A device and method for testing the bonding strength of inner hole coating

Abstract

The present invention discloses an inner hole coating bonding strength test device and a test method, which belong to the field of performance testing technology. The pull rod of the inner hole coating bonding strength test device can apply axial tension to the coating through a guide ring and a power-assisting assembly, and the pull rod can also apply radial pressure to the coating through a tapered surface and a power-assisting assembly. The pressure rod can apply radial tension to the coating through a hook and a power-assisting assembly. The inner hole coating bonding strength test method adopts the above-mentioned inner hole coating bonding strength test device, and the tensile bonding strength test and the shear bonding strength test can be performed on the same device to save time and improve test efficiency. The test results can be used to evaluate the shear bonding strength and tensile bonding strength of the inner curved surface coating and the substrate.

Description

Technical Field

[0001] The invention relates to the technical field of performance testing, and in particular to an inner hole coating bonding strength testing device and a testing method. Background Art

[0002] In many important industrial fields, such as petrochemical, aerospace, weapons and equipment, and machinery manufacturing, there are many internal hole parts that are very important to the overall structure, such as automobile engine cylinders, gas turbine housings, and chemical oil pipelines. Some parts need to work under harsh conditions such as high temperature and high pressure, which places very high demands on the quality of the internal holes of the parts. In order to improve the quality of the internal holes, various processes are often used to prepare coatings on the surface of the internal holes of important internal hole parts in service.

[0003] The bonding strength between the coating and the substrate is a very important indicator for evaluating the quality of the coating. If the coating bonding strength does not meet the standard, the coating may peel off during service. At the very least, the coating will not be able to protect the substrate, and at the worst, the entire part or the entire equipment will be scrapped. Therefore, it is very important to test the bonding strength before formal use.

[0004] Traditional coating bonding strength tests are mainly divided into tensile bonding strength and shear bonding strength. The tensile bonding strength of a coating refers to the coating's ultimate ability to withstand tensile stress in the normal direction (perpendicular to the coating surface), and the shear bonding strength of a coating refers to the coating's ultimate ability to withstand shear stress in the tangential direction (along the coating surface). Most coatings work under a large shear stress, so using a shear test to measure the coating's bonding strength is more in line with actual operating conditions, and the tensile bonding strength can more intuitively represent the bonding strength between the coating and the substrate. The coordinated testing of the two can more comprehensively evaluate the coating's bonding strength.

[0005] The existing shear bond strength test and tensile bond strength test have the following technical defects:

[0006] (1) The test is conducted after the coating is sprayed on the outer edge or flat surface. This is quite different from the working condition where the coating on the inner wall of the inner hole part is sprayed on a curved surface with a certain curvature. The test results cannot evaluate the shear bonding strength and tensile bonding strength between the inner curved surface coating and the substrate.

[0007] (2) Before the existing coating bonding strength test, a special holding device needs to be used during the bonding and insulation stage to ensure that the coating is tightly bonded to the bonding surface. After the bonding is completed, the testing device needs to be switched, which is troublesome and time-consuming.

[0008] (3) The coating of the inner hole part needs to be tested for two kinds of bonding strength in order to comprehensively evaluate the quality of the coating. However, in the prior art, different testing devices need to be switched when testing the shear or tensile bonding strength, which is inefficient. Summary of the invention

[0009] The purpose of the present invention is to provide an inner hole coating bonding strength testing device and testing method to solve the technical problems existing in the prior art that the inner curved surface coating cannot be tested and the loading and testing devices need to be frequently switched.

[0010] As conceived above, the technical solution adopted by the present invention is:

[0011] An inner hole coating bonding strength testing device, comprising:

[0012] A positioning assembly, used to clamp the sample to be tested;

[0013] A guide ring is placed at the center of the sample to be tested, the guide ring has a threaded hole arranged in the axial direction and a guide groove arranged in the radial direction, and the guide groove is connected to the threaded hole;

[0014] A boosting component, one end of which is inserted into the guide groove and the other end of which is bonded to the coating on the inner hole of the sample to be tested;

[0015] A pull rod is threadedly connected to the threaded hole, the interior of the pull rod is hollow, and the bottom end of the pull rod has a tapered surface. The pull rod can apply axial tension to the coating through the guide ring and the power-assisting component, and the pull rod can also apply radial pressure to the coating through the tapered surface and the power-assisting component;

[0016] A pressure rod is slidably disposed in the pull rod, and the pressure rod is coaxially disposed with the pull rod;

[0017] The draw hook is rotatably connected to the guide ring, the bottom end of the pressure rod can abut against one end of the draw hook, and the other end of the draw hook can abut against the power-assisting component, and the pressure rod can apply radial tension to the coating through the draw hook and the power-assisting component.

[0018] Wherein, the power assist component comprises:

[0019] An adapter, inserted into the guide groove;

[0020] a friction head, bonded to the coating;

[0021] A friction rod has one end fixedly connected to the adapter and the other end fixedly connected to the friction head.

[0022] Wherein, a limiting protrusion is arranged on the adapter, and the draw hook can abut against the limiting protrusion.

[0023] Wherein, a limiting hole is arranged on the guide ring, a limiting rod is threadedly connected to the limiting hole, and the bottom end of the limiting rod can abut against the adapter.

[0024] Wherein, the positioning component comprises:

[0025] A base, on which the sample to be tested and the guide ring are placed;

[0026] The upper cover is in contact with the sample to be tested, the upper cover and the base are locked by fasteners, the upper cover is annular, and the pull rod and the pressure rod can pass through the upper cover.

[0027] Wherein, a limiting surface is provided on the inner wall of the upper cover, and a plurality of the limiting surfaces are arranged in a step-like manner, and the sample to be tested can abut against the limiting surfaces.

[0028] Wherein, a positioning groove is arranged on the base, and one end of the sample to be tested is located in the positioning groove.

[0029] Wherein, the pressure rod comprises a rod body and a limiting portion arranged at the top end of the rod body, and the diameter of the limiting portion is greater than the diameter of the rod body.

[0030] There are at least two groups of the power assisting components, which are evenly distributed around the circumference of the guide ring, and one guide groove and one pull hook are provided for each group of the power assisting components.

[0031] A method for testing the bonding strength of an inner hole coating, using the inner hole coating bonding strength testing device as described above, comprising:

[0032] Preparation stage: Push the pull rod inward along the threaded hole until the conical surface abuts against the power assist component, so as to apply radial pressure to the power assist component through the pull rod, so that the power assist component is in close contact with the coating and maintained for a set time, and then reset the pull rod;

[0033] Tensile bonding strength test: Apply axial pressure to the pressure rod, so that the pressure rod slides along the pull rod until it abuts against one end of the hook, and the hook rotates relative to the guide ring, so that the other end of the hook abuts against the power-assisting component, so as to apply radial tension to the power-assisting component, so that the coating is subjected to radial tension, and the magnitude of the axial pressure on the pressure rod is recorded at the moment when the coating falls off;

[0034] Shear bond strength test: Apply axial tension to the tie rod so that the axial tension is transmitted along the guide ring to the power assist assembly, so that the coating is subjected to axial tension. The magnitude of the axial tension on the tie rod is recorded at the moment when the coating falls off.

[0035] Beneficial effects of the present invention:

[0036] The inner hole coating bonding strength testing device proposed in the present invention tests the coating on the inner hole of the sample to be tested, and the test results can be used to evaluate the shear bonding strength and tensile bonding strength between the inner curved surface coating and the substrate; before the coating bonding strength test, the axial pressure on the pull rod is applied to the power assist component through the conical surface, which is converted into radial pressure on the coating to achieve load retention, without the need to switch devices, thus saving time and effort; the tensile bonding strength test and the shear bonding strength test can be performed on the same device to save time and improve test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of an inner hole coating bonding strength testing device provided by an embodiment of the present invention;

[0038] Figure 2 is a cross-sectional view of an inner hole coating bonding strength testing device provided by an embodiment of the present invention;

[0039] Figure 3 yes Figure 2 A magnified view of point A;

[0040] Figure 4 is a schematic structural diagram of an upper cover provided by an embodiment of the present invention;

[0041] Figure 5 is a cross-sectional view of a guide ring provided by an embodiment of the present invention;

[0042] Figure 6 This is a partial structural diagram of the inner hole coating bonding strength testing device provided by an embodiment of the present invention. Figure 1 ;

[0043] Figure 7 This is a partial structural diagram of the inner hole coating bonding strength testing device provided by an embodiment of the present invention. Figure 2 ;

[0044] Figure 8 is a schematic structural diagram of a power assist assembly provided by an embodiment of the present invention;

[0045] Fig. 9 is a schematic diagram of the structure of a retractor provided by an embodiment of the present invention;

[0046] Fig.10 is a schematic diagram of the preparation stage of the inner hole coating bonding strength testing method provided by an embodiment of the present invention;

[0047] Fig.11 Schematic diagram of a tensile bonding strength test of an inner hole coating bonding strength test method provided by an embodiment of the present invention;

[0048] Fig.12It is a schematic diagram of a shear bonding strength test of an inner hole coating bonding strength test method provided in an embodiment of the present invention.

[0049] In the figure:

[0050] 10. Samples to be tested;

[0051] 11. base; 12. upper cover; 121. limiting surface;

[0052] 2. Guide ring; 21. Threaded hole; 22. Guide groove;

[0053] 3. Power assist assembly; 31. Adapter; 32. Friction head; 33. Friction rod;

[0054] 4. Tie rod; 41. Conical surface;

[0055] 5. Press rod;

[0056] 6. Hook;

[0057] 7. Limit rod. DETAILED DESCRIPTION

[0058] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0059] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0061] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0062] See also Figures 1 to 9 The embodiment of the present invention provides an inner hole coating bonding strength testing device, which can hold the coating and the bonding surface before testing so that the coating and the bonding surface are in close contact; it can also test the shear bonding strength and tensile bonding strength of the inner curved surface coating and the substrate, and can perform tensile bonding strength test and shear bonding strength test on the same device to save time and improve test efficiency. In this embodiment, the sample 10 to be tested is introduced as a cylinder sleeve. Of course, the sample 10 to be tested can also be other components with an inner hole, which will not be described one by one here.

[0063] The inner hole coating bonding strength testing device includes a positioning component, a guide ring 2, a power assist component 3, a pull rod 4, a pressure rod 5 and a hook 6, which are described in detail one by one below.

[0064] The positioning assembly is used to clamp the sample 10 to prevent the sample 10 from shifting during testing. While clamping the sample 10, the positioning assembly cannot affect the force applied by other components to the coating of the sample 10, and is convenient for replacing samples 10 of different specifications.

[0065] The positioning assembly includes a base 11 and an upper cover 12, and the upper cover 12 is locked with the base 11 by a fastener, which can be a stud. The sample 10 to be tested is placed on the base 11, and the upper cover 12 abuts against the sample 10 to be tested. When the fastener is locked, the upper cover 12 and the base 11 clamp the sample 10 to be tested. In this embodiment, the base 11 is disc-shaped. The upper cover 12 is annular, which is convenient for placing other components.

[0066] A positioning groove is provided on one side of the base 11, one end of the sample 10 to be tested is located in the positioning groove, and the other end of the sample 10 to be tested abuts against the upper cover 12. A positioning column is provided on the other side of the base 11, and a thread is provided on the outer surface of the positioning column to facilitate clamping and loading of the tensile tester to avoid slipping during the test loading process.

[0067] A limiting surface 121 is provided on the inner wall of the upper cover 12, and a plurality of limiting surfaces 121 are arranged in a step-like manner, and the sample 10 to be tested can abut against the limiting surface 121. Since the limiting surface 121 is annular, the periphery of the sample 10 to be tested can be fully limited. The plurality of limiting surfaces 121 are arranged in a step-like manner, and are limited for samples 10 to be tested with different outer diameters, and can adapt to samples 10 to be tested of various specifications, so as to obtain the bonding strength of coatings with different curvatures.

[0068] The guide ring 2 is placed on the base 11 and located at the center of the sample 10 to be tested. A limit groove is provided on the base 11 at a position corresponding to the guide ring 2. One end of the guide ring 2 is located in the limit groove to prevent radial displacement of the guide ring 2. The guide ring 2 has a threaded hole 21 arranged along the axial direction and a guide groove 22 arranged along the radial direction. The guide groove 22 is connected to the threaded hole 21.

[0069] One end of the power assist component 3 is inserted into the guide groove 22, and the other end is bonded to the coating on the inner hole of the sample 10 to be tested; the force on the pull rod 4 and the pressure rod 5 can be transmitted to the power assist component 3, and then to the coating.

[0070] At least two groups of power-assisting components 3 are provided, and at least two groups of power-assisting components 3 are evenly distributed around the circumference of the guide ring 2, and a guide groove 22 is provided corresponding to each group of power-assisting components 3. In this embodiment, four groups of power-assisting components 3 are provided. The four groups of power-assisting components 3 can move synchronously in the radial direction and simultaneously contact with the coating to realize automatic centering.

[0071] The power assist assembly 3 includes an adapter 31, a friction head 32 and a friction rod 33. The adapter 31 is inserted into the guide groove 22, the friction head 32 is bonded to the coating, one end of the friction rod 33 is fixedly connected to the adapter 31, and the other end is fixedly connected to the friction head 32. An adhesive layer is provided between the friction head 32 and the coating to form a bonding surface for bonding.

[0072] Specifically, one end of the friction head 32 is an arc surface, which is convenient for matching with the coating on the inner hole, and the other end of the friction head 32 is threadedly connected to the friction rod 33. At the same time, the friction rod 33 is threadedly connected to the adapter 31, so that the radial extension length of the power assist component 3 can be adjusted to adapt to different diameters of the sample 10 to be tested. When the inner diameter of the sample 10 to be tested is large, a combination of multiple friction rods 33 can be used.

[0073] The pull rod 4 is threadedly connected to the threaded hole 21 on the guide ring 2, and the pull rod 4 can apply axial tension to the coating through the guide ring 2 and the power-assisting component 3. The axial tension on the pull rod 4 is directly transmitted to the guide ring 2 by reverse locking of the thread, and then transmitted to the coating through the power-assisting component 3.

[0074] The top of the pull rod 4 is provided with a thread on its outer surface, which is convenient for clamping and loading on the tensile testing machine. The middle position of the pull rod 4 is provided with a square protrusion and chamfer on its outer surface, which is convenient for rotating and disassembling it from the threaded hole 21 of the guide ring 2 after use. The bottom end of the pull rod 4 has a conical surface 41, and the pull rod 4 can apply radial pressure to the coating through the conical surface 41 and the power-assisting component 3.

[0075] In order to allow the adapter 31 to slide freely during the test, a certain gap is left between the matching surfaces of the adapter 31 and the guide groove 22, so a limit hole is provided on the guide ring 2, and a limit rod 7 is threadedly connected in the limit hole, and the bottom end of the limit rod 7 can abut against the adapter 31. During the test, the adapter 31 is pressed by the limit rod 7 to prevent the adapter 31 from turning over and causing inaccurate test results.

[0076] Specifically, the rotating pull rod 4 is pushed inward along the threaded hole 21 until the conical surface 41 of the pull rod 4 abuts against the adapter 31 to apply radial pressure to the adapter 31, and transfer the coating through the friction rod 33 and the friction head 32, so that the friction head 32 is in close contact with the coating and maintains it for a set length of time to ensure the bonding strength.

[0077] When axial tension is applied to the pull rod 4, due to the threaded connection between the pull rod 4 and the guide ring 2, the axial tension is transmitted to the adapter 31 through the guide ring 2, and then transmitted to the coating through the friction rod 33 and the friction head 32, so that the coating is subjected to axial tension.

[0078] The interior of the pull rod 4 is hollow, and the pressure rod 5 is slidably arranged in the pull rod 4, and the pressure rod 5 is coaxially arranged with the pull rod 4. Both the pull rod 4 and the pressure rod 5 can pass through the upper cover 12, and the annular upper cover 12 will not interfere with other components arranged inside the sample 10 to be tested.

[0079] The hook 6 is rotatably connected to the guide ring 2, the bottom end of the pressure rod 5 can abut against one end of the hook 6, and the other end of the hook 6 can abut against the power-assisting component 3, and the pressure rod 5 can apply radial tension to the coating through the hook 6 and the power-assisting component 3.

[0080] The adapter 31 is provided with a limit protrusion, and the hook 6 can abut against the limit protrusion. The pressure rod 5 presses down one end of the hook 6 to rotate the hook 6, and the other end of the hook 6 abuts against the power assist component 3, applying radial tension to the power assist component 3, and then applying radial tension to the coating.

[0081] The pressure rod 5 includes a rod body and a limiter disposed at the top of the rod body, and the diameter of the limiter is larger than the diameter of the rod body. A thread is disposed on the outer surface of the limiter to facilitate loading of the tensile testing machine. A draw hook 6 is disposed corresponding to each group of assisting components 3, and the bottom end of the pressure rod 5 can apply force to all draw hooks 6 at the same time, thereby driving all assisting components 3 to move synchronously at the same time, so as to realize automatic centering, so that the guide ring 2 is located in the middle position of the sample to be tested.

[0082] Specifically, when axial pressure is applied to the pressure rod 5, the bottom end of the pressure rod 5 presses down the hook 6, causing the hook 6 to rotate, and the end of the hook 6 abuts against the power-assisting component 3, applying radial tension to the power-assisting component 3, and then applying radial tension to the coating. When the radial tension is large enough, the coating will fall off the sample 10 to be tested. The axial pressure acting on the pressure rod 5 is converted into radial tension by a simple hook 6, solving the problem of difficulty in applying radial tension on the inner hole curved surface.

[0083] See also Figures 10 to 12 The embodiment of the present invention also provides a method for testing the bonding strength of an inner hole coating, using the above-mentioned inner hole coating bonding strength testing device, including a preparation stage, a tensile bonding strength test and a shear bonding strength test. In the accompanying drawings, arrows are used to indicate the direction of force.

[0084] See also Fig.10 In the preparation stage, the rod 4 is pushed inward along the threaded hole 21 until the conical surface 41 abuts against the power assist component 3, so that the rod 4 applies radial pressure to the power assist component 3, so that the power assist component 3 is in close contact with the coating and maintains a set time, and the rod 4 is reset. Specifically, by pushing the rod 4 inward along the threaded hole 21 until the conical surface 41 abuts against the adapter 31, Fig.11 The middle pull rod 4 moves vertically downward, so that the adapter 31 is pushed radially outward and moves radially, so as to apply radial pressure to the coating through the friction rod 33 and the friction head 32, so that the friction head 32 is in close contact with the coating and maintained for a certain period of time under the set temperature conditions to solidify the glue layer.

[0085] In order to make the contact area between the friction head 32 and the coating constant, generally after the coating is made, the coating on the wall of the inner hole located around the friction head 32 is removed so that the contact area between the friction head 32 and the coating is the area of ​​the arc surface of the friction head 32.

[0086] See also Fig.11 When conducting the tensile strength test, an axial pressure is applied to the compression rod 5. Fig.11 The middle pressure rod 5 is subjected to vertical downward axial pressure, so that the pressure rod 5 slides along the pull rod 4 until it abuts against one end of the hook 6. One end of the hook 6 is subjected to downward pressure, so that the hook 6 rotates relative to the guide ring 2, and then the other end of the hook 6 abuts against the power-assisting component 3 to apply radial tension to the power-assisting component 3. The power-assisting component 3 is subjected to radial tension inward in the radial direction, so that the coating is subjected to radial tension. The magnitude of the axial pressure applied to the pressure rod 5 is recorded at the moment the coating falls off.

[0087] The tensile bond strength of the coating is calculated as follows:

[0088] R H =(F*L 1 ) / (L2 *S*N)=(F*L 1 ) / (L 2 *R*θ*H*N)

[0089] Where F is the magnitude of the axial pressure on the compression rod;

[0090] L 1 is the length of the lever arm of the pressure rod acting on the hook;

[0091] L 2 The length of the lever arm of the pull hook acting on the adapter;

[0092] S is the contact area between a single friction head and the coating;

[0093] N is the number of friction heads;

[0094] R is the radius of the curved surface corresponding to a single friction head;

[0095] θ is the radian angle corresponding to a single friction head;

[0096] H is the height of the friction head.

[0097] See also Fig.12 When testing the shear strength, an axial tensile force is applied to the tie rod 4. Fig.12 The middle pull rod 4 is subjected to a vertical upward axial pulling force, so that the axial pulling force is transmitted along the guide ring 2 to the power-assisting component 3, so as to apply an axial pulling force to the power-assisting component 3, so that the coating is subjected to an axial pulling force, and the magnitude of the axial pulling force applied to the pull rod 4 is recorded at the moment when the coating falls off.

[0098] When the pull rod 4 is subjected to axial tension, the pull rod 4 and the guide ring 2 are locked under the action of the thread, and the axial tension on the pull rod 4 can be transmitted along the guide ring 2 to the adapter 31, and then the axial tension is applied to the coating through the friction rod 33 and the friction head 32. By making the axial tension applied to the pull rod 4 evenly applied to the coating, the gap that it is difficult to simulate the actual working conditions to test the shear bonding strength of the inner hole parts is filled.

[0099] The calculation formula of shear bond strength is as follows:

[0100] σ τ =T / (N*S)=T / (N*R*θ*H)

[0101] Where T is the axial tension on the tie rod;

[0102] N is the number of friction heads;

[0103] S is the contact area between a single friction head and the coating;

[0104] R is the radius of the circle corresponding to a single friction head;

[0105] θ is the radian angle corresponding to a single friction head;

[0106] H is the height of the friction head.

[0107] In summary, the above-mentioned inner hole coating bonding strength testing device realizes the following functions:

[0108] 1. Achieved simple and convenient determination of the two bonding strengths of the inner wall coating of the inner hole part

[0109] Through this device, the tension or pressure applied to the pull rod 4 or the pressure rod 5 is converted into a shear force or tension applied to the inner hole coating surface. The instantaneous force when the coating falls off is substituted into the formula to calculate the bonding strength of the coating. Only one device is needed to test both the shear bonding strength and the tensile bonding strength of the coating. The test mode can be switched conveniently according to actual needs, or both tests are conducted simultaneously to comprehensively examine the actual performance and determine whether the coating will fall off and fail during service.

[0110] 2. Achieved the inner wall coating bonding strength test of parts with different inner holes

[0111] The multiple limiting surfaces 121 arranged in a stepped manner on the upper cover 12 can position the samples 10 to be tested of different diameters. When the diameter size difference of the inner hole parts to be tested is large, the coating bonding strength test can be achieved by using different numbers of friction rods 33 and friction heads 32. When the diameter difference is small, the radial position of the adapter 31 can be fine-tuned directly by rotating the pull rod 4, which is simple to operate and reliable in connection.

[0112] 3. Realized the integration of the loading device and the testing device

[0113] When the coating is glued to the friction head 32, it needs to be loaded and automatically aligned so that the two are tightly combined. The device can be loaded by rotating the pull rod 4, without the need for additional devices, reducing testing costs, saving time for frequent replacement of different devices, and improving efficiency.

[0114] The above embodiments are only to illustrate the basic principles and characteristics of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and modifications, which are within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An inner hole coating bonding strength testing device, characterized in that: include: A positioning assembly, used for clamping the sample to be tested (10); A guide ring (2) is placed at the center of the sample (10) to be tested, the guide ring (2) having a threaded hole (21) arranged along the axial direction and a guide groove (22) arranged along the radial direction, the guide groove (22) being connected to the threaded hole (21); A boosting component (3), one end of which is inserted into the guide groove (22) and the other end of which is bonded to the coating on the inner hole of the sample to be tested (10); A pull rod (4) is threadedly connected to the threaded hole (21); the interior of the pull rod (4) is hollow; the bottom end of the pull rod (4) has a conical surface (41); the pull rod (4) can apply axial tension to the coating through the guide ring (2) and the power-assisting component (3); the pull rod (4) can also apply radial pressure to the coating through the conical surface (41) and the power-assisting component (3); A pressure rod (5) is slidably disposed in the pull rod (4), and the pressure rod (5) and the pull rod (4) are coaxially disposed; The draw hook (6) is rotatably connected to the guide ring (2); the bottom end of the pressure rod (5) can abut against one end of the draw hook (6); the other end of the draw hook (6) can abut against the power-assisting component (3); and the pressure rod (5) can apply radial tension to the coating through the draw hook (6) and the power-assisting component (3).

2. The inner hole coating bonding strength testing device according to claim 1, characterized in that: The power assist component (3) comprises: An adapter (31) is inserted into the guide groove (22); A friction head (32) bonded to the coating; A friction rod (33) has one end fixedly connected to the adapter (31) and the other end fixedly connected to the friction head (32).

3. The inner hole coating bonding strength testing device according to claim 2, characterized in that: The adapter (31) is provided with a limiting protrusion, and the draw hook (6) can abut against the limiting protrusion.

4. The inner hole coating bonding strength testing device according to claim 2, characterized in that: The guide ring (2) is provided with a limiting hole, the limiting hole is threadedly connected to a limiting rod (7), and the bottom end of the limiting rod (7) can abut against the adapter (31).

5. The inner hole coating bonding strength testing device according to claim 1, characterized in that: The positioning component comprises: A base (11), the sample to be tested (10) and the guide ring (2) are both placed on the base (11); The upper cover (12) is in contact with the sample to be tested (10), the upper cover (12) and the base (11) are locked by fasteners, the upper cover (12) is annular, and the pull rod (4) and the pressure rod (5) can pass through the upper cover (12).

6. The inner hole coating bonding strength testing device according to claim 5, characterized in that: A limiting surface (121) is provided on the inner wall of the upper cover (12), and a plurality of the limiting surfaces (121) are arranged in a step-like manner, so that the sample (10) to be tested can abut against the limiting surfaces (121).

7. The inner hole coating bonding strength testing device according to claim 5, characterized in that: The base (11) is provided with a positioning groove, and one end of the sample to be tested (10) is located in the positioning groove.

8. The inner hole coating bonding strength testing device according to claim 1, characterized in that: The pressure rod (5) comprises a rod body and a limiting portion arranged at the top end of the rod body, and the diameter of the limiting portion is greater than the diameter of the rod body.

9. The inner hole coating bonding strength testing device according to any one of claims 1 to 8, characterized in that: The power-assisting components (3) are provided in at least two groups, and the at least two groups of the power-assisting components (3) are evenly distributed around the circumference of the guide ring (2), and a guide groove (22) is provided corresponding to each group of the power-assisting components (3), and a pull hook (6) is provided corresponding to each group of the power-assisting components (3).

10. A method for testing the bonding strength of inner hole coating, characterized in that: The inner hole coating bonding strength testing device according to any one of claims 1 to 9 comprises: Preparation stage: the pull rod (4) is pushed inward along the threaded hole (21) until the conical surface (41) abuts against the power assist component (3), so as to apply radial pressure to the power assist component (3) through the pull rod (4), so that the power assist component (3) is in close contact with the coating and maintained for a set time, and the pull rod (4) is reset; Tensile bonding strength test: Apply axial pressure to the pressure rod (5) so that the pressure rod (5) slides along the pull rod (4) until it abuts against one end of the draw hook (6). The draw hook (6) rotates relative to the guide ring (2), so that the other end of the draw hook (6) abuts against the power-assisting component (3), so as to apply radial tension to the power-assisting component (3), so that the coating is subjected to radial tension. The magnitude of the axial pressure applied to the pressure rod (5) is recorded at the moment when the coating falls off. Shear bonding strength test: Apply axial tension to the pull rod (4) so ​​that the axial tension is transmitted along the guide ring (2) to the power assist component (3), so that the coating is subjected to axial tension. The magnitude of the axial tension applied to the pull rod (4) is recorded at the moment when the coating falls off.

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