stress of materials, due to its low spatial resolution, high-precision test data cannot be obtained. Indentation testing technology, with the advantages of high precision, rich test information, and surface micro-damage, has been widely used to measure mechanical parameters such as the elastic modulus and hardness of materials. In recent years, the method for detecting residual stress based on nanoindentation has developed rapidly. Combining methods such as dimensional analysis, indentation energy method, and numerical simulation, a functional relationship between residual stress and indentation response parameters and material mechanical parameters has been inversely established. However, the above-mentioned residual stress expression is usually based on the assumption of equiaxed surface residual stress, and at the same time, a stress-free reference specimen is required as a benchmark, which is contrary to the actual engineering requirements. Therefore, the existing residual stress indentation detection technology is limited in actual engineering applications.

[0004] The pulsed eddy current non-destructive testing technology can overcome the influence of the skin effect and contains rich spectral signals, and can quantitatively measure the residual stress inside the material through the amplitude / frequency of the frequency-domain differential signal and the zero-crossing frequency. Accordingly, the organic combination of pulsed eddy current detection and indentation testing technology is expected to realize the online detection of residual stress on the machined surface, making it possible to accurately measure the three-dimensional residual stress distribution law of metal materials from the surface to the inside with high throughput and low cost. However, up to now, there are few reports at home and abroad on the research of developing instruments using this idea in actual engineering applications, and there are still theoretical and technical problems that need to be studied and solved. Summary of the Invention

[0005] The object of the present invention is to provide a residual stress composite detection device and method based on pulsed eddy current and nanoindentation, so as to solve the problems existing in the above-mentioned prior art and realize the synchronous and co-located testing of the residual stress of the metal materials on the machined surface and subsurface of the workpiece to be measured.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a residual stress composite detection device based on pulsed eddy current and nanoindentation, including a pulsed eddy current non-destructive detection module, a nanoindentation loading and detection module, a motion scanning module, a fixture module, a support module and a parallel detection control module. The fixture module is installed in the middle of the upper end of the support module, and the fixture module is used to clamp the workpiece to be measured. The motion scanning module is installed on the upper end of the support module, and the output end of the motion scanning module is connected to the nanoindentation loading and detection module. The motion scanning module can drive the nanoindentation loading and detection module to move in multiple directions. The output end of the nanoindentation loading and detection module is connected to the pulsed eddy current non-destructive detection module. The pulsed eddy current non-destructive detection module is located above the workpiece to be measured and is used to detect the residual stress inside the workpiece to be measured. The parallel detection control module is electrically connected to the pulsed eddy current non-destructive detection module and is used to control the pulsed eddy current non-destructive detection module to adjust the distance between the pulsed eddy current non-destructive detection module and the surface of the workpiece to be measured. The parallel detection control module is also electrically connected to the motion scanning module and is used to control the motion of the motion scanning module.

[0008] In one embodiment, the support module includes a base and a T-shaped table. The base is in an I shape, and both sides of the base are higher than the middle of the base. The T-shaped table is provided with a plurality of T-shaped long grooves arranged in sequence, and the T-shaped long grooves are used to install the fixture module. The T-shaped table is installed in the middle of the upper surface of the base, and the workpiece to be measured is installed on the T-shaped table.

[0009] In one embodiment, the base is made of marble material; the base includes a middle table and two side tables. The two side tables are symmetrically connected to both sides of the middle table. A plurality of the T-shaped long grooves are arranged in sequence on the middle table, and the arrangement direction of the plurality of T-shaped long grooves is parallel to the connection line between the two side tables. The length direction of the T-shaped long groove is perpendicular to the arrangement direction of the plurality of T-shaped long grooves.

[0010] In one embodiment, the fixture module includes multiple sets of clamping units. Multiple sets of the clamping units are all installed in the T-shaped long groove, and multiple sets of the clamping units are arranged around the outer periphery of the workpiece to be measured. The clamping unit includes a pressing plate, a wedge column, a return spring, a first bolt, and a second bolt. The first end of the pressing plate is used to press on the upper surface of the workpiece to be measured. A through hole is provided in the middle of the pressing plate. The lower bolt head of the first bolt is slidably connected in the T-shaped long groove. The upper end of the first bolt passes through the through hole and is fastened by a nut. The return spring is sleeved on the outer periphery of the first bolt, and a limiting ring is sleeved at each position corresponding to both ends of the return spring on the outer periphery of the first bolt. The lower limiting ring abuts against the upper surface of the intermediate table, and the upper limiting ring is slidably connected to the outer periphery of the first bolt and abuts against the lower end surface of the pressing plate. The lower bolt head of the second bolt is slidably connected in the T-shaped long groove. The upper end of the second bolt is movably connected to the wedge column. The upper end of the wedge column is embedded in the groove at the lower end of the pressing plate, and the wedge column can slide along the outer periphery of the second bolt. A nut is threadedly connected to the outer periphery of the second bolt, and the nut is used to abut against the lower end of the wedge column.

[0011] In one embodiment, the motion scanning module includes a Y-direction motion component, a Z-direction motion component, and two sets of X-direction motion components. The two sets of X-direction motion components are symmetrically arranged and are respectively installed on both sides of the upper end surface of the support module. Both ends of the Y-direction motion component are respectively connected to the output ends of the two sets of X-direction motion components. The Z-direction motion component is connected to the output end of the Y-direction motion component. The nano-indentation loading and detection module is connected to the output end of the Z-direction motion component.

[0012] In one embodiment, the X-direction motion component includes an X-direction AC servo motor, an X-direction gear and rack element, an X-direction connecting plate, and two sets of X-direction guide rail slider elements. The two sets of X-direction guide rail slider elements are parallel to each other and are installed on the upper end of the support module through an X-direction mounting base. The X-direction connecting plate is connected to the slider in the two sets of X-direction guide rail slider elements. The X-direction gear and rack element is installed between the two sets of X-direction guide rail slider elements. The X-direction AC servo motor is installed on the X-direction connecting plate, and the output shaft of the X-direction AC servo motor passes through the X-direction connecting plate and is coaxially connected to the gear in the X-direction gear and rack element.

[0013] The Y-direction movement assembly includes a Y-direction AC servo motor, a Y-direction gear-rack element, a Y-direction connecting plate, and two sets of Y-direction guide rail slider elements. The two sets of guide rail slider elements in the Y-direction movement assembly are parallel to each other and installed on the Y-direction mounting base. The Y-direction connecting plate is connected to the sliders of the two sets of Y-direction guide rail slider elements. The Y-direction gear-rack element is installed between the two sets of Y-direction guide rail slider elements. The Y-direction AC servo motor is installed on the Y-direction connecting plate, and the output shaft of the Y-direction AC servo motor passes through the Y-direction connecting plate and is coaxially connected to the gear in the Y-direction gear-rack element. The two ends of the Y-direction mounting base are respectively installed on the two X-direction connecting plates;

[0014] A grating ruler is installed on one side of the X-direction mounting base and one side of the Y-direction mounting base, and limit travel switches are installed at both ends of the X-direction mounting base and both ends of the Y-direction mounting base. The Z-direction movement assembly is installed on the Y-direction connecting plate;

[0015] The Z-direction movement assembly includes a voice coil motor, a Z-direction connecting block, and a Z-direction fixing plate. A Z-direction mounting plate is installed on one side of the Y-direction connecting plate. Two Z-direction guide rails arranged side by side and extending in the vertical direction are installed on the side of the Z-direction mounting plate away from the Y-direction connecting plate. The two ends of the Z-direction connecting block are slidably connected to the two Z-direction guide rails. The lower end of the voice coil motor is connected to the nano-indentation loading and detection module through the Z-direction fixing plate and screws, and the nano-indentation loading and detection module is connected to the Z-direction connecting block. The voice coil motor can push the nano-indentation loading and detection module to move in the Z direction.

[0016] In an embodiment, the nano-indentation loading and detection module includes a nano-indentation unit and a detection unit. The nano-indentation unit includes a first flexible hinge, a indenter column, and an indenter. The detection unit includes a force sensor, a capacitive displacement sensor unit, and a displacement measuring plate. A piezoelectric stack is installed in the groove of the first flexible hinge, and a pre-tightening screw is installed at the upper end of the first flexible hinge. The pre-tightening force of the piezoelectric stack can be adjusted by tightening the pre-tightening screw. The upper end of the first flexible hinge is connected to the voice coil motor. The lower end of the first flexible hinge is installed with the force sensor. The lower end of the force sensor is connected to the upper end of the indenter column, and an internal thread for mating with the external thread of the indenter column is provided on the force sensor. The displacement measuring plate is pressed between the force sensor and the indenter column. The lower end of the indenter column is connected to the indenter through a positioning pin. The upper part of the capacitive displacement sensor unit is connected to one side of a Z-direction connecting block through screws, and the lower end of the capacitive displacement sensor unit extends towards the displacement measuring plate.

[0017] In one embodiment, the pulsed eddy current non-destructive testing module includes a protective sleeve, a wedge block, a second flexible hinge, an annular piezoelectric stack, and a pulsed eddy current probe unit. The second flexible hinge is sleeved on the outer periphery of the upper part of the indenter column, and the upper end of the second flexible hinge is located on the lower end surface of the displacement measuring plate. The second flexible hinge is connected to the force sensor. An internal thread for adjusting the pre-tightening force of the annular piezoelectric stack by mating with the external thread of the indenter column is provided at the upper end of the second flexible hinge. The annular piezoelectric stack is coaxially sleeved on the outer periphery of the second flexible hinge. The lower end of the second flexible hinge is threadedly connected to the upper end of the protective sleeve. The protective sleeve is sleeved on the outer periphery of the lower part of the indenter column. The wedge block is sleeved on the indenter column and is located inside the protective sleeve. The pulsed eddy current probe unit is installed on the wedge block and is located inside the protective sleeve, and the pulsed eddy current probe unit is arranged around the outer periphery of the indenter column.

[0018] In one embodiment, the pulsed eddy current probe unit includes a receiving coil and a plurality of exciting coils. The receiving coil is sleeved on the outer periphery of the indenter column. The plurality of exciting coils are evenly arranged around the outer periphery of the receiving coil. An iron core is provided in each of the exciting coils. The upper end of each iron core is installed on the wedge block. A pre-tightening compression spring is further sleeved on the outer periphery of the indenter column. The upper end of the pre-tightening compression spring is connected to the lower end of the second flexible hinge, and the lower end of the pre-tightening compression spring is connected to the upper end of the wedge block.

[0019] The present invention also provides a residual stress composite detection method based on pulsed eddy current and nanoindentation. Using the residual stress composite detection device based on pulsed eddy current and nanoindentation according to any one of the above technical solutions, the method includes the following steps:

[0020] S1. Use the fixture module to accurately clamp the workpiece to be measured on the T-shaped table of the support module, and send a motion signal to the motion controller through the industrial computer of the parallel detection control module to adjust the motion scanning module, and move the nanoindentation loading and detection module, so that the pulsed eddy current probe unit of the pulsed eddy current non-destructive testing module is kept within the working range of the surface of the workpiece to be measured, and the indenter of the nanoindentation loading and detection module reaches the surface of the workpiece to be measured.

[0021] S2. Use the pulsed eddy current non-destructive testing module to detect the internal residual stress of the workpiece to be measured. Send a control signal to the annular piezoelectric stack of the pulsed eddy current non-destructive testing module through the piezoelectric amplifier of the parallel detection control module, so that the second flexible hinge of the pulsed eddy current non-destructive testing module generates a micro-motion, adjust the distance between the pulsed eddy current probe unit and the surface of the workpiece to be measured, and make the pulsed eddy current probe unit move in the Z direction relative to the indenter until the maximum received signal is reached, and then stop the motion.

[0022] S3. Detection of the internal residual stress of the workpiece to be measured. An excitation signal is sent to the excitation coil of the pulsed eddy current probe unit by a signal generator. Then, the received signal of the receiving coil of the pulsed eddy current probe unit is amplified by a differential amplifier, and the phase of the reference signal of the signal generator and the received signal is calculated by a lock-in amplifier, read into a data acquisition card, and fed back to the supporting analysis and processing software of the upper industrial control computer for analysis and calculation;

[0023] S4. Perform pre-contact detection. First, adjust the capacitance displacement sensor unit of the nano-indentation loading and detection module within the range of the measuring range; then, drive the indenter to move towards the surface of the workpiece to be measured by the voice coil motor of the motion scanning module until the load signal collected by the force sensor of the nano-indentation loading and detection module changes suddenly. After analysis, the industrial control computer sends a motion command to the voice coil motor to stop it, record the Z-direction stroke of the indenter, and then lift the indenter;

[0024] S5. Use the nano-indentation method to detect the surface residual stress of the workpiece to be measured. Fine-tune and replace the indentation position through the X-direction motion component and Y-direction motion component of the motion scanning module, send a motion command to the voice coil motor to make the indenter approach the surface of the workpiece to be measured. The upper computer trigger command sends a voltage drive signal to the piezoelectric stack of the nano-indentation loading and detection module through a piezoelectric amplifier to control the continuous movement of the indenter. At the same time, the force sensor monitors the change of the indenter load in real time. The load feedback signal is amplified by a charge amplifier and then read into the signal acquisition card, and then transmitted to the industrial control computer. The capacitance displacement sensor unit transmits the measured displacement signal to the industrial control computer. The indentation load-displacement curve of the material is obtained through the calculation and analysis of the industrial control computer, and the specific relationship between the residual stress and the indentation response parameters is established from it, so as to qualitatively and quantitatively detect the residual stress, and then lift the indenter;

[0025] S6. According to the different geometric morphologies of the surface of the workpiece to be measured, the industrial control computer sends commands to the piezoelectric amplifiers of the motion scanning module and the parallel detection control module to perform multiple detections at different positions on the workpiece to be measured with complex geometric features, so as to realize the synchronous and co-located test characterization of the surface and internal residual stress of the workpiece to be measured.

[0026] The present invention has achieved the following technical effects compared with the prior art:

[0027] The residual stress composite detection device and method based on pulsed eddy current and nanoindentation provided by the present invention. The fixture module is installed in the middle of the upper end of the support module, and the fixture module is used to clamp the workpiece to be measured. The motion scanning module is installed at the upper end of the support module, and the output end of the motion scanning module is connected to the nanoindentation loading and detection module. The motion scanning module can drive the nanoindentation loading and detection module to move in multiple directions. The output end of the nanoindentation loading and detection module is connected to the pulsed eddy current non-destructive testing module. The pulsed eddy current non-destructive testing module is located above the workpiece to be measured and is used to detect the residual stress inside the workpiece to be measured. By integrating pulsed eddy current and nanoindentation, and coaxial integration of the pulsed eddy current and nanoindentation detection probes, the degree of integration is high, realizing the multi-factor coupling optimization design and integration of "indentation - eddy current - scanning - control - fusion". Designing an innovative series flexible hinge structure form enables the relative independent and precise movement of the nanoindentation loading and detection module and the pulsed eddy current non-destructive testing module, as well as the free combination of multiple detection modes, realizing the synchronous and in-position testing and characterization of the residual stress on the surface and inside of metal materials. The parallel detection control module is electrically connected to the pulsed eddy current non-destructive testing module and is used to control the pulsed eddy current non-destructive testing module to adjust the distance from the surface of the workpiece to be measured. The parallel detection control module is also electrically connected to the motion scanning module and is used to control the operation of the motion scanning module. Through the above design, adopting the new method of composite detection of pulsed eddy current and nanoindentation, the continuous residual stress detection can be carried out from the surface to the deep layer, realizing the three-dimensional residual stress reconstruction and modeling of metal materials. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the following described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is a schematic structural diagram of the residual stress composite detection device based on pulsed eddy current and nanoindentation in Embodiment 1;

[0030] Figure 2 For Figure 1 front view;

[0031] Figure 3 For Figure 1 top view;

[0032] Figure 4 It is a front view of the Z-direction motion component, the pulsed eddy current non-destructive testing module, and the nanoindentation loading and detection module in Embodiment 1;

[0033] Figure 5 For Figure 4 side view;

[0034] Figure 6 Cross-sectional views of the pulsed eddy current nondestructive testing module and the nanoindentation loading and testing module in Embodiment 1;

[0035] Figure 7 Exploded views of the pulsed eddy current nondestructive testing module and the nanoindentation loading and testing module in Embodiment 1;

[0036] Figure 8 Schematic structural diagram of the pulsed eddy current testing unit in Embodiment 1;

[0037] Figure 9 Exploded view of the pulsed eddy current testing unit in Embodiment 1;

[0038] Figure 10 Control system block diagram of the residual stress composite detection method based on pulsed eddy current and nanoindentation in Embodiment 2;

[0039] In the figure: 1 - Pulsed eddy current nondestructive testing module, 111 - Protective sleeve, 112 - Wedge block, 113 - Second flexible hinge, 114 - Ring piezoelectric stack, 115 - Pulsed eddy current probe unit, 1151 - Excitation coil, 1152 - Receiver coil, 1153 - Iron core, 116 - Pre-tightening compression spring, 2 - Nanoindentation loading and testing module, 211 - Indenter, 212 - Force sensor, 213 - Displacement measuring plate, 214 - First flexible hinge, 215 - Indenter column, 216 - Piezoelectric stack, 217 - Capacitive displacement sensor unit, 218 - Pre-tightening screw, 3 - Motion scanning module, 311 - X-axis AC servo motor, 312 - X-axis gear and rack element, 313 - X-axis guide rail and slider element, 314 - X-axis connecting plate, 315 - Grating scale, 316 - X-axis mounting base, 317 - Voice coil motor, 318 - Y-axis mounting base, 319 - Y-axis guide rail and slider element, 320 - Y-axis connecting plate, 321 - Z-axis connecting block, 322 - Z-axis fixing plate, 323 - Limit travel switch, 4 - Workpiece to be measured, 5 - Fixture module, 51 - Clamping unit, 511 - Pressing plate, 512 - Wedge column, 513 - Return spring, 6 - T-shaped table, 7 - Base. Detailed implementation manners

[0040] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0041] The object of the present invention is to provide a residual stress composite detection device and method based on pulsed eddy current and nanoindentation, so as to solve the problems existing in the prior art and realize the synchronous and co-located testing of the residual stress of the metal materials on the machined surface and subsurface of the workpiece to be measured.

[0042] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] Embodiment 1

[0044] As Figures 1-9 shown, this embodiment provides a residual stress composite detection device based on pulsed eddy current and nanoindentation, including a pulsed eddy current non-destructive detection module 1, a nanoindentation loading and detection module 2, a motion scanning module 3, a fixture module 5, a support module and a parallel detection control module. The fixture module 5 is installed in the middle of the upper end of the support module, and the fixture module 5 is used to clamp the workpiece to be measured 4. The motion scanning module 3 is installed on the upper end of the support module, and the output end of the motion scanning module 3 is connected to the nanoindentation loading and detection module 2. The motion scanning module 3 can drive the nanoindentation loading and detection module 2 to move in multiple directions. The output end of the nanoindentation loading and detection module 2 is connected to the pulsed eddy current non-destructive detection module 1. The pulsed eddy current non-destructive detection module 1 is located above the workpiece to be measured 4 and is used to detect the internal residual stress of the workpiece to be measured 4. By integrating pulsed eddy current and nanoindentation and coaxial combining the pulsed eddy current and nanoindentation detection probes, the degree of integration is high, realizing the multi-factor coupling optimization design and integration of "indentation - eddy current - scanning - control - fusion". Design an innovative series flexible hinge structure form to enable the relative independent and precise movement of the nanoindentation loading and detection module 2 and the pulsed eddy current non-destructive detection module 1 and the free combination of multiple detection modes, realizing the synchronous and co-located testing and characterization of the residual stress on the surface and inside of the metal material. The parallel detection control module is electrically connected to the pulsed eddy current non-destructive detection module 1 and is used to control the pulsed eddy current non-destructive detection module 1 to adjust the distance from the surface of the workpiece to be measured 4. The parallel detection control module is also electrically connected to the motion scanning module 3 and is used to control the motion of the motion scanning module 3. Through the above design, adopting the new method of pulsed eddy current and nanoindentation composite detection, the continuous residual stress detection can be carried out from the surface to the inside and into the surface layer, realizing the three-dimensional residual stress reconstruction and modeling of the metal material.

[0045] Specifically, the support module includes a base 7 and a T-shaped table 6. The base 7 is in an I-shaped structure, and the two sides of the base 7 are higher than the middle of the base 7. The T-shaped table 6 is provided with a plurality of sequentially arranged T-shaped long grooves, and the T-shaped long grooves are used to install the fixture module 5, which is convenient for realizing the position adjustment of the fixture module 5 and adapting to various fixture modules 5. The T-shaped table 6 is installed in the middle of the upper surface of the base 7, and the workpiece to be measured 4 is installed on the T-shaped table 6 to facilitate the subsequent detection of the workpiece to be measured 4.

[0046] The base 7 is made of marble material; the base 7 includes a middle platform and two side platforms, the two side platforms are symmetrically connected to both sides of the middle platform, a plurality of T-shaped long grooves are arranged in sequence on the middle platform, and the arrangement direction of the plurality of T-shaped long grooves is parallel to the connection line between the two side platforms, and the length direction of the T-shaped long groove is perpendicular to the arrangement direction of the plurality of T-shaped long grooves.

[0047] The fixture module 5 includes multiple groups of clamping units 51, the multiple groups of clamping units 51 are all installed in the T-shaped long grooves, and the multiple groups of clamping units 51 are arranged around the outer periphery of the workpiece 4 to be measured, so as to improve the clamping stability of the workpiece 4 to be measured. Preferably, the clamping units 51 are four groups, so as to clamp each side of the workpiece 4 to be measured; the clamping unit 51 includes a pressing plate 511, a wedge column 512, a return spring 513, a first bolt and a second bolt. The first end of the pressing plate 511 is used to press on the upper surface of the workpiece 4 to be measured, so as to limit the workpiece 4 to be measured above the workpiece 4 through the pressing plate 511 and press the workpiece 4 to be measured on the T-shaped table 6, avoiding the workpiece 4 to be measured from shaking during the detection process and affecting the detection result. A through hole is provided in the middle of the pressing plate 511. The lower bolt head of the first bolt is slidably connected in the T-shaped long groove. The upper end of the first bolt passes through the through hole and is fastened by a nut. The return spring 513 is sleeved on the outer periphery of the first bolt, and a limiting ring is sleeved at each position corresponding to both ends of the return spring 513 on the outer periphery of the first bolt. The lower limiting ring abuts against the upper surface of the middle platform, and the upper limiting ring is slidably connected to the outer periphery of the first bolt and abuts against the lower end surface of the pressing plate 511, so as to be able to adapt to the height adjustment of the pressing plate 511. The lower bolt head of the second bolt is slidably connected in the T-shaped long groove. The upper end of the second bolt is movably connected to the wedge column 512. The upper end of the wedge column 512 is embedded in the groove at the lower end of the pressing plate 511, and the wedge column 512 can slide along the outer periphery of the second bolt. A nut is threadedly connected to the outer periphery of the second bolt, and the nut is used to abut against the lower end of the wedge column 512. Therefore, when adjusting the height of the pressing plate 511, the return spring 513 can be compressed, and at the same time, by tightening the nuts on the second bolt and the first bolt, the fixation of the workpiece 4 to be measured is realized.

[0048] The motion scanning module 3 includes a Y-direction motion component, a Z-direction motion component and two groups of X-direction motion components. The two groups of X-direction motion components are symmetrically arranged and are respectively installed on both sides of the upper end surface of the support module. The two ends of the Y-direction motion component are respectively connected to the output ends of the two groups of X-direction motion components, so as to realize driving the Y-direction motion component to move along the X direction through the X-direction motion component. The Z-direction motion component is connected to the output end of the Y-direction motion component, so as to realize driving the Z-direction motion component to move along the Y direction through the Y-direction motion component. The nano-indentation loading and detection module 2 is connected to the output end of the Z-direction motion component, so as to realize the Z-direction movement of the nano-indentation loading and detection module 2.

[0049] The X-direction motion component includes an X-direction AC servo motor 311, an X-direction gear-rack element 312, an X-direction connecting plate 314, and two groups of X-direction guide rail slider elements 313. The two groups of X-direction guide rail slider elements 313 are parallel to each other and are installed on the upper end of the support module through the X-direction mounting base 316. The X-direction connecting plate 314 is connected to the sliders in the two groups of X-direction guide rail slider elements 313, and thus the X-direction connecting plate 314 is supported and guided by the two groups of X-direction guide rail slider elements 313. Combined with the grating scale 315, large-stroke closed-loop precision motion control can be achieved; the X-direction gear-rack element 312 is installed between the two groups of X-direction guide rail slider elements 313, the X-direction AC servo motor 311 is installed on the X-direction connecting plate 314, and the output shaft of the X-direction AC servo motor 311 passes through the X-direction connecting plate 314 and is coaxially connected to the gear in the X-direction gear-rack element 312;

[0050] The Y-direction motion component includes a Y-direction AC servo motor, a Y-direction gear-rack element, a Y-direction connecting plate 320, and two groups of Y-direction guide rail slider elements 319. The two groups of guide rail slider elements in the Y-direction motion component are parallel to each other and are installed on the Y-direction mounting base 318. The Y-direction connecting plate 320 is connected to the sliders in the two groups of Y-direction guide rail slider elements 319, and thus the Y-direction connecting plate 320 is supported and guided by the two groups of Y-direction guide rail slider elements 319. Combined with the grating scale 315, large-stroke closed-loop precision motion control can be achieved; the Y-direction gear-rack element is installed between the two groups of Y-direction guide rail slider elements 319, the Y-direction AC servo motor is installed on the Y-direction connecting plate 320, and the output shaft of the Y-direction AC servo motor passes through the Y-direction connecting plate 320 and is coaxially connected to the gear in the Y-direction gear-rack element. The two ends of the Y-direction mounting base 318 are respectively installed on the two X-direction connecting plates 314 to achieve large-stroke scanning motion in the XY two-dimensional plane;

[0051] Among them, the X-direction guide rail slider element 313 and the Y-direction guide rail slider element 319 have the same structure, and both include a guide rail and a slider. The slider is slidably connected to the guide rail, and the X-direction connecting plate 314 or the Y-direction connecting plate 320 is connected to the slider; the X-direction gear-rack element 312 and the Y-direction gear-rack element have the same structure, and both include a rack and a gear. The gear is connected to the output shaft of the X-direction AC servo motor 311 or the Y-direction AC servo motor, and at the same time the gear meshes with the rack. Then, driven by the X-direction AC servo motor 311 or the Y-direction AC servo motor, the gear rotates, and at the same time the gear travels along the rack, and then drives the X-direction AC servo motor 311 or the Y-direction AC servo motor to travel, realizing the movement of the corresponding connecting plate.

[0052] On one side of the X-direction mounting base 316 and one side of the Y-direction mounting base 318, grating scales 315 are installed. At both ends of the X-direction mounting base 316 and both ends of the Y-direction mounting base 318, limit travel switches 323 are installed. Thus, it can limit the movement of the X-direction connecting plate 314 and the Y-direction connecting plate 320, avoiding exceeding the stroke and causing connection failure, which affects the working efficiency and service life. The Z-direction motion component is installed on the Y-direction connecting plate 320;

[0053] The Z-direction motion component includes a voice coil motor 317, a Z-direction connecting block 321, and a Z-direction fixing plate 322. On one side of the Y-direction connecting plate 320, a Z-direction mounting plate is installed. On the side of the Z-direction mounting plate away from the Y-direction connecting plate 320, two Z-direction guide rails arranged side by side and extending in the vertical direction are installed. The two ends of the Z-direction connecting block 321 are slidably connected to the two Z-direction guide rails. The lower end of the voice coil motor 317 is connected to the nano-indentation loading and detection module 2 through the Z-direction fixing plate 322 and screws, and the nano-indentation loading and detection module 2 is connected to the Z-direction connecting block 321, realizing the macroscopic adjustment of the Z-direction distance between the working end of the nano-indentation loading and detection module 2 and the surface of the workpiece 4 to be measured. The voice coil motor 317 can push the nano-indentation loading and detection module 2 to move in the Z-direction.

[0054] The nano-indentation loading and detection module 2 includes a nano-indentation unit and a detection unit. The nano-indentation unit includes a first flexible hinge 214, a indenter column 215, and an indenter 211. The detection unit includes a force sensor 212, a capacitive displacement sensor unit 217, and a displacement measuring plate 213. In the groove of the first flexible hinge 214, a piezoelectric stack 216 is installed, and a pre-tightening screw 218 is installed at the upper end of the first flexible hinge 214. By tightening the pre-tightening screw 218 and making the pre-tightening screw 218 press the piezoelectric stack 216, the pre-tightening force of the piezoelectric stack 216 can be adjusted. The upper end of the first flexible hinge 214 is connected to the voice coil motor 317. Through the voice coil motor 317, the piezoelectric stack 216 can be driven to elongate, and then the piezoelectric stack 216 drives the first flexible hinge 214 to deform, so as to drive the indenter 211 to move towards the surface of the workpiece. The lower end of the first flexible hinge 214 is installed with a force sensor 212. The lower end of the force sensor 212 is connected to the upper end of the indenter column 215, and the force sensor 212 is provided with an internal thread for mating with the external thread of the indenter column 215. The force sensor 212 is used to collect the load signal of the indenter 211 in real time. The displacement measuring plate 213 is pressed between the force sensor 212 and the indenter column 215. The lower end of the indenter column 215 is connected to the indenter 211 through a positioning pin. The upper part of the capacitive displacement sensor unit 217 is connected to one side of a Z-direction connecting block 321 through screws, and the lower end of the capacitive displacement sensor unit 217 extends towards the displacement measuring plate 213.

[0055] The pulsed eddy current non-destructive testing module 1 includes a protective sleeve 111, a wedge block 112, a second flexible hinge 113, an annular piezoelectric stack 114, and a pulsed eddy current probe unit 115. The second flexible hinge 113 is sleeved on the outer periphery of the upper part of the indenter column 215, and the upper end of the second flexible hinge 113 is located on the lower end face of the displacement measuring plate 213. The second flexible hinge 113 is connected to the force sensor 212. The upper end of the second flexible hinge 113 is provided with an internal thread for adjusting the pre-tightening force of the annular piezoelectric stack 114 in threaded cooperation with the external thread of the indenter column 215. At the same time, the internal thread of the indenter column 215 is in threaded cooperation with the external thread of the force sensor 212 for fixation, realizing macro / micro hybrid drive. The annular piezoelectric stack 114 is coaxially sleeved on the outer periphery of the second flexible hinge 113. The lower end of the second flexible hinge 113 is threadedly connected to the upper end of the protective sleeve 111. Thus, when a control signal is sent to the annular piezoelectric stack 114, the annular piezoelectric stack 114 can elongate and drive the second flexible hinge 113 to undergo micro motion. The second flexible hinge 113 drives the pulsed eddy current probe unit 115 to move in the Z direction relative to the indenter 211 to reach the position of the maximum received signal. The protective sleeve 111 is sleeved on the outer periphery of the lower part of the indenter column 215. The wedge block 112 is sleeved on the outer periphery of the indenter column 215 and is located inside the protective sleeve 111, and the wedge block 112 is used to realize the stable installation of the pulsed eddy current probe unit 115. The pulsed eddy current probe unit 115 is installed on the wedge block 112 and is located inside the protective sleeve 111, and the pulsed eddy current probe unit 115 is arranged around the outer periphery of the indenter column 215.

[0056] The pulsed eddy current probe unit 115 and the nano-indentation unit are coaxially arranged, and the distance between the pulsed eddy current probe unit 115 and the surface of the workpiece 4 to be measured is measured through the real-time voltage-distance relationship of the annular piezoelectric stack 114. The position closed-loop control of the pulsed eddy current probe unit 115 is used to suppress the lift-off effect, realizing the detection of residual stress on the machined surface / inside.

[0057] The pulsed eddy current probe unit 115 includes a receiving coil 1152 and a plurality of exciting coils 1151. The receiving coil 1152 is sleeved on the outer periphery of the indenter column 215. The plurality of exciting coils 1151 are uniformly arranged around the outer periphery of the receiving coil 1152 and are coaxially positioned and assembled with the indenter 211. A iron core 1153 is provided in each exciting coil 1151. The upper end of each iron core 1153 is installed on the wedge block 112. A pre-tightening compression spring 116 is also sleeved on the outer periphery of the indenter column 215. The upper end of the pre-tightening compression spring 116 is connected to the lower end of the second flexible hinge 113, and the lower end of the pre-tightening compression spring 116 is connected to the upper end of the wedge block 112. Through the above design, the pulsed eddy current probe unit 115 adopts a non-contact pulsed eddy current detection mode, and can realize the evaluation of the residual stress inside the material.

[0058] Embodiment 2

[0059] As Figure 10As shown in the figure, this embodiment provides a composite residual stress detection method based on pulsed eddy current and nanoindentation. Using the composite residual stress detection device based on pulsed eddy current and nanoindentation in Embodiment 1, it includes the following steps:

[0060] S1. Use the fixture module 5 to accurately clamp the workpiece 4 to be measured on the T-shaped table 6 of the support module, and send a motion signal to the motion controller through the industrial computer of the parallel detection control module to adjust the motion scanning module 3, and make the nanoindentation loading and detection module 2 move in a large range. The pulsed eddy current probe unit 115 of the pulsed eddy current non-destructive testing module 1 is kept within the working range of the surface of the workpiece 4 to be measured, and the indenter 211 of the nanoindentation loading and detection module 2 reaches the surface of the workpiece 4 to be measured.

[0061] S2. Use the pulsed eddy current non-destructive testing module 1 to detect the internal residual stress of the workpiece 4 to be measured. Send a control signal to the annular piezoelectric stack 114 of the pulsed eddy current non-destructive testing module 1 through the piezoelectric amplifier of the parallel detection control module, so that the second flexible hinge 113 of the pulsed eddy current non-destructive testing module 1 generates fine movement, adjust the distance between the pulsed eddy current probe unit 115 and the surface of the workpiece 4 to be measured, and make the pulsed eddy current probe unit 115 move in the Z direction relative to the indenter 211 until the maximum received signal is reached, and then stop the movement.

[0062] S3. For the detection of the internal residual stress of the workpiece 4 to be measured, send an excitation signal to the excitation coil 1151 of the pulsed eddy current probe unit 115 through a signal generator with controllable frequency and phase sequence. Then, use a differential amplifier to amplify the received signal of the receiving coil 1152 of the pulsed eddy current probe unit 115, and calculate the phase of the reference signal and the received signal of the signal generator through a lock-in amplifier, read it into the data acquisition card, and feedback it to the supporting analysis and processing software of the upper industrial computer for analysis and calculation.

[0063] S4. Perform pre-contact detection. First, adjust the capacitance displacement sensor unit 217 of the nanoindentation loading and detection module 2 within the range of the measuring range. Then, drive the indenter 211 to move towards the surface of the workpiece 4 to be measured through the voice coil motor 317 of the motion scanning module 3 until the load signal collected by the force sensor 212 of the nanoindentation loading and detection module 2 changes suddenly. After analysis, the industrial computer sends a motion command to the voice coil motor 317 to stop it, record the Z-direction stroke of the indenter 211, and then lift the indenter 211.

[0064] S5. The nano-indentation method is used to detect the residual stress on the surface of the workpiece 4 to be measured. The X-direction movement component and the Y-direction movement component of the motion scanning module 3 are used to finely adjust and replace the indentation position. A motion command is sent to the voice coil motor 317 to make the indenter 211 approach the surface of the workpiece 4 to be measured. The upper computer trigger command sends a voltage drive signal to the piezoelectric stack 216 of the nano-indentation loading and detection module 2 through the piezoelectric amplifier, controlling the continuous movement of the indenter 211. At the same time, the force sensor 212 monitors the load change of the indenter 211 in real time. The load feedback signal is amplified by the charge amplifier and then read into the signal acquisition card, and then transmitted to the industrial control computer. The capacitance displacement sensor unit 217 transmits the measured displacement signal to the industrial control computer. The indentation load-displacement curve of the material is obtained through the calculation and analysis of the industrial control computer, and the specific relationship between the residual stress and the indentation response parameters is established therefrom, so as to qualitatively and quantitatively detect the residual stress, and then lift the indenter 211;

[0065] S6. According to the different geometric morphologies of the surface of the workpiece 4 to be measured, the industrial control computer sends commands to the piezoelectric amplifiers of the motion scanning module 3 and the parallel detection control module, and multiple detections at different positions are carried out on the workpiece 4 to be measured with complex geometric features, so as to realize the synchronous and co-located test characterization of the residual stress on the surface and inside of the workpiece 4.

[0066] In the present invention, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A residual stress composite detection device based on pulsed eddy current and nanoindentation, characterized by: It includes a pulsed eddy current nondestructive testing module, a nanoindentation loading and testing module, a motion scanning module, a fixture module, a support module and a parallel detection control module. The fixture module is installed in the middle of the upper end of the support module, and the fixture module is used to clamp the workpiece to be tested. The motion scanning module is installed at the upper end of the support module, and the output end of the motion scanning module is connected to the nanoindentation loading and testing module. The motion scanning module can drive the nanoindentation loading and testing module to move in multiple directions. The output end of the nanoindentation loading and testing module is connected to the pulsed eddy current nondestructive testing module. The pulsed eddy current nondestructive testing module is located above the workpiece to be tested and is used to detect the residual stress inside the workpiece to be tested. The parallel detection control module is electrically connected to the pulsed eddy current nondestructive testing module and is used to control the pulsed eddy current nondestructive testing module to adjust the distance between it and the surface of the workpiece to be tested. The parallel detection control module is also electrically connected to the motion scanning module and is used to control the action of the motion scanning module.

2. The residual stress composite detection device based on pulsed eddy current and nanoindentation according to claim 1 is characterized in that: The support module includes a base and a T-shaped stage. The base is I-shaped, and both sides of the base are higher than the middle of the base. The T-shaped stage is provided with a plurality of T-shaped long grooves arranged in sequence, and the T-shaped long grooves are used to install the fixture module. The T-shaped stage is installed in the middle of the upper surface of the base, and the T-shaped stage is used to install the workpiece to be measured.

3. The residual stress composite detection device based on pulsed eddy current and nanoindentation according to claim 2 is characterized in that: The base is made of marble; the base includes a middle platform and two side platforms, the two side platforms are symmetrically connected to the two sides of the middle platform, and a plurality of T-shaped long grooves are arranged in sequence on the middle platform, and the arrangement direction of the plurality of T-shaped long grooves is parallel to the connecting line between the two side platforms, and the length direction of the T-shaped long grooves is perpendicular to the arrangement direction of the plurality of T-shaped long grooves.

4. The residual stress composite detection device based on pulsed eddy current and nanoindentation according to claim 3 is characterized in that: The clamp module includes a plurality of clamping units, and the plurality of clamping units are installed in the T-shaped long slot, and the plurality of clamping units are arranged around the outer periphery of the workpiece to be measured; the clamping unit includes a pressure plate, a wedge column, a reset spring, a first bolt, and a second bolt. The first end of the pressure plate is used to press the upper surface of the workpiece to be measured, and a through hole is provided in the middle of the pressure plate. The lower end bolt head of the first bolt is slidably connected to the T-shaped long slot, and the upper end of the first bolt passes through the through hole and is fastened by a nut. The reset spring is sleeved on the outer periphery of the first bolt, and the first bolt A limiting ring is provided at each position corresponding to the two ends of the return spring on the outer circumference. The lower limiting ring abuts against the upper surface of the intermediate platform, and the upper limiting ring is slidably connected to the outer circumference of the first bolt and abuts against the lower end surface of the pressure plate. The lower end bolt head of the second bolt is slidably connected to the T-shaped long groove, and the upper end of the second bolt is movably connected to the wedge column. The upper end of the wedge column is embedded in the groove at the lower end of the pressure plate, and the wedge column can slide along the outer circumference of the second bolt. The outer circumference of the second bolt is threaded with a nut, and the nut is used to abut against the lower end of the wedge column.

5. The residual stress composite detection device based on pulsed eddy current and nanoindentation according to claim 1 is characterized in that: The motion scanning module includes a Y-axis motion component, a Z-axis motion component and two groups of X-axis motion components. The two groups of X-axis motion components are symmetrically arranged and respectively installed on both sides of the upper end surface of the supporting module. The two ends of the Y-axis motion component are respectively connected to the output ends of the two groups of X-axis motion components, the Z-axis motion component is connected to the output end of the Y-axis motion component, and the nanoindentation loading and detection module is connected to the output end of the Z-axis motion component.

6. The residual stress composite detection device based on pulsed eddy current and nanoindentation according to claim 5 is characterized in that: The X-axis motion assembly comprises an X-axis AC servo motor, an X-axis gear rack element, an X-axis connecting plate and two groups of X-axis guide rail slider elements, the two groups of X-axis guide rail slider elements are parallel to each other and are installed on the upper end of the support module through an X-axis mounting base, the X-axis connecting plate is connected to the sliders in the two groups of X-axis guide rail slider elements, the X-axis gear rack element is installed between the two groups of X-axis guide rail slider elements, the X-axis AC servo motor is installed on the X-axis connecting plate, and the output shaft of the X-axis AC servo motor passes through the X-axis connecting plate and is coaxially connected to the gear in the X-axis gear rack element; The Y-direction motion assembly comprises a Y-direction AC servo motor, a Y-direction gear rack element, a Y-direction connecting plate and two groups of Y-direction guide rail slider elements, the two groups of the guide rail slider elements in the Y-direction motion assembly are parallel to each other and are installed on the Y-direction mounting base, the Y-direction connecting plate is connected to the sliders in the two groups of the Y-direction guide rail slider elements, the Y-direction gear rack element is installed between the two groups of the Y-direction guide rail slider elements, the Y-direction AC servo motor is installed on the Y-direction connecting plate, and the output shaft of the Y-direction AC servo motor passes through the Y-direction connecting plate and is coaxially connected to the gear in the Y-direction gear rack element, and the two ends of the Y-direction mounting base are respectively installed on the two X-direction connecting plates; A grating ruler is installed on one side of the X-axis mounting base and one side of the Y-axis mounting base, and limit travel switches are installed on both ends of the X-axis mounting base and both ends of the Y-axis mounting base, and the Z-axis motion component is installed on the Y-axis connecting plate; The Z-axis motion component includes a voice coil motor, a Z-axis connecting block and a Z-axis fixed plate. A Z-axis mounting plate is installed on one side of the Y-axis connecting plate. The Z-axis mounting plate is installed on a side away from the Y-axis connecting plate with two Z-guide rails arranged side by side and extending in a vertical direction. Both ends of the Z-axis connecting block are slidably connected to the two Z-guide rails. The lower end of the voice coil motor is connected to the nanoindentation loading and detection module through the Z-axis fixed plate and screws, and the nanoindentation loading and detection module is connected to the Z-axis connecting block. The voice coil motor can push the nanoindentation loading and detection module to move along the Z direction.

7. The residual stress composite detection device based on pulsed eddy current and nanoindentation according to claim 6 is characterized in that: The nanoindentation loading and detection module includes a nanoindentation unit and a detection unit. The nanoindentation unit includes a first flexible hinge, a pressure head column and a pressure head. The detection unit includes a force sensor, a capacitive displacement sensor unit and a displacement measuring plate. A piezoelectric stack is installed in the groove of the first flexible hinge, and a pre-tightening screw is installed at the upper end of the first flexible hinge. The pre-tightening force of the piezoelectric stack can be adjusted by tightening the pre-tightening screw. The upper end of the first flexible hinge is connected to the voice coil motor. The lower end of the first flexible hinge is installed with the force sensor. The lower end of the force sensor is connected to the upper end of the pressure head column, and the force sensor is provided with an internal thread for matching with the external thread of the pressure head column. The displacement measuring plate is pressed between the force sensor and the pressure head column. The lower end of the pressure head column is connected to the pressure head through a positioning pin. The upper part of the capacitive displacement sensor unit is connected to one side of the Z-direction connecting block through a screw, and the lower end of the capacitive displacement sensor unit extends in a direction close to the displacement measuring plate.

8. The residual stress composite detection device based on pulsed eddy current and nanoindentation according to claim 7 is characterized in that: The pulse eddy current nondestructive testing module includes a protective sleeve, a wedge block, a second flexible hinge, an annular piezoelectric stack and a pulse eddy current probe unit. The second flexible hinge is sleeved on the outer periphery of the upper part of the pressure head column, and the upper end of the second flexible hinge is located at the lower end surface of the displacement measuring plate. The second flexible hinge is connected to the force sensor. The upper end of the second flexible hinge is provided with an internal thread for cooperating with the external thread of the pressure head column to adjust the preload force of the annular piezoelectric stack. The annular piezoelectric stack is coaxially sleeved on the outer periphery of the second flexible hinge. The lower end of the second flexible hinge is threadedly connected to the upper end of the protective sleeve. The protective sleeve is sleeved on the outer periphery of the lower part of the pressure head column. The wedge block is sleeved on the outer periphery of the pressure head column and is located in the protective sleeve. The pulse eddy current probe unit is installed on the wedge block and is located in the protective sleeve, and the pulse eddy current probe unit is arranged around the outer periphery of the pressure head column.

9. The residual stress composite detection device based on pulsed eddy current and nanoindentation according to claim 8 is characterized in that: The pulse eddy current probe unit includes a receiving coil and multiple excitation coils. The receiving coil is sleeved on the outer circumference of the pressure head column, and the multiple excitation coils are evenly arranged around the outer circumference of the receiving coil. Each of the excitation coils is provided with an iron core, and the upper end of each of the iron cores is installed on the wedge block. The outer circumference of the pressure head column is also sleeved with a pre-loaded compression spring, and the upper end of the pre-loaded compression spring is connected to the lower end of the second flexible hinge, and the lower end of the pre-loaded compression spring is connected to the upper end of the wedge block.

10. A residual stress composite detection method based on pulsed eddy current and nanoindentation, characterized in that: The residual stress composite detection device based on pulsed eddy current and nanoindentation according to any one of claims 1 to 9 comprises the following steps: S1. Use the fixture module to accurately position the workpiece to be tested on the T-stage of the support module, and send a motion signal to the motion controller through the industrial computer of the parallel detection control module, adjust the motion scanning module, and move the nanoindentation loading and detection module. The pulsed eddy current probe unit of the pulsed eddy current nondestructive testing module and the surface of the workpiece to be tested are kept within the working range, and the indenter of the nanoindentation loading and detection module reaches the surface of the workpiece to be tested; S2. Use the pulsed eddy current nondestructive testing module to detect the residual stress inside the workpiece to be tested. The piezoelectric amplifier of the parallel detection control module sends a control signal to the annular piezoelectric stack of the pulsed eddy current nondestructive testing module, so that the second flexible hinge of the pulsed eddy current nondestructive testing module produces micro-motion, and the distance between the pulsed eddy current probe unit and the surface of the workpiece to be tested is adjusted, so that the pulsed eddy current probe unit moves relative to the pressure head in the Z direction, and stops moving when the maximum receiving signal is reached; S3. Detection of residual stress inside the workpiece, sending an excitation signal to the excitation coil of the pulsed eddy current probe unit through a signal generator, and then amplifying the receiving signal of the receiving coil of the pulsed eddy current probe unit using a differential amplifier, and calculating the phase of the signal generator reference signal and the receiving signal through a phase-locked amplifier, reading them into a data acquisition card, and feeding them back to the supporting analysis and processing software of the upper industrial computer for analysis and calculation; S4. Perform pre-contact detection. First, adjust the capacitive displacement sensor unit of the nanoindentation loading and detection module to within the measuring range; then, drive the indenter to move toward the surface of the workpiece through the voice coil motor of the motion scanning module until the load signal collected by the force sensor of the nanoindentation loading and detection module changes suddenly. After analysis, the industrial computer sends a motion command to the voice coil motor to stop it, records the Z-direction stroke of the indenter, and then lifts the indenter; S5. Use nanoindentation method to detect the residual stress on the surface of the workpiece to be measured. Fine-tune the indentation position through the X-axis motion component and the Y-axis motion component of the motion scanning module, send a motion command to the voice coil motor to make the indenter close to the surface of the workpiece to be measured. The host computer triggers the command to send a voltage drive signal to the piezoelectric stack of the nanoindentation loading and detection module through the piezoelectric amplifier to control the continuous movement of the indenter. At the same time, the force sensor monitors the load change of the indenter in real time. The load feedback signal is amplified by the charge amplifier and read into the signal acquisition card, and then transmitted to the industrial computer. The capacitive displacement sensor unit transmits the measured displacement signal to the industrial computer. The indentation load-displacement curve of the material is obtained through the calculation and analysis of the industrial computer, and the specific relationship between the residual stress and the indentation response parameter is established, so as to make qualitative and quantitative detection of the residual stress, and then lift the indenter; S6. According to the different surface geometric morphologies of the workpiece under test, the industrial computer sends instructions to the piezoelectric amplifiers of the motion scanning module and the parallel detection control module to carry out multiple detections at different positions on the workpiece under test with complex geometric features, thereby realizing synchronous and in-situ test characterization of the residual stress on the surface of the workpiece under test and its internal structure.

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