A method and device for detecting the combined hardness of ultrasonic and brinell hardness

Abstract

The application provides a kind of ultrasonic hardness and brinell hardness composite hardness detection method and device, belongs to hardness detection equipment technical field, it can at least partially solve the existing actual production detection, need to consider two kinds of needs of on-site rapid nondestructive screening and high-precision authoritative assessment simultaneously, existing hardness detection device is difficult to meet the efficient, integrated, multi-scene compatible hardness detection demand, the ultrasonic hardness detection module and brinell hardness detection module are integrated in the same detection platform in the application, can switch three detection modes as needed, including ultrasonic hardness detection mode and brinell hardness detection mode, and first use ultrasonic to complete on-site large-scale rapid nondestructive preliminary screening, then carry out high-precision brinell hardness detection directly to preliminary screening abnormal sample composite detection mode.In the detection process of the application, the detection equipment does not need to be replaced, the needs of rapid screening and evaluation are considered, multiple scenes are adapted, the detection efficiency is effectively improved, and the integrated efficient detection requirements are met.

Description

Technical Field

[0001] This invention belongs to the technical field of hardness testing equipment, specifically relating to a method and apparatus for testing a composite hardness of ultrasonic hardness and Brinell hardness. Background Technology

[0002] Hardness is an important mechanical property indicator characterizing the ability of metallic materials to resist localized plastic deformation, and it is widely used in casting, forging, heat treatment, machining, and product quality inspection. Currently, commonly used hardness testing methods in industry are mainly divided into two categories: traditional static indentation methods and portable non-destructive testing methods.

[0003] The Brinell hardness test method, as a classic static indentation test method, offers stable test force and a large indentation area, reflecting the average hardness of a material. It exhibits good measurement stability for coarse-grained materials such as cast iron and cast steel, as well as rough-surfaced workpieces. The test results are traceable and highly authoritative, making it suitable for arbitration testing and precise evaluation. However, its drawbacks are also quite obvious: the testing process leaves a noticeable indentation on the workpiece surface, classifying it as a destructive test and unsuitable for precision finished parts; furthermore, traditional Brinell hardness testers are mostly benchtop structures, which are bulky and cumbersome to operate, making it difficult to meet the needs of rapid on-site testing of large workpieces.

[0004] Ultrasonic hardness testing, based on the principle of ultrasonic contact impedance, offers advantages such as minimal indentation, fast testing speed, good portability, and minimal damage to the workpiece surface. It is suitable for rapid, non-destructive screening of finished parts, thin-walled parts, and large workpieces on-site. However, ultrasonic hardness testing is susceptible to factors such as material grain size, surface roughness, and elastic modulus. It exhibits poor stability in coarse-grained materials, and its accuracy is lower than the standard Brinell hardness method. Therefore, it is generally only used for rapid initial inspection and is difficult to use as a final judgment criterion.

[0005] In actual production testing, it is often necessary to simultaneously meet the dual requirements of rapid on-site non-destructive screening and high-precision authoritative evaluation. Currently, testing personnel typically need to equip themselves with two separate sets of equipment: an ultrasonic hardness tester and a Brinell hardness tester. This is not only inconvenient to carry and cumbersome to operate, resulting in low testing efficiency, but also because the data from the two sets of equipment are independent, making unified control and comparison calibration impossible. This makes it difficult to meet the demands for efficient, integrated, and multi-scenario compatible hardness testing.

[0006] The existing technologies that are currently closest to this invention mainly fall into the following two categories: One type is the multifunctional portable hardness tester, which often adopts a combined structure of ultrasonic hardness and Leeb hardness testing. This type of device can achieve rapid non-destructive testing and has good portability. However, Leeb hardness is a dynamic rebound testing method, not a standard static indentation method. Its measurement accuracy and the authority of the results are lower than those of Brinell hardness, and it cannot meet the requirements for high-precision, arbitrable testing of coarse-grained materials.

[0007] Another type is the benchtop multi-functional hardness tester, which integrates multiple static indentation testing functions such as Brinell, Rockwell, and Vickers, offering high testing accuracy and a wide range of applications. However, its overall benchtop structure makes it unportable and unable to perform on-site testing of large workpieces; furthermore, it uses macroscopic indentation methods and lacks ultrasonic non-destructive testing capabilities, making it unsuitable for testing finished workpieces with high surface quality requirements.

[0008] In summary, among existing hardness testing technologies, ultrasonic hardness testing and Brinell hardness testing each have their irreplaceable advantages, but they also each have significant technical bottlenecks: ultrasonic hardness testing is fast, non-destructive, and portable, but it is sensitive to surface quality and relies on elastic modulus calibration; Brinell hardness testing provides stable and reliable results and has wide applicability, but it is a destructive test, inefficient, and requires bulky equipment. In actual industrial testing, users often need to simultaneously consider non-destructive testing, testing efficiency, and measurement accuracy, and a single testing method cannot meet the complex and ever-changing testing needs. Therefore, existing technologies lack an integrated composite testing device that can simultaneously integrate ultrasonic hardness testing and Brinell hardness testing, making it difficult to achieve rapid non-destructive screening and high-precision authoritative testing on the same device. This results in problems such as limited functionality, poor adaptability to different scenarios, and inconvenience in use.

[0009] Therefore, we propose a composite hardness testing method and apparatus based on ultrasonic hardness and Brinell hardness. Summary of the Invention

[0010] The present invention aims to solve at least one of the technical problems existing in the prior art, and provides a method and apparatus for testing composite hardness of ultrasonic hardness and Brinell hardness.

[0011] One aspect of the present invention provides a method for testing a composite hardness of ultrasonic hardness and Brinell hardness, comprising the following steps: S1. Select a detection mode to perform the measurement operation. The detection modes include ultrasonic hardness detection mode, Brinell hardness detection mode, and composite detection mode. In the ultrasonic hardness testing mode or the Brinell hardness testing mode, the target area is measured to obtain a single hardness value; in the composite testing mode, the target area is measured sequentially using the ultrasonic hardness testing mode, and the adjacent positions of the target area are measured using the Brinell hardness testing mode to obtain a first hardness value and a second hardness value, respectively. S2. The measurement results are uploaded to the data processing unit and displayed through the display unit. In the ultrasonic hardness testing mode or the Brinell hardness testing mode, the data processing unit directly displays the measurement results through the display unit. In the composite testing mode, the data processing unit compares the difference between the first hardness value and the second hardness value with a preset threshold range to generate an evaluation report characterizing the uniformity of the material structure, and displays the evaluation report along with the measurement results through the display unit.

[0012] Furthermore, in the ultrasonic hardness testing mode, the range of the applied load is 1N to 100N; in the Brinell hardness testing mode, the range of the applied load is 500N to 30000N.

[0013] Furthermore, the distance between the center of the adjacent location and the center of the measurement point within the target area is 0.5mm to 2mm.

[0014] Specifically, the assessment report includes: If the difference between the first hardness value and the second hardness value is within a preset threshold range, an evaluation result showing uniform material structure is generated. If the first hardness value is higher than the second hardness value, and the difference between the first hardness value and the second hardness value is not within the preset threshold range, an evaluation result is generated indicating that the material structure contains a local hard phase. If the first hardness value is lower than the second hardness value, and the difference between the first hardness value and the second hardness value is not within a preset threshold range, an assessment result is generated indicating that the material structure contains a local soft phase.

[0015] Specifically, the composite hardness testing method further includes the following steps: The measurement operation of the composite detection mode is repeatedly performed at multiple points, and the corresponding evaluation report is generated by the data processing unit. Based on the evaluation report of each point, the data processing unit generates a hardness distribution cloud map and outputs it through the display unit.

[0016] Another aspect of the present invention provides a composite hardness testing device for ultrasonic hardness and Brinell hardness, comprising a frame body, a worktable, a Brinell indentation measuring unit, a data processing unit, and a display unit; the worktable is disposed on the frame body; the Brinell indentation measuring unit is built into the frame body or electrically connected to the frame body; the display unit and the data processing unit are electrically connected. An ultrasonic hardness testing unit includes a first loading mechanism and an ultrasonic testing unit body connected to the output end of the first loading mechanism; The Brinell hardness testing unit includes a second loading mechanism and a Brinell hardness testing unit body connected to the output end of the second loading mechanism. A switching mechanism is provided, with its fixed end connected to the frame body and its free end connected to the fixed ends of the first loading mechanism and the second loading mechanism. This mechanism is used to drive the ultrasonic hardness testing unit and the Brinell hardness testing unit to switch measurement positions and to ensure that the center distance between the two measurement points in the composite testing mode is 0.5mm to 2mm. The measurement and control system is installed on the frame body and is electrically connected to the first loading mechanism, the ultrasonic testing unit body, the second loading mechanism, the Brinell hardness testing unit body, the switching mechanism, the Brinell indentation measurement unit and the data processing unit, respectively.

[0017] Preferably, the ultrasonic hardness testing unit includes multiple replaceable probes or parameter-adjustable probes.

[0018] Preferably, the measuring indenter of the Brinell hardness testing unit includes a cemented carbide indenter with a sphere diameter of 2.5 mm, 5 mm, and 10 mm.

[0019] Furthermore, the switching mechanism includes a linear guide or a rotary table, which is driven by a drive assembly to achieve the switching of measurement stations.

[0020] Furthermore, the measurement and control system includes a microcontroller, a force sensor, a displacement sensor, and a signal acquisition and processing circuit. The microcontroller, the force sensor, the displacement sensor, and the signal acquisition and processing circuit are all electrically connected to the first loading mechanism, the main body of the ultrasonic detection unit, the second loading mechanism, the main body of the Brinell hardness detection unit, the switching mechanism, and the data processing unit, respectively.

[0021] The beneficial effects of this invention are as follows: 1. This invention integrates an ultrasonic hardness testing unit and a Brinell hardness testing unit, which can cover a wide range of hardness testing ranges from 10HV to 2000HV and from 8HBW to 650HBW, adapting to the hardness testing needs of most metal materials. It also takes into account the advantages of ultrasonic testing being non-destructive and fast, and the characteristics of Brinell testing being high accuracy and stable results, thus meeting the hardness testing requirements of different testing scenarios and different industry standards. 2. This invention provides test loads that meet the respective testing standards of the ultrasonic testing unit and the Brinell hardness testing unit through two independent loading mechanisms: the first loading mechanism can output a stable low load of 1N to 100N, meeting the testing requirements of small indentation and low damage in ultrasonic hardness testing; the second loading mechanism can output a large load of 500N to 30000N, meeting the standard test force requirements of Brinell hardness testing. Furthermore, the two independent loading mechanisms do not interfere with each other, and the two testing modes can be quickly switched without replacing the loading module. While ensuring the testing accuracy of each mode, the testing efficiency is effectively improved. Compared to the accuracy loss and structural complexity caused by switching between extremely low and extremely high forces using the same loading mechanism, this invention has a simpler structure, lower cost, and more stable control. 3. This invention enables rapid switching between two detection units via a switching mechanism. Combined with an integrated measurement and control system and data processing unit, it can complete the control, data acquisition, analysis, and comparison of two detection modes on the same set of equipment. It can use the ultrasonic mode alone to complete rapid non-destructive screening on-site, or the Brinell mode alone to complete high-precision authoritative arbitration testing. It can also use the composite detection mode to complete multi-point material uniformity analysis and hardness distribution cloud map generation. It has a high degree of integration and strong scene adaptability, which can meet the diverse hardness testing needs in different industrial scenarios. When using the composite detection mode, the center distance between the two measurement points is controlled between 0.5mm and 2mm. This avoids the indentation of the previous measurement from interfering with the result of the subsequent measurement, and ensures that the two measurement points are in the same material structure region. This greatly improves the accuracy of the comparison and analysis of the two detection results and provides reliable data support for the evaluation of material structure uniformity. 4. This invention automatically completes the switching of measurement positions between two detection units through the cooperation between the switching mechanism, the measurement and control system, the data processing unit and the display unit. It eliminates the need for manual disassembly and replacement of detection components, greatly improving detection efficiency, and has a high degree of automation, effectively reducing errors caused by manual operation. 5. This invention, through the built-in or external Brinell indentation measurement unit, is compatible with both benchtop, vertical, and portable models. The configuration scheme can be flexibly selected according to actual usage needs. It can be adapted to both precision arbitration testing in a laboratory environment and rapid testing of large workpieces in the field outdoors. This effectively improves the device's scene adaptability and usage flexibility, overcomes the shortcomings of traditional single-function hardness testers with poor scene adaptability, and can better meet the diverse hardness testing needs of different industries and scenarios. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the overall steps of the composite hardness testing method for ultrasonic hardness and Brinell hardness according to a specific embodiment of the present invention. Figure 2 This is a flowchart illustrating the combined hardness testing method of ultrasonic hardness and Brinell hardness according to a specific embodiment of the present invention, in the selection of the combined testing mode. Figure 3 This is a schematic diagram of the overall structure of the composite hardness testing device for ultrasonic hardness and Brinell hardness according to a specific embodiment of the present invention. Figure 4 This is a partial schematic diagram of the switching mechanism of the composite hardness testing device for ultrasonic hardness and Brinell hardness according to a specific embodiment of the present invention.

[0023] The components include: 1. Frame body; 2. Worktable; 3. Workpiece to be tested; 4. Ultrasonic testing unit body; 5. First loading mechanism; 6. Brinell hardness testing unit body; 7. Second loading mechanism; 8. Switching mechanism; 9. Measurement and control system; 10. Data processing unit; 11. Brinell indentation measurement unit; 12. Linear guide rail; 13. First slider; 14. Second slider; 15. Stepper motor; 16. Target area; 17. Adjacent position; 18. Display unit. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] The composite hardness testing method for ultrasonic hardness and Brinell hardness provided in this invention includes the following steps: S1. Selecting a testing mode to perform a measurement operation, the testing modes include ultrasonic hardness testing mode, Brinell hardness testing mode, and composite testing mode; measuring the target area 16 in the ultrasonic hardness testing mode or the Brinell hardness testing mode to obtain a single hardness value; in the composite testing mode, sequentially measuring the target area 16 using the ultrasonic hardness testing mode and measuring the adjacent position 17 of the target area 16 using the Brinell hardness testing mode to obtain a first hardness value and a second hardness value respectively; S2. Uploading the measurement results to the data processing unit 10 and displaying them through the display unit 18, wherein, in the ultrasonic hardness testing mode or the Brinell hardness testing mode, the data processing unit 10 directly displays the measurement results through the display unit 18; in the composite testing mode, the data processing unit 10 compares the difference between the first hardness value and the second hardness value with a preset threshold range to generate an evaluation report characterizing the uniformity of the material structure, and outputs the evaluation report and the measurement results together through the display unit 18.

[0026] Specifically, in the ultrasonic hardness testing mode, the range of the applied load is 1N to 100N; in the Brinell hardness testing mode, the range of the applied load is 500N to 30000N.

[0027] Based on the above basic implementation method, in step S1, if the ultrasonic hardness testing mode is selected, the measurement and control system 9 controls the first loading mechanism 5 to output a preset first load, the load range of which is controlled between 1N and 100N, driving the detection probe of the ultrasonic detection unit body 4 to fit against the surface of the target measurement point of the workpiece 3 to be tested; then the ultrasonic detection unit collects the ultrasonic response signal of the target point based on the ultrasonic contact impedance principle, and transmits it to the data processing unit 10 after processing by the signal acquisition and processing circuit. The data processing unit 10 calculates the ultrasonic hardness value of the measurement point according to the pre-calibrated material elastic modulus parameters and signal characteristics, and finally transmits the hardness measurement result to the display unit 18 for output display, completing a single detection process, and almost no work hardening occurs in this detection process. If the Brinell hardness testing mode is selected, the measurement and control system 9 first controls the switching mechanism 8 to move the ultrasonic testing unit out of the measurement station while driving the Brinell hardness testing unit to the measurement station. Then, the second loading mechanism 7 outputs a second load according to preset parameters, with the load range controlled between 500N and 30000N, driving the selected Brinell carbide indenter to vertically press into the surface of the measurement point of the workpiece 3 to be tested. After holding the pressure for a set time, the load is unloaded. During the loading process, the force sensor and displacement sensor collect parameters such as force value and indentation depth in real time. After unloading, the Brinell indentation measurement unit 11 performs imaging measurement on the indentation left on the workpiece surface to obtain the average diameter data of the indentation. After all the collected parameters are transmitted to the data processing unit 10, the Brinell hardness value of the measurement point is calculated according to the standard Brinell hardness calculation formula. Finally, the hardness measurement result is transmitted to the display unit 18 for output and display, completing a single Brinell hardness test.

[0028] Specifically, the center distance between the adjacent location 17 and the measurement point within the target area 16 is 0.5mm to 2mm.

[0029] Furthermore, the evaluation report includes: if the difference between the first hardness value and the second hardness value is within a preset threshold range, an evaluation result indicating uniform material structure is generated; if the first hardness value is higher than the second hardness value, and the difference between the first hardness value and the second hardness value is not within a preset threshold range, an evaluation result indicating the presence of a local hard phase in the material structure is generated; if the first hardness value is lower than the second hardness value, and the difference between the first hardness value and the second hardness value is not within a preset threshold range, an evaluation result indicating the presence of a local soft phase in the material structure is generated.

[0030] Furthermore, the composite hardness testing method further includes the following steps: repeatedly performing the measurement operation of the composite testing mode at multiple points, generating corresponding evaluation reports through the data processing unit 10, generating hardness distribution cloud maps based on the evaluation reports of each point, and outputting and displaying them through the display unit 18.

[0031] In one specific implementation, if the composite testing mode is selected, the ultrasonic hardness testing unit first completes the measurement of the first hardness value of the target point in the target area 16 according to the ultrasonic hardness testing process described above. Then, the measurement and control system 9 controls the switching mechanism 8 to move the Brinell hardness testing unit to the preset measurement position, so that the distance between the center of the Brinell measurement point and the center of the ultrasonic measurement point is stably maintained within the range of 0.5mm to 2mm. Then, the measurement of the adjacent position 17 is completed according to the Brinell hardness testing process described above to obtain the second hardness value. After obtaining the two hardness values, the data processing unit 10 compares the difference between the two with the preset threshold range. According to the magnitude and direction of the difference, the uniformity of the material structure in this area is judged, and the corresponding evaluation result is generated: if the difference is within the preset threshold range, an evaluation result of uniform material structure in this area is generated; if the first hardness value is higher than the second hardness value and the difference exceeds the threshold range, an evaluation result of the presence of a local hard phase in this area is generated; if the first hardness value is lower than the second hardness value and the difference exceeds the threshold range, an evaluation result of the presence of a local soft phase in this area is generated; finally, the two hardness measurement results and the uniformity of structure evaluation report are transmitted to the display unit 18 for output, completing one composite test. The formulas for calculating the first hardness value and the second hardness value are as follows:

[0032] When it is necessary to test the uniformity of the microstructure over a large area of ​​a workpiece, the above-mentioned composite testing process only needs to be repeated at multiple preset points. The data processing unit 10 will integrate the test data and evaluation results of all points and automatically generate a hardness distribution cloud map of the target area 16 of the workpiece, which more intuitively shows the distribution of material hardness and internal structure, making it easier for inspectors to quickly judge the overall quality of the workpiece. In the composite testing mode, it is possible to obtain the overall macroscopic representative hardness of the material under test, and also to detect and identify local hard or soft phases, providing a new testing method for casting, welding, heat treatment and other fields. In addition, when using the ultrasonic hardness testing unit, due to the small load, it is difficult to produce work hardening, and it will not cause significant changes to the surface structure and properties of the workpiece test area, nor will it leave observable destructive indentations. Combined with the fact that the distance between the two test points is only 0.5mm to 2mm, it is possible to effectively compare the micro-area hardness with the macroscopic average hardness, and avoid the interference of the indentation generated by the ultrasonic hardness testing unit on the Brinell indentation image recognition, making positioning easier to achieve. It successfully solves the technical pain point that a single hardness testing method cannot simultaneously meet the requirements of non-destructive testing, testing efficiency, and high-precision authoritative testing, and greatly improves the adaptability of hardness testing devices to complex and ever-changing industrial testing scenarios.

[0033] Specifically, when generating a hardness distribution cloud map, the operator can first customize the test parameters on the display unit 18 interface: supporting the selection of rectangular or circular measurement areas, and setting the grid spacing (e.g., 3mm×3mm) and the total number of measurement points (e.g., 10×10) as needed. After the parameters are confirmed, the device will automatically locate each grid point as the target position according to the grid plan, and perform a composite test process of "ultrasonic hardness test → Brinell hardness test at adjacent position 17 in the same area" for each measurement point. The ultrasonic hardness value and Brinell hardness value corresponding to each measurement point will be automatically recorded and stored by the data processing unit 10. After all measurement points are tested, the data processing unit 10 will generate two hardness distribution cloud maps of ultrasonic hardness and Brinell hardness based on the collected full data, and automatically calculate the overall hardness average value and standard deviation of the entire test area, and can also generate an ultrasonic / Brown hardness difference distribution map. The data processing unit 10 also has built-in deviation judgment rules, which can automatically identify abnormal points where the deviation between the two hardness test values ​​exceeds 15%, and mark them with a special color on the cloud map, making it convenient for quality inspectors to quickly locate and focus on checking. It can be widely applied to the batch uniformity acceptance of large castings, forgings, and heat-treated parts, filling the technical gap that traditional hardness testing cannot quickly complete the quantitative evaluation of large-area microstructure uniformity.

[0034] In another embodiment, the present invention also provides a composite hardness testing device for ultrasonic hardness and Brinell hardness, which is used to implement the above-described composite hardness testing method for ultrasonic hardness and Brinell hardness. The device includes a frame body 1, a worktable 2, a Brinell indentation measuring unit 11, a data processing unit 10, and a display unit 18. The worktable 2 is disposed on the frame body 1. The Brinell indentation measuring unit 11 is built into the frame body 1 or electrically connected to the frame body 1. The display unit 18 and the data processing unit 10 are electrically connected. The ultrasonic hardness testing unit includes a first loading mechanism 5 and an ultrasonic testing unit body 4 connected to the output end of the first loading mechanism 5. The Brinell hardness testing unit includes a second loading mechanism 7 and an ultrasonic testing unit body 4 connected to the output end of the second loading mechanism 5. The output end of mechanism 7 is connected to the main body 6 of the Brinell hardness testing unit; a switching mechanism 8, the fixed end of which is connected to the frame body 1, and the free end of which is connected to the fixed ends of the first loading mechanism 5 and the second loading mechanism 7, is used to drive the ultrasonic hardness testing unit and the Brinell hardness testing unit to switch measurement positions, and to make the center distance between the two measurement points in the composite testing mode 0.5mm to 2mm; a measurement and control system 9, which is installed on the frame body 1 and is electrically connected to the first loading mechanism 5, the main body 4 of the ultrasonic testing unit, the second loading mechanism 7, the main body 6 of the Brinell hardness testing unit, the switching mechanism 8, the Brinell indentation measurement unit 11 and the data processing unit 10 respectively.

[0035] In one specific implementation, the frame body 1 serves as the load-bearing base of the entire machine, possessing high rigidity and high stability. This effectively resists structural deformation and vibration interference generated during the loading process of the Brinell hardness testing unit, ensuring high-precision measurement. The worktable 2 is used to stably place and position various workpieces under test, ensuring no deviation or shaking during the workpiece testing process and guaranteeing a consistent measurement benchmark. The Brinell indentation measurement unit 11, as the core imaging acquisition component for Brinell hardness testing, accurately acquires indentation images and completes size recognition. Its built-in or external structural design can accommodate desktop, vertical, and portable models. The data processing unit 10 is responsible for receiving, processing, comparing, and analyzing data throughout the entire process. It is used to achieve dual hardness data fusion, microstructure uniformity assessment, and cloud map generation. The measurement data and evaluation report are then displayed intuitively and visually through the display unit 18, facilitating quick reading of the test results by operators. The dual independently configured ultrasonic hardness testing unit and Brinell hardness testing unit each have their own independent loading mechanism, avoiding the accuracy loss and structural complexity caused by switching between extremely low and extremely high forces in the same loading mechanism. This results in a simpler structure, lower cost, and more stable control.

[0036] Furthermore, the ultrasonic hardness testing unit includes multiple replaceable probes or parameter-adjustable probes.

[0037] In one specific implementation, the ultrasonic hardness testing unit also includes a piezoelectric vibrator, a frequency detection circuit, and a diamond indenter. By configuring replaceable and parameter-adjustable probes, the optimal testing parameters can be flexibly matched according to the hardness, grain size, and surface condition of the workpiece being tested. This greatly expands the testing range of ultrasonic micro-area hardness, covering the full range of micro-area testing from extremely soft metals to superhard alloys. Simultaneously, the adjustable probe structure can adapt to different accuracy levels of testing requirements. General-purpose probes are used for rapid screening of conventional workpieces, while precision probes are used for accurate micro-area measurement in high-precision testing scenarios. This effectively improves the versatility and adaptability of the device, meeting the differentiated testing needs of various industrial scenarios.

[0038] Furthermore, the measuring indenter of the Brinell hardness testing unit includes cemented carbide indenters with ball diameters of 2.5 mm, 5 mm, and 10 mm.

[0039] In one specific implementation, the multi-specification cemented carbide ball indenter is compatible with national standard multi-level test force testing specifications. It matches the appropriate ball diameter indenter to workpieces of different thicknesses, hardnesses, and grain characteristics, effectively avoiding problems such as excessive indentation, indentation distortion, and insufficient testing accuracy caused by single-specification indenters. Simultaneously, cemented carbide material possesses advantages such as high hardness, high wear resistance, and strong deformation resistance. Long-term repeated loading operations will not cause indenter wear or deformation, ensuring the regularity and measurement accuracy of the Brinell indentation over a long period. It is suitable for standard hardness testing and quality arbitration testing of various metal workpieces such as cast steel, cast iron, aluminum alloys, and heat-treated hardened parts.

[0040] Furthermore, the switching mechanism 8 includes a linear guide rail 12 or a rotary table, which is driven by a drive assembly to realize the switching of the measurement station.

[0041] In one specific implementation, the linear guide rail 12 or the rotary table structure, in conjunction with the drive assembly, enables automated, high-precision, and rapid switching between the ultrasonic testing station and the Brinell testing station. This replaces the traditional manual probe disassembly and alignment methods, completely eliminating manual alignment errors. Simultaneously, this structure can precisely control the spacing accuracy of the dual testing points, stably achieving measurements of adjacent positions 17 within the same area at a range of 0.5mm to 2mm. This ensures consistency between the micro-area and macro-area testing areas while avoiding interference between the two measurements, significantly improving the automation, testing efficiency, measurement repeatability, and measurement accuracy of the composite testing mode. Specifically, when the switching mechanism 8 uses a linear guide rail 12, it is equipped with a first slider 13, a second slider 14, and a lead screw. The driving component uses a stepper motor 15. When the stepper motor 15 starts, it drives the lead screw to rotate, which in turn drives the first slider 13 and the second slider 14 to drive the first loading mechanism 5 and the second loading mechanism 7 to perform linear reciprocating motion along the guide rail, respectively. The movement position of the two detection units is precisely controlled by the preset stroke parameters, ensuring that the center distance between the two measurement points in the composite detection mode is stably within the preset range of 0.5mm to 2mm. The positioning accuracy can reach 0.02mm, which fully meets the positioning accuracy requirements of the micro-area adjacent point measurement and will not affect the accuracy of tissue uniformity assessment due to the spacing deviation.

[0042] Specifically, the measurement and control system 9 includes a microcontroller, a force sensor, a displacement sensor, and a signal acquisition and processing circuit. The microcontroller, the force sensor, the displacement sensor, and the signal acquisition and processing circuit are all electrically connected to the first loading mechanism 5, the ultrasonic detection unit body 4, the second loading mechanism 7, the Brinell hardness detection unit body 6, the switching mechanism 8, and the data processing unit 10, respectively.

[0043] In one specific implementation, the measurement and control system 9 serves as the core control hub of the entire testing device. Through a microcontroller, it achieves full-device logic control and parameter adjustment, precisely controlling the magnitude of the load, the holding time, and the selection of the testing mode. Force and displacement sensors collect real-time data on the load and indentation displacement of the ultrasonic hardness testing unit or the Brinell hardness testing unit, achieving closed-loop precise load control and preventing measurement failures caused by excessive or insufficient load. The signal acquisition and processing circuit filters, amplifies, and reduces noise in the ultrasonic frequency signal, indentation image signal, and force-displacement signal, eliminating environmental interference signals and ensuring the accuracy of the acquired data. The entire measurement and control system 9 works collaboratively to achieve fully automated closed-loop control of the testing process, effectively reducing errors caused by manual intervention and improving the overall testing accuracy and operational stability of the equipment.

[0044] To help better understand the present invention, the following embodiments of this application disclose part of the specific implementation process of a composite hardness testing method and apparatus for ultrasonic hardness and Brinell hardness, which includes the exemplary embodiments 1 to 4 shown below.

[0045] Example 1, the first aspect provides a method for testing the combined hardness of ultrasonic hardness and Brinell hardness, including the following steps: S1. Place the cast aluminum alloy workpiece on the workbench and fix it with flat-nose pliers or a magnetic chuck. Grind the surface of the measurement area with sandpaper until the roughness Ra≤0.8μm. S2. The operator selects "Composite Detection Mode" on the software interface of the display unit and enters the material "ZL104 Cast Aluminum". The measurement and control system automatically matches the loading force of the first loading mechanism to 3N and the loading force of the second loading mechanism to 500kgf. After clicking "Start Measurement", the switching mechanism moves the ultrasonic hardness detection unit directly above the target area. The first loading mechanism presses the diamond indenter into the workpiece surface with a force of 3N and holds the load for 1 second. The frequency detection circuit measures the hardness value as 85HV (equivalent) and uploads it to the data processing unit.

[0046] The probe of the ultrasonic hardness testing unit is raised, and the switching mechanism moves the ultrasonic hardness testing unit away, moving the Brinell hardness testing unit to a nearby position in the same target area. The measurement and control system controls the moving distance so that the distance d = 1.2mm between the center of the Brinell indenter and the center of the indentation of the ultrasonic hardness test. The second loading mechanism presses a φ5mm cemented carbide ball into the workpiece surface with a force of 500kgf, holds the load for 15 seconds, and then unloads. The camera built into the frame body captures the Brinell indentation image, and the image processing algorithm measures the indentation diameter d1 = 2.86mm. Based on the Brinell hardness value calculation formula, the Brinell hardness value HBW = 62 (500kgf / φ5mm ball) is calculated and then uploaded to the data processing unit. The Brinell hardness value calculation formula is as follows:

[0047] Among them, F kgf Where is the applied force (unit: kgf), D is the diameter of the cemented carbide ball (unit: mm), d is the indentation diameter (unit: mm), and π is pi.

[0048] S3. The data processing unit compares the UCI equivalent hardness of 85HV (approximately 72HBW, converted based on aluminum alloy experience) with the measured Brinell hardness of 62HBW. The difference between the two is calculated to be 16%, exceeding the software's preset uniformity threshold (typically ±8%). The system determines that there is microstructure inhomogeneity in this area, and the high ultrasonic hardness value indicates the presence of a local hard phase (possibly a primary silicon or eutectic silicon enrichment area). The Brinell hardness value represents the macroscopic average hardness. The final output report states: Brinell hardness is 62HBW (representative hardness), microstructure uniformity is poor, and the ultrasonic hardness test shows a local hardness fluctuation of +16%. It is recommended to perform multi-point composite measurements in adjacent areas to assess the overall degree of segregation. S4. The operator selects "Grid Measurement" in the software interface of the display unit, sets a 5×5 dot matrix with a spacing of 2mm. The device automatically repeats the above process to generate a hardness distribution cloud map, visually displaying the casting segregation area.

[0049] The second aspect provides a composite hardness testing device for ultrasonic hardness and Brinell hardness, including a frame body with sufficient rigidity and vibration reduction performance, made of cast iron or welded steel structure, with leveling feet at the bottom, and an upper crossbeam fixed on the upper part of the frame, and an open working space in the middle. The worktable is a precision lifting mechanism or a fixed platform, installed at the bottom of the frame body, and has T-slots or magnetic chucks on its surface for placing and fixing the workpiece to be measured. The main body of the ultrasonic testing unit includes a UCI probe, a piezoelectric vibrator (PZT), a frequency detection circuit, and a diamond indenter (136° cone angle). The first loading mechanism is connected above the UCI probe. The first loading mechanism is a micro stepper motor combined with spring loading, providing a small load of 1N to 100N, with a force control accuracy of ±0.5N, and is independently installed on a slider of the positioning and switching mechanism; The main body of the Brinell hardness testing unit includes a spherical indenter (a cemented carbide ball with selectable diameters of φ2.5mm, φ5mm, and φ10mm), an indenter base, and a force sensor; The second loading mechanism is a servo motor-driven ball screw, coupled with closed-loop control from a force sensor, providing a large load of 500N to 30000N with a force control accuracy of ±1%. This mechanism is independently mounted on another slider of the positioning and switching mechanism. The switching mechanism includes a linear guide rail and two independent sliders, driven by a stepper motor through a lead screw. The repeatability is better than 0.02mm. The two sliders respectively carry the main body of the ultrasonic testing unit and the main body of the Brinell hardness testing unit. They can move along the guide rail under program control, so that the UCI probe and the Brinell spherical indenter can reach the measurement position above the worktable in sequence. The Brinell indentation measurement unit is equipped with a built-in high-resolution industrial camera (5 megapixels) and a telecentric lens, along with ring LED illumination. It is installed near the Brinell indenter. During measurement, the camera automatically focuses and acquires indentation images. The image processing algorithm extracts the indentation edges and calculates the average diameter. The measurement and control system is based on an embedded industrial computer or PLC, integrating a multi-channel force sensor acquisition card, motor driver, frequency counter and image acquisition card, and is electrically connected to all loading mechanisms, switching mechanisms, frequency detection circuits and cameras.

[0050] The data processing unit and display unit are integrated into an industrial panel PC, which is equipped with dedicated measurement and control software. The software has functions such as parameter setting, automatic measurement, data storage, report generation, and organization uniformity evaluation.

[0051] Example 2 differs from Example 1 only in step S2. The operator selects "Ultrasonic Hardness Testing Mode" on the software interface of the display unit and inputs the material type "45 Steel." Upon receiving this signal, the measurement and control system automatically calls the pre-stored parameters, setting the loading force of the first loading mechanism to 10N and the holding time to 1 second. After clicking "Start Measurement," the switching mechanism moves the ultrasonic hardness testing unit directly above the target area. The first loading mechanism presses the diamond indenter into the workpiece surface with a force of 3N, holds the load for 1 second, and then unloads. The frequency detection circuit collects the resonant frequency change and transmits the data to the data processing unit. The data processing unit calculates the equivalent Vickers hardness value and displays it on the screen. The remaining devices and operating steps are consistent with Example 1.

[0052] Example 3 differs from Example 1 only in step S2. The operator selects "Brinell Hardness Testing Mode" on the software interface of the display unit and inputs the material type "annealed steel." Upon receiving this signal, the measurement and control system automatically calls the pre-stored parameters, sets the loading force of the second loading mechanism to 3000 kgf, and the holding time to 10-15 seconds. A 10mm cemented carbide indenter is selected for the Brinell hardness testing unit. After clicking "Start Measurement," the switching mechanism moves the Brinell hardness testing unit directly above the target area. The second loading mechanism presses the 10mm cemented carbide indenter into the workpiece surface with a force of 3000 kgf, holding the load for 13 seconds before unloading. The built-in camera in the frame automatically captures images of the indentation. The image processing algorithm measures the indentation diameter d (accurate to 0.01 mm) and uploads it to the data processing unit. The data processing unit calculates the Brinell hardness value according to the Brinell hardness calculation formula and displays the result on the screen. The remaining devices and operating steps are consistent with Example 1.

[0053] Example 4, taking the on-site testing of the hardness of the weld heat-affected zone of a large water turbine runner as an example, discloses a composite hardness testing method combining ultrasonic hardness and Brinell hardness, including the following steps: S1. Attach the portable device to the surface of the rotary blades using the magnetic base, and adjust the C-shaped opening so that the measuring area is located below the pressure head; S2. The operator selects "Composite Detection Mode" on the software interface of the display unit and inputs the material "ZL104 Cast Aluminum". The measurement and control system automatically matches the loading force of the first loading mechanism to 5N and the holding time to 1 second, and the loading force of the second loading mechanism to 3000kgf and the holding time to 10 seconds. After clicking "Start Measurement", the switching mechanism moves the ultrasonic hardness detection unit directly above the target area. The first loading mechanism presses the diamond indenter into the workpiece surface with a force of 5N, holds the load for 1 second, and then unloads. The frequency detection circuit measures the hardness value to be 210HV (equivalent) and uploads it to the data processing unit. The ultrasonic hardness testing unit's probe is raised, and the switching mechanism moves the ultrasonic hardness testing unit away, relocating the Brinell hardness testing unit to a nearby position within the same target area. The measurement and control system controls the movement distance, ensuring the distance d = 1.5mm between the center of the Brinell indenter and the center of the indentation from the ultrasonic hardness test. The second loading mechanism presses a φ10mm cemented carbide ball into the workpiece surface with a force of 3000kgf, holds the load for 10 seconds, and then unloads. The operator uses a mobile phone macro lens (with built-in ruler) to take a photo of the indentation. The mobile app automatically identifies the indentation diameter, obtaining d = 3.15mm, and calculates the Brinell hardness value as 180HBW. The data is transmitted to a tablet computer via Bluetooth. S3. The tablet computer software compared the ultrasonic equivalent hardness (210HV≈198HBW) with the Brinell hardness of 180HBW, and the calculated difference was +10%, exceeding the +8% threshold. Judgment: The weld heat-affected zone exhibits uneven microstructure, and the ultrasonic hardness value is too high, suggesting the possible presence of martensite or bainite hard phases. The Brinell value is the macroscopic average hardness. Finally, the representative Brinell hardness was shown to be 180HBW, with localized hardness deviations of approximately 10%, recommending a metallographic re-examination.

[0054] On the other hand, a composite hardness testing device for ultrasonic hardness and Brinell hardness is disclosed, including a frame body with a C-type open clamp structure or a magnetic adsorption base, which weighs no more than 5kg and can be held by hand or magnetically adsorbed onto the surface of large workpieces. The Brinell indentation measurement unit does not have a built-in optical system; instead, it uses a positioning mark and Bluetooth communication module pre-installed on the frame. After measuring the Brinell indentation, the user can take photos of the indentation using a mobile phone (with a built-in macro lens) or an external portable microscope, and transmit the photos to the data processing and display units via a mobile app or Bluetooth. The data processing unit and display unit use a tablet computer or mobile APP instead of an industrial tablet computer. The APP has an embedded image processing algorithm that can automatically identify the diameter of the indentation photo and calculate the Brinell hardness. The device has a built-in rechargeable lithium battery that supports continuous operation for 8 hours.

[0055] The remaining modules are the same as in Example 1.

[0056] As demonstrated in Examples 1 to 4, the ultrasonic hardness and Brinell hardness composite hardness testing method and apparatus of the present invention fully combine the advantages of ultrasonic UCI hardness testing (micro-area, rapid, and easy to operate) with the advantages of Brinell hardness testing (high representativeness and accuracy). Through a high-precision switching mechanism, it enables sequential testing of adjacent positions within the same area, obtaining effective measurement results reflecting the overall average hardness of the workpiece, and accurately identifying localized microstructure segregation and uneven microstructure with equal hardness and softness. This provides more comprehensive and reliable hardness testing data for material performance evaluation. Compared to traditional single hardness testing methods, the present invention significantly reduces errors caused by manual operation, improves the degree of automation and testing efficiency, and is adaptable to various application scenarios such as benchtop laboratory testing and on-site testing of large workpieces, possessing good applicability and widespread application value.

[0057] In summary, the embodiments disclosed herein have at least the following technical effects: 1. This invention integrates an ultrasonic hardness testing unit and a Brinell hardness testing unit, which can cover a wide range of hardness testing ranges from 10HV to 2000HV and from 8HBW to 650HBW, adapting to the hardness testing needs of most metal materials. It also takes into account the advantages of ultrasonic testing being non-destructive and fast, and the characteristics of Brinell testing being high accuracy and stable results, thus meeting the hardness testing requirements of different testing scenarios and different industry standards. 2. This invention provides test loads that meet the respective testing standards of the ultrasonic testing unit and the Brinell hardness testing unit through two independent loading mechanisms: the first loading mechanism can output a stable low load of 1N to 100N, meeting the testing requirements of small indentation and low damage in ultrasonic hardness testing; the second loading mechanism can output a large load of 500N to 30000N, meeting the standard test force requirements of Brinell hardness testing. Furthermore, the two independent loading mechanisms do not interfere with each other, and the two testing modes can be quickly switched without replacing the loading module. While ensuring the testing accuracy of each mode, the testing efficiency is effectively improved. Compared to the accuracy loss and structural complexity caused by switching between extremely low and extremely high forces using the same loading mechanism, this invention has a simpler structure, lower cost, and more stable control. 3. This invention enables rapid switching between two detection units via a switching mechanism. Combined with an integrated measurement and control system and data processing unit, it can complete the control, data acquisition, analysis, and comparison of two detection modes on the same set of equipment. It can use the ultrasonic mode alone to complete rapid non-destructive screening on-site, or the Brinell mode alone to complete high-precision authoritative arbitration testing. It can also use the composite detection mode to complete multi-point material uniformity analysis and hardness distribution cloud map generation. It has a high degree of integration and strong scene adaptability, which can meet the diverse hardness testing needs in different industrial scenarios. When using the composite detection mode, the center distance between the two measurement points is controlled between 0.5mm and 2mm. This avoids the indentation of the previous measurement from interfering with the result of the subsequent measurement, and ensures that the two measurement points are in the same material structure region. This greatly improves the accuracy of the comparison and analysis of the two detection results and provides reliable data support for the evaluation of material structure uniformity. 4. This invention automatically completes the switching of measurement positions between two detection units through the cooperation between the switching mechanism, the measurement and control system, the data processing unit and the display unit. It eliminates the need for manual disassembly and replacement of detection components, greatly improving detection efficiency, and has a high degree of automation, effectively reducing errors caused by manual operation. 5. This invention, through the built-in or external Brinell indentation measurement unit, is compatible with both benchtop, vertical, and portable models. The configuration scheme can be flexibly selected according to actual usage needs. It can be adapted to both precision arbitration testing in a laboratory environment and rapid testing of large workpieces in the field outdoors. This effectively improves the device's scene adaptability and usage flexibility, overcomes the shortcomings of traditional single-function hardness testers with poor scene adaptability, and can better meet the diverse hardness testing needs of different industries and scenarios.

[0058] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for testing the combined hardness of ultrasonic hardness and Brinell hardness, characterized in that, Includes the following steps: S1. Select a detection mode to perform the measurement operation. The detection modes include ultrasonic hardness detection mode, Brinell hardness detection mode, and composite detection mode. In the ultrasonic hardness testing mode or the Brinell hardness testing mode, the target area is measured to obtain a single hardness value. In the composite testing mode, the target area is measured by ultrasonic hardness testing mode and the adjacent position of the target area is measured by Brinell hardness testing mode in sequence to obtain the first hardness value and the second hardness value respectively. S2. The measurement results are uploaded to the data processing unit and displayed through the display unit. In the ultrasonic hardness testing mode or the Brinell hardness testing mode, the data processing unit directly displays the measurement results through the display unit. In the composite detection mode, the data processing unit compares the difference between the first hardness value and the second hardness value with a preset threshold range, generates an evaluation report characterizing the uniformity of the material structure, and outputs and displays the evaluation report together with the measurement results through the display unit.

2. The composite hardness testing method for ultrasonic hardness and Brinell hardness according to claim 1, characterized in that, In the ultrasonic hardness testing mode, the range of the applied load is 1N to 100N; in the Brinell hardness testing mode, the range of the applied load is 500N to 30000N.

3. The composite hardness testing method for ultrasonic hardness and Brinell hardness according to claim 1, characterized in that, The distance between the center of the adjacent location and the center of the measurement point within the target area is 0.5mm to 2mm.

4. The composite hardness testing method for ultrasonic hardness and Brinell hardness according to claim 1, characterized in that, The assessment report includes: If the difference between the first hardness value and the second hardness value is within a preset threshold range, an evaluation result showing uniform material structure is generated. If the first hardness value is higher than the second hardness value, and the difference between the first hardness value and the second hardness value is not within the preset threshold range, an evaluation result is generated indicating that the material structure contains a local hard phase. If the first hardness value is lower than the second hardness value, and the difference between the first hardness value and the second hardness value is not within a preset threshold range, an assessment result is generated indicating that the material structure contains a local soft phase.

5. The method for testing the combined hardness of ultrasonic hardness and Brinell hardness according to claim 1, characterized in that, The composite hardness testing method further includes the following steps: The measurement operation of the composite detection mode is repeatedly performed at multiple points, and the corresponding evaluation report is generated by the data processing unit. Based on the evaluation report of each point, the data processing unit generates a hardness distribution cloud map and outputs it through the display unit.

6. A composite hardness testing device for ultrasonic hardness and Brinell hardness, characterized in that, The device includes a frame body, a worktable, a Brinell indentation measurement unit, a data processing unit, and a display unit; the worktable is mounted on the frame body; the Brinell indentation measurement unit is built into the frame body or electrically connected to the frame body; the display unit and the data processing unit are electrically connected. An ultrasonic hardness testing unit includes a first loading mechanism and an ultrasonic testing unit body connected to the output end of the first loading mechanism; The Brinell hardness testing unit includes a second loading mechanism and a Brinell hardness testing unit body connected to the output end of the second loading mechanism. A switching mechanism is provided, with its fixed end connected to the frame body and its free end connected to the fixed ends of the first loading mechanism and the second loading mechanism. This mechanism is used to drive the ultrasonic hardness testing unit and the Brinell hardness testing unit to switch measurement positions and to ensure that the center distance between the two measurement points in the composite testing mode is 0.5mm to 2mm. The measurement and control system is installed on the frame body and is electrically connected to the first loading mechanism, the ultrasonic testing unit body, the second loading mechanism, the Brinell hardness testing unit body, the switching mechanism, the Brinell indentation measurement unit and the data processing unit, respectively.

7. The composite hardness testing device for ultrasonic hardness and Brinell hardness according to claim 6, characterized in that, The ultrasonic hardness testing unit includes multiple replaceable probes or parameter-adjustable probes.

8. The composite hardness testing device for ultrasonic hardness and Brinell hardness according to claim 6, characterized in that, The measuring indenter of the Brinell hardness testing unit includes cemented carbide indenters with ball diameters of 2.5 mm, 5 mm, and 10 mm.

9. The composite hardness testing device for ultrasonic hardness and Brinell hardness according to claim 6, characterized in that, The switching mechanism includes a linear guide or a rotary table, which is driven by a drive assembly to achieve the switching of measurement stations.

10. The composite hardness testing device for ultrasonic hardness and Brinell hardness according to claim 6, characterized in that, The measurement and control system includes a microcontroller, a force sensor, a displacement sensor, and a signal acquisition and processing circuit. The microcontroller, the force sensor, the displacement sensor, and the signal acquisition and processing circuit are all electrically connected to the first loading mechanism, the main body of the ultrasonic detection unit, the second loading mechanism, the main body of the Brinell hardness detection unit, the switching mechanism, and the data processing unit, respectively.

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