A device for detecting ductility of a zinc alloy

Abstract

The application discloses a zinc alloy ductility detection device and relates to the technical field of metal ductility detection.The device comprises a base, a stand fixedly installed on the top of the base, a clamp assembly, a mapping assembly, a mark tape and an electrically sensitive recording paper.The clamp assembly comprises an upper clamp fixedly connected to the top end of the stand and a lower clamp slidingly fitted on the stand.The mapping assembly comprises a bracket fixedly installed on the top of the base, a guide groove fixedly installed on one side of the bracket along the lifting direction of the lower clamp, one winding mechanism and one electric clamp jaw fixedly installed above and below the bracket, respectively.The mark tape is wound on the upper winding mechanism.The mark tape comprises an insulating base material and a conductive ablation layer attached to the surface of the insulating base material.The zinc alloy sheet is clamped by the insulating clamp block, so that the clamping damage is avoided and the premature fracture is prevented.The cooperation of the detection circuit and the conductive ablation layer enables the ablation trace to terminate at the moment of fracture, so that the displacement error caused by the response delay and the mechanical inertia is eliminated.

Description

Technical Field

[0001] This invention relates to the field of metal stretch testing technology, and more specifically, to a zinc alloy stretch testing device. Background Technology

[0002] Zinc alloys possess excellent casting properties, mechanical properties, and corrosion resistance, and are widely used in various industrial fields such as automobiles, electronics, communications, and hardware. In the development and production of zinc alloy products, ductility (usually measured by elongation after fracture and reduction of area) is a key mechanical indicator for evaluating the plastic deformation capacity of materials. Zinc alloy ductility testing devices are specialized testing equipment used to apply axial tensile loads to zinc alloy sheet or bar samples and determine their ductility parameters such as elongation after fracture. For thin sheet zinc alloy samples, a vertical tensile testing machine with special fixtures is usually used for tensile testing, and the elongation is calculated by measuring the change in length of the gauge section of the sample before and after fracture.

[0003] However, existing zinc alloy elongation testing devices still have some shortcomings in practical use. First, existing devices usually obtain elongation data by manually measuring the gauge length, which is cumbersome and prone to human error. This makes it difficult to meet the requirements of modern industrial production for testing efficiency and data traceability. Existing tensile testing machines generally have signal response delay and mechanical inertia problems at the moment of specimen fracture. During this period, the lower clamp will continue to move downwards, causing the gauge length after fracture to be extra stretched, resulting in the measured elongation containing false elongation and introducing systematic measurement errors. Second, zinc alloys have relatively low hardness. The wedge-shaped or serrated clamps used in traditional tensile testing machines are prone to forming indentations and scratches on the specimen surface during clamping. These clamping damages become stress concentration sources during tensile testing, causing the specimen to fracture prematurely from the clamping section before reaching the true elongation. This results in a lower measured elongation value, which cannot truly reflect the material's ductility.

[0004] To address the aforementioned issues, a zinc alloy elongation testing device is proposed. Summary of the Invention

[0005] To solve the above-mentioned technical problems, a zinc alloy elongation testing device is provided, which solves the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention can be implemented using the following technical solutions:

[0007] This invention provides a zinc alloy ductility testing device, including a base and a column fixedly installed on the top of the base, and further comprising:

[0008] The clamping assembly includes an upper clamp fixedly connected to the top of a column, a lower clamp slidably fitted on the column, the lower clamp being able to rise and fall relative to the upper clamp, and clamping fixtures respectively provided on the upper clamp and the lower clamp, both clamping fixtures including insulating clamping blocks for clamping zinc alloy sheets.

[0009] The mapping assembly includes a bracket fixedly mounted on the top of the base. A guide groove is fixedly mounted on one side of the bracket along the lifting direction of the lower clamp. A winding mechanism and an electric gripper are fixedly mounted on the upper and lower sides of the bracket. A marking tape is wound on the upper winding mechanism. The marking tape passes through the upper electric gripper, the guide groove, and the lower electric gripper in sequence, and is wound up by the lower winding mechanism. The marking tape is an electrosensitive recording paper, which includes an insulating substrate and a conductive ablation layer attached to the surface of the insulating substrate.

[0010] The power supply and conductive components include a DC power supply fixedly installed above one side of the guide groove. Each of the two electrodes of the DC power supply is fixedly connected to a conductive spring piece 1, which elastically abuts against the surface of the zinc alloy sheet and the conductive ablation layer, respectively. A slide block is slidably fitted below the side of the guide groove. The bottom of the slide block is fixedly connected to the lower clamp. A conductive spring piece 2 is fixedly connected to the middle of the slide block. The two ends of the conductive spring piece 2 elastically abut against the surface of the zinc alloy sheet and the conductive ablation layer, respectively.

[0011] The detection assembly includes an industrial camera that is fixedly mounted on the other side of the bracket;

[0012] A detection circuit consisting of a zinc alloy sheet, a DC power supply, conductive spring 1, conductive spring 2, and a conductive ablation layer is formed and changes synchronously with the lifting and lowering of the lower fixture. When the zinc alloy sheet breaks, the circuit is disconnected, causing the ablation mark to stop at the moment of breakage. The length of the ablation mark measured by the industrial camera is used to characterize the displacement at the moment of breakage, so as to eliminate the measurement interference caused by response delay and mechanical inertia.

[0013] Furthermore, the conductive ablation layer is an aluminum-plated layer with a thickness of 0.01 micrometers to 10 micrometers.

[0014] Furthermore, the sheet resistance of the conductive ablation layer is 0.5Ω / sq to 100Ω / sq, the ablation voltage of the conductive ablation layer is not higher than 50V, and the ablation current is not higher than 100mA, so as to avoid Joule heating when a large current passes through the zinc alloy sheet, which would affect its ductility.

[0015] Furthermore, the contact points between conductive spring 1 and the zinc alloy sheet, and between conductive spring 1 and the conductive ablation layer are arranged at the same height, and the contact points between conductive spring 2 and the zinc alloy sheet, and between conductive spring 2 and the conductive ablation layer are arranged at the same height.

[0016] Furthermore, the two electric grippers are located directly above and below the guide groove cavity, respectively. When the marking tape is transferred between the two winding mechanisms, the electric grippers located between the guide groove and the winding mechanism are configured as guides for the marking tape, guiding the marking tape into and out of the upper and lower ends of the guide groove, so that the marking tape can smoothly enter and exit the upper and lower ends of the guide groove. When in the detection work, the two electric grippers hold the marking tape, keeping the marking tape stable in the guide groove and maintaining the electrical conductivity between the first conductive spring, the second conductive spring, and the conductive ablation layer.

[0017] Furthermore, the clamping fixture includes T-shaped slots respectively opened in the middle of the opposite side of the upper and lower clamps, wedge-shaped sliders respectively slidably connected to the inclined inner walls on both sides of the T-shaped slots, grooves opened on the two wedge-shaped sliders near the bottom of the T-shaped slots, and hydraulic cylinders respectively fixedly installed inside the upper and lower clamps. The insulating clamping blocks are respectively fixedly connected to the opposite side of the two wedge-shaped sliders. The telescopic end of the hydraulic cylinder is fixedly connected to a push-pull plate, which is embedded in the corresponding groove. The hydraulic cylinder drives the push-pull plate to move up and down. Through the geometric constraint between the push-pull plate and the groove, the wedge-shaped slider slides along the inclined inner wall of the T-shaped slot, thereby causing the insulating clamping blocks to move closer or separate, realizing the clamping or release of the zinc alloy sheet.

[0018] Furthermore, it also includes a synchronous force application assembly for driving the lower clamp to lift and lower, which includes screws rotatably connected to both sides of the base, a main sprocket located inside the base, a driven sprocket fixedly fitted outside the two screws, and an annular chain meshing with the two driven sprockets and the outside of the main sprocket, wherein the outside of the two screws is threadedly connected to the inside of both sides of the lower clamp.

[0019] The synchronous force application assembly also includes a reducer and a motor fixedly connected in the base. The drive end of the motor is fixedly connected to the input end of the reducer, and the output end of the reducer is fixedly connected to the main sprocket.

[0020] As described above, the features and advantages of the zinc alloy elongation testing device of the present invention are:

[0021] This invention achieves instantaneous capture of the physical circuit break signal at the moment of fracture by setting insulating clamps on the upper and lower clamps respectively, thus electrically isolating the zinc alloy sheet from the clamp body. Combined with a detection circuit consisting of the zinc alloy sheet, a DC power supply, conductive spring sheet one, conductive spring sheet two, and a conductive ablation layer on the marking strip, the invention provides electrical insulation isolation between the zinc alloy sheet and the clamp body. When the zinc alloy sheet is broken, the detection circuit instantly disconnects at the fracture cross-section, and the ablation effect of the conductive ablation layer stops immediately within microseconds, leaving an ablation mark on the marking strip that precisely corresponds to the fracture location. The termination position of this ablation mark is completely unaffected by the response delay and mechanical inertia of the tensile testing machine's control system. This eliminates the interference of additional displacement caused by the continued descent of the lower clamp after fracture on the elongation measurement results, significantly improving the accuracy of zinc alloy ductility testing.

[0022] This invention achieves automatic tape feeding and precise positioning of the marking tape by setting up a winding mechanism, electric grippers, and guide grooves. Combined with an industrial camera for automatic image acquisition and length calculation of ablation traces, it realizes automated measurement and data recording of fracture displacement during the stretching test, avoiding operational errors caused by manual gauge length and manual reading, improving testing efficiency and data traceability. At the same time, the marking tape can be collected and archived for future reference, facilitating subsequent quality traceability and data analysis. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the zinc alloy elongation testing device shown in this invention;

[0024] Figure 2 for Figure 1 Another perspective diagram of the structure;

[0025] Figure 3 This is a schematic diagram showing the structural cooperation between the clamp assembly and the mapping assembly of the zinc alloy elongation detection device of the present invention;

[0026] Figure 4 for Figure 3 Another perspective diagram of the structure;

[0027] Figure 5 This is a schematic diagram of the structure and fit of the conductive spring of the zinc alloy stretch detection device shown in this invention;

[0028] Figure 6 This is a schematic diagram of the conductive spring two structures of the zinc alloy elongation detection device of the present invention.

[0029] Figure 7 This is a schematic diagram of the fixture assembly structure of the zinc alloy elongation testing device shown in this invention;

[0030] Figure 8This is a schematic diagram of the synchronous force application component structure of the zinc alloy elongation detection device of the present invention.

[0031] The reference numerals in the accompanying drawings of this invention are as follows:

[0032] 11. Base; 12. Column; 13. Zinc alloy sheet;

[0033] Fixture assemblies: 21. Upper fixture; 22. Lower fixture; 23. Clamping fixture; 231. T-slot; 232. Wedge slider; 233. Insulating clamp; 234. Groove; 235. Hydraulic cylinder; 236. Push-pull plate;

[0034] Synchronous force application components: 31. Screw; 32. Reducer; 33. Motor; 34. Main sprocket; 35. Spur sprocket;

[0035] Mapping components: 41. Support; 42. Guide groove; 43. Winding mechanism; 44. Electric gripper; 45. Marking tape; 46. Insulating substrate; 47. Conductive ablation layer;

[0036] Power supply and conductive components: 51. DC power supply; 52. Conductive spring one; 53. Slide; 54. Conductive spring two;

[0037] Detection components: 61. Industrial camera. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0039] See Figures 1-8 As shown, an embodiment of the present invention is provided, and a zinc alloy ductility testing device will be described in detail below:

[0040] A zinc alloy elongation testing device is mainly used to accurately test the elongation and other ductility properties of zinc alloy sheet 13. The device applies an axial tensile load to the zinc alloy sheet 13 until fracture, and uses an electrical discharge ablation marking technique to accurately record the displacement at the moment of fracture, thereby obtaining accurate elongation data.

[0041] See Figures 1-2 As shown, the zinc alloy elongation testing device mainly includes a base 11, a column 12, a clamp assembly, a mapping assembly, a power supply and conductive assembly, and a testing assembly.

[0042] Regarding the base 11 and the columns 12, the base 11 serves as the load-bearing foundation of the entire device and is typically constructed of cast iron or welded steel plates, possessing sufficient rigidity and stability to withstand the tensile loads and reaction forces generated during testing. The columns 12 are fixedly mounted on top of the base 11 to support and mount the upper clamp 21 and other related components. The number of columns 12 can be set according to actual needs, typically four, to ensure structural symmetry and uniform stress distribution.

[0043] See Figures 1-2 and Figure 7 As shown, the clamping assembly includes an upper clamp 21 fixedly connected to the top of the column 12, a lower clamp 22 slidably fitted onto the column 12, and clamping fixtures 23 respectively disposed on the upper clamp 21 and the lower clamp 22. The upper clamp 21 is fixedly installed at the top of the column 12 and remains stationary during the test. The lower clamp 22 is slidably fitted onto the column 12 and can be raised and lowered relative to the upper clamp 21, thereby applying a tensile load to the zinc alloy sheet 13 clamped between the upper clamp 21 and the lower clamp 22. The two clamping fixtures 23 are respectively disposed in the middle of opposite sides of the upper clamp 21 and the lower clamp 22, and each clamping fixture 23 includes an insulating clamping block 233 for clamping the zinc alloy sheet 13. The insulating clamp 233 is made of insulating material (such as engineering plastic or insulating rubber) and has two functions: First, the insulating clamp 233 provides electrical insulation between the zinc alloy sheet 13 and the clamp body, ensuring that the current in the detection circuit (which will be described in detail below) flows only through the preset conductive path and does not form a short circuit through the clamp body; Second, the insulating clamp 233 made of the above material has more elasticity on its surface than metal material, avoiding the indentation and scratches caused by traditional metal clamps on the surface of zinc alloy sample, and eliminating the stress concentration source introduced by clamping damage.

[0044] See Figure 7As shown, regarding the specific structure of the clamping fixture 23, the clamping fixture 23 includes T-shaped slots 231 respectively opened in the middle of the opposite side of the upper fixture 21 and the lower fixture 22, wedge-shaped sliders 232 respectively slidably connected to the inclined inner walls on both sides of the T-shaped slots 231, grooves 234 opened in the two wedge-shaped sliders 232 near the bottom of the T-shaped slots 231, and hydraulic cylinders 235 respectively fixedly installed inside the upper fixture 21 and the lower fixture 22. Insulating clamping blocks 233 are respectively fixedly connected to the opposite side of the two wedge-shaped sliders 232. The telescopic end of the hydraulic cylinder 235 is fixedly connected to a push-pull plate 236, and the push-pull plate 236 is respectively embedded in the corresponding groove 234. Hydraulic cylinder 235 drives push-pull plate 236 to move up and down. Through the geometric constraint between push-pull plate 236 and groove 234 (i.e., the horizontal movement of push-pull plate 236 is restricted, allowing it to slide relative to each other only along the extension direction of groove 234), the vertical movement of push-pull plate 236 is converted into the sliding movement of wedge slider 232 along the inclined inner wall of T-shaped slot 231. This causes the two wedge sliders 232 to move the insulating clamping block 233 closer together or separate, achieving clamping or releasing of the zinc alloy sheet 13. This clamping structure, with wedge slider 232 and T-shaped slot 231, produces a self-locking effect. Even if hydraulic cylinder 235 releases pressure in the clamped state, wedge slider 232 will not automatically loosen under tensile reaction force, thus ensuring the safety and reliability of the testing process. The specific structure and working principle of the hydraulic cylinder 235 driving wedge slider 232 to achieve clamping are existing technologies in this field and will not be elaborated further here.

[0045] See Figures 3-6As shown, the mapping assembly includes a bracket 41 fixedly mounted on the top of the base 11. A guide groove 42 is fixedly mounted on one side of the bracket 41 along the lifting direction of the lower clamp 22. The cavity of the guide groove 42 is used to accommodate and guide the marking tape 45 through vertically. A winding mechanism 43 (a miniaturized winch, mainly composed of a power motor 33 and a winding roller, representing mature existing technology) and an electric gripper 44 are fixedly mounted above and below the bracket 41. Unused marking tape 45 is wound on the upper winding mechanism 43. After being drawn out from the upper winding mechanism 43, the marking tape 45 passes sequentially through the upper electric gripper 44, the cavity of the guide groove 42, and the lower electric gripper 44, and is then wound up by the lower winding mechanism 43. The marking tape 45 is electrosensitive recording paper, which includes an insulating substrate 451 and a conductive ablation layer 452 attached to the surface of the insulating substrate 451. Electrosensitive recording paper is a mature industrial recording medium. Its working principle is as follows: when current passes through the conductive ablation layer 452, the Joule heat generated by the current causes localized vaporization or ablation of the conductive ablation layer 452 at the location where the current passes, forming visible ablation marks. When the current is interrupted, the ablation process immediately stops. The specific material of the conductive ablation layer 452 can be selected from one of the following: an aluminum plating layer, a chromium plating layer, a conductive carbon black coating, a conductive graphite coating, or a conductive resin coating, preferably an aluminum plating layer. The thickness of the conductive ablation layer 452 is from 0.1 micrometers to 0.1 micrometers, the sheet resistance is from 0.1 Ω / sq to 0.1 Ω / sq, the ablation voltage is not higher than V, and the ablation current is not higher than mA, to avoid the Joule heat generated when a large current passes through the zinc alloy sheet 13, which would affect its ductility.

[0046] See Figure 5 As shown, regarding the function of the electric grippers 44, the two electric grippers 44 are located directly above and below the cavity of the guide groove 42, respectively. When the marking tape 45 is transferred between the two winding mechanisms 43 (i.e., when replacing a new segment of marking tape 45), the teeth of the electric grippers 44 located between the guide groove 42 and the winding mechanism 43 are configured as guides for the marking tape 45, guiding the marking tape 45 into and out of the upper and lower ends of the guide groove 42, allowing the marking tape 45 to smoothly enter and exit the cavity of the guide groove 42. During the inspection process, the two electric grippers 44 hold the marking tape 45, keeping the marking tape 45 in a stable tension state in the guide groove 42, ensuring stable electrical conduction between the marking tape 45 and the first conductive spring 52 and the second conductive spring 54. The specific structure and driving method of the winding mechanism 43 and the electric grippers 44 can adopt mature technologies known in the art, such as a winding roller driven by a stepper motor 33 and a pneumatically or electrically driven gripper, which will not be described in detail here.

[0047] See Figures 5-6As shown, regarding the power supply and conductive components, the power supply and conductive components include a DC power supply 51 fixedly installed above one side of the guide groove 42. Both electrodes of the DC power supply 51 are fixedly connected to conductive spring pieces 52, which elastically abut against the surfaces of the zinc alloy sheet 13 and the conductive ablation layer 452, respectively. A slide block 53 is slidably fitted to the lower side of the guide groove 42. The bottom of the slide block 53 is fixedly connected to the lower clamp 22, and a conductive spring piece 54 is fixedly connected to the middle of the slide block 53. Both ends of the conductive spring piece 54 elastically abut against the surfaces of the zinc alloy sheet 13 and the conductive ablation layer 452, respectively. Both conductive spring pieces 52 and 54 are made of metal materials with good conductivity and elasticity (such as beryllium bronze or phosphor bronze). Their elastic abutment method ensures that each contact point maintains good electrical contact during the test. Even if the zinc alloy sheet 13 deforms or shifts during the stretching process, the conductive spring pieces can maintain reliable abutment through their own elastic deformation.

[0048] The contact points of conductive spring 1 52 and zinc alloy sheet 13 are arranged at the same height as the contact points of conductive spring 1 52 and conductive ablation layer 452; similarly, the contact points of conductive spring 2 54 and zinc alloy sheet 13 are arranged at the same height as the contact points of conductive spring 2 54 and conductive ablation layer 452. The core purpose of this equal-height arrangement is to establish a precise one-to-one correspondence—the marking point at the upper end of zinc alloy sheet 13 and the ablation start point at the upper end of marking strip 45 are at the same horizontal height, and the marking point at the lower end of zinc alloy sheet 13 and the ablation end point at the lower end of marking strip 45 are at the same horizontal height. Therefore, the amount of displacement of zinc alloy sheet 13 under tension and the length of the ablation mark on marking strip 45 form a precise and equal mapping relationship, eliminating system measurement errors introduced by the height difference of the conductive points.

[0049] See Figures 3-4 As shown, the detection assembly includes an industrial camera 61 fixedly mounted on the other side of the bracket 41. The industrial camera 61 is positioned facing the cavity of the guide groove 42, and its field of view covers the area traversed by the marking strip 45 within the guide groove 42. The industrial camera 61 is used to acquire images of the ablation marks on the surface of the marking strip 45 after testing, and to identify the start and end boundaries of the ablation marks using a built-in or external image processing module, calculating the length between them to obtain the length data of the ablation marks. The industrial camera 61 and its image processing algorithm can employ well-established technologies known in the art, such as CCD or CMOS. The industrial camera 61 combined with an edge detection algorithm will not be elaborated further here.

[0050] See Figure 8As shown, regarding the synchronous force application assembly, the zinc alloy elongation testing device also includes a synchronous force application assembly for driving the lower clamp 22 to rise and fall. The synchronous force application assembly includes screws 31 rotatably connected to both sides of the base 11, a main sprocket 34 disposed inside the base 11, driven sprockets 35 fixedly fitted onto the outside of the two screws 31, and an annular chain meshing with the outside of the two driven sprockets 35 and the main sprocket 34. The outside of the two screws 31 are threadedly connected to the inside of both sides of the lower clamp 22. The synchronous force application assembly also includes a reducer 32 and a motor 33 fixedly connected inside the base 11. The drive end of the motor 33 is fixedly connected to the input end of the reducer 32, and the output end of the reducer 32 is fixedly connected to the main sprocket 34. The motor 33, after being reduced in speed and torque by the reducer 32, drives the main sprocket 34 to rotate. The main sprocket 34 synchronously drives two driven sprockets 35 to rotate via a ring chain. The two driven sprockets 35 respectively drive two screws 31 to rotate synchronously, which in turn drives the lower clamp 22 to smoothly rise and fall along the column 12 through threaded transmission, applying an axial tensile load to the zinc alloy sheet 13 clamped between the upper clamp 21 and the lower clamp 22. The specific structure and working principle of the above-mentioned synchronous force application component are prior art in this field and will not be described in detail here.

[0051] The specific working process of the present invention will be described in detail below with reference to the accompanying drawings:

[0052] Before the test begins, the operator first places one end of the zinc alloy sheet 13 sample in the clamping fixture 23 of the upper clamp 21 and the other end in the clamping fixture 23 of the lower clamp 22. Then, the hydraulic cylinder 235 is activated, and its telescopic end extends, pushing the push-pull plate 236 to move. The push-pull plate 236 drives the wedge-shaped slider 232 to slide along the inclined inner wall of the T-shaped slot 231 through the groove 234, causing the two insulating clamps 233 to come together and clamp the ends of the zinc alloy sheet 13 from both sides. The clamping fixtures 23 of the upper clamp 21 and the lower clamp 22 operate simultaneously, clamping the upper and lower ends of the zinc alloy sheet 13 respectively. Because the insulating clamps 233 are made of insulating material, the zinc alloy sheet 13 is electrically insulated from the clamp body.

[0053] After the zinc alloy sheet 13 is clamped, the operator elastically abuts the two contact ends of the conductive spring piece 1 52 against the corresponding positions on the upper surface of the zinc alloy sheet 13 and the conductive ablation layer 452 of the marking strip 45, and elastically abuts the two contact ends of the conductive spring piece 2 54 against the corresponding positions on the lower surface of the zinc alloy sheet 13 and the conductive ablation layer 452 of the marking strip 45.

[0054] At this point, the industrial camera 61 first measures the distance between conductive spring 1 52 and conductive spring 2 54 on the zinc alloy sheet 13 as the initial value.

[0055] The zinc alloy sheet 13, DC power supply 51, conductive spring 1 52, conductive spring 2 54, and conductive ablation layer 452 on the marking strip 45 constitute a complete detection circuit. The current provided by the DC power supply 51 flows through conductive spring 1 52, through the zinc alloy sheet 13 and conductive ablation layer 452, and then flows back to the power supply through conductive spring 2 54, continuously generating an ablation effect on the conductive ablation layer 452, forming continuous ablation marks.

[0056] Then the test program is started. Motor 33 starts to rotate, and after being reduced in speed and torque by reducer 32, it drives main sprocket 34 to rotate. Main sprocket 34 drives two slave sprockets 35 to rotate synchronously through a ring chain. The two slave sprockets 35 drive two screws 31 to rotate synchronously. Through threaded transmission, the lower clamp 22 is driven to move smoothly downward along column 12, applying an axial tensile load to the zinc alloy sheet 13 held between the upper clamp 21 and the lower clamp 22. During the tensile process, conductive spring 54 descends together with the lower clamp 22. The contact point of conductive spring 54 on the surface of zinc alloy sheet 13 moves downward accordingly, and at the same time, the contact point on the surface of conductive ablation layer 452 of marking strip 45 also moves downward synchronously. Since the contact points of the conductive spring sheet 2 54 and the zinc alloy sheet 13 are arranged at the same height as the contact points of the conductive spring sheet 2 54 and the conductive ablation layer 452, the amount of displacement of the zinc alloy sheet 13 being stretched is accurately mapped to the extension of the ablation mark on the marking strip 45, that is, the length of the ablation mark is equal to the current stretching displacement of the zinc alloy sheet 13 in real time.

[0057] When the zinc alloy sheet 13 is stretched to break, the detection circuit is instantly disconnected at the fracture surface. The current returns to zero within microseconds, and the ablation effect of the conductive ablation layer 452 immediately stops, leaving a clearly defined ablation mark on the marking strip 45. The termination position of this ablation mark precisely corresponds to the instant the zinc alloy sheet 13 breaks, completely unaffected by the continued descent of the lower clamp 22 due to control system response delay and mechanical inertia. Subsequently, even if the lower clamp 22 continues to descend a certain distance during the signal response period, no additional ablation marks will be generated on the marking strip 45.

[0058] After the test, the industrial camera 61 captures images of the ablation marks on the marking strip 45. The image processing algorithm automatically identifies the start and end boundaries of the ablation marks and calculates the length between them. Since the length of the ablation mark is exactly equal to the displacement of the zinc alloy sheet 13 at the moment of fracture (i.e., the elongation of the gauge length), the operator can directly substitute this length value into the elongation calculation formula (i.e., the ratio between the elongation and the initial value) to obtain the post-fracture elongation data of the zinc alloy sheet 13.

[0059] After the test is completed, the control motor 33 rotates in the reverse direction, driving the lower clamp 22 to move upward and return to its initial position. Then, the control hydraulic cylinder 235 reverses its movement, causing the push-pull plate 236 to move in the reverse direction, driving the wedge slider 232 to slide in the reverse direction along the inclined inner wall of the T-shaped slot 231, causing the two insulating clamps 233 to separate from each other and releasing the end of the zinc alloy sheet 13. The operator can then remove the broken zinc alloy sheet 13 sample. The used marking tape 45 segment is wound up by the lower winding mechanism 43, while the upper winding mechanism 43 simultaneously releases a new marking tape 45 segment, which is guided by the electric gripper 44 into the guide groove 42, ready for the next test.

[0060] It should be noted that the specific implementation methods of the motor 33 drive, hydraulic cylinder 235 drive, industrial camera 61 image acquisition and processing, and coordinated control of winding mechanism 43 and electric gripper 44 in this invention can all adopt mature technologies known in the art. Those skilled in the art can implement these functions without creative effort based on the description and teaching of this invention and common knowledge in the art. Therefore, these prior art details will not be elaborated in this specific embodiment.

[0061] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0062] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A zinc alloy ductility testing device, comprising a base and a column fixedly mounted on the top of the base, characterized in that: Also includes: The clamping assembly includes an upper clamp fixedly connected to the top of a column, a lower clamp slidably fitted on the column, the lower clamp being able to rise and fall relative to the upper clamp, and clamping fixtures respectively provided on the upper clamp and the lower clamp, both clamping fixtures including insulating clamping blocks for clamping zinc alloy sheets. The mapping assembly includes a bracket fixedly mounted on the top of the base. A guide groove is fixedly mounted on one side of the bracket along the lifting direction of the lower clamp. A winding mechanism and an electric gripper are fixedly mounted on the upper and lower sides of the bracket. A marking tape is wound on the upper winding mechanism. The marking tape passes through the upper electric gripper, the guide groove, and the lower electric gripper in sequence, and is wound up by the lower winding mechanism. The marking tape is an electrosensitive recording paper, which includes an insulating substrate and a conductive ablation layer attached to the surface of the insulating substrate. The power supply and conductive components include a DC power supply fixedly installed above one side of the guide groove. Each of the two electrodes of the DC power supply is fixedly connected to a conductive spring piece 1, which elastically abuts against the surface of the zinc alloy sheet and the conductive ablation layer, respectively. A slide block is slidably fitted below the side of the guide groove. The bottom of the slide block is fixedly connected to the lower clamp. A conductive spring piece 2 is fixedly connected to the middle of the slide block. The two ends of the conductive spring piece 2 elastically abut against the surface of the zinc alloy sheet and the conductive ablation layer, respectively. The detection assembly includes an industrial camera that is fixedly mounted on the other side of the bracket; A detection circuit consisting of a zinc alloy sheet, a DC power supply, conductive spring 1, conductive spring 2, and a conductive ablation layer is formed and changes synchronously with the lifting and lowering of the lower fixture. When the zinc alloy sheet breaks, the circuit is disconnected, causing the ablation mark to stop at the moment of breakage. The length of the ablation mark measured by the industrial camera is used to characterize the displacement at the moment of breakage, so as to eliminate the measurement interference caused by response delay and mechanical inertia.

2. The zinc alloy elongation testing device according to claim 1, characterized in that: The conductive ablation layer is an aluminum-plated layer with a thickness ranging from 0.01 micrometers to 10 micrometers.

3. The zinc alloy ductility testing device according to claim 2, characterized in that: The sheet resistance of the conductive ablation layer is 0.5Ω / sq to 100Ω / sq. The ablation voltage of the conductive ablation layer is not higher than 50V and the ablation current is not higher than 100mA, so as to avoid Joule heating when a large current passes through the zinc alloy sheet, which would affect its ductility.

4. The zinc alloy ductility testing device according to claim 1, characterized in that: The contact points of conductive spring 1 with the zinc alloy sheet and the contact points of conductive spring 1 with the conductive ablation layer are arranged at the same height. The contact points of conductive spring 2 with the zinc alloy sheet and the contact points of conductive spring 2 with the conductive ablation layer are also arranged at the same height.

5. The zinc alloy elongation testing device according to claim 1, characterized in that: Two electric grippers are located directly above and below the guide groove cavity, respectively. When the marking tape is transferred between the two winding mechanisms, the electric grippers located between the guide groove and the winding mechanism are configured as guides for the marking tape, guiding the marking tape into and out of the upper and lower ends of the guide groove, so that the marking tape can smoothly enter and exit the upper and lower ends of the guide groove. When in the detection work, the two electric grippers hold the marking tape, keeping the marking tape stable in the guide groove and maintaining the electrical conductivity between conductive spring 1, conductive spring 2 and conductive ablation layer.

6. The zinc alloy ductility testing device according to claim 1, characterized in that: The clamping fixture includes T-shaped slots respectively opened in the middle of the opposite side of the upper and lower clamps, wedge-shaped sliders respectively slidably connected to the inclined inner walls on both sides of the T-shaped slots, grooves opened on the two wedge-shaped sliders near the bottom of the T-shaped slots, and hydraulic cylinders respectively fixedly installed inside the upper and lower clamps. The insulating clamping blocks are respectively fixedly connected to the opposite side of the two wedge-shaped sliders. The telescopic end of the hydraulic cylinder is fixedly connected to a push-pull plate, which is embedded in the corresponding groove. The hydraulic cylinder drives the push-pull plate to move up and down. Through the geometric constraint between the push-pull plate and the groove, the wedge-shaped slider slides along the inclined inner wall of the T-shaped slot, thereby causing the insulating clamping blocks to move closer or separate, realizing the clamping or release of the zinc alloy sheet.

7. The zinc alloy elongation testing device according to claim 1, characterized in that: It also includes a synchronous force application assembly for driving the lower clamp to lift and lower, which includes screws rotatably connected to both sides of the base, a main sprocket located inside the base, a driven sprocket fixedly fitted outside the two screws, and an annular chain meshing with the two driven sprockets and the outside of the main sprocket, wherein the outside of the two screws is threadedly connected to the inside of both sides of the lower clamp. The synchronous force application assembly also includes a reducer and a motor fixedly connected in the base. The drive end of the motor is fixedly connected to the input end of the reducer, and the output end of the reducer is fixedly connected to the main sprocket.

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