Testing device for characterizing coating
By designing a testing device for coatings, which uses a housing, contact elements, and actuators to simulate coating loading, the problems of complexity and high cost in coating property testing are solved, enabling rapid and economical evaluation of coating properties.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SCHAEFFLER TECHNOLOGIES AG & CO KG
- Filing Date
- 2024-10-22
- Publication Date
- 2026-05-01
AI Technical Summary
Existing technologies for testing coating properties are complex and costly, necessitating simplified and cost-effective testing equipment.
A test device comprising a housing, contact elements, insulating elements, and actuators was designed to simulate current and pressure loading of the coating under actual conditions, measure resistance through a 4-wire circuit, simulate insertion/removal and fretting corrosion through the actuators, and monitor coating performance changes through a sensor unit.
It simplifies, speeds up, and costs up to the cost of coating characteristic testing, enabling accurate assessment of thin-film resistance, insertion/removal cycle count, fretting corrosion, and thermal load capacity, while reducing testing complexity and cost.
Smart Images
Figure CN121969922A_ABST
Abstract
Description
Test apparatus for characterizing coatings Technical Field
[0001] The following statement relates to a test apparatus for characterizing coatings, particularly contact coatings of electrical conductor units, which enables simple, rapid and economical characterization of the coatings. Background Technology
[0002] To characterize coatings, particularly contact coatings in plug connectors, separate test procedures are typically used to determine five application-oriented properties. These properties include sheet resistance, mating cycle count, fretting corrosion resistance, thermal load capacity, and current carrying capacity. Testing these contact-specific properties is relatively complex, requires a considerable amount of measuring equipment, and usually must be performed in different locations.
[0003] There is always a need to simplify the testing of the contact-specific properties of coatings while reducing testing costs.
[0004] Based on this situation, the current objective is to identify measures that enable cost-effective and easy-to-use testing equipment for characterizing coatings. Summary of the Invention
[0005] The current objective is achieved through the features of the independent principal claim. Advantageous embodiments are provided in the dependent claims. The teachings of the dependent claims may be combined with the teachings of the principal and dependent claims in any manner, provided it is technically feasible.
[0006] Therefore, this objective is achieved by a testing apparatus for characterizing coatings, particularly contact coatings of electrical conductor units. The testing apparatus includes: a housing for housing components for performing a series of measurement procedures to characterize the coating; a first contact element and a second contact element, each indirectly mounted on the housing for contacting a sample; a sample holder for receiving and positioning the sample between the first and second contact elements; a first insulating element for electrical and / or thermal insulation of the first contact element; a second insulating element for electrical and / or thermal insulation of the second contact element; each of the first and second contact elements having electrical terminals for connecting to a power source and for transmitting electrical energy through the sample, wherein the first contact element is indirectly mounted on the housing and is movable relative to the second contact element, and the pressure applied to the sample can be adjusted by the movable first contact element; and the sample holder can be indirectly or directly connected to the housing, the first actuator, and / or the second actuator depending on the measurement method to be performed.
[0007] Numerous components can be arranged inside or outside the housing of the testing apparatus and attached directly or indirectly to the housing. First and second contact elements serve as clamping devices for the sample body during inspection. The sample body can be arranged between the contact elements and subjected to adjustable pressure through them. By acting on the sample body, the loading of the coating in the plug, for example, when the plug is inserted, can be simulated. To avoid electrical and / or thermal effects, the contact elements are indirectly connected to the housing via insulating elements or mounted on the housing. Electrical terminals allow the sample body to be exposed to or subjected to current. The resistance and heat generated due to the current flow allow inference of the coating properties during inspection. The sample holder is specifically designed to be coupled to the housing, the first actuation element, and / or the second actuation element. This allows for a large number of tests to be performed on the testing apparatus with minimal modification. Therefore, the testing apparatus allows for the easy, rapid, and cost-effective determination of a large number of contact-specific properties of the coating.
[0008] The advantages are described below, followed by a description of preferred modified implementations. The descriptions, particularly regarding the advantages and definitions of the features, are largely descriptive and preferred examples, not limiting ones. If the description is limiting, this will be explicitly stated.
[0009] The sample holder can be made of a non-conductive and / or non-thermal conductive material. Therefore, the sample holder can be designed as an electrical insulator and / or thermal insulator. This allows for the reduction or prevention of cinematic and / or thermal influence factors that may distort measurement results. The sample holder can be connected to the housing, the first actuation element, and / or the second actuation element via a cylindrical rod or the like. The sample holder particularly has a connecting element for connecting to a piston rod that acts longitudinally with the first actuation element and / or the second actuation element (26). This allows for quick and easy reconfiguration of the test apparatus and allows for the performance of other measurement procedures using the test apparatus.
[0010] The first and second contact elements are arranged in an interchangeable manner within the testing apparatus. The contact elements specifically have the same coating as the test specimen and / or are composed of the same base material as the sample. This identical composition enables improved measurement results and simulation of coating performance under real-world conditions.
[0011] Pressure is applied to the sample at intervals. The pressure is particularly in the range of 0.2 N to 4 N. The applied pressure can preferably be increased by 0.2 N at intervals. Increasing the pressure by 0.5 N or 1 N or a combination thereof is also conceivable.
[0012] In the preferred embodiment described above, to characterize the thin-film resistance of the coating, the testing apparatus has a 4-wire circuit at the electrical terminals of the first and second contact elements to measure the resistance of the sample. Resistance can be measured using a 4-wire circuit. Directly measuring the thin-film resistance is practically impossible and not useful because the coating cannot be contacted individually. It is more practical to use the testing apparatus to simulate electrical contact and measure the total resistance of the sample. A meaningful comparison can then be made using the resistance value of a reference sample.
[0013] The first contact element can be used to simulate the pressure typically generated during electrical contact. This pressure acts on a sample body clamped between the contact elements and connected to the two circuits via the electrical terminals of the contact elements. The constant current source used in the first circuit can provide I... F =10 mA current, where the maximum applied voltage is 20 mV (DC). The voltmeter is used throughout the simulated contact R. x Internal measurement voltage drop U m The measuring leads used can be attached to electrical terminals via cable connectors. Furthermore, measurement recording is performed, capturing the voltage U in a computer-controlled manner. M Curve over time and test current I F The curve over time allows for the calculation of the resistance R. x Specifically, the testing device has a receiving unit for receiving and displaying the measured resistance value.
[0014] In the preferred embodiment described above, to characterize the number of insertion and removal cycles of the coating, the sample holder is mounted so as to be displaced substantially orthogonally to the direction of pressure applied by the first actuating device. In practice, different contact layers must be able to withstand a certain number of assembly and disassembly processes without wear.
[0015] To determine the number of insertion / extraction cycles, a first actuation device can be arranged on the housing. The piston rod of the first actuation device can be connected to the test body via a sample holder. Preferably, the first actuation device is designed as a pneumatic actuator, particularly a short-stroke pneumatic cylinder. The pneumatic actuator can be connected to a compressed air control unit, which allows adjustment of the stroke distance and the retraction and extension times. For example, the stroke distance can particularly be 5 mm. The retraction or extension time can be adjusted to a constant 0.5 seconds, wherein there is a waiting interval of at least 2 seconds between retraction and extension. Furthermore, at least 3 seconds must be waited after each cycle and before the start of a new cycle. In addition, a suitable pressure must be used, which can particularly be 2 N. The number of cycles completed without any detected wear represents the number of insertion / extraction cycles.
[0016] In the preferred embodiment described above, to characterize the coating's resistance to fretting corrosion, the sample holder is mounted so as to be displaced substantially orthogonally to the direction of pressure applied by the first contact element by means of a second actuation device. To simulate fretting corrosion in the testing apparatus, the sample body needs to undergo rapid, short movements. For this reason, the second actuation device is preferably designed as a piezoelectric actuator, particularly as a piezoelectric stack. Preferably, the second actuation device is arranged on the housing.
[0017] Piezoelectric stacks are capable of deformation when excited by voltage. Depending on the length of the stack, various length variations subsequently occur. Generally, the length variation is in the range of a few micrometers, and the response time is in the range of microseconds. With a suitable control system, the size of the piezoelectric stack can be increased or decreased over a wide frequency range.
[0018] In particular, the second actuation device has a reset mechanism. By combining the piezoelectric stack with the reset mechanism—specifically designed as a tension or compression spring—uniaxial vibration or micro-motion can be achieved.
[0019] The control system must be adjusted to ensure, for example, a movement frequency of 1 Hz (“retraction and extension”), a friction path of 50 µm, and 100,000 cycles. In addition to frictional stress, a constant pressure of 2 N should be applied to the sample.
[0020] Subsequently, the contact resistance of the friction pair can be determined using a 4-wire circuit as already described. A second sensor unit can be used to determine any changes in the path of the first contact element during the measurement procedure. This allows for inference of layer wear. The coating's resistance to fretting corrosion can be determined by the changes in contact resistance and layer wear over time. Advantageously, all measurement procedures can be performed on the testing apparatus.
[0021] In the preferred embodiment described above, to characterize the thermal load capacity and current carrying capacity of the coating, the testing apparatus includes: a power supply applied to electrical terminals of a first contact element and a second contact element to allow current to pass through the sample body; and at least one first sensor unit for measuring the temperature on the coating of at least one contact element and / or the sample body. Specifically, the testing apparatus includes an evaluation unit for receiving and displaying the measurements from the at least one first sensor unit. Preferably, the at least one first sensor unit is designed as a thermocouple. In particular, the at least one first sensor unit may be indirectly arranged on the housing.
[0022] The current-carrying capacity of an electrical contact determines the maximum permissible current that can be conducted through it. This current is particularly limited by its thermal load capacity, as the actual contact heats up due to power losses caused by its contact resistance when current flows through it. High temperatures are sometimes generated because the conductive area of the contact region is typically greatly reduced. These effects are also reflected in the performance of different coatings.
[0023] The test specimen can be positioned between two contact elements and subjected to pressure to test thermal load capacity and current carrying capacity. At least one first sensor unit for temperature detection is positioned on the sample body and / or contact elements, and at least one first sensor unit is attached to the housing, particularly by means of a magnetic retainer. Furthermore, a power supply, particularly a constant current source, and an ammeter are connected to electrical terminals. By connecting the power supply with an initial current of 1 A, the coating of the sample body is heated. The thermal stability of at least one first sensor unit must then be waited for until the temperature is determined and captured by the evaluation unit. This procedure is repeated with increasing current, and the current is increased by 1 A after each cycle. Once a temperature of 200°C is reached, the test is complete.
[0024] In the preferred embodiment described above, the first insulating element is designed as a cylinder and extends through at least one opening in the housing. Preferably, the pressure exerted on the first contact element via the first insulating element can be adjusted by means of a spindle press or a weight. In particular, the testing device has a first spring element mounted on the housing and the first insulating element to generate a first spring force acting on the first insulating element in the opposite direction to the pressure. Preferably, the first insulating element is made of plastic.
[0025] In the preferred embodiment described above, the second insulating element is designed as a cylinder with external threads and extends through a cutout with internal threads in the housing. Specifically, the distance between the second contact element and the first contact element and / or the sample body can be adjusted by the threads. Preferably, the second insulating element can be locked by means of an attachment device, particularly a screw and nut. Specifically, the first insulating element is made of plastic.
[0026] In the preferred embodiment described above, the first contact element is indirectly mounted on the housing via a lever arrangement structure, which is rotatably arranged on the joint, particularly on the cross spring joint. Preferably, a spring unit for returning the lever arrangement structure to the starting position is arranged on the lever arm or in the joint. In particular, the pressure on the first contact element can be adjusted via the lever arrangement structure by means of a spindle press or a weight.
[0027] In the preferred embodiment described above, a force measuring device, particularly a load sensor, for measuring pressure is arranged on the second insulating element of the second contact element. Preferably, the force measuring device is arranged between the housing and the second insulating element. This force measuring device allows for precise determination and adjustment of the pressure introduced via the first contact element. This allows the coating of the sample to withstand a predetermined pressure in the contact area.
[0028] In the preferred embodiment described above, a second sensor unit is arranged on the housing. This second sensor unit is used to indirectly or directly measure the movement of the first contact element. Specifically, the second sensor unit is designed as a distance sensor, preferably an inductive sensor. The second sensor unit allows monitoring of the travel distance of the first contact element. Changes in the travel distance are a direct indicator of surface wear of the sample's coating, characterized by the testing apparatus. Attached Figure Description
[0029] The preferred technical solution will now be described in more detail with reference to the accompanying drawings and through preferred exemplary embodiments. In the drawings, the term "figure" is abbreviated as "Fig.".
[0030] In the accompanying drawings: Figure 1 shows a perspective view of a first embodiment of the test apparatus, Figure 2 shows a schematic side view of a second embodiment of the test apparatus, Figure 3 shows a schematic front view of the test apparatus according to Figure 2, and Figure 4 shows a circuit diagram of a 4-wire circuit.
[0031] The exemplary embodiments described are merely examples and may be modified and / or supplemented in various ways within the scope of the claims. Detailed Implementation
[0032] Figure 1 shows a perspective view of a first embodiment of a test apparatus 10 for characterizing coatings, comprising: a housing 12 for housing components for performing a large number of measurement procedures; a first contact element 14 indirectly mounted on the housing; and a second contact element 16 for contacting a sample body 18, the sample body 18 being positionable between the first contact element 14 and the second contact element 16 by means of a test sample holder 20. The sample holder 20 is displaceably mounted on the housing 12 via piston rods 22 of actuators 24, 26. Actuators 24, 26 may be specifically designed as either the first actuator 24 or the second actuator 26. To avoid electrical and / or thermal influences, the contact elements 14, 16 are indirectly connected to or mounted on the housing 12 via insulating elements 28, 30. The first contact element 14 is mounted such that it can be displaced axially via a cylindrical first insulating element 28 and can withstand pressure F in the direction toward the second contact element 16. DThe testing apparatus 10 also includes a first spring element 32, which is mounted on the housing 12 and the first insulating element 28 to generate a first spring force, which is along the pressure F. D The opposite direction of the action acts on the first insulating element 28 to bring it into the starting position. The second insulating element 30 is designed as a cylinder with external threads and extends through a cutout with internal threads in the housing 12. This allows the distance between the second contact element 16 and the first contact element 14 and / or the sample body 18 to be adjusted by the threads, and the second insulating element 30 can be locked by means of an attachment device 34, in particular a screw and nut. The contact elements 14, 16 have electrical terminals 36 for connecting to a power source and for allowing electrical energy to be transferred through the sample body 18. A second sensor unit 38 is arranged on the housing 12 on the first insulating element, which is used to measure the movement of the first contact element 14 indirectly or directly. The travel distance of the first contact element 14 can be monitored by means of the second sensor unit 38.
[0033] Figures 2 and 3 show schematic side views of a second embodiment of the test apparatus 10. This embodiment differs from the embodiment shown in Figure 1 in that the first contact element 14 is mounted to be movable via the lever arrangement structure 40, pivotable about the engagement portion 42, and able to withstand pressure F. D Furthermore, the testing device 10 has a force measuring device 44, which is arranged between the housing 12 and the second contact element 16 to measure the pressure F. D The first actuator 24 and the second actuator 26 are arranged on two opposite walls of the housing 12. This allows the sample holder 20 to be coupled to either the first actuator 24 or the second actuator 26 without much reconfiguration.
[0034] Figure 4 shows a circuit diagram of a 4-wire circuit connected to the electrical terminals 36 of contact elements 14 and 16, and the circuit is designed to determine the resistance of the sample body 18.
[0035] List of reference numerals: 10 Test apparatus; 12 Housing; 14 First contact element; 16 Second contact element; 18 Sample body; 20 Sample holder; 22 Piston rod; 24 First actuator; 26 Second actuator; 28 First insulating element; 30 Second insulating element; 32 First spring element; 34 Attachment device; 36 Electrical terminal; 38 Second sensor unit; 40 Lever arrangement structure; 42 Joint; 44 Force measuring device F D pressure.
Claims
1. A testing apparatus for characterizing a coating, particularly a contact coating of an electrical conductor unit, the testing apparatus comprising: a housing (12) for housing components for performing a large number of measurement procedures for characterizing the coating; A first contact element (14) and a second contact element (16) are indirectly mounted on the housing (12) for contacting the sample body (18); A sample holder (20) for receiving the sample body (18) and positioning the sample body between the first contact element (14) and the second contact element (16); a first insulating element (28) for electrical and / or thermal insulation of the first contact element (14); a second insulating element (30) for electrical and / or thermal insulation of the second contact element (16); the first contact element (14) and the second contact element (16) each having an electrical terminal (36), the electrical terminal... The sample holder (20) is used to connect to a power source and to transmit electrical energy through the sample body (18). The first contact element (14) is indirectly mounted on the housing (12) and is mounted in a manner that allows it to move relative to the second contact element (16). The pressure applied to the sample body (18) can be adjusted by the first contact element (14) which is mounted in a movable manner. The sample holder (20) can be indirectly or directly connected to the housing (12), the first actuator (24), and / or the second actuator (26) depending on the measurement procedure to be performed.
2. The testing apparatus according to claim 1, wherein, To characterize the thin-film resistance of the coating, the testing device (10) has a four-wire circuit at the electrical terminals (36) of the first contact element (14) and the second contact element (16) to measure the resistance of the sample body (18), wherein, in particular, the testing device (10) has a receiving unit for receiving and displaying the measured value of the resistance.
3. The testing apparatus according to claim 1 or 2, wherein, To characterize the number of insertion and removal cycles of the coating, the sample holder (20) is mounted to be able to be displaced substantially orthogonally to the direction of the pressure of the first contact element (14) by means of a first actuator (24), specifically, the first actuator (24) is designed as a short-stroke pneumatic cylinder, specifically, the first actuator (24) is arranged on the housing (12).
4. The testing apparatus according to any one of the preceding claims, wherein, To characterize the coating’s resistance to fretting corrosion, the sample holder (20) is mounted to be able to be displaced substantially orthogonally to the direction of the pressure exerted by the first contact element (14) by means of a second actuator (26). In particular, the second actuator (26) is designed as a piezoelectric actuator, especially as a piezoelectric stack. In particular, the second actuator (26) has a reset mechanism. In particular, the second actuator (26) is arranged on the housing (12).
5. The testing apparatus according to any one of the preceding claims, wherein, To characterize the thermal load capacity and current carrying capacity of the coating, the test device (10) has: a power supply applied to the electrical terminals (36) of the first contact element (14) and the second contact element (16) for transmitting current through the sample body (18); and at least one first sensor unit for measuring the temperature on the coating of at least one contact element (14, 16) and / or the sample body (18). In particular, the test device (10) has an evaluation unit for receiving and displaying the measurements of the at least one first sensor unit. In particular, the at least one first sensor unit is designed as a thermocouple. In particular, the at least one first sensor unit can be indirectly arranged on the housing (12).
6. The testing apparatus according to any one of the preceding claims, wherein, The first insulating element (28) is designed to be cylindrical and extends through at least one opening in the housing (12). In particular, the pressure on the first contact element (14) via the first insulating element (28) can be adjusted by means of a spindle press or a weight. In particular, the test device (10) has a first spring element (32) mounted on the housing (12) and the first insulating element (28) to generate a first spring force acting on the first insulating element (28) in the opposite direction to the pressure. In particular, the first insulating element (28) is made of plastic.
7. The testing apparatus according to any one of the preceding claims, wherein, The second insulating element (30) is designed as a cylinder with external threads and extends through a cutout with internal threads in the housing (12). In particular, the distance between the second contact element (16) and the first contact element (14) and / or the sample body (18) can be adjusted by the threads. In particular, the second insulating element (30) can be locked by means of an attachment device (34), in particular a screw and nut. In particular, the first insulating element (28) is made of plastic.
8. The testing apparatus according to any one of claims 1 to 5, wherein, The first contact element (14) is indirectly mounted on the housing (12) via a lever arrangement structure (40) which is rotatably arranged on the joint (42), particularly on the cross spring joint. In particular, a spring unit for returning the lever arrangement structure (40) to the starting position is arranged on the lever arm or in the joint (42). In particular, the pressure on the first contact element (14) can be adjusted via the lever arrangement structure (40) by means of a spindle press or a weight.
9. The testing apparatus according to any one of the preceding claims, wherein, A force measuring device (44), particularly a load sensor, for measuring the pressure is arranged on the second insulating element (30) of the second contact element (16). Specifically, the force measuring device (44) is arranged between the housing (12) and the second insulating element (30).
10. The testing apparatus according to any one of the preceding claims, wherein, A second sensor unit (38) is arranged on the housing (12). The second sensor unit is used to measure the movement of the first contact element (14) indirectly or directly. In particular, the second sensor unit (38) is designed as a distance sensor, preferably as an inductive sensor.