WO2022179208A1 - 一种用于测量导电涂层与被保护基材之间电偶腐蚀的试样及评价方法 - Google Patents

一种用于测量导电涂层与被保护基材之间电偶腐蚀的试样及评价方法 Download PDF

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WO2022179208A1
WO2022179208A1 PCT/CN2021/131983 CN2021131983W WO2022179208A1 WO 2022179208 A1 WO2022179208 A1 WO 2022179208A1 CN 2021131983 W CN2021131983 W CN 2021131983W WO 2022179208 A1 WO2022179208 A1 WO 2022179208A1
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substrate
conductive coating
galvanic corrosion
sample
conductive
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PCT/CN2021/131983
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English (en)
French (fr)
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李冬冬
刘兰轩
汪洋
刘秀生
秦卫华
冯增辉
吴东恒
郭蓓
束俊杰
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武汉材料保护研究所有限公司
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Publication of WO2022179208A1 publication Critical patent/WO2022179208A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N17/00—Investigating resistance of materials to the weather, to corrosion, or to light
    • G01N17/02—Electrochemical measuring systems for weathering, corrosion or corrosion-protection measurement
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
    • G01N1/34—Purifying; Cleaning
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
    • G01N1/36—Embedding or analogous mounting of samples
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N17/00—Investigating resistance of materials to the weather, to corrosion, or to light
    • G01N17/006—Investigating resistance of materials to the weather, to corrosion, or to light of metals

Definitions

  • the present disclosure belongs to the technical field of material surface engineering, and particularly relates to a sample for measuring galvanic corrosion between a conductive coating and other conductive materials and an evaluation method.
  • Conductive coating is a functional material that is widely used in the fields of conduction, electromagnetic shielding, and antistatic. According to the coating composition and conductive mechanism, it can be divided into intrinsic type, doped type and composite type conductive coating: the film-forming substance of the intrinsic type conductive coating is its conductive material, such as polyaniline, polypyrrole, polythiophene, etc. The molecule of the material contains a conjugated ⁇ bond structure, and the conductivity can be significantly improved by electrochemical or chemical "doping"; The filler realizes the conductive function.
  • the commonly used conductive fillers mainly include pure metal powder (silver, copper, nickel, etc.), metal-coated powder (silver, copper, etc.
  • composite conductive coating is to add conductive fillers in the conductive film-forming material, and the film-forming material and conductive fillers are both. as a conductive material.
  • the conductive coating is directly coated on the surface of the substrate.
  • the potential difference between the conductive coating and the substrate is likely to cause galvanic corrosion, leading to corrosion of the substrate or filler, and then coating bulges. , falling off, etc. Therefore, it is necessary to establish a method for evaluating the galvanic corrosion between the conductive coating and the metal substrate, which can be used in the laboratory to measure the galvanic corrosion tendency, the galvanic corrosion start time, the galvanic corrosion rate, etc. between the conductive coating and the metal substrate. , to evaluate the corrosion resistance of conductive coatings.
  • the evaluation methods of galvanic corrosion mainly include "GB/T 15748-2013 Test Method for Galvanic Corrosion of Marine Metal Materials” and "HB 5374-87 Method for Determination of Galvanic Current of Different Metals", which are used for different metals (metals and alloys, metal coatings and coatings, inorganic films on metal surfaces), and galvanic corrosion evaluation between metals and carbon fiber-epoxy composites.
  • the main problems in the evaluation of galvanic corrosion between conductive coatings and metal substrates are as follows:
  • the main indicators of evaluation are galvanic corrosion rate (galvanic current density) and corrosion morphology.
  • Conductive coatings have both conductive properties and protective functions, and their ability to protect against substrate corrosion is an important indicator for evaluating their performance. Therefore, comprehensively considering the galvanic corrosion start time, galvanic corrosion rate (galvanic current density) and corrosion morphology, etc., the performance of conductive coatings can be evaluated more reasonably.
  • the present disclosure provides a sample for measuring galvanic corrosion between a conductive coating and a substrate, wherein the test portion of the sample is composed of the substrate to be tested, the conductive coating to be tested and a microporous insulating layer, The microporous insulating layer is located between the substrate and the conductive coating. After the microporous insulating layer is filled with a conductive medium, an ion path can be formed on the surface of the conductive coating and the substrate. Layers are connected with independent leads.
  • the substrate is selected from substrates that are susceptible to or capable of galvanic corrosion by themselves when in contact with the conductive material while in an electrolyte; and/or
  • the substrate is selected from substrates that cause the conductive material to be susceptible or capable of galvanic corrosion when in contact with the conductive material while being in an electrolyte; and/or
  • the substrate is selected from substrates that are easily or can generate current between the substrate and the conductive material when in contact with the conductive material and at the same time in the electrolyte; and/or
  • the substrate is selected from substrates that are susceptible to corrosion in electrolytes; and/or
  • the substrate is selected from substrates having electrical conductivity.
  • the substrate includes a material body or a material coating; the material body or material coating is selected from, but not limited to, conductors, semiconductors, and conductive materials.
  • the conductor comprises: metal, graphite, carbon-based conductor material.
  • the semiconductor comprises: silicon-containing material, germanium-containing material, gallium-containing material, selenium-containing material, manganese oxide, chromium oxide, iron oxide, copper oxide.
  • the substrate comprises metal, metallized coating, conductive coating, carbon fiber material.
  • surfaces other than the test portion of the sample are coated with an insulating protective layer.
  • the resistivity between the substrate and the microporous insulating layer is above 1 ⁇ 10 11 ⁇ m; the resistivity between the conductive coating and the microporous insulating layer is 1 ⁇ 10 11 ⁇ m or more.
  • the microporous structure of the microporous insulating layer is filled with the conductive medium, its resistivity differs from the resistivity of the conductive medium itself by no more than 5%.
  • the pore structure of the microporous structure is such that the time required for the corrosive medium to conduct from one side of the microporous insulating layer to the other side is no more than 180 s.
  • the thickness of the microporous insulating layer does not exceed 20 ⁇ m.
  • the microporous insulating layer is a porous ceramic coating.
  • the present disclosure provides an electrochemical device for measuring galvanic corrosion between a conductive coating and a substrate, including the sample for measuring galvanic corrosion between a conductive coating and a substrate described in any one of the above .
  • the present disclosure provides the use of the sample for measuring galvanic corrosion between a conductive coating and a substrate of any one of the above for evaluating galvanic corrosion of a conductive coating.
  • the present disclosure provides the use of the electrochemical device for measuring galvanic corrosion between a conductive coating and a substrate for evaluating the galvanic corrosion of a conductive coating.
  • the present disclosure provides a method for evaluating galvanic corrosion of a conductive coating, using any of the samples described above to conduct a galvanic corrosion test.
  • the evaluation method further includes the total time from the measurement of the galvanic current to the measurement of the occurrence of the galvanic corrosion as an index for evaluating the galvanic corrosion.
  • FIG. 1 is a schematic structural diagram of a sample disclosed for measuring galvanic corrosion between a conductive coating and a substrate;
  • FIG. 2 is a device diagram of an evaluation experiment for galvanic corrosion of the disclosed conductive coating.
  • FIG. 3 is a device diagram of a galvanic corrosion experiment process of a conductive coating in some embodiments of the present disclosure, wherein the arrows indicate the moving direction of the corrosive medium, and the black dots also indicate the corrosive medium.
  • FIG. 4 is a device diagram of an experimental process of galvanic corrosion of conductive coatings in some embodiments of the present disclosure, wherein the arrows indicate the moving direction of the corrosive medium, and the black dots also indicate the corrosive medium.
  • the present disclosure aims at evaluating the galvanic corrosion between the conductive coating and other conductive materials, and discloses a sample and an evaluation method that can more comprehensively evaluate the galvanic corrosion between the conductive coating and other conductive materials.
  • An embodiment of the present disclosure provides a sample for measuring galvanic corrosion between a conductive coating and a substrate.
  • the test portion of the sample is composed of the substrate to be tested, the conductive coating to be tested, and a microporous insulating layer.
  • the microporous insulating layer is located between the substrate to be tested and the conductive coating to be tested, and is composed of insulating materials.
  • the layer contains a microporous structure.
  • the conductive coating and the surface of the substrate can form ions Vias, substrates and conductive coatings are connected with individual leads.
  • corrosive media are also referred to as conductive media.
  • the insulating material provided by the present disclosure is interposed between the substrate and the conductive coating, so that the corrosive medium plays a good insulating role between the substrate and the conductive coating before penetrating the conductive coating;
  • electrolytes such as water or seawater that exists in natural conditions
  • the micropores in the insulating material can make the corrosive medium quickly pass through the microporous insulating material to reach the substrate to form an ion path. Even if the addition of the microporous insulating layer does not affect the measurement of galvanic corrosion, avoid the corrosive medium infiltrating the conductive layer and failing to reach the substrate or delaying reaching the substrate to affect the measurement of galvanic corrosion, such as being unable to measure, or The measurement error is large.
  • the microporous insulating layer of the present disclosure not only realizes effective measurement of galvanic corrosion between the substrate and the conductive coating in the electrolyte, but also does not affect the accuracy of the galvanic corrosion measurement due to the addition of the microporous insulating layer .
  • the substrate is selected from a group that is susceptible to or capable of galvanic corrosion by itself in contact with the conductive material while in an electrolyte, such as water or seawater as it exists in nature substrate; and/or
  • the substrate is selected from substrates that cause the conductive material to be susceptible to or capable of galvanic corrosion in contact with the conductive material while in an electrolyte such as water or seawater that exists in natural conditions. material; and/or
  • the substrate is selected from substrates that are in contact with the conductive material while being in an electrolyte (such as water or seawater that exists under natural conditions), and which are prone to or can generate electrical current between the substrate and the conductive material; and / or
  • the substrate is selected from substrates that are susceptible to corrosion in electrolytes; and/or
  • the substrate is selected from substrates having electrical conductivity.
  • the substrate includes a body of material or a coating of material.
  • the material body or material coating is selected from, but not limited to, conductors, semiconductors, conductive materials.
  • the conductors include, but are not limited to, metals, carbon-based conductor materials.
  • semiconductors include, but are not limited to, silicon-containing materials, germanium-containing materials, gallium-containing materials, selenium-containing materials, manganese oxides, chromium oxides, iron oxides, copper oxides.
  • the conductive materials in the material coating include but are not limited to polyaniline, polypyrrole, polythiophene, metal oxides (such as tin oxide, zinc oxide, antimony dioxide), metal-coated powders (Clad metals or non-metals such as silver, copper, etc.), carbon-based conductive fillers (such as graphene, carbon nanotubes, graphite, carbon fiber, carbon black).
  • the substrate comprises metal, metallized coating, conductive coating, carbon fiber material.
  • surfaces other than the test portion of the specimen are coated with an insulating protective layer.
  • the insulating protective layer can protect the substrate, prevent the wire connected with the sample from contacting the corrosive medium during the measurement process, and prevent the interface between the air and the corrosive medium from causing additional corrosion of the conductive coating, so as to eliminate errors during the experiment.
  • the insulating protective layer can resist the corrosion of the corrosive medium, isolate the test wire from the corrosive medium during the measurement and avoid additional corrosion at the interface during the experimental test.
  • the insulating protective layer is wax.
  • the resistivity between the substrate and the microporous insulating layer is more than 1 ⁇ 10 11 ⁇ m; the resistivity between the conductive coating and the microporous insulating layer is more than 1 ⁇ 10 11 ⁇ m . That is, as long as the resistivity between the substrate and the microporous insulating layer satisfies the insulation between the substrate and the conductive coating, no electronic paths are formed.
  • the resistivity between the substrate and the microporous insulating layer is 1 ⁇ 10 11 ⁇ m-5 ⁇ 10 11 ⁇ m, 1 ⁇ 10 11 ⁇ m-1 ⁇ 10 12 ⁇ m Or 5 ⁇ 10 11 ⁇ m-1 ⁇ 10 12 ⁇ m, such as greater than or equal to 1 ⁇ 10 11 ⁇ m, greater than or equal to 4 ⁇ 10 11 ⁇ m, greater than or equal to 6 ⁇ 10 11 ⁇ m , greater than or equal to 8 ⁇ 10 11 ⁇ m, or greater than or equal to 1 ⁇ 10 12 ⁇ m, etc.
  • the resistivity between the conductive coating and the microporous insulating layer is 1 ⁇ 10 11 ⁇ m to 5 ⁇ 10 11 ⁇ m, 1 ⁇ 10 11 ⁇ m to 1 ⁇ 10 12 ⁇ m m or 5 ⁇ 10 11 ⁇ m-1 ⁇ 10 12 ⁇ m, such as greater than or equal to 1 ⁇ 10 11 ⁇ m, greater than or equal to 3 ⁇ 10 11 ⁇ m, greater than or equal to 5 ⁇ 10 11 ⁇ m m, greater than or equal to 7 ⁇ 10 11 ⁇ m, greater than or equal to 9 ⁇ 10 11 ⁇ m, or greater than or equal to 1 ⁇ 10 12 ⁇ m, and the like.
  • the microporous structure of the microporous insulating layer is filled with the conductive medium
  • its resistivity differs from the resistivity of the conductive medium (corrosion medium) itself by no more than 5%, for example, 1 %-5%, 0.1%-4% or 1%-3.5%, such as not more than 4.5%, not more than 4%, not more than 3.5%, not more than 3%, not more than 2.5%, not more than 2%, not more than 2% 1.5%, no more than 1%, no more than 0.5%, etc.
  • the resistivity of the corrosive medium and the corrosive medium itself that is, the corrosive medium is under natural conditions without adding a microporous insulating layer
  • resistivity difference ⁇ 5% so as to ensure the validity and accuracy of galvanic corrosion measurement (guaranteed that the accuracy reaches more than 95%), and does not affect the corrosion medium (that is, the conductive medium above) due to the addition of a microporous insulating layer. resistivity.
  • the measurement of galvanic corrosion satisfies the following standards, and the area ratio of the corrosion medium to the test sample is not less than 20mL/cm 2 (GB/T 15748), then the corrosion product contained in the solution itself produces The effect is so small that its effect is negligible for measuring resistivity of galvanic corrosion.
  • the corrosion medium passes through the microporous insulating layer at a slower speed, resulting in a gradual error in the measurement of galvanic corrosion. increase.
  • the conductive medium is a corrosive medium that penetrates into the microporous structure.
  • the pore structure of the microporous structure is such that the time required for the corrosive medium to conduct from one side of the microporous insulating layer to the other side does not exceed 180 s. In order to reduce the error of the measurement results, the shorter the time, the better. Since the test time is generally 1h as the starting measurement time, 180s can meet the error requirements.
  • the required time (s) ⁇ the total time from the start of the test to the measured current is not 0 ⁇ the percentage of error (%), such as the total time from the start of the test to the measured current is not 0 is 50 minutes , the required error rate is 5%, then the required time is ⁇ 150s.
  • the above required time will affect the time point when the corrosion current is not 0. Within the range of the above required time, it can be ensured that after the corrosive medium penetrates the conductive coating, it is ensured that the corrosive medium passes through and continuously passes through the microporous insulating layer. Therefore, the retardation caused by the corrosion medium passing through the microporous insulating layer is reduced, and the accuracy of the galvanic corrosion measurement is effectively improved.
  • the thickness of the microporous insulating layer does not exceed 20 ⁇ m, such as 2-20 ⁇ m, 5-15 ⁇ m, or 10-12 ⁇ m.
  • the thickness of the microporous insulating layer is within the above range, which can further effectively control the time for the corrosive medium to pass through the microporous insulating layer to a lower range, ensure that the corrosive medium passes through and continuously pass through the microporous insulating layer, and further effectively improves the galvanic Accuracy of corrosion measurements.
  • the microporous insulating layer only needs to meet the following conditions: insulating in a dry state, and in a wet state, after the microporous structure of the microporous insulating layer is filled with a conductive medium, it is filled with a conductive medium at this time.
  • the resistivity of the microporous insulating layer of the medium (corrosion medium) is not more than 5% different from the resistivity of the conductive medium (corrosion medium) itself.
  • the microporous insulating layer is a porous ceramic coating or a porous polymer layer. In some embodiments, the microporous insulating layer is a porous ceramic coating. In some embodiments, the porous ceramic coating is selected from one of zirconia ceramics, alumina ceramics, silicon nitride ceramics, aluminum nitride ceramics, lead borate glass ceramics, barium tin borate ceramics, and beryllium oxide ceramics.
  • the present disclosure also provides an electrochemical device for measuring the galvanic corrosion between the conductive coating and the substrate, comprising: the sample for measuring the galvanic corrosion between the conductive coating and the substrate as described above.
  • the electrochemical device includes:
  • the specimen, the test portion of the specimen is immersed in a corrosive medium, to avoid contact of the substrate with the corrosive medium;
  • a reference electrode at least a portion of which is immersed in a corrosive medium
  • the galvanic current measuring device is respectively electrically connected with the conductive coating of the sample, the base material of the electrical connection sample and the reference electrode.
  • the galvanic current measuring device is respectively electrically connected to the conductive coating of the sample, the base material of the electrical connection sample and the reference electrode, so that the conductive coating of the sample is the working electric shock of the galvanic current measuring device.
  • the base material of the sample is the counter electrode (CE) of the galvanic current measuring device
  • the reference electrode is the reference electrode (RE) of the galvanic current measuring device.
  • the working shock (WE) interface end of the galvanic current measuring device is electrically connected to the conductive coating of the sample
  • the counter electrode (CE) interface end of the galvanic current measuring device is electrically connected to the substrate of the sample
  • the electrical The reference electrode (RE) interface end of the even current measuring device is electrically connected with the reference electrode.
  • the conductive coating of the sample is used as the working electric shock (WE)
  • the substrate of the sample is used as the counter electrode (CE), so that the counter current can be measured.
  • the galvanic current measuring device is selected from a zero-resistance ammeter, a galvanic corrosion measuring instrument, a potentiostat that can be connected to a zero-resistance circuit, or an electrochemical workstation.
  • the corrosive medium may be selected from seawater, artificial seawater or brine.
  • An embodiment of the present disclosure provides an electrochemical device for measuring galvanic corrosion between a conductive coating and a substrate, including a sample for measuring galvanic corrosion between the conductive coating and the substrate.
  • An embodiment of the present disclosure provides the use of the sample for measuring the galvanic corrosion between the conductive coating and the substrate in evaluating the galvanic corrosion of the conductive coating.
  • An embodiment of the present disclosure provides the use of the electrochemical device for measuring galvanic corrosion between a conductive coating and a substrate in evaluating the galvanic corrosion of a conductive coating.
  • An embodiment of the present disclosure provides a method for evaluating galvanic corrosion of a conductive coating, using the above-mentioned sample to conduct a galvanic corrosion test.
  • the evaluation method includes the steps of:
  • the evaluation method further includes the total time from the measurement of the galvanic current to the measurement of the occurrence of the galvanic corrosion as an index for evaluating the galvanic corrosion.
  • the sample used in this disclosure uses a microporous insulating material between the substrate and the conductive coating, and before the corrosive medium penetrates the conductive coating, it plays a good insulating role between the substrate and the conductive coating; the corrosive medium After penetrating the conductive coating, the corrosive medium can quickly reach the substrate through the microporous insulating material, forming an ion pathway.
  • the galvanic corrosion problem between the conductive coating and all other (conductive) materials can be measured, such as metals, metal coating, other conductive coatings, carbon fiber materials, etc.
  • the recommended sample size is 110mm ⁇ 25mm ⁇ (2 ⁇ 3)mm. Due to special needs, other sizes can be used, such as ⁇ 25mm ⁇ 110mm.
  • Conductive substrates with a certain mechanical strength can be directly machined, such as metals and their alloys, carbon fiber composite materials, etc. Process substrates of suitable size (if there are no special requirements, use insulating materials), and then prepare corresponding conductive materials, such as metal plating and coatings, inorganic film layers of metal substrates, conductive coatings, etc.
  • the surface of the sample shall be treated according to the pretreatment requirements of the conductive paint or the actual situation. At one end of the sample, copper is drawn out by welding or mechanical fixing to ensure stable and reliable contact between the wire and the substrate.
  • the ceramic coating should be as thin as possible to minimize the test error.
  • test area is generally about 25cm 2 . After the test area is determined, use the method of immersing in ground wax or other sealing coating to coat the surface of the conductive coating with an insulating protective layer to seal the sample.
  • the surface should be cleaned with alcohol or other suitable methods, and the surface of the sample should be kept clean before the end of the test.
  • the electrolyte can use natural seawater, 3.5% NaCl solution, artificial seawater, etc. as required, and the ratio of the test solution volume to the test area is not less than 20mL/cm 2 .
  • 2Zero-resistance technology is used to measure galvanic current.
  • the instrument can use zero-resistance ammeter, galvanic corrosion measuring instrument, potentiostat or electrochemical workstation that can be connected to zero-resistance circuit, etc.
  • Auxiliary instruments include constant temperature water bath device, beaker, saturated calomel electrodes, etc.
  • At least 3 sets of galvanic corrosion samples shall be set, and at least 3 uncoupled comparison samples shall be set for each.
  • the circuit should be connected immediately, the galvanic current should be measured, and the measurement time should be recorded.
  • a plate-shaped 2A12 aluminum alloy with a size of 100 mm ⁇ 50 mm ⁇ 1 mm is selected as the base material, and one end of the copper wire is drawn out by soldering.
  • the insulating coating is prepared by spraying with plasma spraying equipment (model GTV F6), the powder is heated and melted, and sprayed onto the surface of the above-mentioned 2A12 aluminum alloy substrate with high-speed airflow, and obtained through process control.
  • the measured coating thickness is 56.3 ⁇ m
  • the measured resistivity between the ceramic coating and the 2A12 aluminum alloy substrate is 5.8 ⁇ 10 11 ⁇ m
  • artificial seawater is added to its surface After about 2-5s, its resistivity can be measured to drop significantly, confirming that it has penetrated from the ceramic coating to the aluminum plate.
  • artificial seawater is used as the corrosive medium
  • the formula of artificial seawater is shown in GB/T 15748 "Test Method for Galvanic Corrosion of Marine Metal Materials”.
  • the resistivity of artificial seawater was measured to be 4.7 ⁇ m
  • the resistivity between the two sides was measured to be 4.8 ⁇ m after fully wetting one side of the ceramic coating with artificial seawater.
  • the 2A12 aluminum alloy surface covered with a zirconia porous ceramic coating (the coating thickness is still 56.3 ⁇ m) was prepared in parallel according to the same process, and the silver conductive coating was sprayed on the surface of the 2A12 aluminum alloy, and the coating thickness was 83.6 ⁇ m, and the silver conductivity was measured.
  • the resistivity between the coating and 2A12 is 6.3 ⁇ 10 11 ⁇ m.
  • the sample preparation meets the requirements.
  • the test area is selected as 50cm 2 , and the sample is sealed by preparing an insulating coating with fluorocarbon paint according to the test area.
  • the structure of the obtained sample is shown in Figure 1. Conduct necessary cleaning of the conductive coating surface with a cleaning agent.
  • the silver conductive paint can measure an obvious corrosion current within 8 to 10 hours, indicating that the silver conductive paint can protect the substrate well before 6 hours.
  • the artificial seawater may have slowly penetrated the conductive coating and reached the substrate through the insulating porous material. Therefore, at the measurement points of 8h and 10h, the corrosion current of the three groups of samples can be measured, and the corrosion current is not 0, indicating that the conductive Galvanic corrosion has occurred between the coating and the substrate 2A12.
  • the corrosion current direction it can be known that the silver conductive coating is the cathode and 2A12 is the anode.
  • a plate-shaped 921A steel alloy with a size of 100mm ⁇ 50mm ⁇ 1mm is selected as the base material, and one end of the copper wire is drawn out by soldering.
  • the insulating coating is prepared by spraying with plasma spraying equipment (model GTV F6), the powder is heated and melted, and sprayed onto the surface of the above-mentioned 921A steel alloy substrate with high-speed airflow, and obtained through process control. Porous ceramic coating with through holes.
  • the measured coating thickness is 62.7 ⁇ m, and the measured resistivity between the ceramic coating and the 921A steel alloy substrate is 6.7 ⁇ 10 11 ⁇ m.
  • artificial seawater is used as the corrosive medium, and the formula of artificial seawater is shown in GB/T 15748 "Test Method for Galvanic Corrosion of Marine Metal Materials".
  • the resistivity of artificial seawater was measured to be 4.6 ⁇ m, and the resistivity between the two was measured after fully wetting one side of the ceramic coating with artificial seawater.
  • the 921A steel alloy coated with alumina porous ceramic coating (the coating thickness is still 62.7 ⁇ m) was prepared in parallel according to the same process.
  • the copper conductive coating was sprayed on the surface of the 921A steel alloy, and the coating thickness was 72.8 ⁇ m.
  • the copper conductive coating was measured.
  • the resistivity between the layer and 921A was 6.9 ⁇ 10 11 ⁇ m.
  • the sample preparation meets the requirements.
  • the test area was selected as 50cm 2 , and the sample was sealed by preparing an insulating coating with fluorocarbon paint according to the test area.
  • the structure of the obtained sample is shown in Figure 1.
  • Conduct necessary cleaning of the conductive coating surface with a cleaning agent Put 1500mL of artificial seawater into the beaker, immerse the sample and reference electrode in the artificial seawater, make the liquid level in the middle of the insulating coating of the sample (keep the part above the liquid level dry), and connect the test circuit according to the test requirements, such as As shown in Figure 2, immediately connect the circuit, measure the galvanic current, and record the measurement time.
  • Parallel samples were set to 3 groups.
  • Example 1 Other samples and their preparation, test instruments and device connection, measurement and evaluation are the same as in Example 1.
  • the present disclosure provides a sample and an evaluation method for measuring galvanic corrosion between a conductive coating and a protected substrate.
  • the sample used in the present disclosure adopts a microporous insulating material between the substrate and the conductive coating. Before the corrosive medium penetrates the conductive coating, it plays a good insulating role between the substrate and the conductive coating; after the corrosive medium penetrates the conductive coating, the corrosive medium can quickly reach the substrate through the microporous insulating material to form an ion path .
  • This disclosure can measure galvanic corrosion between conductive coatings and all other (conductive) materials (ie, substrates), such as metals, metal-to-metal coatings, other conductive coatings, carbon fiber materials, when the accuracy of the measurement equipment allows etc., has a wide range of applications and good application prospects.

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Abstract

一种用于测量导电涂层（3）与被保护的基材（1）之间电偶腐蚀的试样（6）及评价方法，导电涂层（3）与基材（1）之间设置有微孔绝缘层（2），微孔绝缘层（2）由绝缘材料构成，层中包含微孔结构，微孔结构填充导电介质后能够使导电涂层（3）和基材（1）表面形成离子通路，基材（1）及导电涂层（3）均连接有独立的引线（5）。试样（6）能够更全面地对导电涂层(3)与其他导电材料间电偶腐蚀情况进行评价。

Description

一种用于测量导电涂层与被保护基材之间电偶腐蚀的试样及评价方法
相关申请的交叉引用
本公开要求于2021年02月26日提交中国专利局的申请号为“202110220381.4”名称为“一种用于测量导电涂层与被保护基材之间电偶腐蚀的试样及评价方法”的中国专利申请的优先权，其全部内容通过引用结合在本公开中。
技术领域
本公开属于材料表面工程技术领域，具体涉及到一种导电涂层与其他导电材料间电偶腐蚀的测量用试样及评价方法。
背景技术
导电涂层是一种在导电、电磁屏蔽、抗静电等领域应用广泛的功能材料。按照涂料组成及导电机理可分为本征型、掺杂型与复合型导电涂料：本征型导电涂料的成膜物质即为其导电材料，如聚苯胺、聚吡咯、聚噻吩等，这类材料的分子中含有共扼π键结构，可通过电化学或化学“掺杂”手段，使其导电率明显提高；掺杂型导电涂料的导电材料为导电填料，通过在成膜物质中添加导电填料实现导电功能，常用的导电填料主要有纯金属粉(银、铜、镍等)、金属包覆粉体(银、铜等包覆金属或非金属)、碳系导电填料(石墨烯、碳纳米管、石墨、碳纤维、炭黑等)、金属氧化物(氧化锡、氧化锌、二氧化锑等)；复合型导电涂料是在导电成膜物中添加导电填料，成膜物和导电填料均作为导电材料。
导电涂料直接涂覆在基材表面，当腐蚀介质渗入涂层到达基材时，导电涂层与基材间的电位差容易引起电偶腐蚀现象，导致基材或填料腐蚀，进而出现涂层鼓包、脱落等现象。因此，需要建立一种评价导电涂层与金属基材间电偶腐蚀的方法，用于实验室测量导电涂料与金属基材间的电偶腐蚀倾向、电偶腐蚀开始时间、电偶腐蚀速率等，评价导电涂层的耐蚀性。
目前，电偶腐蚀评价方法主要有《GB/T 15748-2013船用金属材料电偶腐蚀试验方法》《HB 5374-87不同金属电偶电流测定方法》，用于不同金属(金属及合金、金属镀层和涂层、金属表面无机膜层)、金属与碳纤维-环氧复合材料间的电偶腐蚀评价。用于导电涂料与金属基材间电偶腐蚀评价主要存在以下问题：
(1)未涉及到导电涂层与其他导电材料之间的电偶腐蚀问题；
(2)测试电路连通后，电偶腐蚀即开始，无法测量腐蚀介质经由导电涂层表面渗透至基材引起电偶腐蚀的时间，即无法有效评价导电涂层从保护基材到保护失效，进而引发电偶腐 蚀的过程；
(3)评价的主要指标为其电偶腐蚀速率(电偶电流密度)和腐蚀形貌。
导电涂料兼具导电性能和防护功能，其对基材腐蚀的防护能力，是评价其性能的重要指标。因此，综合考虑电偶腐蚀开始时间、电偶腐蚀速率(电偶电流密度)和腐蚀形貌等，能对导电涂料性能进行更为合理的评价。
发明内容
本公开提供一种用于测量导电涂层与基材之间电偶腐蚀的试样，所述试样的测试部分由待测的基材、待测的导电涂层与微孔绝缘层构成，所述微孔绝缘层位于所述基材和导电涂层之间，所述微孔绝缘层填充导电介质后能够使所述导电涂层和基材表面形成离子通路，所述基材及导电涂层均连接有独立的引线。
在一些实施方式中，所述基材选自在与所述导电材料相互接触并同时处于电解质中，所述基材自身易产生或能产生电化学腐蚀的基材；和/或
所述基材选自在与所述导电材料相互接触并同时处于电解质中，所述基材引起所述导电材料易产生或能产生电化学腐蚀的基材；和/或
所述基材选自在与所述导电材料相互接触并同时处于电解质中，所述基材与导电材料之间易产生或能产生电流的基材；和/或
所述基材选自在电解质中易腐蚀的基材；和/或
所述基材选自具有导电性的基材。
在一些实施方式中，所述基材包括材料本体或材料涂层；所述材料本体或材料涂层选自但不限于：导体、半导体、导电材料。
在一些实施方式中，所述导体包括：金属、石墨、碳系导体材料。
在一些实施方式中，所述半导体包括：含硅材料、含锗材料、含镓材料、含硒材料、锰氧化物、铬氧化物、铁氧化物、铜氧化物。
在一些实施方式中，所述基材包括金属、金属镀涂层、导电涂层、碳纤维材料。
在一些实施方式中，所述试样测试部分以外的表面涂覆有绝缘保护层。
在一些实施方式中，所述基材与微孔绝缘层之间的电阻率在1×10 11Ω·m以上；所述导电涂层与微孔绝缘层之间的电阻率在1×10 11Ω·m以上。
在一些实施方式中，所述微孔绝缘层的微孔结构填满导电介质后，其电阻率与导电介质本身的电阻率相差不超过5％。
在一些实施方式中，所述微孔结构的孔隙结构使得腐蚀介质自微孔绝缘层一侧传导至另 一侧所需的时间不超过180s。
在一些实施方式中，所述微孔绝缘层的厚度不超过20μm。
在一些实施方式中，所述微孔绝缘层为多孔陶瓷涂层。
本公开提供一种用于测量导电涂层与基材之间电偶腐蚀的电化学装置，包括上文中任一项所述的用于测量导电涂层与基材之间电偶腐蚀的试样。
本公开提供上文任一项所述的用于测量导电涂层与基材之间电偶腐蚀的试样在用于评价导电涂层电偶腐蚀的用途。
本公开提供所述的用于测量导电涂层与基材之间电偶腐蚀的电化学装置在用于评价导电涂层电偶腐蚀的用途。
本公开提供一种导电涂层电偶腐蚀的评价方法，采用上文任一项所述的试样进行电偶腐蚀测试。
在一些实施方式中，根据上文所述的评价方法，包括如下步骤：
(1)获得以待测导电涂层、微孔绝缘层和基材为组成部分的试样；
(2)获得待测腐蚀介质；
(3)将试样测试部分浸入腐蚀介质，避免基材接触腐蚀介质；
(4)按要求选择参比电极，进行电路和测量仪器的连接，采用零阻电流法测量电偶电流。
在一些实施方式中，所述评价方法还包括将从所述测量电偶电流开始至测量到所述电偶腐蚀发生时的总时间作为评价所述电偶腐蚀的指标。
附图说明
图1为本公开用于测量导电涂层与基材之间电偶腐蚀的试样的结构示意图；
图2为本公开导电涂层电偶腐蚀的评价实验的装置图。
图3为本公开的一些实施方式中导电涂层电偶腐蚀实验过程的装置图，其中箭头表示腐蚀介质的移动方向，黑色圆点同样表示腐蚀介质。
图4为本公开一些实施方式中导电涂层电偶腐蚀实验过程的装置图，其中箭头表示腐蚀介质的移动方向，黑色圆点同样表示腐蚀介质。
图中的附图标注为：
1，基材；2，微孔绝缘层；3，导电涂层；4，封闭绝缘层；5，引线；6，试样；7，参比电极；8，腐蚀介质。
具体实施方式
本公开针对导电涂层与其他导电材料间的电偶腐蚀评价问题，公开一种能够更全面地对导电涂层与其他导电材料间电偶腐蚀情况进行评价的试样及评价方法。
本公开一实施方式提供一种用于测量导电涂层与基材之间电偶腐蚀的试样，试样的测试部分由待测的基材、待测的导电涂层与微孔绝缘层构成，微孔绝缘层位于待测基材和待测导电涂层之间，由绝缘材料构成，层中包含微孔结构，微孔绝缘层填充导电介质后能够使导电涂层和基材表面形成离子通路，基材及导电涂层均连接有独立的引线。在本文中，腐蚀介质也称为导电介质。
参照图3，本公开提供的绝缘材料介于基材和导电涂层之间，使得腐蚀介质在渗透导电涂层前，在基材和导电涂层之间起到良好的绝缘作用；可以实现基材和导电材料在电解质(诸如自然条件下存在的水或海水)中进行电偶腐蚀的有效测量，从而避免基材和导电材料直接接触而导致无法测量电流，从而无法测定电偶腐蚀的过程。
参照图4，绝缘材料中的微孔可以在当腐蚀介质渗透导电涂层后，可以使得腐蚀介质迅速通过微孔绝缘材料到达基材，形成离子通路。即使得不因微孔绝缘层的加入而影响电偶腐蚀情况的测量，避免腐蚀介质在渗透导电层而无法到达基材或者滞后到达基材而影响电偶腐蚀情况的测量，诸如无法测量，或者测量的误差较大。综上，本公开的微孔绝缘层不仅实现基材和导电涂层之间在电解质中的电偶腐蚀的有效测量，而且并不因微孔绝缘层的加入而影响电偶腐蚀测量的准确性。在一些实施方式中，所述基材选自在与所述导电材料相互接触并同时处于电解质(诸如自然条件下存在的水或海水)中，所述基材自身易产生或能产生电化学腐蚀的基材；和/或
所述基材选自在与所述导电材料相互接触并同时处于电解质(诸如自然条件下存在的水或海水)中，所述基材引起所述导电材料易产生或能产生电化学腐蚀的基材；和/或
所述基材选自在与所述导电材料相互接触并同时处于电解质(诸如自然条件下存在的水或海水)中，所述基材与导电材料之间易产生或能产生电流的基材；和/或
所述基材选自在电解质中易腐蚀的基材；和/或
所述基材选自具有导电性的基材。
在一些实施方式中，基材包括材料本体或材料涂层。
在一些实施方式中，材料本体或材料涂层选自但不限于：导体、半导体、导电材料。
在一些可选的实施方式中，导体包括但不限于：金属、碳系导体材料。
在一些可选的实施方式中，半导体包括但不限于：含硅材料、含锗材料、含镓材料、含硒材料、锰氧化物、铬氧化物、铁氧化物、铜氧化物。
在一些可选的实施方式中，材料涂层中的导电材料包括但不限于聚苯胺、聚吡咯、聚噻吩、金属氧化物(诸如氧化锡、氧化锌、二氧化锑)、金属包覆粉体(诸如银、铜等包覆金属或非金属)、碳系导电填料(诸如石墨烯、碳纳米管、石墨、碳纤维、炭黑)。
在一些实施方式中，基材包括金属、金属镀涂层、导电涂层、碳纤维材料。在一些实施方式中，试样测试部分以外的表面涂覆有绝缘保护层。绝缘保护层能够保护基材，防止在测量过程中连接有试样的导线与腐蚀介质接触，同时防止空气与腐蚀介质之间界面产生对导电涂层的额外腐蚀，以排除实验过程中的误差。绝缘保护层能够耐腐蚀介质的腐蚀，在测量期间使测试用导线与腐蚀介质隔离并避免在实验测试过程中，界面产生的额外腐蚀。在一些实施方式中，绝缘保护层为蜡。
在一些实施方式中，基材与微孔绝缘层之间的电阻率在1×10 11Ω·m以上；导电涂层与微孔绝缘层之间的电阻率在1×10 11Ω·m以上。即基材与微孔绝缘层之间的电阻率只要满足基材和导电涂层之间绝缘，不会形成电子通路即可。
在一些实施方式中，基材与微孔绝缘层之间的电阻率为1×10 11Ω·m-5×10 11Ω·m、1×10 11Ω·m-1×10 12Ω·m或者5×10 11Ω·m-1×10 12Ω·m，例如大于或等于1×10 11Ω·m、大于或等于4×10 11Ω·m、大于或等于6×10 11Ω·m、大于或等于8×10 11Ω·m、或者大于或等于1×10 12Ω·m等。在一些实施方式中，导电涂层与微孔绝缘层之间的电阻率为1×10 11Ω·m-5×10 11Ω·m、1×10 11Ω·m-1×10 12Ω·m或者5×10 11Ω·m-1×10 12Ω·m，例如大于或等于1×10 11Ω·m、大于或等于3×10 11Ω·m、大于或等于5×10 11Ω·m、大于或等于7×10 11Ω·m、大于或等于9×10 11Ω·m、或者大于或等于1×10 12Ω·m等。
在上述电阻率的控制下，可以进一步保证，在腐蚀介质在渗透导电涂层之前，即无腐蚀介质进入基材中时，有效保证基材和导电涂层之间的完全绝缘，同时提高测量的准确性和广泛适应性，可以广泛应用于上文所述的任一项的基材和导电涂层。在一些实施方式中，为保证试验结果准确性，微孔绝缘层的微孔结构填满导电介质后，其电阻率与导电介质(腐蚀介质)本身的电阻率相差不超过5％，例如为1％-5％、0.1％-4％或1％-3.5％，诸如不超过4.5％、不超过4％、不超过3.5％、不超过3％、不超过2.5％、不超过2％、不超过1.5％、不超过1％、不超过0.5％等。
即腐蚀介质渗透导电涂层后，腐蚀介质在穿过并填满微孔绝缘层过程时，此时腐蚀介质的电阻率和腐蚀介质本身(即腐蚀介质在未添微孔绝缘层的自然条件下)的电阻率相差≤5％，从而保证电偶腐蚀测量的有效性和精确性(保证精确性达到95％以上)，不因加入微孔绝缘层而影响腐蚀介质(即上文的导电介质)电阻率。需要说明的是，本实施方式和实施例中，测定电偶腐蚀满足以下标准，腐蚀介质与测试样面积比不小于20mL/cm 2(GB/T 15748)，则 包含的腐蚀产物对溶液本身产生的影响极小，其影响对于测量电偶腐蚀的电阻率而言可以忽略不计。
而当在所述电阻率相差大于5％的情况下，诸如由于微孔绝缘层中微孔较小，腐蚀介质在穿过微孔绝缘层的速度较慢，从而导致电偶腐蚀测量的误差逐渐增大。
在本公开中，导电介质为渗入微孔结构中的腐蚀介质。在一些实施方式中，微孔结构的孔隙结构使得腐蚀介质自微孔绝缘层一侧传导至另一侧所需的时间不超过180s。为减少测量结果误差，时间越短越好，鉴于试验时间一般以1h为起始测量时间，180s可满足误差要求。即所需的时间(s)≤从测试起始到测得的电流不为0的总时间×误差百分比(％)，诸如从测试起始到测得的电流不为0的总时间为50分钟，要求的误差率为5％，则所需的时间≤150s。
上述所需时间会影响到腐蚀电流不为0的时间点，在上述的所需时间的范围内，可以保证，当腐蚀介质渗透导电涂层之后，保证腐蚀介质通过且连续通过微孔绝缘层，从而降低腐蚀介质因穿过微孔绝缘层而产生的延迟性，有效提高电偶腐蚀测量的准确性。
在一些实施方式中，微孔绝缘层的厚度不超过20μm，例如2-20μm，5-15μm，或10-12μm。
微孔绝缘层的厚度在上述范围内，可以进一步将腐蚀介质穿过微孔绝缘层的时间有效控制在更下的范围内，保证腐蚀介质通过且连续通过微孔绝缘层，进一步有效提高电偶腐蚀测量的准确性。
在一些实施方式中，所述微孔绝缘层只要满足以下条件即可：在干态下绝缘，并且在湿态下，微孔绝缘层的微孔结构填满导电介质后，此时填充有导电介质(腐蚀介质)的微孔绝缘层电阻率与导电介质(腐蚀介质)本身的电阻率相差不超过5％。
在一些实施方式中，微孔绝缘层为多孔陶瓷涂层或多孔聚合物层。在一些实施方式中，微孔绝缘层为多孔陶瓷涂层。在一些实施方式中，多孔陶瓷涂层选自氧化锆陶瓷、氧化铝陶瓷、氮化硅陶瓷，氮化铝陶瓷，硼酸铅玻璃陶瓷，硼酸锡钡陶瓷，氧化铍陶瓷中的一种。本公开还提供一种用于测量导电涂层与基材之间电偶腐蚀的电化学装置，包括：如上所述的用于测量导电涂层与基材之间电偶腐蚀的试样。
在一些实施方式中，该电化学装置包括：
容器，容器中包含腐蚀介质；
试样，试样测试部分浸入腐蚀介质，避免基材接触腐蚀介质；以及
参比电极，参比电极的至少一部分浸入腐蚀介质；
电偶电流测量装置，电偶电流测量装置分别与试样的导电涂层、电连接试样的基材以及参比电极电连接。
如图3所示，电偶电流测量装置分别与试样的导电涂层、电连接试样的基材以及参比电 极电连接，使得试样的导电涂层为电偶电流测量装置的工作电击(WE)，试样的基材为电偶电流测量装置的对电极(CE)，参比电极为电偶电流测量装置的参比电极(RE)。换句话说，电偶电流测量装置的工作电击(WE)接口端与试样的导电涂层电连接，电偶电流测量装置的对电极(CE)接口端与试样的基材电连接，电偶电流测量装置的参比电极(RE)接口端与参比电极电连接。电化学装置中，试样的导电涂层作为工作电击(WE)，试样的基材作为对电极(CE)，这样就可以测量对电偶电流。
在一些实施方式中，电偶电流测量装置选自零阻电流表、电偶腐蚀测量仪、可接零阻电路的恒电位仪或电化学工作站。
在一些实施方式中，腐蚀介质可以选自海水、人造海水或盐水。
本公开一实施方式提供一种用于测量导电涂层与基材之间电偶腐蚀的电化学装置，包括用于测量导电涂层与基材之间电偶腐蚀的试样。
本公开一实施方式提供所述的用于测量导电涂层与基材之间电偶腐蚀的试样在用于评价导电涂层电偶腐蚀的用途。
本公开一实施方式提供所述的用于测量导电涂层与基材之间电偶腐蚀的电化学装置在用于评价导电涂层电偶腐蚀的用途。
本公开一实施方式提供一种导电涂层电偶腐蚀的评价方法，采用上述的试样进行电偶腐蚀测试。
在一些实施方式中，评价方法包括如下步骤：
(1)获得以待测导电涂层、微孔绝缘层和基材为组成部分的试样；
(2)获得待测腐蚀介质；
(3)将试样测试部分浸入腐蚀介质，避免基材接触腐蚀介质；
(4)按要求选择参比电极，进行电路和测量仪器的连接，采用零阻电流法测量电偶电流。
在一些实施方式中，评价方法还包括将从测量电偶电流开始至测量到所述电偶腐蚀发生时的总时间作为评价所述电偶腐蚀的指标。
相比于现有技术，本公开的有益效果在于：
(1)现有标准中无针对导电涂层电偶腐蚀的测量方法，参照标准测量具有局限性，无法反应腐蚀介质中导电涂层对基体的防护作用。本公开所使用的试样时采用微孔绝缘材料介于基材和导电涂层之间，腐蚀介质渗透导电涂层前，在基材和导电涂层之间起到良好的绝缘作用；腐蚀介质渗透导电涂层后，腐蚀介质能迅速通过微孔绝缘材料到达基材，形成离子通路。不仅可测得电偶腐蚀发生后的相关参数，还可以评价腐蚀介质由导电涂层表面渗入至金属基材过程中的相关参数，如电偶腐蚀开始时间，电偶腐蚀发生前导电涂层与金属基材间电 偶电压变化等。
(2)在测量设备精度允许的情况下，可以测量导电涂层与其他所有(导电)材料(即基材)间的电偶腐蚀问题，如金属、金属渡涂层、其他导电涂层、碳纤维材料等。
为更好的理解本公开，下面的实施例是对本公开的进一步说明，但本公开的内容不仅仅局限于下面的实施例。
实施例
实施例1
(1)试样及其制备
①推荐试样尺寸为110mm×25mm×(2～3)mm，因特殊需要，可使用其他尺寸，如φ25mm×110mm。本身具有一定机械强度的导电基材可直接机械加工制得，如金属及其合金、碳纤维复合材料等；本身不具备所需机械强度或本身即需要基材的导电材料，可根据实际情况先机械加工合适尺寸的基材(如无特殊要求，采用绝缘材料)，再制备相应的导电材料，如金属镀层和涂层、金属基材的无机膜层、导电涂料等。试样表面按导电涂料前处理要求或实际情况进行处理。在试样一端采用焊接或机械固定的方式引出铜导电，保证导线与基材接触稳定、可靠。
②在基材表面制备均匀的陶瓷涂层，在保障绝缘性和透水性的前提下，陶瓷涂层尽可能薄，以尽量减小试验误差。
③按照导电涂料施工前处理要求处理陶瓷涂层表面，依照施工工艺在其表面涂覆导电涂料。待导电涂料完全固化，在其表面(靠近基材铜导线一端)采取机械固定的方式引出铜导线，保证导线与导电涂层接触稳定、可靠。
按上述试样制备方法制备3组试样，并自银导电涂层表面引出铜导线。
④试验面积一般约为25cm 2，确定试验面积后，采用浸地蜡或其他封闭涂层的方法，在导电涂层的表面涂覆绝缘保护层，对试样进行封闭。
⑤试样准备完成后，应用酒精或其他合适的方式对表面进行必要的清洁，在试验结束前应保持试样表面清洁。
⑥用游标卡尺或千分尺准确测量试验面积。
(2)试验仪器及装置连接
①试验溶液：电解液根据需要可采用天然海水、3.5％NaCl溶液、人造海水等，试验溶液体积与试验面积的比值不低于20mL/cm 2。
②采用零阻技术测量电偶电流，仪器可采用零阻电流表、电偶腐蚀测量仪、可接零阻电 路的恒电位仪或电化学工作站等，辅助仪器包含恒温水浴装置、烧杯、饱和甘汞电极等。
③电偶腐蚀试样至少设置3组，同时应至少各设置3个未偶联的对比试样。
(3)测量
①试样放置进溶液中后，应立即连通电路，开始测量电偶电流，并记录测量时间。
②同时测量偶联试样的电偶电位和未偶联对比试样的电极电位，如1h、4h、8h、24h，之后每日上午、下午各一次。
(4)评价
①绘制电偶电流-时间曲线，可了解电偶腐蚀在某一时刻的电偶腐蚀速度。
②记录电偶腐蚀电流出现(不为零)的时间。
③根据电偶电流、试验面积、时间计算平均电偶电流密度。
④观察试验结束后涂层外观形貌。
⑤结合组元的极性、开路电位差、阴极和阳极极化等评价电偶腐蚀情况。
本实施例选择尺寸为100mm×50mm×1mm的板状2A12铝合金作为基材，一端采用锡焊的方式引出铜导线。按照热喷涂氧化锆陶瓷制备工艺，即利用等离子喷涂设备(型号GTV F6)喷涂制备绝缘涂层，将粉体加热熔化，用高速气流雾化喷涂至上述2A12铝合金基材表面，通过工艺控制获得具有贯穿性通孔的多孔陶瓷涂层，测得涂层厚度为56.3μm，测量陶瓷涂层与2A12铝合金基材间的电阻率为5.8×10 11Ω·m，向其表面滴加人造海水后，约2-5s后即可测量到其电阻率明显下降，证实其已自陶瓷涂层渗透至铝板。本实施例以人造海水为腐蚀介质，人造海水的配方见GB/T 15748《船用金属材料电偶腐蚀试验方法》。测量人造海水的电阻率为4.7Ω·m，将陶瓷涂层一侧用人造海水充分润湿后测量二者间电阻率为4.8Ω·m。按相同工艺平行制备表面覆有氧化锆多孔陶瓷涂层(涂层厚度仍为56.3μm)的2A12铝合金表面，在此2A12铝合金表面喷涂银导电涂层，涂层厚度83.6μm，测量银导电涂层与2A12间的电阻率为6.3×10 11Ω·m。试样制备符合要求。试验面积选择为50cm 2，按照试验面积采用氟碳涂料制备绝缘涂层对试样进行封闭，封闭后用游标卡尺精确测量试验面积为50.26cm 2。所得试样的结构如图1所示。采用清洁剂对导电涂层表面进行必要的清洁。在烧杯中装入1500mL人造海水，将试样和参比电极浸入人造海水中，使液面处于试样绝缘涂层的中间位置(保持液面以上部位干燥)，按照测试要求连接测试电路，如图2所示，立即连通电路，测量电偶电流，并记录测量时间。平行试样设置为3组。
表1实施例1待测试样测得的不同时间下的电偶电流
Figure PCTCN2021131983-appb-000001
试验结果评价：综合三组平行试验，在人造海水中，银导电漆在8～10h内即可测量到明显的腐蚀电流，说明银导电漆在6h之前可对基材起到较好的保护作用，6h之后人造海水可能已慢慢透过导电涂层，经绝缘多孔材料达到基材，因此在8h和10h测量点，三组试样均能测到腐蚀电流，腐蚀电流不为0，说明导电涂层与基材2A12间已发生电偶腐蚀。根据腐蚀电流方向可知银导电涂层为阴极，2A12为阳极。
实施例2
本实施例选择尺寸为100mm×50mm×1mm的板状921A钢合金作为基材，一端采用锡焊的方式引出铜导线。按照热喷涂氧化铝陶瓷制备工艺，即利用等离子喷涂设备(型号GTV F6)喷涂制备绝缘涂层，将粉体加热熔化，用高速气流雾化喷涂至上述921A钢合金基材表面，通过工艺控制获得具有贯穿性通孔的多孔陶瓷涂层。
测得涂层厚度为62.7μm，测量陶瓷涂层与921A钢合金基材间的电阻率为6.7×10 11Ω·m，向其表面滴加人造海水后，约2-5s后即可测量到其电阻率明显下降，证实其已自陶瓷涂层渗透至钢板。本实施例以人造海水为腐蚀介质，人造海水的配方见GB/T 15748《船用金属材料电偶腐蚀试验方法》。测量人造海水的电阻率为4.6Ω·m，将陶瓷涂层一侧用人造海水充分润湿后测量二者间电阻率为4.7Ω·m。按相同工艺平行制备表面覆有氧化铝多孔陶瓷涂层(涂层厚度仍为62.7μm)的921A钢合金，在此921A钢合金表面喷涂铜导电涂层，涂层厚度72.8μm，测量铜导电涂层与921A间的电阻率为6.9×10 11Ω·m。
试样制备符合要求。试验面积选择为50cm 2，按照试验面积采用氟碳涂料制备绝缘涂层对试样进行封闭，封闭后用游标卡尺精确测量试验面积为50.32cm 2。所得试样的结构如图1所示。采用清洁剂对导电涂层表面进行必要的清洁。在烧杯中装入1500mL人造海水，将试样和参比电极浸入人造海水中，使液面处于试样绝缘涂层的中间位置(保持液面以上部位干燥)，按照测试要求连接测试电路，如图2所示，立即连通电路，测量电偶电流，并记录测量时间。平行试样设置为3组。
其他试样及其制备、试验仪器及装置连接、测量以及评价同实施例1。
实验结果如下：
表2
Figure PCTCN2021131983-appb-000002
试验结果评价：综合三组平行试验，在人造海水中，铜导电漆在32h内即可测量到明显的腐蚀电流，说明银导电漆在24h之前可对基材起到较好的保护作用，24h之后人造海水可能已慢慢透过导电涂层，经绝缘多孔材料达到基材，因此在32h测量点，三组试样均能测到腐蚀电流，腐蚀电流不为0，说明导电涂层与基材921A间已发生电偶腐蚀。根据腐蚀电流方向可知铜导电涂层为阴极，921A为阳极。
以上所述是本公开的优选实施方式而已，当然不能以此来限定本公开之权利范围，应当指出，对于本技术领域的普通技术人员来说，在不脱离本公开原理的前提下，还可以做出若干改进和变动，这些改进和变动也视为本公开的保护范围。
工业实用性
本公开提供一种用于测量导电涂层与被保护基材之间电偶腐蚀的试样及评价方法，本公开所使用的试样时采用微孔绝缘材料介于基材和导电涂层之间，腐蚀介质渗透导电涂层前，在基材和导电涂层之间起到良好的绝缘作用；腐蚀介质渗透导电涂层后，腐蚀介质能迅速通过微孔绝缘材料到达基材，形成离子通路。不仅可测得电偶腐蚀发生后的相关参数，还可以评价腐蚀介质由导电涂层表面渗入至金属基材过程中的相关参数，如电偶腐蚀开始时间，电偶腐蚀发生前导电涂层与金属基材间电偶电压变化等，具有多范围的应用价值。
本公开在测量设备精度允许的情况下，可以测量导电涂层与其他所有(导电)材料(即基材)间的电偶腐蚀问题，如金属、金属渡涂层、其他导电涂层、碳纤维材料等，具有广泛的应用范围和良好的应用前景。

Claims (16)

  1. 一种用于测量导电涂层与基材之间电偶腐蚀的试样，其特征在于，所述试样的测试部分由待测的基材、待测的导电涂层与微孔绝缘层构成，所述微孔绝缘层位于所述基材和导电涂层之间，所述微孔绝缘层填充导电介质后能够使所述导电涂层和基材表面形成离子通路，所述基材及导电涂层均连接有独立的引线。
  2. 根据权利要求1所述的用于测量导电涂层与基材之间电偶腐蚀的试样，其特征在于，所述基材选自在与所述导电材料相互接触并同时处于电解质中，所述基材自身易产生或能产生电化学腐蚀的基材；和/或
    所述基材选自在与所述导电材料相互接触并同时处于电解质中，所述基材引起所述导电材料易产生或能产生电化学腐蚀的基材；和/或
    所述基材选自在与所述导电材料相互接触并同时处于电解质中，所述基材与导电材料之间易产生或能产生电流的基材；和/或
    所述基材选自在电解质中易腐蚀的基材；和/或
    所述基材选自具有导电性的基材。
  3. 根据权利要求1-2中任一项所述的用于测量导电涂层与基材之间电偶腐蚀的试样，其特征在于，
    所述基材包括材料本体或材料涂层；所述材料本体或材料涂层选自但不限于：导体、半导体、导电材料；
    优选地，所述导体包括：金属、石墨、碳系导体材料；
    优选地，所述半导体包括：含硅材料、含锗材料、含镓材料、含硒材料、锰氧化物、铬氧化物、铁氧化物、铜氧化物。
  4. 根据权利要求1-3中任一项所述的用于测量导电涂层与基材之间电偶腐蚀的试样，其特征在于，所述基材包括金属、金属镀涂层、导电涂层、碳纤维材料。
  5. 根据权利要求1-4中任一项所述的用于测量导电涂层与基材之间电偶腐蚀的试样，其特征在于，所述试样测试部分以外的表面涂覆有绝缘保护层。
  6. 根据权利要求1-5中任一项所述的用于测量导电涂层与基材之间电偶腐蚀的试样，其特征在于，所述基材与微孔绝缘层之间的电阻率在1×10 11Ω·m以上；所述导电涂层与微孔绝缘层之间的电阻率在1×10 11Ω·m以上。
  7. 根据权利要求1-6中任一项所述的用于测量导电涂层与基材之间电偶腐蚀的试样，其特征在于，所述微孔绝缘层的微孔结构填满导电介质后，其电阻率与导电介质本身的电阻率相 差不超过5％。
  8. 根据权利要求1-7中任一项所述的用于测量导电涂层与基材之间电偶腐蚀的试样，其特征在于，所述微孔结构的孔隙结构使得腐蚀介质自微孔绝缘层一侧传导至另一侧所需的时间不超过180s。
  9. 根据权利要求1-8中任一项所述的用于测量导电涂层与基材之间电偶腐蚀的试样，其特征在于，所述微孔绝缘层的厚度不超过20μm。
  10. 根据权利要求1-9中任一项所述的用于测量导电涂层与基材之间电偶腐蚀的试样，其特征在于，所述微孔绝缘层为多孔陶瓷涂层。
  11. 一种用于测量导电涂层与基材之间电偶腐蚀的电化学装置，包括权利要求1-10中任一项所述的用于测量导电涂层与基材之间电偶腐蚀的试样。
  12. 权利要求1-10中任一项所述的用于测量导电涂层与基材之间电偶腐蚀的试样在用于评价导电涂层电偶腐蚀的用途。
  13. 权利要求11所述的用于测量导电涂层与基材之间电偶腐蚀的电化学装置在用于评价导电涂层电偶腐蚀的用途。
  14. 一种导电涂层电偶腐蚀的评价方法，其特征在于，采用权利要求1-10任一项所述的试样进行电偶腐蚀测试。
  15. 根据权利要求14所述的评价方法，其特征在于，包括如下步骤：
    (1)获得以待测导电涂层、微孔绝缘层和基材为组成部分的试样；
    (2)获得待测腐蚀介质；
    (3)将试样测试部分浸入腐蚀介质，避免基材接触腐蚀介质；
    (4)按要求选择参比电极，进行电路和测量仪器的连接，采用零阻电流法测量电偶电流。
  16. 根据权利要求14所述的评价方法，其特征在于，所述评价方法还包括：
    将从所述测量电偶电流开始至测量到所述电偶腐蚀发生时的总时间作为评价所述电偶腐蚀的指标。
PCT/CN2021/131983 2021-02-26 2021-11-22 一种用于测量导电涂层与被保护基材之间电偶腐蚀的试样及评价方法 WO2022179208A1 (zh)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117214076A (zh) * 2023-09-14 2023-12-12 大连理工大学 一种海洋结构物腐蚀状态综合分析装置及监测方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112986125A (zh) * 2021-02-26 2021-06-18 武汉材料保护研究所有限公司 一种用于测量导电涂层与被保护的基材之间电偶腐蚀的试样及评价方法

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003215024A (ja) * 2001-11-13 2003-07-30 Jfe Engineering Kk 異種金属接触腐食による金属材の腐食量予測方法及び寿命予測方法、金属材、構造物の設計方法及び金属材の製造方法
US20050082174A1 (en) * 2003-10-21 2005-04-21 Rockwell Scientific Licensing, Llc Evaluation of the corrosion inhibiting activity of a coating
CN103018299A (zh) * 2012-12-07 2013-04-03 山东电力集团公司电力科学研究院 电偶型腐蚀传感器
CN108165918A (zh) * 2018-01-04 2018-06-15 中国科学院上海硅酸盐研究所 一种海洋防腐防污复合涂层及其制备方法
CN109900630A (zh) * 2019-01-31 2019-06-18 中国科学院金属研究所 一种评价复杂金属偶对电偶腐蚀的测试装置和方法
CN111141671A (zh) * 2020-01-21 2020-05-12 鞍钢股份有限公司 一种复合钢筋覆层与芯材的电偶腐蚀模拟试验装置及方法
CN111812019A (zh) * 2020-07-21 2020-10-23 深圳职业技术学院 金属大气腐蚀监测传感器
CN112986125A (zh) * 2021-02-26 2021-06-18 武汉材料保护研究所有限公司 一种用于测量导电涂层与被保护的基材之间电偶腐蚀的试样及评价方法

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6196060B1 (en) * 1998-07-20 2001-03-06 Intevep, S. A. Apparatus and method for monitoring hydrogen permeation
ATE456038T1 (de) * 2007-02-06 2010-02-15 Royal Scient Soc Galvanisches korrosionsüberwachungs- und analysesystem
EP2124034A1 (en) * 2008-05-20 2009-11-25 BAE Systems PLC Corrosion sensors
WO2017033242A1 (ja) * 2015-08-21 2017-03-02 株式会社日立製作所 劣化検出構造体、劣化検出方法及び劣化検出システム
WO2020139080A1 (en) * 2018-12-28 2020-07-02 Cardilli Emanuele Corrosion monitoring system and method
JP7132886B2 (ja) * 2019-05-28 2022-09-07 株式会社豊田中央研究所 腐食侵入水素測定装置および腐食侵入水素評価方法
AU2020329576A1 (en) * 2019-08-12 2022-02-24 Hempel A/S A coated structure with a monitoring system, a monitoring system, and a method for monitoring a condition of a coated structure

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003215024A (ja) * 2001-11-13 2003-07-30 Jfe Engineering Kk 異種金属接触腐食による金属材の腐食量予測方法及び寿命予測方法、金属材、構造物の設計方法及び金属材の製造方法
US20050082174A1 (en) * 2003-10-21 2005-04-21 Rockwell Scientific Licensing, Llc Evaluation of the corrosion inhibiting activity of a coating
CN103018299A (zh) * 2012-12-07 2013-04-03 山东电力集团公司电力科学研究院 电偶型腐蚀传感器
CN108165918A (zh) * 2018-01-04 2018-06-15 中国科学院上海硅酸盐研究所 一种海洋防腐防污复合涂层及其制备方法
CN109900630A (zh) * 2019-01-31 2019-06-18 中国科学院金属研究所 一种评价复杂金属偶对电偶腐蚀的测试装置和方法
CN111141671A (zh) * 2020-01-21 2020-05-12 鞍钢股份有限公司 一种复合钢筋覆层与芯材的电偶腐蚀模拟试验装置及方法
CN111812019A (zh) * 2020-07-21 2020-10-23 深圳职业技术学院 金属大气腐蚀监测传感器
CN112986125A (zh) * 2021-02-26 2021-06-18 武汉材料保护研究所有限公司 一种用于测量导电涂层与被保护的基材之间电偶腐蚀的试样及评价方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117214076A (zh) * 2023-09-14 2023-12-12 大连理工大学 一种海洋结构物腐蚀状态综合分析装置及监测方法
CN117214076B (zh) * 2023-09-14 2024-05-14 大连理工大学 一种海洋结构物腐蚀状态综合分析装置及监测方法

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