Reusable electrochemical electrode bracket capable of quickly replacing sample

Abstract

The invention belongs to the technical field of metal material corrosion tests, and particularly relates to a reusable electrochemical electrode bracket capable of quickly replacing a sample. Comprising a polytetrafluoroethylene shell, a gold-plated copper vibrating needle and an L-shaped electrode lead, the teflon shell is divided into an external thread fixed part and an internal thread movable part, the external thread fixed part is a cylindrical teflon block, the right end is provided with a copper gold-plated vibrating needle mounting groove, the outer surface of the right end is provided with external threads, and the left end is provided with a lead groove; an L-shaped electrode lead connected with the gold-plated copper vibrating needle penetrates through the polytetrafluoroethylene block external thread fixing piece and is fixed in the lead groove in an L shape; the internal thread movable piece is a cylindrical polytetrafluoroethylene block, a rectangular groove is formed in the right end, and internal threads are arranged on the inner surface of the left end and connected with the external threads of the external thread fixed piece. The device is suitable for corrosion electrochemical measurement in various normal temperature environments, and has the advantages of reusability, quick sample replacement, high test efficiency and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal material corrosion test, and particularly relates to a reusable electrochemical electrode bracket capable of quickly replacing samples. Background Technique

[0002] Electrochemical test and measurement technology is an important technology, which is particularly crucial for characterizing various parameters such as the corrosion performance and electrochemical performance of materials. For example, according to relevant national standards, for stainless steel used in surgical implants, the pitting potential is required to be higher than 1.2V. SCE This quantitative index puts forward higher requirements for each link in electrochemical test and measurement.

[0003] In electrochemical test and measurement technology, in order to measure the steady-state polarization curve of a single electrode, it is necessary to measure the electrode potential and the current passing through the electrode simultaneously. Measuring the electrode potential and the current flowing through the electrode usually adopts a three-electrode system. The research electrode (also called the working electrode or test electrode) in the three-electrode system is an essential component in the electrochemical research method. The research electrode most commonly used in electrochemical measurement is a solid metal electrode, which requires the electrode to have good reproducibility characteristics. Therefore, strict requirements are put forward for the preparation and processing of solid metal electrodes, including the composition of the electrode material, surface state, etc. For example, a high surface finish is generally required to minimize the difference between the apparent area and the true area. For filamentous, sheet-like, cylindrical, and square components applied in actual engineering, the electrode should have a definite and easily calculable apparent area when preparing the electrode, and the non-working surface must be insulated.

[0004] In "Guidelines for Potentiostatic and Potentiodynamic Polarization Measurements in Electrochemical Testing Methods for Metals and Alloys"

[0005] (GB / T 24196—2009), "Method for Measuring Pitting Potential of Stainless Steel" (GB / T 17899—1999),

[0006] "Corrosion of Metals and Alloys - Determination of Critical Pitting Temperature under Potentiostatic Control" (GB / T 32550—2016), "Electrochemical Test Method for Crevice Corrosion of Stainless Steel" (GB / T 13671-1992),

[0007] In national and important industry recommended technical standards such as "Pitting Potential of Stainless Steel Products for Surgical Implants" (YY / T 1074—2002) and "Open Circuit Potential Measurement Method for Evaluating Long-Term Corrosion Behavior of Metallic Implant Materials and Medical Devices in Surgical Implants" (YY / T 1552—2017), most standards only put forward principle requirements for the preparation and encapsulation of working electrodes. Only a small number of standards put forward relatively specific requirements for the coating and sealing of specimens in the preparation of working electrodes, including: welding wires to specimens by brazing (such as soldering) or spot welding; cleaning the specimen surface with alcohol and acetone, drying it, and then coating or embedding it with insulating sealant (704 glue, epoxy resin, vinyl resin) so that the finally exposed test surface is about 1 cm 2 , and there shall be no gaps or pinholes in the insulating coating surface. This requires soldering or spot welding tools and auxiliary test equipment such as plastic cups for resin compounding during the specimen encapsulation process.

[0008] When welding wires to specimens by brazing (such as soldering) or spot welding, it is required to weld a wire about 20 - 30 cm long to the surface or side of each specimen with a soldering tool, and it is difficult to disassemble after the welding connection between the specimen and the wire is completed. Secondly, when coating or embedding the non-exposed surface of the specimen with 704 glue or epoxy resin, since the amount of 704 glue used is large, the time from coating completion to complete drying is long, up to 24 h or even longer. The embedding process of specimens with epoxy resin is relatively complex, and the curing time is as long as 2 - 3 d, resulting in a relatively low overall test efficiency for corrosion electrochemistry tests. Moreover, after the test is completed, since most are one-time sample preparation and encapsulation, a large number of solid specimen wastes are formed, including epoxy resin, PTFE sleeves, etc. These composite solid wastes are difficult to recycle and treat. Therefore, in the practice of working electrode preparation in some industrial laboratories, due to the increasingly high current safety and environmental protection requirements, more complete safety and environmental protection supporting equipment and management procedure documents are required, resulting in a long test preparation link, which greatly affects the test efficiency and the output efficiency of research results. Moreover, with the development and progress of micro-component processing technology and the refined division of labor in professional laboratories, it is imperative to reduce the structural configuration of "all-inclusive" laboratories. Take the specific problems in the preparation of working electrodes in electrochemical testing and experiments as an example. Reducing the number of soldering operations and the amount of waste after working electrode preparation and testing is an urgent problem to be solved.

[0009] In the Chinese Patent Application Publication Specification, CN107167501A discloses that the working electrode is a metal sample connecting wire, which is then encapsulated with epoxy resin. The disadvantages of using such a working electrode are as follows: Whenever a corrosion test is completed, it is often necessary to observe the corrosion morphology of the sample with a scanning electron microscope (SEM) or study the composition of the corrosion products with energy dispersive spectroscopy (EDS). This requires disassembling the electrode. The electrode disassembly operation in the prior art is very cumbersome, resulting in low test efficiency. Moreover, during the disassembly process, it is extremely easy to change the state of the metal surface after the reaction, which will affect the subsequent test results.

[0010] In the Chinese Patent Application Publication Specification, CN110082408A discloses a detachable working electrode, which includes a bottom shell, a top cover, a spring, and a wire. The disadvantages of using such a working electrode and its assembly process are as follows: When the other end of the spring abuts against the metal sample, due to the lack of a detailed and feasible structural design, there is a risk of small contact area and poor electrical contact; the processing requirements for the polytetrafluoroethylene bottom shell and the cylindrical metal sample are high, and there will be circumferential gaps during the clamping process, resulting in problems such as poor sealing and crevice corrosion. Summary of the Invention

[0011] The purpose of the present invention is to provide a reusable electrochemical electrode bracket with a sample that can be quickly replaced to overcome the above problems existing in the prior art.

[0012] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0013] A reusable electrochemical electrode bracket with a sample that can be quickly replaced, including a polytetrafluoroethylene outer shell, a copper-gold-plated spring pin, and an L-shaped electrode lead; the polytetrafluoroethylene outer shell is divided into an external thread fixing part and an internal thread movable part. The external thread fixing part is a cylindrical polytetrafluoroethylene block, with a copper-gold-plated spring pin installation groove opened at the right end, an external thread on the outer surface of the right end, a lead groove opened at the left end, and the L-shaped electrode lead connected to the copper-gold-plated spring pin passes through the external thread fixing part of the polytetrafluoroethylene block and is fixed in the lead groove in an L shape; the internal thread movable part is a cylindrical polytetrafluoroethylene block, with a rectangular groove opened at the right end and an internal thread on the inner surface of the left end, and is connected to the external thread of the external thread fixing part by a thread.

[0014] Solder or spot-weld the L-shaped electrode lead to the end face of the copper-gold-plated spring pin fixing boss, then pass the L-shaped electrode lead through the external thread fixing part of the polytetrafluoroethylene outer shell and bend the L-shaped electrode lead into an L shape and embed it in the lead groove, ensuring that the end face of the copper-gold-plated spring pin fixing boss is flush with the end face of the external thread fixing part of the polytetrafluoroethylene outer shell. The gap between the L-shaped electrode lead and the polytetrafluoroethylene outer shell is filled and sealed with glue. A square test piece is embedded in the rectangular groove of the internal thread movable part of the polytetrafluoroethylene outer shell and filled and sealed with sealant. Then, the two parts of the polytetrafluoroethylene outer shell are assembled by threads, and a fluorine sealing rubber ring is installed at the thread connection for sealing.

[0015] Solder or spot-weld the L-shaped electrode lead with a length of 20 - 30 cm to the end face of the copper-gilded spring pin fixing boss; pass the L-shaped electrode lead through the external thread fixing part of the polytetrafluoroethylene housing and bend the L-shaped electrode lead into an L shape, ensuring that the end face of the copper-gilded spring pin fixing boss is flush with the end face of the external thread fixing part of the polytetrafluoroethylene housing, and fill the gap between the L-shaped electrode lead and the polytetrafluoroethylene housing with glue for caulking and sealing; embed the cut and surface-pre-ground square test piece into the rectangular groove of the internal thread movable part of the polytetrafluoroethylene housing, ensuring that the surface of the test piece is flush with the end face of the internal thread movable part of the polytetrafluoroethylene housing, fill the edge gap of the test piece with 704 glue or curing quick-drying glue, and dry for standby; if necessary, gently pre-grind the electrode head of the dried embedded test piece on a pre-grinder to ensure that a small amount of cured glue at the edge of the test piece is removed, place the fluorine sealing rubber ring at the root of the external thread fixing part of the polytetrafluoroethylene housing, and screw the internal thread movable part of the polytetrafluoroethylene housing onto the external thread fixing part of the polytetrafluoroethylene housing to form a complete electrode for use; after the electrochemical test is completed, unscrew and remove the internal thread movable part of the polytetrafluoroethylene housing, eject the square test piece, and remove the small amount of cured glue residue.

[0016] The L-shaped electrode lead is 1.5 mm 2 single-core copper wire.

[0017] The material of the copper-gilded spring pin is beryllium copper gilded 3U at the head, with a current of 3 A and a stroke of 0.45 mm.

[0018] The external thread fixing part is a cylindrical polytetrafluoroethylene block, with a copper-gilded spring pin installation groove with a diameter of 4.4 mm and a depth of 3.3 mm opened at the right end.

[0019] The internal thread movable part is a cylindrical polytetrafluoroethylene block, with a 10×10 mm rectangular groove opened at the right end.

[0020] The beneficial effects achieved by the present invention are:

[0021] The present invention is applicable to the corrosion electrochemistry measurement in various normal temperature environments. The electrochemistry working electrode support assembly and its assembly process that can be reused and quickly replace the specimen based on the refined design and precision machining technology have the advantages of being reusable, quickly replacing the specimen, and high test efficiency.

[0022] Reduce the number of soldering times. From the original need to perform soldering or spot-welding once for each specimen and the wire, it is reduced to only 3 - 5 times of soldering the wire and the copper-gilded spring pin for each series of tests. After processing the polytetrafluoroethylene housing kit with the set dimensions, only process the square specimens that meet the size requirements. During the test, only manually rotate and unscrew the movable part of the polytetrafluoroethylene housing kit, take out the square metal specimen, after replacing the new specimen, gently apply 704 glue to the edge of the exposed part of the specimen, and the curing time is 15 - 30 min to complete the replacement of the new specimen.

[0023] By implementing an electrochemical working electrode bracket with reusable and quickly replaceable specimens, the preparation time of the working electrode is shortened from the original 2 - 3 days to about 0.3 days, significantly reducing the amount of solid waste in specimen packaging and the difficulty of waste treatment, which is conducive to saving resources and sustainable environmental protection. Brief Description of the Drawings

[0024] Figure 1 It is a schematic diagram of a reusable electrochemical electrode bracket with quickly replaceable specimens;

[0025] In the figure: 1. L-shaped electrode lead; 2. Polytetrafluoroethylene outer shell; 3. Gold-plated copper spring pin; 4. Fluorine sealing rubber ring; 5. Test piece. Detailed Implementation Modes

[0026] The present invention will be described in detail below in conjunction with the drawings and specific embodiments.

[0027] The electrochemical electrode bracket includes: polytetrafluoroethylene outer shell 2, fluorine sealing rubber ring 4, gold-plated copper spring pin 3, L-shaped electrode lead 1; the polytetrafluoroethylene outer shell 2 is divided into two parts, an external thread fixing part and an internal thread movable part. The external thread fixing part is a cylindrical polytetrafluoroethylene block, with a gold-plated copper spring pin installation groove with a diameter of 4.4 mm and a depth of 3.3 mm at the right end, an external thread on the outer surface of the right end, and a lead groove at the left end, so that the L-shaped electrode lead 1 connected to the gold-plated copper spring pin 3 can pass through the external thread fixing part of the polytetrafluoroethylene block and be fixed in the lead groove in an L shape; the internal thread movable part is a cylindrical polytetrafluoroethylene block, with a 10×10 mm rectangular groove at the right end and an internal thread on the inner surface of the left end, which can be connected to the external thread of the external thread fixing part through threads.

[0028] The assembly method of the electrode bracket is as follows: Solder or spot-weld the L-shaped electrode lead 1 to the surface of the fixed boss end of the gold-plated copper spring pin 3, then pass the L-shaped electrode lead 1 through the external thread fixing part of the polytetrafluoroethylene outer shell 2 and bend the L-shaped electrode lead 1 into an L shape and embed it in the lead groove, ensuring that the end face of the fixed boss of the gold-plated copper spring pin 3 is flush with the end face of the external thread fixing part of the polytetrafluoroethylene outer shell 2. The gap between the L-shaped electrode lead 1 and the polytetrafluoroethylene outer shell 2 is filled and sealed with glue. A square test piece 5 is embedded in the rectangular groove of the internal thread movable part of the polytetrafluoroethylene outer shell 2 and filled with sealant, and then the two parts of the polytetrafluoroethylene outer shell 2 are assembled through threads, and a fluorine sealing rubber ring 4 is installed at the thread connection for sealing.

[0029] The L-shaped electrode lead 1 is a 1.5 mm 2 single-core copper wire; the material of the gold-plated copper spring pin 3 is beryllium copper with gold plating 3U at the head, the current is 3 A, and the stroke is 0.45 mm.

[0030] The usage method of the electrochemical working electrode bracket is as follows:

[0031] Solder or spot-weld the L-shaped electrode lead 1 with a length of 20 - 30 cm to the surface of the fixed boss end of the copper-gilded spring pin 3; pass the L-shaped electrode lead 1 through the external thread fixing part of the polytetrafluoroethylene housing 2 and bend the L-shaped electrode lead 1 into an L shape, ensuring that the surface of the fixed boss end of the copper-gilded spring pin 3 is flush with the end face of the external thread fixing part of the polytetrafluoroethylene housing 2, and fill the gap between the L-shaped electrode lead 1 and the polytetrafluoroethylene housing 2 with glue for caulking and sealing; embed the cut and surface-pre-ground square test piece 5 into the rectangular groove of the internal thread movable part of the polytetrafluoroethylene housing 2, ensuring that the surface of the test piece 5 is flush with the end face of the internal thread movable part of the polytetrafluoroethylene housing 2, and fill the edge gap of the test piece 5 with 704 glue or curing quick-drying glue, and dry for standby; if necessary, gently pre-grind the electrode head with the embedded test piece 5 on a pre-grinder to ensure that a small amount of cured glue at the edge of the test piece 5 is removed, place the fluorine sealing rubber ring 4 at the root of the external thread fixing part of the polytetrafluoroethylene housing 2, and screw the internal thread movable part of the polytetrafluoroethylene housing 2 onto the external thread fixing part of the polytetrafluoroethylene housing 2 to form a complete electrode for use; after the electrochemical test is completed, unscrew and remove the internal thread movable part of the polytetrafluoroethylene housing 2, eject the square test piece 5, and remove the small amount of cured glue residue. Repeat the above steps to achieve rapid replacement of the specimen.

Claims

1. A multiplexed electrochemical electrode holder capable of quickly replacing samples, characterized in that: It includes a polytetrafluoroethylene shell, a copper-plated gold-plated spring pin, and an L-shaped electrode lead; the polytetrafluoroethylene shell is divided into an external threaded fixing part and an internal threaded movable part, the external threaded fixing part is a cylindrical polytetrafluoroethylene block, a copper-plated gold-plated spring pin installation groove is opened at the right end, an external thread is opened on the outer surface of the right end, and a lead groove is opened at the left end, the L-shaped electrode lead connected to the copper-plated gold-plated spring pin passes through the external threaded fixing part of the polytetrafluoroethylene block and is fixed in the lead groove in an L shape; the internal threaded movable part is a cylindrical polytetrafluoroethylene block, a rectangular groove is opened at the right end, an internal thread is opened on the inner surface of the left end, and is connected to the external thread of the external threaded fixing part.

2. The multiplexed electrochemical electrode holder capable of quickly replacing samples according to claim 1, characterized in that: Solder or spot weld the L-shaped electrode lead to the end face of the copper-plated gold-plated spring pin fixing boss, then pass the L-shaped electrode lead through the external threaded fixing of the polytetrafluoroethylene shell and bend the L-shaped electrode lead into an L shape and embed it into the lead groove, ensuring that the end face of the copper-plated gold-plated spring pin fixing boss is flush with the end face of the external threaded fixing of the polytetrafluoroethylene shell, and seal the gap between the L-shaped electrode lead and the polytetrafluoroethylene shell with glue, embed the square test piece into the rectangular groove of the internal threaded movable part of the polytetrafluoroethylene shell and fill the gap with sealant, then assemble the two parts of the polytetrafluoroethylene shell through threads, and install fluorine sealing rubber rings at the threaded connection to seal.

3. The multiplexed electrochemical electrode holder capable of quickly replacing samples according to claim 1, characterized in that: Solder or spot weld a 20-30 cm long L-shaped electrode lead to the end face of the copper-plated gold-plated spring pin fixing boss; pass the L-shaped electrode lead through the external thread fixing part of the polytetrafluoroethylene shell and bend the L-shaped electrode lead into an L shape, ensuring that the end face of the copper-plated gold-plated spring pin fixing boss is flush with the end face of the external thread fixing part of the polytetrafluoroethylene shell, and seal the gap between the L-shaped electrode lead and the polytetrafluoroethylene shell with glue; embed the cut and pre-grinded square test piece into the rectangular groove of the internal thread movable part of the polytetrafluoroethylene shell, ensuring that the surface of the test piece is flush with the internal thread movable part of the polytetrafluoroethylene shell. The end faces of the test pieces are flush, and the gaps at the edges of the test pieces are filled with 704 glue or cured quick-drying glue, which are then dried for later use. If necessary, the electrode head of the dry embedded test piece is gently pre-grinded on a pre-grinder to ensure that a small amount of cured glue at the edge of the test piece is removed. The fluorine sealing rubber ring is placed at the root of the external threaded fixing of the polytetrafluoroethylene shell, and the internal threaded movable part of the polytetrafluoroethylene shell is rotated and screwed to the external threaded fixing of the polytetrafluoroethylene shell to form a complete electrode for standby use. After the electrochemical test is completed, loosen and remove the internal threaded movable part of the polytetrafluoroethylene shell, eject the square test piece, and remove a small amount of cured glue residue.

4. The multiplexed electrochemical electrode holder capable of quickly replacing samples according to claim 1, characterized in that: L-type electrode lead wire is 1.5mm 2 Single core copper conductor.

5. The multiplexed electrochemical electrode holder capable of quickly replacing samples according to claim 1, characterized in that: The copper-plated gold-plated spring needle is made of beryllium copper gold-plated 3U, with a current of 3A and a stroke of 0.45mm.

6. The multiplexed electrochemical electrode holder capable of rapidly replacing samples according to claim 1, characterized in that: The external thread fixing is a cylindrical polytetrafluoroethylene block with a copper-plated gold-plated spring pin installation groove with a diameter of 4.4 mm and a depth of 3.3 mm at the right end.

7. The multiplexed electrochemical electrode holder capable of rapidly replacing samples according to claim 1, characterized in that: The internal thread movable part is a cylindrical polytetrafluoroethylene block with a 10×10mm rectangular groove opened at the right end.

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