Indentation apparatus for determining the mechanical properties of a material

Abstract

The application discloses a kind of indentation devices for determining the mechanical properties of material, comprising: first sleeve, second sleeve;Head assembly, head assembly is movably arranged in first channel between fixed state and release state;Fixed and release mechanism is arranged in second sleeve, and fixed and release mechanism includes: bushing movably passes through first through hole and first channel;Suction accessory, suction accessory is arranged at one end of bushing close to head assembly, when second sleeve is in second position, suction accessory adsorbs head assembly, when second sleeve is in first position, head assembly can be switched between fixed state and release state;When push rod is in extended position, push rod at least partially extends second channel and stops and abuts head assembly to make head assembly switch from fixed state to release state;When push rod is in retracted position, push rod is retracted into second channel.The indentation device is compact in structure, high in adaptability and good in stability.

Description

Technical Field

[0001] This invention relates to the field of materials testing and experimental mechanics, and in particular to an indentation device for determining the mechanical properties of materials, which is suitable for the rapid evaluation of the physical and mechanical properties of metallic materials and other engineering materials, such as hardness and ultimate strength. Background Technology

[0002] The mechanical properties of materials, such as hardness, ultimate tensile strength, and work hardening behavior, are of great significance in engineering structural safety assessment, manufacturing process quality control, and service condition monitoring. With the increasing demands of advanced manufacturing and on-site testing, the rapid, convenient, and repeatable measurement of material mechanical parameters has become particularly crucial. Dynamic indentation testing, as a method based on inverting material properties through indentation response, has shown broad application prospects in both industrial fields and scientific research due to its advantages such as ease of operation, small equipment size, and flexible testing locations.

[0003] However, existing indentation devices typically accelerate the indenter head using its own gravity and are usually released by a mechanical clamping mechanism. While this method can meet accuracy requirements when testing in the horizontal direction, if the test position is on an inclined surface, side wall, or even top wall, the acceleration direction will not be consistent with the gravity direction, leading to increased fluctuations in the indentation speed, making the measurement results unstable or even unusable, which severely limits the application scenarios.

[0004] Furthermore, existing mechanical clamping mechanisms typically employ a four-lobed spring chuck structure. This type of structure experiences wear during long-term, repeated use, leading to inconsistent release actions. This manifests as changes in clamping force, increased friction, or delayed release, ultimately making it difficult to maintain a stable initial position and acceleration process for the indenter. Measurement errors inevitably accumulate due to changes in structural condition, thus affecting the overall reliability and repeatability of the test.

[0005] Therefore, there is an urgent need for an indentation device that can operate stably in any spatial orientation, possesses high durability and repeatability, and provides stable indenter acceleration and reliable release. In particular, a new indenter fixing and release mechanism is needed that avoids the wear and stability degradation problems caused by mechanical clamping, while also featuring a compact structure, high consistency of action, and unrestricted applicability. These problems are precisely the technical challenges that this invention aims to solve. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an indentation device for measuring the mechanical properties of materials. The indentation device has a compact structure, high adaptability, and can effectively avoid the stability reduction problem caused by mechanical clamping wear compared with existing indentation devices.

[0007] To address the aforementioned technical problems, the present invention provides the following technical solution: An indentation apparatus for measuring the mechanical properties of materials according to an embodiment of the present invention includes: a first sleeve defining a first channel extending axially within the first sleeve, and a first end cap having a first through hole in the axial direction; a second sleeve movably fitted onto the first sleeve between a first position and a second position along the axial direction; an indenter assembly movably disposed within the first channel between a fixed state and a released state; a first elastic member disposed within the first channel and connected to the first end cap, the first elastic member being located between the indenter assembly and the first end cap; a second elastic member disposed within the second sleeve and located between the second sleeve and the first end cap; and a fixing and releasing mechanism disposed within the second sleeve. The sleeve, the fixing and releasing mechanism includes: a bushing having a second channel extending axially, the bushing being movably disposed through the first through hole and the first channel; an adsorption member disposed at one end of the bushing near the pressure head assembly, wherein when the second sleeve is in the second position, the adsorption member adsorbs the pressure head assembly, and when the second sleeve is in the first position, the pressure head assembly is switchable between the fixed state and the released state; and a push rod movably disposed through the second channel between an extended position and a retracted position, wherein when the push rod is in the extended position, the push rod at least partially extends out of the second channel and abuts against the pressure head assembly to switch the pressure head assembly from the fixed state to the released state; and when the push rod is in the retracted position, the push rod retracts into the second channel.

[0008] According to an embodiment of the present invention, an indentation device for determining the mechanical properties of materials is provided. A second sleeve is movably fitted onto a first sleeve, and a fixing and releasing mechanism is moved between a first position and a second position. This allows the adsorption element to cooperate with the indenter assembly. Simultaneously, the fixing and releasing mechanism is configured as a bushing and a push rod structure passing through the bushing. The push rod pushes the indenter assembly, overcoming the adsorption connection between the adsorption element and the indenter assembly. This allows the indenter assembly to switch from a fixed state to a released state, impacting the test object along the first channel under the action of a first elastic element. Therefore, on the one hand, the elastic element accelerates the indenter assembly, avoiding the problem of large fluctuations in indentation speed caused by the inconsistency between the acceleration direction and the gravity direction in existing technologies that rely on gravity acceleration. On the other hand, the adsorption element and the indenter assembly are adsorbed and cooperated, and the fixing and releasing mechanism separates them, allowing the indenter assembly to switch from a fixed state to a released state. This ensures that the release action is completed without mechanical deformation, avoiding the wear problem caused by repeated loading in existing mechanical clamping structures, thereby significantly improving the stability and durability of the indentation test.

[0009] According to some embodiments of the present invention, the pressure head assembly includes: a pressure head body; a pressure head tip disposed at one end of the pressure head body away from the second end cap; and a permanent magnet disposed at one end of the pressure head body near the second end cap.

[0010] According to some embodiments of the present invention, the bushing includes a magnetic bushing disposed at the end of the bushing facing the pressure head assembly and capable of engaging with the permanent magnet.

[0011] According to some embodiments of the present invention, the magnetic bushing is formed as a sleeve structure and disposed on the inner circumferential side of the end of the bushing, and the push rod includes a first rod body and a second rod body, wherein the diameter of the first rod body is larger than the inner diameter of the magnetic bushing and the diameter of the second rod body is smaller than the inner diameter of the magnetic bushing.

[0012] According to some embodiments of the present invention, the indentation device further includes an inductor coil and a signal processing device, wherein the inductor coil is sleeved on the first sleeve to sense the movement of the indenter assembly, and the signal processing device is connected to the inductor coil to perform sensing signal processing.

[0013] According to some embodiments of the present invention, the bushing includes a bushing body and an inner end cap disposed at one end of the bushing body, the inner end cap having a second through hole communicating with the hollow channel of the bushing body.

[0014] According to some embodiments of the present invention, the fixing and releasing mechanism further includes a triggering component, the triggering component including: a mounting base, the mounting base being disposed at one end of the inner end cover away from the first end cover and the mounting base having a third through hole, the third through hole being connected to the second through hole and the second channel, the push rod being disposed through the second channel, the second through hole and the third through hole, and at least a portion of the push rod extending out of the third through hole.

[0015] According to some embodiments of the present invention, the triggering assembly further includes: a third elastic element and a trigger key, the mounting base having a mounting groove, the trigger key being disposed in the mounting groove and sleeved on the end of the push rod, and the third elastic element being disposed between the trigger key and the mounting base and located within the mounting groove.

[0016] According to some embodiments of the present invention, the mounting base further includes a fastening sleeve facing the inner end cap, the fastening sleeve being at least partially fitted around the outer periphery of the inner end cap and the second sleeve.

[0017] According to some embodiments of the present invention, the second sleeve has a first external thread on the side away from the first sleeve, the outer peripheral side of the inner end cap has a second external thread, the inner end cap is abutted to the second sleeve, and the fastening sleeve has a first internal thread adapted to the first external thread and a second internal thread adapted to the second external thread on the side facing the inner end cap.

[0018] According to some embodiments of the present invention, the outer diameter of the fastening sleeve is equal to the outer diameter of the second sleeve.

[0019] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0020] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, which will help to understand the purpose and advantages of the present invention, wherein: Figure 1 This is a schematic diagram of an indentation device for measuring the mechanical properties of materials according to an embodiment of the present invention; Figure 2 This is a cross-sectional view of an indentation device for measuring the mechanical properties of materials according to an embodiment of the present invention, with the second sleeve in the second position; Figure 3 This is a cross-sectional view of an indentation device for measuring the mechanical properties of materials according to an embodiment of the present invention, with the second sleeve in the first position and the indenter assembly in a fixed state. Figure 4 This is a cross-sectional view of an indentation apparatus for measuring the mechanical properties of materials according to an embodiment of the present invention, starting when the second sleeve is in the first position and the indenter assembly is in the released state. Figure 5 This is a cross-sectional view of an indentation device for measuring the mechanical properties of materials according to an embodiment of the present invention, when the second sleeve is in the first position and the indenter assembly is in the released state during impact. Figure 6 This is a schematic diagram of the first sleeve structure of an indentation device for measuring the mechanical properties of materials according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the second sleeve structure of an indentation device for measuring the mechanical properties of materials according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the first end cap structure of an indentation device for measuring the mechanical properties of materials according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the bushing structure of an indentation device for measuring the mechanical properties of materials according to an embodiment of the present invention; Figure 10 This is a schematic diagram of the push rod structure of an indentation device for measuring the mechanical properties of materials according to an embodiment of the present invention.

[0021] Figure Labels Indentation device 100 First sleeve 10; first channel 11; first end cap 12; first through hole 121; second sleeve 20; edge 21; first external thread 22; Indenter assembly 30; Indenter body 31; Indenter tip 32; Permanent magnet 33; First elastic element 41; Second elastic element 42; Fixing and releasing mechanism 50; bushing 51; adsorption element 52; push rod 53; second channel 511; inner end cap 512; bushing body 513; second through hole 5121; second external thread 5122; first rod 531; second rod 532; Mounting base 61; third elastic element 62; trigger key 63; fastening sleeve 64; third through hole 613; mounting groove 612; first internal thread 641; second internal thread 642; Inductor coil 70. Detailed Implementation

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

[0023] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0026] An indentation apparatus 100 for measuring the mechanical properties of materials according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0027] As attached Figures 1-10 As shown, the indentation device 100 for measuring the mechanical properties of materials according to an embodiment of the present invention includes a first sleeve 10, a second sleeve 20, an indenter assembly 30, a first elastic element 41, a second elastic element 42, and a fixing and releasing mechanism 50.

[0028] The first sleeve 10 has a hollow structure, defining a first channel 11 extending axially, and one end of the first sleeve 10 (such as...) Figure 2 The upper end of the pressure head assembly 30 has a first end cap 12, which has a first through hole 121 in the axial direction, so that the first through hole 121 communicates with the first channel 11. The first elastic element 41 is disposed in the first channel 11 and is located between the pressure head assembly 30 and the first end cap 12. The second elastic element 42 is disposed in the second sleeve 20 and is located between the second sleeve 20 and the first end cap 12, so that the second sleeve 20 and the first sleeve 10 can form a self-rebound under the action of the elastic characteristics of the second elastic element 42. The pressure head assembly 30 can be subjected to elastic preload under the action of the elastic characteristics of the first elastic element 41.

[0029] The second sleeve 20 is axially movably sleeved on the outer periphery of the first sleeve 10 between a first position and a second position. In the first position, the distance between the first sleeve 10 and the second sleeve 20 is the largest. In the second position, the cylinder portions of the second sleeve 20 and the first sleeve 10 overlap to reduce the distance between them and allow the pressure head assembly 30 to cooperate with the adsorption member 52 of the fixing and releasing mechanism 50.

[0030] Furthermore, the fixing and releasing mechanism 50 is located on the second sleeve 20, such as... Figures 2-5 The fixing and releasing mechanism 50 is located in the second sleeve 20 and can pass through the first sleeve 10. The fixing and releasing mechanism 50 includes a bushing 51, an adsorption member 52, and a push rod 53. The bushing 51 has a second channel 511 extending axially. The bushing 51 is movably inserted into the first channel 11 and the first through hole 121. The adsorption member 52 is located at one end of the bushing 51 near the pressure head assembly 30 (e.g., Figure 2 (left end of the middle), when the second sleeve 20 is in the second position (e.g.) Figure 2 The adsorption element 52 can adsorb the pressure head assembly 30 when the second sleeve 20 is in the first position (e.g. Figures 3-4 ), and when push rod 53 is in the extended position (e.g. Figure 4 The push rod 53 extends out of the second channel 511 to stop the pressure head assembly 30, thereby disengaging the pressure head assembly 30 from the adsorption member 52, so that it can accelerate the impact on the object to be tested (such as...) under the action of the first elastic member 41. Figure 5 At this time, the pressure head assembly 30 is in the released state; while when the second sleeve 20 is in the first position (e.g. Figures 3-4 ), and when push rod 53 is in the retracted position (e.g. Figure 3 At this time, the pressure head assembly 30 is in a fixed state under the combined action of the first elastic member 41 and the adsorption member 52.

[0031] Therefore, the indentation device 100 for determining the mechanical properties of materials according to an embodiment of the present invention, by movably fitting the second sleeve 20 onto the first sleeve 10 and driving the fixing and releasing mechanism 50 to move between the first position and the second position, allows the adsorption member 52 to cooperate with the indenter assembly 30. Simultaneously, the fixing and releasing mechanism 50 is configured as a bushing 51 and a push rod 53 passing through the bushing 51, enabling the push rod 53 to push the indenter assembly 30, thereby overcoming the adsorption connection between the adsorption member 52 and the indenter assembly 30, and thus allowing the indenter assembly 30 to switch from a fixed state to a released state, forming an impact on the test object along the first channel 11 under the action of the first elastic member 41. Through the above structure, the present invention effectively overcomes the problem of indentation speed deviation caused by changes in installation direction in traditional gravity-based acceleration devices, enabling the device to maintain stable loading capacity in any direction (including sidewalls, overhead surfaces, and inclined surfaces). Furthermore, since the fixing and releasing mechanism 50 is based on adsorption fixation rather than mechanical engagement, it will not produce significant wear over long-term use, and its operational retention does not decrease over time, thereby significantly improving test repeatability.

[0032] Compared to traditional dynamic indentation instruments that rely on gravity to accelerate the indenter, this invention can operate in any testing direction. Furthermore, due to its spring-loaded design, it ensures the stability of the indentation speed, preventing significant errors caused by different test site orientations. Compared to devices that use mechanical structures like four-lobed springs to fix the indenter, this invention relies on the adsorption between the adsorption component 52 and the indenter assembly 30 for fixation, avoiding mechanical wear and ensuring highly consistent indenter release. Compared to large indentation devices, this device is compact and easy to operate, making it particularly suitable for rapid on-site testing of engineering structures and for obtaining material mechanical parameters of curved surfaces or hard-to-access locations. Through the above structural design, this invention effectively solves the problems of limited application range, poor release stability, and insufficient consistency of action in traditional indentation devices 100, significantly improving their reliability, applicability, and repeatability in practical engineering applications.

[0033] like Figures 2-5 In some embodiments, a first limiting member and a second limiting member are provided between the first sleeve 10 and the second sleeve 20. When the second sleeve 20 moves axially closer to the first sleeve 10, it is in a second position under the action of the second limiting member; when the second sleeve 20 moves axially away from the first sleeve 10, it is in a first position under the action of the first limiting member, thereby preventing the first sleeve 10 and the second sleeve 20 from disengaging.

[0034] like Figures 2-5In some embodiments, the pressure head assembly 30 includes a pressure head body 31, a pressure head tip 32, and a permanent magnet 33. The pressure head tip 32 is located at the end of the pressure head body 31 away from the second end cap, and the permanent magnet 33 is located at the end of the pressure head body 31 near the second end cap.

[0035] Preferably, the tip 32 of the indenter can be a cemented carbide component, thereby providing a longer service life when the metal object to be tested is subjected to mechanical property testing.

[0036] like Figures 1-5 , Figure 9 In some embodiments, the bushing 51 includes a magnetic bushing, which may be disposed at the end of the bushing 51 toward the pressure head assembly 30 (e.g., Figure 2 (at the left end of the pressure head assembly 30), thereby achieving magnetic attraction with the permanent magnet 33 in the pressure head assembly 30.

[0037] like Figures 1-5 , Figure 10 In some examples, the magnetic bushing is a sleeve structure, and the end of the bushing 51 is fitted onto the outer periphery of the magnetic bushing. The push rod 53 includes a first rod body 531 and a second rod body 532 connected to each other. The diameter of the first rod body 531 is larger than the inner diameter of the magnetic bushing 51, and the diameter of the second rod body 532 is smaller than the inner diameter of the magnetic bushing 51. This allows the push rod 53 to move along the second channel 511 in the extended and retracted positions. Furthermore, due to the above-mentioned dimensional settings, in the extended position, the magnetic bushing can achieve a limiting fit with the first rod body 531, reducing the influence of manual pushing force on the measurement results.

[0038] like Figure 1 , Figure 2 In some embodiments, the indentation device 100 further includes an inductor coil 70 and a signal processing device. The inductor coil 70 is sleeved on the first sleeve 10 to sense the movement of the indenter assembly 30, and the signal processing device is connected to the inductor coil 70 to perform induction signal processing. Thus, the mechanical properties of the object under test, such as hardness, are obtained.

[0039] like Figures 2-5 , Figure 9 In some embodiments of the present invention, the bushing 51 includes a bushing body 513 and an inner end cap 512. The inner end cap 512 is located at the end of the bushing body and has a second through hole 5121. The second through hole 5121 and the hollow channel of the bushing body 513 together form a second channel 511. Preferably, the second through hole 5121 and the hollow channel are arranged coaxially.

[0040] like Figures 2-5In some examples, the fixing and releasing mechanism 50 further includes a triggering component, which includes: a mounting base 61, located at the end of the inner end cover 512 away from the first end cover 12, and having a third through hole 613. The third through hole 613 is connected to the second through hole 5121 and the second channel 511. A push rod 53 passes through the second channel 511, the second through hole 5121, and the third through hole 613, with at least a portion of the push rod 53 extending out of the third through hole 613. Thus, one end of the push rod 53 can extend out of the second channel 511 to cooperate with the pressure head assembly 30, and the other end can extend out of the third through hole 613, enabling manual switching between the fixed and released states of the pressure head assembly 30.

[0041] like Figures 2-5 Furthermore, the triggering assembly also includes: a third elastic element 62 and a trigger key 63. The mounting base 61 has a mounting groove 612. The trigger key 63 is disposed in the mounting groove 612 and sleeved on the end of the push rod 53. The third elastic element 62 is disposed between the trigger key 63 and the mounting base 61 and is located within the mounting groove 612. Thus, when the second sleeve 20 is in the first position and the pressure head assembly 30 has cooperated with the adsorption member 52 (e.g. Figure 3 At this time, the user presses the trigger button 63, pushing the push rod 53 to extend out of the second channel 511 to stop the pressure head assembly 30, causing the pressure head assembly 30 to disengage from the adsorption member 52. Subsequently, under the elastic pre-tightening force of the first elastic member 41, the pressure head assembly 30 accelerates to impact the object to be tested (such as...). Figure 4 At this time, the trigger key 63, under the action of the third elastic element 62, drives the push rod 53 to retract to the second channel 511 (as shown). Figure 5 ).

[0042] like Figures 2-5 In some embodiments of the present invention, in order to achieve a compact overall structure of the indentation device 100 and to facilitate disassembly and maintenance, the mounting base 61 further includes a fastening sleeve 64 facing the inner end cover 512, and the fastening sleeve 64 is at least partially sleeved on the outer periphery of the inner end cover 512 and the second sleeve 20.

[0043] like Figures 2-5 , Figure 7 , Figure 9 As shown, in some examples, the second sleeve 20 has a first external thread 22 on the side away from the first sleeve 10, the outer peripheral side of the inner end cap 512 has a second external thread 5122, the inner end cap 512 is abutted to the second sleeve 20, and the fastening sleeve 64 has a first internal thread 641 adapted to the first external thread 22 and a second internal thread 642 adapted to the second external thread 5122 on the side facing the inner end cap 512.

[0044] Preferably, such as Figures 1-5The outer diameter of the fastening sleeve 64 is equal to the outer diameter of the second sleeve 20, thereby ensuring that the overall appearance of the indentation device 100 is flat.

[0045] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An indentation device for determining the mechanical properties of materials, characterized in that, include: A first sleeve, wherein a first channel extending axially is defined within the first sleeve, and a first end cap is provided within the first sleeve, wherein the first end cap has a first through hole in the axial direction. The second sleeve is movably fitted onto the first sleeve along the axial direction between a first position and a second position; A pressure head assembly, which is movably disposed within the first channel between a fixed state and a released state; A first elastic element is disposed in the first channel and connected to the first end cap. The first elastic element is located between the pressure head assembly and the first end cap. The second elastic element is disposed inside the second sleeve and located between the second sleeve and the first end cap; A fixing and releasing mechanism, wherein the fixing and releasing mechanism is disposed on the second sleeve, the fixing and releasing mechanism comprising: A bushing having a second channel extending axially, the bushing being movably disposed through the first through hole and the first channel; An adsorption element is disposed at one end of the bushing near the pressure head assembly. When the second sleeve is in the second position, the adsorption element adsorbs the pressure head assembly. When the second sleeve is in the first position, the pressure head assembly can switch between the fixed state and the released state. A push rod is movably disposed in the second channel between an extended position and a retracted position. When the push rod is in the extended position, it extends at least partially out of the second channel and abuts against the pressure head assembly to switch the pressure head assembly from the fixed state to the released state. When the push rod is in the retracted position, it retracts into the second channel.

2. The indentation device for determining the mechanical properties of materials according to claim 1, characterized in that, The pressure head assembly includes: a pressure head body; a pressure head tip, the pressure head tip being disposed at the end of the pressure head body away from the second end cap; and a permanent magnet, the permanent magnet being disposed at the end of the pressure head body near the second end cap.

3. The indentation device for determining the mechanical properties of materials according to claim 2, characterized in that, The bushing includes a magnetic bushing, which is located at the end of the bushing facing the pressure head assembly and can be attracted to the permanent magnet.

4. The indentation device for determining the mechanical properties of materials according to claim 3, characterized in that, The magnetic bushing is formed as a sleeve structure and is located on the inner circumference of the end of the bushing. The push rod includes a first rod body and a second rod body. The diameter of the first rod body is larger than the inner diameter of the magnetic bushing and the diameter of the second rod body is smaller than the inner diameter of the magnetic bushing.

5. The indentation apparatus for determining the mechanical properties of materials according to claim 2, characterized in that, Also includes: An inductor coil and a signal processing device are provided. The inductor coil is sleeved on the first sleeve to sense the movement of the pressure head assembly, and the signal processing device is connected to the inductor coil to perform induction signal processing.

6. The indentation apparatus for determining the mechanical properties of materials according to claim 1, characterized in that, The bushing includes a bushing body and an inner end cap located at one end of the bushing body. The inner end cap has a second through hole, which communicates with the hollow channel of the bushing body.

7. The indentation apparatus for determining the mechanical properties of materials according to claim 6, characterized in that, The fixing and releasing mechanism further includes a triggering component, which includes: a mounting base, the mounting base being disposed at one end of the inner end cover away from the first end cover and having a third through hole, the third through hole being connected to the second through hole and the second channel, the push rod being disposed through the second channel, the second through hole and the third through hole, and at least a portion of the push rod extending out of the third through hole.

8. The indentation apparatus for determining the mechanical properties of materials according to claim 7, characterized in that, The triggering component further includes a third elastic element and a trigger key. The mounting base has a mounting groove, the trigger key is disposed in the mounting groove and sleeved on the end of the push rod, and the third elastic element is disposed between the trigger key and the mounting base and located within the mounting groove.

9. The indentation apparatus for determining the mechanical properties of materials according to claim 7, characterized in that, The mounting base also includes a fastening sleeve facing the inner end cap, the fastening sleeve being at least partially fitted around the outer periphery of the inner end cap and the second sleeve.

10. The indentation apparatus for determining the mechanical properties of materials according to claim 9, characterized in that, The second sleeve has a first external thread on the side away from the first sleeve, and the outer peripheral side of the inner end cap has a second external thread. The inner end cap is connected to the second sleeve for a stop connection. The fastening sleeve has a first internal thread that matches the first external thread and a second internal thread that matches the second external thread on the side facing the inner end cap.

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