A device and method for preparing samples for characterizing performance of inner hole thermal spray coatings

Abstract

The embodiment of the present invention discloses a sample preparation device for characterizing the performance of an inner hole thermal spray coating and a sample preparation method, including a metal structure provided with an inner hole surface to be sprayed, a sample holder provided on the outer side of the metal structure, a sample mounting hole coaxial with the inner hole and having a radius greater than the radius of the inner hole provided on the sample holder, at least one fixed card plate provided on the inner wall of the sample mounting hole, a detachable sample provided on the fixed card plate, and a detection surface of the sample circumscribed to the inner hole of the metal structure. The sample preparation device for characterizing the performance of an inner hole thermal spray coating of the present invention can restore the actual spraying conditions to the greatest extent through the internal surface plane block discrete method, and can prepare a flat coating test that meets the actual test needs. The sample prepared by this method can meet the test requirements of most performance indicators and can accurately reflect the true performance of small-sized inner hole coatings. Technical means such as pre-setting an isolation film on the inner surface of the card plate before spraying can realize the sample preparation device with the characteristic of being reusable.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of coating performance detection, and specifically to a device for preparing a sample for characterizing the performance of an inner hole thermal spray coating and a sample preparation method. Background Art

[0002] High-performance coatings can greatly improve the rust resistance, corrosion resistance, and wear resistance of metal materials, and have been widely used in actual production. Among them, thermal spraying is a commonly used metal surface coating preparation process. Its basic principle is to use a certain heat source (such as electric arc, plasma spraying or combustion flame, etc.) to heat powdered or filamentary metal or non-metallic materials to a molten or semi-molten state, and then use compressed air and other technical means to spray it at a certain speed onto the pretreated substrate surface, and deposit it to form a surface coating with various functions. In recent years, with the continuous improvement of the performance requirements for the inner hole surface of cylindrical parts such as small engine pistons, aircraft actuators, and landing gears, the preparation technology of inner hole coatings, especially small-sized inner hole coatings, has developed rapidly. An important process after coating preparation is to test and evaluate the performance of the prepared coating. Typical coating performance test indicators include the bonding strength between the coating and the substrate, bending performance, coating friction and wear performance, electrochemical performance, etc. According to the current material performance testing standards, many performance tests need to be based on flat specimens. Since the inner surface curvature of the prepared small-sized inner hole coating is large, it cannot be directly used for testing performance indicators such as bonding strength and dry wear performance.

[0003] Therefore, in order to accurately obtain the true performance indicators of the inner hole coating, it is urgently necessary to design a preparation method for a small-size inner hole thermal spray coating performance characterization sample preparation device. Summary of the invention

[0004] To this end, an embodiment of the present invention provides a device for preparing a sample for characterizing the performance of an inner hole thermal spray coating and a sample preparation method to solve the problem in the prior art that the true performance index of the inner hole coating cannot be accurately obtained.

[0005] In order to achieve the above purpose, the embodiment of the present invention provides the following technical solutions:

[0006] A device for preparing samples for characterizing the performance of inner hole thermal spray coatings, comprising a metal structure provided with an inner hole surface to be sprayed, a sample rack corresponding to the inner hole provided on the outer side of the metal structure, a sample mounting hole coaxial with the inner hole and having a radius larger than the inner hole radius provided on the sample rack, at least one fixed card plate provided on the inner wall of the sample mounting hole, a detachable sample provided on the fixed card plate, and a detection surface of the sample circumscribing the inner hole of the metal structure.

[0007] Furthermore, a groove for embedding the sample is provided on the top surface of the fixing clamp, and the fixing clamp and the sample are connected by a pin or an interference connection.

[0008] Furthermore, a sliding bracket is provided at the bottom of the fixed card plate, a sliding block is provided at the bottom of the sliding bracket, and a sliding groove matching the sliding block is provided in the sample rack.

[0009] Furthermore, a pad is provided at the bottom of the fixed clamping plate.

[0010] Furthermore, the sample is a cylinder or a cuboid.

[0011] Furthermore, a demoulding hole is provided at the bottom of the fixed clamping plate.

[0012] A method for preparing a sample using an inner hole thermal spray coating performance characterization sample preparation device comprises the following steps:

[0013] Step S01, measuring the inner hole radius of the metal structure, and installing the inner hole of the metal structure on the three-jaw chuck;

[0014] Step S02, measuring the radius of the sample installation hole of the sample rack, matching a fixed cardboard of corresponding size according to the radius difference between the sample installation hole radius and the inner hole radius, matching a sample of corresponding size according to the fixed cardboard, and installing the sample and the fixed cardboard, and the fixed cardboard and the sample rack;

[0015] Step S03, installing the sample holder to the outside of the metal structure, ensuring that the sample installation hole is coaxial with the inner hole, and using a lever dial indicator to coaxially detect the radius runout value of the sample installation hole and the inner hole during the installation process until the radius runout values ​​of the two holes tend to be consistent;

[0016] Step S04: thermal spraying is performed on the inner hole and the sample mounting hole under the same working conditions, and the fixing clamp and the sample are removed after the spraying is completed.

[0017] Furthermore, in step S02, the size of the sample is first determined according to the radius difference, and if the thickness of the sample is less than the radius difference, a pad is added to make up for it.

[0018] Furthermore, in step S03, a tubular structure matching the inner hole is inserted into the inner hole, and then the assembled sample rack is sleeved on the tubular structure, and then the sample rack is fixed on the metal structure.

[0019] The embodiments of the present invention have the following advantages:

[0020] The device for preparing samples for characterizing the performance of the inner hole thermal spray coating described in the embodiment of the present invention is provided with a coaxial sample holder outside the inner hole, and the sample circumscribed with the inner hole is fixed in the sample holder. The sample and the inner hole coating are completed in the same batch and under the same process conditions, so as to ensure the consistency of the sample performance and the inner hole coating performance. The inner surface plane block discrete method is used to restore the actual spraying conditions to the greatest extent, and at the same time, a plane coating test that meets the actual test requirements can be prepared. The sample prepared by this method can meet the test requirements of most performance indicators and can accurately reflect the real performance of the small-sized inner hole coating, such as coating bonding strength test, bending performance test, dry friction and wear performance test, electrochemical performance test, etc. Moreover, the fixed card and the sample are detachably connected, and the isolation film is pre-set on the inner surface of the card before spraying, and other technical means are used to realize the reusable characteristics of the sample preparation device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0022] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0023] Figure 1 A product structure diagram of a device for preparing a sample for characterizing the performance of an inner hole thermal spray coating provided by an embodiment of the present invention;

[0024] Figure 2 A front view structural diagram of a device for preparing a sample for characterizing the performance of an inner hole thermal spray coating provided by an embodiment of the present invention;

[0025] Figure 3 for Figure 1 Exploded view of the fixed pallet;

[0026] Figure 4 A front structural diagram of a fixed clamping plate provided in another embodiment of the present invention;

[0027] Figure 5 A flow chart of a sample preparation method provided in an embodiment of the present invention.

[0028] In the figure:

[0029] 1. Metal structure; 2. Inner hole; 3. Sample rack; 4. Sample mounting hole; 5. Sample; 6. Fixed clamp; 7. Groove; 8. Pin; 9. Pin hole; 10. Thermal spray gun; 11. Sliding bracket; 12. Sliding block; 13. Pad. DETAILED DESCRIPTION

[0030] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] like Figure 1 As shown, a device for preparing samples for characterizing the performance of inner hole thermal spray coatings comprises a metal structure 1 provided with an inner hole 2 to be sprayed on the surface, the metal structure 1 being, for example, a small engine piston, an aircraft actuator cylinder, a landing gear cylinder, etc. A sample holder 3 is provided on the outer side of the metal structure 1. In this embodiment, the sample holder 3 is fixedly connected to the metal structure 1 by screws. A sample mounting hole 4 having a radius greater than the inner hole 2 is provided on the sample holder 3. The sample mounting hole is coaxial with the inner hole 2. At least one fixed card plate 6 is provided on the inner wall of the sample mounting hole 4. In this embodiment, the number of fixed card plates 6 is preferably greater than 6. A detachable sample 5 is provided on the fixed card plate 6. The detection surface of the sample 5 is a plane tangent to the inner hole 2. After the fixed card plate 6 is fixed to the sample holder 3, the sample holder 3 is fixed to the outside of the inner hole 2 and is coaxial with the inner hole 2. The thermal spraying gun 10 penetrates into the inner hole 2 for spraying, and the sample 5 is also sprayed at the same time, as shown in FIG. Figure 2 As shown, the distance from the center of sample 5 to the axis is the same as the radius of inner hole 2, so that sample 5 and inner hole 2 coating are completed in the same batch and under the same process conditions, ensuring the consistency of the performance of sample 5 and the performance of inner hole 2 coating.

[0032] like Figure 3As shown, the fixed card plate 6 is provided with a groove 7 for embedding the sample 5, and the fixed card plate 6 and the sample 5 are detachably connected, such as a pin 8 connection, an interference connection, a bolt connection, etc. Specifically, the fixed card plate 6 and the sample 5 are bolted, and the inner wall of the groove 7 on the fixed card plate 6 is provided with an internal thread, and the sample 5 is provided with an external thread meshing with the internal thread. Alternatively, the fixed card plate 6 and the sample 5 are connected by a pin 8, and pin holes 9 for connecting the groove 7 are provided on both sides of the fixed card plate 6, and the pin 8 is inserted into the sample 5 through the pin holes 9. A demolding hole is provided at the bottom of the fixed card plate 6, and the sample 5 can be ejected from the fixed card plate 6 by bolts after the spraying is completed for subsequent testing. An isolation film is set on the inner surface of the groove 7 before the spraying test begins, and the isolation film can be removed after the spraying is completed to achieve the reuse of the fixed card plate 6.

[0033] like Figure 4 As shown, the fixed card plate 6 is connected to the sample rack 3 by bolts, or a sliding bracket 11 is provided at the bottom of the fixed card plate 6, a slider 12 is provided at the bottom of the sliding bracket 11, and a slide groove matching the slider 12 is provided in the sample rack 3, so that it is convenient to debug the fixed card plate 6. After the sample rack 3 is installed on the metal structure 1, the fixed card plate 6 can be directly slid and removed without removing the sample rack 3.

[0034] After the sample holder 3 , the fixed card plate 6 and the sample 5 are made into standard sizes, a pad 13 is added to the bottom of the fixed card plate 6 to adjust the overall thickness of the fixed card plate 6 to meet the production requirements of the samples 5 with different sizes of inner holes 2 .

[0035] The sample 5 is a cylinder or a cuboid. For the cylindrical sample 5, a bonding strength test sample 5 is prepared and tested according to the standard ASTM CA633. For the cuboid sample 5, the corresponding sample 5 can be processed and tested according to the requirements of the bending, dry friction and wear and electrochemical performance test samples 5. In order to ensure the reliability of the experimental data, the test needs to be repeated 3 times, that is, at least 3 cylindrical samples 5 and 3 cuboid samples 5 are prepared.

[0036] like Figure 5 As shown, a method for preparing a sample using an inner hole thermal spray coating performance characterization sample preparation device comprises the following steps:

[0037] Step S01, measuring the inner hole radius of the metal structure 1, and installing the inner hole 2 of the metal structure 1 on the three-jaw chuck;

[0038] Step S02, measuring the radius of the sample mounting hole 4 of the sample rack 3, matching the fixed card plate 6 of the corresponding size according to the radius difference between the sample mounting hole radius and the inner hole radius, matching the sample 5 of the corresponding size according to the fixed card plate 6, and installing the sample 5 and the fixed card plate 6, and the fixed card plate 6 and the sample rack 3. If the fixed card plate 6 and the sample 5 are both standard parts, the size of the sample 5 is first determined according to the radius difference, and if the thickness of the sample 5 is less than the radius difference, a pad 13 is added to make up for it.

[0039] Step S03, install the sample holder 3 to the outside of the metal structure 1 to ensure that the sample installation hole 4 is coaxial with the inner hole 2. During the installation process, use a lever dial indicator to coaxially detect the radius runout value of the sample installation hole 4 and the inner hole 2 until the radius runout values ​​of the two holes tend to be consistent.

[0040] Before the sample holder 3 is installed on the outside of the metal structure 1, a tubular structure that matches the inner hole 2 can be inserted into the inner hole 2, and then the assembled sample holder 3 can be sleeved on the tubular structure. When the sample holder 3 is fixed on the metal structure 1, the sample mounting hole 4 can be coaxially aligned with the inner hole 2 through the tubular structure. The sample holder 3 is first pre-aligned with the metal structure 1, and then fine-tuned through the lever dial indicator, which can improve the efficiency and accuracy of the alignment of the two.

[0041] Step S04, under the same working conditions, the inner hole 2 and the sample mounting hole 4 are both thermally sprayed. The thermal spraying gun 10 first penetrates into the inner hole 2 for spraying. After the inner hole 2 is sprayed, the thermal spraying gun 10 only shrinks axially and comes into the sample holder 3, and then sprays the sample 5 in the hole. Since the distance from the top surface of the sample 5 to the axis is the same as the distance from the hole wall of the inner hole 2 to the axis, the coating of the sample 5 and the inner hole 2 are completed in the same batch and under the same process conditions, ensuring the consistency of the performance of the sample 5 and the coating performance of the inner hole 2. After the spraying is completed, the sample holder 3 is first removed, and then the fixed clamping plate 6 is removed from the sample holder 3, and finally the sample 5 is removed from the fixed clamping plate 6.

[0042] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A device for preparing samples for characterizing the performance of inner hole thermal spray coatings, comprising a metal structure provided with an inner hole surface to be sprayed, characterized in that: A sample rack corresponding to the inner hole is provided on the outer side of the metal structure, and a sample mounting hole coaxial with the inner hole and having a radius larger than the radius of the inner hole is provided on the sample rack. At least one fixed card plate is provided on the inner wall of the sample mounting hole, and a detachable sample is provided on the fixed card plate, and the detection surface of the sample is circumscribed to the inner hole of the metal structure.

2. The device for preparing samples for characterizing the performance of inner hole thermal spray coatings according to claim 1 is characterized in that: A groove for embedding the sample is provided on the top surface of the fixed clamping plate, and the fixed clamping plate and the sample are connected by pins or interference connection.

3. The device for preparing samples for characterizing the performance of inner hole thermal spray coatings according to claim 2, characterized in that: A sliding bracket is provided at the bottom of the fixed clamping plate, a sliding block is provided at the bottom of the sliding bracket, and a sliding groove matched with the sliding block is provided in the sample rack.

4. The device for preparing samples for characterizing the performance of inner hole thermal spray coatings according to claim 2, characterized in that: A pad is provided at the bottom of the fixed clamping plate.

5. The device for preparing samples for characterizing the performance of inner hole thermal spray coatings according to claim 1, characterized in that: The sample is a cylinder or a cuboid.

6. The device for preparing samples for characterizing the performance of inner hole thermal spray coatings according to claim 1, characterized in that: A mold unloading hole is provided at the bottom of the fixed clamping plate.

7. A method for preparing a sample using the inner hole thermal spray coating performance characterization sample preparation device according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step S01, measuring the inner hole radius of the metal structure, and installing the inner hole of the metal structure on the three-jaw chuck; Step S02, measuring the radius of the sample installation hole of the sample rack, matching a fixed cardboard of corresponding size according to the radius difference between the sample installation hole radius and the inner hole radius, matching a sample of corresponding size according to the fixed cardboard, and installing the sample and the fixed cardboard, and the fixed cardboard and the sample rack; Step S03, installing the sample holder to the outside of the metal structure, ensuring that the sample installation hole is coaxial with the inner hole, and using a lever dial indicator to coaxially detect the radius runout value of the sample installation hole and the inner hole during the installation process until the radius runout values ​​of the two holes tend to be consistent; Step S04: thermal spraying is performed on the inner hole and the sample mounting hole under the same working conditions, and the fixing clamp and the sample are removed after the spraying is completed.

8. The sample preparation method according to claim 7, characterized in that: In step S02, the size of the sample is first determined according to the radius difference, and if the thickness of the sample is less than the radius difference, a pad is added to make up for it.

9. The sample preparation method according to claim 7, characterized in that: In the step S03, a tubular structure matching the inner hole is inserted into the inner hole, and then the assembled sample rack is sleeved on the tubular structure, and then the sample rack is fixed on the metal structure.

Images