Method for monitoring friction wear of coating based on friction electric signal

Abstract

A method for monitoring friction wear of a coating based on a friction electric signal belongs to the technical field of friction wear monitoring of a friction pair substrate surface coating, and comprises the following steps: preparing a coating on the surface of a friction pair substrate, rubbing the coating in the use process of a friction pair, and monitoring the electric signal generated in the friction process of the friction pair. And the frictional wear state of the friction pair is judged according to the monitored electric signal difference, alarm is triggered when the magnitude of the current signal reaches a threshold value, and stage early warning is performed before the substrate is worn by setting the threshold value. According to the invention, a real-time on-line monitoring system for coating wear is established based on the magnitude difference of friction electric signals. The system has the capability of continuous real-time monitoring and can feed back the state of the coating in time, so that the risk of damage to the substrate is remarkably reduced. According to the method, early warning can be obtained before the substrate is abraded, and then proper maintenance measures are taken, so that the reliability of equipment is ensured, and the service life of the equipment is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of friction and wear monitoring of coatings on the surface of friction pair substrates, and in particular relates to a method for monitoring coating friction and wear based on triboelectric signals. Background Art

[0002] The coating has the characteristics of corrosion resistance, wear resistance, insulation and lubricity, making it an effective means of protecting the base material. During use, the coating will inevitably be worn by friction with other materials, thus affecting its protective ability. Regular inspection and maintenance of the coating surface can effectively avoid coating failure, so it is very necessary to monitor the life of the coating. However, regular inspection and maintenance are very time-consuming and costly, and it is impossible to monitor the coating in real time around the clock.

[0003] There are several existing coating damage monitoring methods. Ultrasonic monitoring method: When ultrasonic waves pass through the material, its propagation speed changes. The thickness of the coating is obtained by measuring the propagation time of the ultrasonic wave, thereby detecting wear that changes over time; Acoustic emission detection method: Acoustic emission technology is a real-time dynamic non-destructive detection method that can directly detect the crack propagation behavior during the failure process of thermal barrier coatings. By analyzing the obtained parameters, the damage and failure of the coating can be obtained qualitatively, quantitatively and positionally, and the life of the coating can be predicted; Chemical analysis: The chemical composition of the coating can be analyzed through technologies such as X-ray photoelectron spectroscopy to detect changes that indicate wear or degradation. The above methods all require the collection of the obtained physical or chemical signals, and then the wear state of the coating is obtained after analysis. The procedures are complicated and cannot achieve continuous real-time monitoring. Summary of the invention

[0004] The invention discloses a method for monitoring friction and wear of coating based on triboelectric signals, aiming at solving the problems existing in the prior art method for monitoring friction and wear of substrate surface coating.

[0005] To achieve the above purpose, the technical solution of the present invention is:

[0006] A method for monitoring friction and wear of coatings based on triboelectric signals comprises the following steps: preparing a coating on the surface of a friction pair substrate, rubbing the coating during use of the friction pair, monitoring the electrical signals generated during the friction of the friction pair based on the law of changes in the current electrical signals generated during the friction process, and judging the friction and wear state of the friction pair based on the difference in the electrical signals obtained by monitoring, triggering an alarm when the current signal reaches a threshold, and providing a staged warning before the substrate is worn by setting the threshold.

[0007] Preferably, the material selected for the coating is an inorganic material or an organic material, the inorganic material is one of diamond-like carbon film, silicate, phosphate, zinc coating, magnesium coating, metal compound, and ceramic, and the organic material is one of polytetrafluoroethylene, silicone resin, acrylic resin, polyurethane, epoxy resin, and other resins.

[0008] Preferably, the coating is prepared by one or more of spin coating, spray coating, ion sputtering, magnetron sputtering, chemical deposition or other methods.

[0009] Preferably, the coating structure is a single layer, a double layer or a multi-layer.

[0010] Preferably, the method for monitoring the triboelectric signal generated during the friction movement of the friction pair is to electrically connect the friction pair to a monitor through a single-electrode or double-electrode method.

[0011] Preferably, the monitor first amplifies the electrical signal through a signal amplifier, and then analyzes the electrical signal through a microprocessor or a single-chip microcontroller to monitor the coating status.

[0012] Preferably, when the coating is damaged, the electrical signal changes from small to large or from large to small, and the monitor determines whether a threshold value is reached based on the change in the electrical signal and issues an alarm.

[0013] The beneficial effects of the method for monitoring friction and wear of coatings based on triboelectric signals of the present invention are as follows:

[0014] At present, the coating friction and wear monitoring methods usually face the problems of lack of real-time data and insufficient continuous monitoring. In practical applications, the coating generates friction due to the movement of the friction pair. During this process, the charge on the surface of the friction contact is transferred and redistributed, thereby generating friction current. The present invention proposes to use the change of friction current of the coating during the friction process to provide early warning of coating wear. Based on the difference in the size of the friction electric signal, a real-time online monitoring system for coating friction and wear is established. When the coating is worn to a certain extent, the friction current triggers the threshold and an alarm occurs. The system has the ability of continuous real-time monitoring and can provide timely feedback on the status of the coating, thereby significantly reducing the risk of damage to the friction pair substrate. This method can obtain early warning before the substrate wears, and then take appropriate maintenance measures to ensure the reliability of the equipment and extend its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of a double-layer structure coating provided by the present invention;

[0016] Figure 2 It is the principle diagram of the single-electrode triboelectric signal monitoring method;

[0017] Figure 3 The triboelectric signal monitoring result in Example 5;

[0018] Figure 4 A schematic diagram of a single-layer structure coating provided by the present invention;

[0019] Figure 5 It is the principle diagram of the double-electrode triboelectric signal monitoring method;

[0020] Figure 6 This is the triboelectric signal monitoring result in Example 6.

[0021] In the figure: 1, surface coating; 2, bottom coating; 3, substrate. DETAILED DESCRIPTION

[0022] The following description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0023] The following embodiments may be understood as individually expressing a part of a local structure or method of the present invention, or may be understood as a combination of the embodiments to explain the connotation of a larger structure or method of the present invention.

[0024] Example 1

[0025] A method for monitoring friction and wear of coating based on triboelectric signals comprises the following steps: Figure 4 , 5 As shown, a single-layer structural coating is prepared on the surface of the friction pair substrate, and the friction pair is electrically connected to a monitor through a single electrode or a double electrode method. The monitor includes a detection device and an early warning device. The detection device is used to detect the size of the electrical signal. When the coating is worn through, the electrical signal reaches a threshold value and the early warning device gives an alarm.

[0026] In this embodiment, the material selected from the coating is an inorganic material or an organic material, the inorganic material is one of diamond-like carbon film, silicate, phosphate, zinc coating, magnesium coating, metal compound or ceramic, and the organic material is one of polytetrafluoroethylene, silicone resin, acrylic resin, polyurethane, epoxy resin or other resins. The coating is prepared by spin coating, spray coating, ion sputtering, magnetron sputtering, chemical deposition or other methods. When the electrical signal reaches the threshold, it means that the coating is worn through and the substrate is about to be worn.

[0027] Example 2

[0028] A method for monitoring friction and wear of coating based on triboelectric signals comprises the following steps: Figure 1 , 3As shown, a double-layer structural coating is prepared on the surface of the friction pair substrate, and the two coating materials are both inorganic materials or both organic materials or a combination of organic materials and inorganic materials; the preparation method of the coating is arbitrarily selected as in Example 1; when the surface coating 1 is worn through and contacts the bottom coating 2, the friction electric signal changes; when the bottom coating 2 is worn through and contacts the substrate 3, the friction electric signal changes again, and the wear state of the coating is judged by the change.

[0029] In this embodiment, the coating wear state can be judged by the change, which means that the surface coating and the bottom coating can be monitored in real time by the change of the electrical signal, thereby realizing the staged monitoring of the friction pair wear state, which is beneficial to the control of the friction pair wear.

[0030] Implementation 3

[0031] A method for monitoring friction and wear of coatings based on triboelectric signals comprises the following steps: preparing a multilayer structure coating on the surface of a substrate, the coating material and the preparation method being the same as above; each time a layer of coating is worn through, the triboelectric signal changes; and judging the wear state of the coating by the change.

[0032] In this embodiment, a multi-layer coating is provided to further achieve staged monitoring and control of the wear state of the friction pair.

[0033] Example 4

[0034] Based on Examples 1-3, this embodiment discloses: a method for monitoring the friction electric signal generated during the friction movement of the friction pair is to electrically connect the friction pair to a monitor through a single electrode or a double electrode method; the monitor first amplifies the signal through a signal amplifier, and then analyzes the electrical signal through a microprocessor or a single-chip microcontroller to monitor the coating status.

[0035] In the above embodiments, the motion form of the friction pair is relative linear motion or relative rotational motion; the contact form of the friction pair is point, line or surface contact.

[0036] Example 5

[0037] A method for monitoring friction and wear of coating based on triboelectric signals comprises the following steps:

[0038] A. First, a zinc coating is prepared on the surface of the substrate by a chemical method as the bottom coating 2;

[0039] B. Then, a layer of diamond-like carbon film is prepared on the surface of the bottom coating 2 by magnetron sputtering as the surface coating 1, such as Figure 1 As shown;

[0040] C. Figure 2A steel ball and the double-layer structure coating are selected to form a friction pair, and the friction pairs are in point contact; the steel ball is fixed in position and moves back and forth relative to the coating; the current is collected using a single electrode method, one end of the wire is connected to the steel ball, and the other end is connected to the monitor, and the electrical signal is transmitted to the display through the monitor; the triboelectric signal obtained by monitoring is as follows Figure 3 As shown, when the steel ball rubs against the surface coating, the friction current is small. As the friction progresses, the surface coating is destroyed, the steel ball contacts the bottom coating, and the friction current becomes larger. At this time, the current value sets a threshold to trigger an alarm, so that protective measures can be taken in time before the substrate is worn.

[0041] Example 6

[0042] A method for monitoring friction and wear of coating based on triboelectric signals comprises the following steps:

[0043] A. Prepare an acrylic resin surface coating 1 on the substrate surface by spraying, such as Figure 4 ;

[0044] B. Figure 5 A copper ball and the single-layer structure surface coating 1 are selected to form a friction pair, and the friction pairs are in point contact; the copper ball is fixed in position and reciprocates relative to the coating; the current is collected using a double-electrode method, the positive end of the wire is connected to the copper ball, the negative end is connected to the base metal, and finally connected to the monitor, and the electrical signal is transmitted to the display through the monitor; the triboelectric signal obtained by monitoring is as follows Figure 6 As shown in the figure, when the copper ball rubs against the coating, the contact area gradually increases, and the friction current also gradually increases; the current value at point A sets a threshold to trigger an alarm, and protective measures can be taken in time before the substrate is worn.

[0045] Real-time Example 7

[0046] A method for monitoring friction and wear of coating based on triboelectric signals comprises the following steps:

[0047] A. preparing a magnesium surface coating 1 on a substrate surface by ion sputtering;

[0048] B. A steel ball and the single-layer structure surface coating 1 are selected to form a friction pair, and the friction pairs are in point contact; the steel ball is fixed in position and reciprocates relative to the coating; a double-electrode method is used for current collection, the positive end of the wire is connected to the steel ball, the negative end is connected to the base metal, and finally connected to the monitor, and the electrical signal is transmitted to the display through the monitor; when the steel ball contacts the magnesium coating, the current is 100nA, and when the magnesium coating is worn through, the current becomes 1nA, and the coating wear state can be obtained through the change in current size, that is, an alarm is provided when it is worn through.

[0049] Real-time Example 8

[0050] A method for monitoring friction and wear of coating based on triboelectric signals comprises the following steps:

[0051] A. Spin-coating polytetrafluoroethylene, polyurethane, and polydimethylsiloxane on the surface of the substrate in sequence to form a multilayer coating;

[0052] B. An aluminum ball and the multilayer structure coating are selected to form a friction pair, and the friction pairs are in point contact; the aluminum ball is fixed in position and reciprocates relative to the coating; the current is collected using a dual-electrode method, the positive end of the wire is connected to the aluminum ball, the negative end is connected to the base metal, and finally connected to the monitor, and the electrical signal is transmitted to the display through the monitor; as the friction progresses, the friction electricity of the aluminum ball when it contacts the surface polydimethylsiloxane is 500nA, when it wears through the surface and contacts the polyurethane, the friction electricity becomes 1nA, and when it contacts the bottom polytetrafluoroethylene, the friction electricity becomes 1000nA. The wear state of the coating can be obtained by the change in current size, that is, the wear state of each coating is monitored in stages.

Claims

1. A method for monitoring friction and wear of coatings based on triboelectric signals, characterized by: The following steps are involved: A coating is prepared on the surface of the friction pair substrate. During the use of the friction pair, the coating is rubbed. Based on the law of changes in the current electrical signals generated during the friction process, the electrical signals generated during the friction process of the friction pair are monitored, and the friction and wear state of the friction pair is judged based on the difference in the monitored electrical signals. When the current signal reaches a threshold, an alarm is triggered. By setting the threshold, a staged early warning can be given before the substrate is worn.

2. A method for monitoring friction and wear of coatings based on triboelectric signals as claimed in claim 1, characterized in that: The material selected for the coating is an inorganic material or an organic material. The inorganic material is one of diamond-like carbon film, silicate, phosphate, zinc coating, magnesium coating, metal compound, and ceramic. The organic material is one of polytetrafluoroethylene, silicone resin, acrylic resin, polyurethane, epoxy resin, and other resins.

3. A method for monitoring friction and wear of coatings based on triboelectric signals as claimed in claim 1, characterized in that: The coating is prepared by one or more of spin coating, spray coating, ion sputtering, magnetron sputtering, chemical deposition or other methods.

4. A method for monitoring friction and wear of coatings based on triboelectric signals as claimed in claim 1, characterized in that: The coating structure is single-layer, double-layer or multi-layer.

5. A method for monitoring friction and wear of coatings based on triboelectric signals according to any one of claims 1 to 4, characterized in that: The method for monitoring the triboelectric signal generated during the friction movement of the friction pair is to electrically connect the friction pair to a monitor through a single electrode or a double electrode method.

6. A method for monitoring friction and wear of coatings based on triboelectric signals as claimed in claim 5, characterized in that: The monitor first amplifies the electrical signal through a signal amplifier, and then analyzes the electrical signal through a microprocessor or a single-chip microcontroller to monitor the coating state.

7. A method for monitoring friction and wear of coatings based on triboelectric signals as claimed in claim 6, characterized in that: When the coating is damaged, the electrical signal changes from small to large or from large to small. The monitor determines whether the threshold is reached based on the change of the electrical signal and issues an alarm.

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