Ultrahigh-temperature crack propagation cold clamping device

Abstract

The utility model relates to the field of low-cycle fatigue performance detection of metal materials, and discloses an ultra-high-temperature crack propagation cold clamping device which comprises a group of flat high-temperature furnaces, through grooves are formed in the centers of the opposite sides of the two flat high-temperature furnaces in the group, and fixing assemblies are installed in the through grooves. The fixing assembly comprises two upper clamping blocks and two lower clamping blocks, the bottom of one upper clamping block is connected and provided with an upper cushion block, the top of one lower clamping block is connected and provided with a lower cushion block, a sample is clamped between the two upper clamping blocks and the two lower clamping blocks, and a groove is formed in the middle of the sample. Through the upper clamping block, the lower clamping block and the two cushion blocks, the coaxiality of the sample and a testing machine during assembly is improved, the stress stability of the sample in the axial direction is enhanced, and the crack length monitoring precision is improved; a cold clamping technology is adopted, and a flat high-temperature furnace is adopted to only heat the center area of the sample, so that the problem of tool deformation caused by high temperature is avoided.

Description

Technical Field

[0001] This utility model relates to the field of low-cycle fatigue performance testing of metallic materials, specifically a cold clamping device for ultra-high temperature crack propagation. Background Technology

[0002] In aerospace, gas turbine, and nuclear energy fields, high-temperature components need to operate for extended periods under extreme high-temperature and high-stress conditions. For example, high-temperature alloys are widely used in aero-engines and gas turbines, but they are prone to crack initiation and propagation under high-stress cyclic loading, affecting the safety and reliability of the equipment. Ultra-high temperature crack propagation tests can assess the crack propagation rate and fracture toughness of these materials in high-temperature environments, providing data support for designing safer and more reliable aerospace vehicles.

[0003] Currently, the tooling for ultra-high temperature crack propagation may deform or fail due to the high temperature, affecting the detection of crack propagation. The mismatch of the thermal expansion coefficients of the materials may cause changes in the gap between the tooling and the test piece, thus affecting the monitoring accuracy of crack propagation. In general, conventional crack propagation tests require heating both the sample and the tooling in a high-temperature furnace. However, the coaxiality of the sample assembly cannot be guaranteed under ultra-high temperature conditions. Therefore, a cold clamping device for ultra-high temperature crack propagation of MT samples is designed.

[0004] Conventional samples and tooling are heated in a high-temperature furnace. However, in ultra-high temperature environments, it is impossible to guarantee that the tooling material will deform or fail due to its inability to withstand high temperatures. Mismatch in the thermal expansion coefficients of the materials may cause changes in the gap between the tooling and the test piece, thus affecting the detection of crack propagation. Direct clamping of MT samples can easily cause poor coaxiality and crack deviation, making it difficult to meet the requirements of crack propagation for crack length measurement accuracy. Utility Model Content

[0005] The purpose of this invention is to provide a cold clamping device for ultra-high temperature crack propagation, so as to solve the technical problems in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A cold clamping device for ultra-high temperature crack propagation includes a set of flat high-temperature furnaces. Two of the flat high-temperature furnaces in the set have through slots centered on opposite sides. A fixing component is installed inside the through slot. The fixing component includes two upper clamping blocks and two lower clamping blocks. An upper pad is connected to the bottom of one upper clamping block and a lower pad is connected to the top of one lower clamping block. A sample is clamped between the two upper clamping blocks and the two lower clamping blocks. A groove is formed in the middle of the sample, and measuring holes are formed on both sides of the sample.

[0008] Preferably, the top view of the through slot is semi-circular, and the two flat high-temperature furnaces in the group are symmetrical to each other.

[0009] Preferably, the sample is vertically inserted inside the two through slots, and the grooves are located centered inside the two flat high-temperature furnaces.

[0010] Preferably, the two upper clamping blocks and the two lower clamping blocks are symmetrical to each other, and both the upper and lower pads are arranged in an "L" shape.

[0011] Preferably, the upper clamping block and the lower clamping block are provided with through holes at their front and rear ends, the bottom of the upper clamping block and the top of the lower clamping block are provided with screw holes at both ends, and the upper pad block and the lower pad block are provided with connecting grooves inside.

[0012] Preferably, the through holes between the front and rear ends of the upper clamping block and the lower clamping block are interconnected.

[0013] Preferably, the width of the connecting groove matches the diameter of the screw hole.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] 1) This cold clamping device, by setting a fixing component, has designed L-shaped pads on the upper and lower clamping blocks. After the position is fixed with bolts, the sample is clamped on both sides. This can improve the coaxiality of the sample and the testing machine during assembly, enhance the stability of the sample under axial force, and improve the accuracy of crack length monitoring.

[0016] 2) This cold clamping device, by setting up a flat high-temperature furnace and through holes, adopts cold clamping technology. After the fatigue testing machine clamps the upper and lower sides of the sample, it does not heat the clamping block tooling. The flat high-temperature furnace only heats the central area of ​​the sample, thus avoiding the tooling deformation problem caused by high temperature. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of a cold clamping device for ultra-high temperature crack propagation according to an embodiment of the present invention;

[0018] Figure 2 This is a cross-sectional structural diagram of the fixing component in an embodiment of the present utility model;

[0019] Figure 3 This is a schematic diagram of the sample structure in an embodiment of this utility model;

[0020] Figure 4 This is a schematic diagram of the structure of the lower clamping block in an embodiment of this utility model.

[0021] In the figure: 1. Flat high-temperature furnace; 2. Through groove; 3. Fixing component; 4. Upper clamping block; 6. Lower clamping block; 8. Upper pad block; 9. Lower pad block; 10. Sample; 11. Groove; 12. Measuring hole; 13. Through hole; 14. Screw hole; 15. Connecting groove. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Example 1

[0024] Combination Figures 1-4 A cold clamping device for ultra-high temperature crack propagation includes a set of flat high temperature furnaces 1. Two flat high temperature furnaces 1 in the set are provided with through slots 2 on opposite sides and the through slots 2 are equipped with fixing components 3.

[0025] See Figure 2 and Figure 3 Furthermore, the fixing component 3 includes two upper clamping blocks 4 and two lower clamping blocks 6. An upper pad 8 is connected and installed at the bottom of one upper clamping block 4, and a lower pad 9 is connected and installed at the top of one lower clamping block 6. A sample 10 is clamped between the two upper clamping blocks 4 and the two lower clamping blocks 6. A groove 11 is provided in the middle of the sample 10, and a measuring hole 12 is provided on both sides of the sample 10.

[0026] The top view of the through groove 2 is semi-circular, and the two flat high-temperature furnaces 1 in the set are symmetrical to each other. The interior of the two flat high-temperature furnaces 1 is used to heat the sample 10.

[0027] The sample 10 is vertically inserted inside the two through slots 2. The groove 11 is located in the center inside the two flat high-temperature furnaces 1. The groove 11 is used to remove the direction of crack propagation. The through hole 13 is used to connect the potentiometric wire to measure the crack length.

[0028] The two upper clamping blocks 4 and the two lower clamping blocks 6 are symmetrical to each other. The upper pad block 8 and the lower pad block 9 are both set in an "L" shape. The upper clamping blocks 4 and the lower clamping blocks 6 clamp and fix the sample 10 by the fatigue testing machine fixture.

[0029] Specifically, the two upper clamping blocks 4 and the two lower clamping blocks 6 clamp the sample 10. The upper pad 8 and the lower pad 9 are fixed to the corresponding upper clamping blocks 4 and lower clamping blocks 6 respectively. The side of the sample 10 contacts the protruding parts of the upper pad 8 and the lower pad 9 to ensure the coaxiality of the assembly. The hydraulic connection of the testing machine clamps the sample 10 with the upper clamping blocks 4 and the lower clamping blocks 6.

[0030] Example 2

[0031] See Figure 4 Furthermore, based on Embodiment 1, the upper clamping block 4 and the lower clamping block 6 are provided with through holes 13 at their front and rear ends, the bottom of the upper clamping block 4 and the top of the lower clamping block 6 are provided with screw holes 14 at both ends, and the upper pad block 8 and the lower pad block 9 are provided with connecting grooves 15 inside.

[0032] The through holes 13 between the front and rear ends of the upper clamping block 4 and the lower clamping block 6 are interconnected. The through holes 13 are used to connect a water cooling device for cooling the upper clamping block 4 and the lower clamping block 6.

[0033] The width of the connecting groove 15 matches the diameter of the screw hole 14. The connecting groove 15 is used to connect bolts. The upper pad 8, lower pad 9 and upper clamping block 4 and lower clamping block 6 are fixed to each other by the threaded connection between the bolts and the screw hole 14.

[0034] Specifically, the bolts are passed through the connecting grooves 15 in the upper pad 8 and the lower pad 9 and threaded into the corresponding screw holes 14 to fix the upper pad 8 and the lower pad 9. The water cooling device is connected to the through hole 13 to ensure the cooling of the upper clamping block 4 and the lower clamping block 6.

[0035] In actual operation, the bolts are passed through the connecting grooves 15 in the upper pad 8 and the lower pad 9, and the screw holes 14 in the upper clamping block 4 and the lower clamping block 6 are connected to the bolts, so that the upper pad 8 and the lower pad 9 are fixed to the upper clamping block 4 and the lower clamping block 6 respectively. The through hole 13 can be used to connect the water cooling device to ensure the cooling of the upper clamping block 4 and the lower clamping block 6. The groove 11 in the middle of the sample 10 is used to determine the crack propagation direction. The two measuring holes 12 are used to connect the potentiometric wire to measure the crack length. The fatigue testing machine is tightly connected to the upper clamping block 4, the lower clamping block 6 and the sample 10 through hydraulic clamping.

[0036] During assembly, first place the two upper clamping blocks 4 and the two lower clamping blocks 6 into the fatigue testing machine fixture. The upper pad 8 is fixed to the bottom of the upper clamping block 4 by bolts and screw holes 14. Similarly, the lower pad 9 is fixed to the top of the lower clamping block 6 by bolts and screw holes 14. The upper pad 8 and the lower pad 9 are symmetrical about the center of the groove 11 of the specimen 10. The sides of both ends of the specimen 10 are in contact with the protruding parts of the upper pad 8 and the lower pad 9, respectively, to ensure the coaxiality of the assembly. The upper clamping blocks 4 and the lower clamping blocks 6 are clamped tightly by the hydraulic connection of the testing machine. Finally, the two flat high-temperature furnaces 1 are closed and the height is adjusted so that the groove 11 of the specimen 10 is exactly in the middle position of the flat high-temperature furnace 1. The entire set of equipment is installed, ensuring a tight connection between the specimen 10 and the tooling, and good coaxiality of the assembly.

[0037] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A cold clamping device for ultra-high temperature crack propagation, comprising a set of flat high-temperature furnaces (1), wherein two of the flat high-temperature furnaces (1) in the set are provided with through slots (2) centered on opposite sides, characterized in that: A fixing component (3) is installed inside the through groove (2); The fixing component (3) includes two upper clamping blocks (4) and two lower clamping blocks (6). An upper pad (8) is connected and installed at the bottom of one of the upper clamping blocks (4), and a lower pad (9) is connected and installed at the top of one of the lower clamping blocks (6). A sample (10) is clamped between the two upper clamping blocks (4) and the two lower clamping blocks (6). A groove (11) is provided in the middle of the sample (10), and a measuring hole (12) is provided on both sides of the sample (10).

2. The ultra-high temperature crack propagation cold clamping device according to claim 1, characterized in that: The top view of the through slot (2) is semi-circular, and the two flat high-temperature furnaces (1) in the group are symmetrical to each other.

3. The ultra-high temperature crack propagation cold clamping device according to claim 1, characterized in that: The sample (10) is vertically inserted inside the two through slots (2), and the groove (11) is located in the center inside the two flat high-temperature furnaces (1).

4. The ultra-high temperature crack propagation cold clamping device according to claim 1, characterized in that: The two upper clamping blocks (4) and the two lower clamping blocks (6) are symmetrical to each other, and the upper pad block (8) and the lower pad block (9) are both arranged in an "L" shape.

5. The ultra-high temperature crack propagation cold clamping device according to claim 1, characterized in that: The upper clamping block (4) and the lower clamping block (6) are provided with through holes (13) at their front and rear ends. The bottom of the upper clamping block (4) and the top of the lower clamping block (6) are provided with screw holes (14) at both ends. The upper pad (8) and the lower pad (9) are provided with connecting grooves (15) inside.

6. The ultra-high temperature crack propagation cold clamping device according to claim 5, characterized in that: The through holes (13) between the front and rear ends of the upper clamping block (4) and the lower clamping block (6) are interconnected.

7. The ultra-high temperature crack propagation cold clamping device according to claim 5, characterized in that: The width of the connecting groove (15) matches the diameter of the screw hole (14).

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