An encapsulation device and method for tubular specimens in fretting corrosion research

Abstract

The present invention discloses a packaging device for tubular specimens in fretting corrosion research, which includes a plastic core component, a soft mold component, and a clamping component coaxially sleeved from the inside to the outside in the radial direction in sequence; the plastic core component includes an upper plastic column and a lower plastic column connected up and down, and has a draft angle; the overall soft mold component is a sleeve structure with a closed lower end, an open upper end, and an annular gap space, and the annular gap space is larger than the contour of the tubular specimen for pouring; the inner side of the inner wall of the sleeve structure is in close contact with the outer side of the plastic core component, and the inner side of the outer wall of the sleeve structure conforms to the outer side shape of the pre-packaged tubular specimen; the clamping component includes an upper clamp and a lower clamp respectively tightly sleeved on the upper and lower parts of the soft mold component. The packaging device has a simple structure, flexible design, and low cost; epoxy resin, nail polish, and photocuring resin are used for staged packaging, and the packaging method is easy to operate, avoiding problems such as edge crevice corrosion and peeling off of the sealing layer.

Description

Technical Field

[0001] The present invention relates to the technical field of fretting corrosion experimental research, and more specifically, to a packaging device and method for tubular specimens in fretting corrosion research. Background Art

[0002] Fretting refers to the relative movement with extremely small amplitude (the relative movement with a displacement amplitude generally in the micron order is called fretting) that occurs on nominally stationary contact surfaces under the action of alternating loads, and is commonly present in closely fitting components in fields such as the machinery industry, the power industry, aerospace vehicles, nuclear reactors, transportation tools, and human implants. Fretting can cause frictional wear on the contact surfaces of components, and also accelerate the initiation and propagation of fatigue cracks, leading to material damage and failure. The fretting damage mode in a corrosive medium is called fretting corrosion. Fretting corrosion is the result of the combined action of mechanical, chemical, and electrochemical factors, and there is a synergistic effect between wear and corrosion, which often accelerates the material damage and failure process. Therefore, it is of extremely important significance to carry out relevant experimental research on fretting corrosion phenomena and the synergistic effect between wear and corrosion.

[0003] Corrosion electrochemistry testing technology is applied to fretting corrosion research to analyze the corrosion tendency and corrosion rate of metals. Before testing using a three-electrode system, the working electrode (metal specimen) should be insulated and packaged to expose a determined surface area for accurately calculating the current density. The packaging operation should avoid generating gaps, otherwise it will seriously affect the experimental results. The packaging of tubular specimens needs to consider both the inner and outer surfaces, and also the clamping and fixing problems after packaging. Under multiple restrictions, the difficulty is extremely high. The current packaging methods mainly rely on coatings, epoxy resins, heat shrinkable tubes, etc. to cover the non-working surfaces, and it is difficult to achieve the packaging of tubular specimens.

[0004] Therefore, there is an urgent need to design and develop a packaging device suitable for tubular specimens and a supporting packaging method to meet the requirements of fretting corrosion experiments. Summary of the Invention

[0005] Aiming at the above technical difficulties, the present invention provides a packaging device and method for tubular specimens in fretting corrosion research.

[0006] To solve the above technical problems, the present invention provides a packaging device for tubular specimens in fretting corrosion research, which includes a plastic core component, a soft mold component, and a clamping component coaxially sleeved from the inside to the outside in the radial direction; the plastic core component includes an upper plastic column and a lower plastic column connected up and down, and draft angles of the core are respectively provided at the top of the upper plastic column and the bottom of the lower plastic column; the overall soft mold component is a sleeve structure with a closed bottom, an open top, and an annular gap space, and the annular gap space is larger than the contour of the pre-packaged tubular specimen for pouring during the packaging process; the inner side of the inner wall of the sleeve structure is in close contact with the outer side of the plastic core component, and the inner side of the outer wall of the sleeve structure fits the outer side shape of the pre-packaged tubular specimen; the clamping component includes an upper clamp and a lower clamp respectively tightly sleeved on the upper and lower parts of the soft mold component.

[0007] Furthermore, for the packaging device of the tubular specimen of the present invention, where:

[0008] The upper plastic column and the lower plastic column are respectively composed of multiple sections connected in the axial direction.

[0009] A base is provided at the bottom of the lower plastic column, and the base supports the soft mold component.

[0010] The material of the soft mold component is silicone rubber.

[0011] The axial positions of the upper clamp and the lower clamp are determined according to the top and bottom positions of the pre-packaged tubular specimen. The upper clamp and the lower clamp apply forces to both the top and bottom of the pre-packaged tubular specimen.

[0012] For the convenience of the process, the soft mold component in the present invention is a split structure. A base is provided at the bottom of the lower plastic column, and the base is provided with a first step surface and a second step surface; the soft mold component includes an inner sleeve, an outer sleeve, and a washer; the inner sleeve is in close contact with the surface of the plastic core component; the washer is sleeved at the bottom of the inner sleeve and located on the first step surface, and the outer sleeve is placed on the washer; the radial contour of the first step surface is consistent with the outer shape of the washer, and the outer diameter of the outer sleeve is larger than the outer diameter of the washer; the axial dimension of the outer sleeve is larger than the axial dimension of the tubular specimen. Both the inner sleeve and the outer sleeve are silicone rubber tubes, and the washer is a rubber washer.

[0013] Meanwhile, the present invention also provides a method for packaging a tubular specimen using the above packaging device, and the steps are as follows:

[0014] S1. Axially connect the upper plastic column and the lower plastic column with bolts to form a plastic core component; sleeve the soft mold component on the outside of the plastic core component, and pre-install the lower clamp;

[0015] S2. Insert the pre - encapsulated tubular specimen after cleaning into the annular gap space of the soft mold assembly. Clamp the lower end of the soft mold assembly with the tubular specimen inside into the lower clamp, and clamp the upper clamp tightly on the upper part outside the soft mold assembly. At this time, the upper clamp and the lower clamp apply forces to the upper and lower ends of the tubular specimen.

[0016] S3. After standing the prepared epoxy resin to defoam, pour it into the annular gap space of the soft mold assembly. Wait for it to cure after filling.

[0017] S4. After the epoxy resin cures, disassemble the upper clamp, bolts and upper shaping column from above in sequence, disassemble the lower shaping column and lower clamp from below in sequence, and finally remove the soft mold assembly to obtain the preliminarily encapsulated tubular specimen.

[0018] S5. Weld wires on the outer surface of the preliminarily encapsulated tubular specimen, and the position of the solder joints is on the non - working surface of the tubular specimen.

[0019] S6. Take a silicone sheet with an area equal to the working surface area of the tubular specimen, cover and press it tightly on the working surface of the tubular specimen. Apply nail polish on the non - working surface around the silicone sheet and then promptly remove the covered silicone sheet. Wait for the nail polish to fully cure.

[0020] S7. After the nail polish cures, use photo - curable resin to cover the solder joints and fix the wires at the same time, and then irradiate with an ultraviolet lamp. After the photo - fixing resin cures, the encapsulation of the tubular specimen is completed.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] The encapsulation device proposed by the present invention is mainly composed of a shaping core assembly, a soft mold assembly and a clamping assembly, which solves the problem of encapsulating tubular specimens. The combined use of the shaping core assembly and the inner sleeve ensures the outer dimensions of the specimen at the clamping part after encapsulation, and has a simple structure, flexible design and low cost. The combined use of the outer sleeve and the clamping assembly suspends the tubular specimen in the epoxy resin, and encapsulates the inside and both end surfaces at one time.

[0023] Using the encapsulation device designed by the present invention to realize the encapsulation of tubular specimens, in the encapsulation process, epoxy resin, nail polish and photo - curable resin are used for staged encapsulation, which not only ensures the strength and hardness of the clamping position after encapsulation, but also solves the problem of crevice corrosion at the edge of the working surface, and also avoids the loosening and falling off of the encapsulation layer at the solder joint position caused by wire vibration. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of the encapsulation device for the tubular specimen described in the present invention.

[0025] Figure 2 Schematic diagram of a tubular specimen after preliminary encapsulation;

[0026] Figure 3 Schematic diagram of a tubular specimen after complete encapsulation;

[0027] Figure 4 is Figure 3 The sectional view of the cutting position shown by A - A in

[0028] In the figure:

[0029] 101 - Upper shaping column, 102 - Lower shaping column, 103 - Bolt

[0030] 104 - First step surface, 105 - Second step surface, 201 - Inner sleeve

[0031] 202 - Outer sleeve, 203 - Washer, 301 - Upper clamp

[0032] 302 - Lower clamp, 4 - Tubular specimen, 5 - Epoxy resin

[0033] 6 - Conducting wire, 7 - Working surface of the tubular specimen, 8 - Nail polish

[0034] 9 - Solder joint, 10 - Photo - curable resin Specific embodiments

[0035] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the following embodiments are by no means any limitation to the present invention.

[0036] As Figure 1 shown, the present invention provides an encapsulation device for a tubular specimen in fretting corrosion research, which is characterized in that it includes a shaping core component, a soft mold component, and a clamping component coaxially sleeved in sequence from inside to outside in the radial direction.

[0037] The shaping core component includes an upper shaping column 101 and a lower shaping column 102 connected up and down. The top of the upper shaping column 101 and the bottom of the lower shaping column 102 are respectively provided with a draft angle of the core. The upper shaping column 101 and the lower shaping column 102 can be respectively composed of multiple sections connected in the axial direction, and their connection form can adopt bolt 103 connection, but is not limited to this connection structure. The bottom of the shaping core component is provided with a base for supporting the soft mold component.

[0038] The overall soft mold assembly is a sleeve structure with a closed bottom, an open top, and an annular gap space. The annular gap space is larger than the contour of the pre-encapsulated tubular specimen 4 for pouring during the encapsulation process. The inner side of the inner wall of the sleeve structure is in close contact with the outer side of the shaping core assembly, and the inner side of the outer wall of the sleeve structure conforms to the outer side shape of the pre-encapsulated tubular specimen 4. Whether the soft mold assembly is an integral or split structure is not limited in the present invention.

[0039] For simplicity of the process, ease of manufacturing, assembly, and disassembly, as Figure 1 shown, in this embodiment, a split-type soft mold assembly is provided. Corresponding to this split-type soft mold assembly, a base is provided at the bottom of the lower shaping column 102 of the shaping core assembly. The base is provided with a first step surface 104 and a second step surface 105. The soft mold assembly includes an inner sleeve 201, an outer sleeve 202, and a gasket 203. The inner sleeve 201 is in close contact with the surface of the shaping core assembly. The gasket 203 is sleeved on the bottom of the inner sleeve 201 and is located on the first step surface 104, and the outer sleeve 202 is placed on the gasket 203. The radial contour of the first step surface 104 is consistent with the outer shape of the gasket 203, and the outer diameter of the outer sleeve 202 is larger than the outer diameter of the gasket 203. The axial dimension of the outer sleeve 202 is larger than the axial dimension of the tubular specimen 4. In this embodiment, both the inner sleeve 201 and the outer sleeve 202 are silicone tubes, and the gasket 203 is a rubber gasket. In this embodiment, the clamping assembly includes an upper clamp 301 and a lower clamp 302 that are respectively tightly sleeved on the upper and lower parts of the soft mold assembly. The axial positions of the upper clamp 301 and the lower clamp 302 are determined according to the top and bottom positions of the pre-encapsulated tubular specimen 4, and the upper clamp 301 and the lower clamp 302 apply forces to both the top and bottom of the pre-encapsulated tubular specimen 4.

[0040] In the present invention, in the shaping core assembly, the shapes of the upper shaping column 101 and the lower shaping column 102 are not limited to cylindrical or conical shapes, and can be designed and manufactured separately according to the clamping method and the shape of the fixture. The shaping core assembly can be composed of any number of parts, and the connection method between the parts is not limited to bolt connection.

[0041] The soft mold assembly can be composed of any number of parts, and each part forms an annular gap space with a closed bottom and an open top for pouring and encapsulation by pressing. The soft mold assembly can be composed of standard parts such as silicone tubes and rubber gaskets, or can be customized according to requirements.

[0042] The process of encapsulating a tubular specimen using the encapsulation device described in the above embodiment is as follows:

[0043] First, draft angles of the core are machined at the upper end of the upper shaping column 101 and the lower end of the lower shaping column 102 respectively. A base is provided at the bottom end of the lower shaping column 102, and a first step surface 104 and a second step surface 105 are provided on the base to support the soft mold assembly in the encapsulation device. A bolt through-hole is machined in the upper shaping column 101, and a threaded hole is provided in the upper part of the lower shaping column 102. The upper shaping column 101 and the lower shaping column 102 are axially connected into a shaping core assembly by a bolt 103. Both the inner sleeve 201 and the outer sleeve 202 in the soft mold assembly are made of silicone tubes with appropriate inner and outer diameters. The inner sleeve 201 is sleeved outside the shaping core assembly, and then a rubber washer 203 is put on, so that the washer 203 lies flat on the first step surface 104. The outer sleeve 202 is placed on the washer 302, and the lower clamp 302 is pre-installed. The lower clamp 302 lies flat on the second step surface 105. In the present invention, the inner diameter of the inner sleeve 201 is slightly smaller than the outer diameter of the shaping core assembly. With the elasticity of the material of the inner sleeve 201, the inner sleeve 201 can be tightly sleeved outside the shaping core assembly conformingly. In order to make the outer sleeve 202 stand stably, the wall thickness of the outer sleeve 202 is thicker than that of the inner sleeve 201. At the same time, in order to fix the pre-encapsulated tubular specimen 4 in the soft mold assembly, the inner diameter of the outer sleeve 202 is slightly smaller than the outer diameter of the tubular specimen 4.

[0044] S2. The pre-encapsulated tubular specimen 4 after cleaning is inserted into the annular gap between the outer sleeve 202 and the inner sleeve 201. The tubular specimen 4 is suspended and clamped by the elasticity of the outer sleeve 202. The lower end of the outer sleeve 202 is clamped into the lower clamp 302, and the upper clamp 301 is clamped tightly on the upper part of the outer sleeve 202. The height position of the upper clamp 301 is basically at the position of the upper end face of the tubular specimen 4. At this time, the upper clamp 301 and the lower clamp 302 tightly clamp the upper and lower ends of the outer sleeve 202 and the tubular specimen 4 respectively.

[0045] S3. After the prepared epoxy resin is left standing for defoaming, it is poured into the annular gap space of the soft mold assembly from the upper opening between the outer sleeve 202 and the inner sleeve 201. After filling, wait for it to cure.

[0046] S4. After the epoxy resin is cured, the upper clamp 301, the bolt 103 and the upper shaping column 101 are disassembled in sequence from above, the lower shaping column 102 and the lower clamp 302 are disassembled in sequence from below, and finally the outer sleeve 202 and the inner sleeve 201 are removed to obtain the preliminarily encapsulated tubular specimen 4, as Figure 2 shown. Since draft angles of the core are provided on both the upper shaping column 101 and the lower shaping column 102 in the present invention, and the inner sleeve 201 has elasticity, the disassembly is very convenient and fast.

[0047] S5. Weld a wire 6 to the outer surface of the tubular specimen 4 after preliminary encapsulation. The position of the solder joint 9 is on the non-working surface of the tubular specimen, such as Figure 3 and Figure 4 shown.

[0048] S6. Take a silica gel sheet with the same area as the working surface 7 of the tubular specimen, cover and press it tightly on the working surface 7 of the tubular specimen, apply nail polish 8 on the non-working surface around the silica gel sheet, then promptly remove the covered silica gel sheet and wait for the nail polish 8 to fully cure, such as Figure 3 and Figure 4 shown.

[0049] S7. After the nail polish cures, use a photo-curing resin 10 to cover the solder joint 9 and fix the wire 6 at the same time, then irradiate it with an ultraviolet lamp. After the photo-curing resin 10 cures, the encapsulation of the tubular specimen is completed, such as Figure 3 and Figure 4 shown.

[0050] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "bottom", "top", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating and implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention.

[0051] Although the present invention has been described above in conjunction with the drawings, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative rather than restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many variations without departing from the purpose of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. An encapsulation device for tubular specimens in fretting corrosion research, characterized in that, It includes a shaping core component, a soft mold component, and a clamping component that are coaxially sleeved from the inside to the outside in the radial direction; The shaping core component includes an upper shaping column (101) and a lower shaping column (102) that are connected up and down. Draft angles of the core are respectively provided at the top of the upper shaping column (101) and the bottom of the lower shaping column (102); A base is provided at the bottom of the lower shaping column (102), and the base is provided with a first step surface (104) and a second step surface (105); The overall soft mold component is a sleeve structure with a closed bottom, an open top, and an annular gap space. The annular gap space is larger than the contour of the pre-encapsulated tubular specimen (4) for pouring during the encapsulation process; The inner side of the inner wall of the sleeve structure is in close contact with the outer side of the shaping core component, and the inner side of the outer wall of the sleeve structure fits the outer side shape of the pre-encapsulated tubular specimen (4); The soft mold component is a split structure; The soft mold component includes an inner sleeve (201), an outer sleeve (202), and a gasket (203); The inner sleeve (201) is in close contact with the surface of the shaping core component; The gasket (203) is sleeved at the bottom of the inner sleeve (201) and is located on the first step surface (104), and the outer sleeve (202) is placed on the gasket (203); The radial contour of the first step surface (104) is the same as the outer shape of the gasket (203), and the outer diameter of the outer sleeve (202) is larger than the outer diameter of the gasket (203); The axial dimension of the outer sleeve (202) is larger than the axial dimension of the tubular specimen (4); The clamping component includes an upper clamp (301) and a lower clamp (302) that are respectively tightly sleeved on the upper and lower parts of the soft mold component. The axial positions of the upper clamp (301) and the lower clamp (302) are determined according to the top and bottom positions of the pre-encapsulated tubular specimen (4); The upper clamp (301) and the lower clamp (302) apply forces to both the top and bottom of the pre-encapsulated tubular specimen (4).

2. The encapsulation device for tubular specimens according to claim 1, characterized in that, The upper shaping column (101) and the lower shaping column (102) are respectively composed of multiple sections connected axially.

3. The encapsulation device for tubular specimens according to claim 1, characterized in that, A base is provided at the bottom of the lower shaping column (102), and the base supports the soft mold component.

4. The encapsulation device for tubular specimens according to claim 1, characterized in that, The material of the soft mold component is silicone.

5. The encapsulation device for tubular specimens according to claim 1, characterized in that, Both the inner sleeve (201) and the outer sleeve (202) are silicone tubes, and the gasket (203) is a rubber gasket.

6. A packaging method for tubular specimens in fretting corrosion research, characterized in that, Using the encapsulation device as described in any one of claims 1 to 5, and including the following steps: S1. Use bolts (103) to axially connect the upper shaping column (101) and the lower shaping column (102) to form a shaping core component; Sleeve the soft mold component on the outside of the shaping core component, and pre-install the lower clamp (302); S2. Insert the pre - encapsulated tubular specimen (4) after cleaning into the annular clearance space of the soft mold assembly. Clamp the lower end of the soft mold assembly with the tubular specimen (4) inside into the lower clamp (302), and clamp the upper clamp (301) tightly on the upper part outside the soft mold assembly. At this time, the upper clamp (301) and the lower clamp (302) apply forces to the upper and lower ends of the tubular specimen (4). S3. After allowing the prepared epoxy resin to stand for defoaming, pour it into the annular clearance space of the soft mold assembly. Wait for it to cure after filling. S4. After the epoxy resin cures, remove the upper clamp (301), bolt (103) and upper shaping column (101) in sequence from above, remove the lower shaping column (102) and lower clamp (302) in sequence from below, and finally remove the soft mold assembly to obtain the preliminarily encapsulated tubular specimen (4). S5. Weld a wire (6) on the outer surface of the preliminarily encapsulated tubular specimen (4). The position of the solder joint (9) is on the non - working surface of the tubular specimen. S6. Take a silicone sheet with an area equal to the working surface (7) area of the tubular specimen, cover and press it tightly on the working surface (7) of the tubular specimen. Apply nail polish (8) on the non - working surface around the silicone sheet and then promptly remove the covered silicone sheet. Wait for the nail polish (8) to cure completely. S7. After the nail polish cures, use a photo - curing resin (10) to cover the solder joint (9) and fix the wire (6) at the same time. Then irradiate it with an ultraviolet lamp. After the photo - fixing resin (10) cures, the encapsulation of the tubular specimen is completed.

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