Wear early-warning intelligent material based on conductive core-shell micro-nano particles and preparation method of wear early-warning intelligent material

Abstract

The invention provides a wear early-warning intelligent material based on conductive core-shell micro-nano particles and a preparation method of the wear early-warning intelligent material, and belongs to the technical field of sensing materials. Conductive core-shell micro-nano particles are used as basic sensing function units to be doped into a polymer matrix to form a sensing layer, a three-layer structure material of a bottom residual life layer, a middle sensing layer and a surface self-lubricating wear-resistant layer is designed, and the material is prepared on a metal auxiliary surface. The surface self-lubricating wear-resistant layer is consumed in the wear process, so that the wear reaches the middle sensing layer, and the resistance of the middle sensing layer is obviously changed due to the damage of the conductive micro-nano particles as an early warning signal, so that the early warning information that the surface self-lubricating wear-resistant layer is worn out and friction pair parts need to be replaced in time is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensing materials, in particular to a wear early warning intelligent material based on conductive core-shell micro-nanoparticles and a preparation method thereof. BACKGROUND

[0002] Friction and wear of mechanical equipment are inevitable, and the friction pair components need to be protected by lubricating wear-resistant materials. As a consumable, the service life of the lubricating wear-resistant material determines the maintenance cycle of the mechanical equipment. Although the lubricating wear-resistant material is tested a lot when it is developed to evaluate its service life, the service life of the material is closely related to the service environment and working conditions of the mechanical equipment. The failure caused by the wear of the lubricating wear-resistant material leads to the damage of the mechanical components, and the equipment damage and even safety accidents. Therefore, the wear early warning of the lubricating wear-resistant material is crucial to avoid serious friction damage of the friction pair components, and can also reduce the maintenance cost.

[0003] There are many schemes for monitoring the working state and residual life of liquid lubricating materials, such as lubricating oil wear debris particle measurement, oil temperature and viscosity monitoring, etc. For friction pair components that cannot use liquid lubricants and have compact structure, solid lubricating materials can only be used to realize the lubrication and wear protection between friction pairs, such as vapor deposition carbon-based thin film, sprayed coating, bonded solid lubricating composite material, etc. However, the working state and wear life monitoring of solid lubricating materials is more difficult than the performance detection of lubricating oil.

[0004] At present, many schemes have been proposed for wear life early warning or state diagnosis monitoring of friction pair components. For example, patent 202011101134.4 proposes to install a data acquisition system, an oil supply system, a control system and an alarm system in a sliding bearing machine, to study the vibration characteristics of the rotor bearing system under oil film whirling and oil film oscillation conditions, and to establish a fault judgment model caused by oil film whirling and oil film oscillation under different conditions, so that different disposal measures can be taken to deal with different oil film whirling and oil film oscillation faults. Patent 202310968394.9 analyzes the state of dynamic pressure sliding bearing through motion parameters. Patent 202410906215.3 establishes a relationship model between the copper-based wear particle content of the oil and the wear state by real-time monitoring of the copper-based wear particle content of the oil, to early warn the bearing wear. However, the above schemes have two problems: 1. They are only suitable for oil-lubricated sliding bearings, and are not suitable for oil-free and solid-lubricated sliding bearings; 2. The installation of other electronic devices is too much, which increases the complexity of the system. SUMMARY

[0005] Therefore, the application aims to provide a wear early warning intelligent material based on conductive core-shell micro-nano particles and a preparation method thereof.

[0006] To achieve the above-mentioned application purposes, the application provides the following technical solutions.

[0007] The application provides a wear early warning intelligent material based on conductive core-shell micro-nano particles, which comprises a lubrication wear-resistant layer located at a surface layer, a sensing layer located at an intermediate layer, and a remaining life layer located at a bottom layer.

[0008] The lubrication wear-resistant layer comprises a first resin matrix and a first lubricating filler and a first wear-resistant filler doped in the first resin matrix.

[0009] The remaining life layer comprises a second resin matrix and a second lubricating filler and a second wear-resistant filler doped in the second resin matrix.

[0010] The sensing layer comprises a third resin matrix and conductive core-shell micro-nano particles doped in the third resin matrix.

[0011] Preferably, the conductive core-shell micro-nano particles are conductive shell-coated insulating core structures or insulating shell-coated conductive core structures.

[0012] The particle size of the conductive core-shell micro-nano particles is 10 nm to 100 μm.

[0013] Preferably, the components of the conductive shell or the conductive core include conductive polymers and / or metal micro-nano particles.

[0014] The components of the insulating core or the insulating shell include insulating polymers and / or insulating inorganic materials.

[0015] In the conductive core-shell micro-nano particles, the thickness of the shell layer is 1 to 60% of the diameter of the entire conductive core-shell micro-nano particle.

[0016] Preferably, the mass of the conductive core-shell micro-nano particles in the sensing layer is 10 to 60% of the third resin matrix.

[0017] Preferably, the components of the first resin matrix, the second resin matrix, and the third resin matrix independently include one or more of acrylic resin, epoxy resin, polyimide, and polyurethane.

[0018] The first lubricating filler and the second lubricating filler independently include one or more of graphite, molybdenum disulfide, nano-graphene, and polytetrafluoroethylene.

[0019] The first wear-resistant filler and the second wear-resistant filler independently comprise one or more of zirconium dioxide, silicon dioxide, carbon fiber and glass fiber.

[0020] Preferably, in the lubricating wear-resistant layer, the mass of the first lubricating filler is 1-20% of the mass of the first resin matrix, and the mass of the first wear-resistant filler is 1-20% of the mass of the first resin matrix.

[0021] In the remaining life layer, the mass of the second lubricating filler is 1-20% of the mass of the second resin matrix, and the mass of the second wear-resistant filler is 1-20% of the mass of the second resin matrix.

[0022] Preferably, the sensing layer is connected with the electrode.

[0023] Preferably, the thickness of the lubricating wear-resistant layer is 1.5-1.8 mm, the thickness of the intermediate sensing layer is 30-100 microns, and the thickness of the remaining life layer is 0.2-0.5 mm.

[0024] The application provides a preparation method of the above-mentioned wear-prewarning intelligent material based on the conductive core-shell micro-nano particles, comprising the following steps:

[0025] The remaining life layer raw material, the sensing layer raw material and the lubricating wear-resistant layer raw material are sequentially applied on the surface of the substrate, and curing is performed to obtain the wear-prewarning intelligent material based on the conductive core-shell micro-nano particles on the surface of the substrate.

[0026] The lubricating wear-resistant layer raw material comprises a first resin matrix, a first lubricating filler, a first wear-resistant filler and a curing agent.

[0027] The conductive core-shell micro-nano particles comprise a third resin matrix, conductive core-shell micro-nano particles and a curing agent.

[0028] The remaining life layer raw material comprises a second resin matrix, a second lubricating filler, a second wear-resistant filler and a curing agent.

[0029] Preferably, the curing comprises heating curing or photocuring.

[0030] The application provides a wear-out early warning intelligent material based on conductive core-shell micro-nano particles, which comprises a lubricating wear-resistant layer located on a surface layer, a sensing layer located on an intermediate layer, and a remaining life layer located on a bottom layer; the lubricating wear-resistant layer comprises a first resin matrix and a first lubricating filler and a first wear-resistant filler doped in the first resin matrix; the remaining life layer comprises a second resin matrix and a second lubricating filler and a second wear-resistant filler doped in the second resin matrix; and the sensing layer comprises a third resin matrix and a conductive core-shell micro-nano particle doped in the third resin matrix. The wear-out early warning principle of the wear-out early warning intelligent material based on conductive core-shell micro-nano particles is that when a friction pair attached with the material is rubbed against a counterpart to a certain extent, the lubricating wear-resistant layer on the surface layer is continuously worn out and consumed, and reaches the intermediate sensing layer, the wear-out causes the conductive core-shell micro-nano particles to be broken. For the intermediate layer of the conductive shell-coated insulating shell micro-nano particles, the wear-out causes the conductive shell to be broken, the internal insulating core is released, the conductive path formed by the mutual contact of the conductive shells is destroyed and blocked, the resistance of the intermediate early warning layer is greatly increased, the early warning electrical signal is transmitted to the external detection device, and it is judged that the lubricating layer of the self-lubricating wear-resistant protective material has been worn out, only the remaining life layer is left, and the friction pair component needs to be replaced in time. Similarly, for the intermediate layer of the insulating shell-coated conductive shell micro-nano particles, the wear-out causes the insulating shell to be broken, the internal conductive core is released, and the conductive core material is ground and flattened on the wear surface under the mutual shearing and grinding action in the wear-out process, a conductive path is formed, the conductivity of the intermediate early warning layer is greatly increased, the early warning electrical signal is transmitted to the external detection device, and it is judged that the lubricating layer of the self-lubricating wear-resistant protective material has been worn out, only the remaining life layer is left, and the friction pair component needs to be replaced in time.

[0031] The wear-out early warning intelligent material based on conductive core-shell micro-nano particles provided by the application solves the problem that the current solid lubricating material cannot early warn the wear-out life, avoids the serious wear and damage of the friction pair component caused by the failure of the lubricating wear-resistant protective material, and even avoids the unexpected shutdown of the equipment and safety accidents. The working principle of the wear-out early warning intelligent material provided by the application is simple and easy to realize: the three-layer material structure realizes the functions of lubricating wear consumption, wear-out early warning, and remaining material wear protection from top to bottom. The intermediate wear function in the application mainly depends on the structural change of the micro-nano core-shell particles with specific conductivity when the wear occurs and breaks, and the shell material and core material of the conductive and insulating are widely selected, and the synthesis process is also diverse according to the material selection. By manufacturing the wear-out early warning intelligent material of the application on the surface of the friction pair component, not only the solid lubrication and wear-resistant protection of the compact structure friction pair component can be realized, but also the wear of the intelligent early warning material can be realized, which is of great benefit to avoiding the serious wear and damage of the component.

[0032] The application provides a preparation method of the above-mentioned wear early warning intelligent material based on the conductive core-shell micro-nano particles, and the method is simple in operation, and the preparation process on the surface of a substrate (such as a metal part) is also simple and universal, and can be prepared by spraying, spin coating, self-leveling and curing, and different preparation processes can be adapted to different part surface shapes, and the method is suitable for industrialized batch production. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is a schematic diagram of the overall structure of the wear early warning intelligent material based on the conductive core-shell micro-nano particles.

[0034] Figure 2 It is a schematic diagram of the components of each layer of the wear early warning intelligent material based on the conductive core-shell micro-nano particles.

[0035] Figure 3 It is a schematic diagram of the wear early warning principle of the wear early warning intelligent material based on the conductive core-shell micro-nano particles.

[0036] Figure 4 It is a schematic diagram of the preparation process of the wear early warning intelligent material based on the conductive core-shell micro-nano particles.

[0037] Figure 5 It is a wear early warning electrical signal and friction coefficient change curve of the wear early warning intelligent material based on the conductive core-shell micro-nano particles obtained in Example 1.

[0038] Figure 6 It is a wear early warning electrical signal and friction coefficient change curve of the wear early warning intelligent material based on the conductive core-shell micro-nano particles obtained in Example 2.

[0039] Figure 7 It is a wear early warning electrical signal and friction coefficient change curve of the wear early warning intelligent material based on the conductive core-shell micro-nano particles obtained in Example 3.

[0040] Figure 8 It is a wear early warning electrical signal and friction coefficient change curve of the wear early warning intelligent material based on the conductive core-shell micro-nano particles obtained in Example 4. DETAILED DESCRIPTION

[0041] The application provides a wear early warning intelligent material based on conductive core-shell micro-nano particles, which comprises a lubrication wear-resistant layer on a surface layer, a sensing layer on an intermediate layer and a remaining life layer on a bottom layer.

[0042] The lubrication wear-resistant layer comprises a first resin matrix and a first lubricating filler and a first wear-resistant filler doped in the first resin matrix.

[0043] The remaining life layer comprises a second resin matrix and a second lubricating filler and a second wear-resistant filler doped in the second resin matrix.

[0044] The sensing layer comprises a third resin matrix and conductive core-shell micro-nano particles doped in the third resin matrix.

[0045] In the present application, the lubricating wear-resistant layer comprises a first resin matrix and a first lubricating filler and a first wear-resistant filler doped in the first resin matrix. In the present application, the first resin matrix is preferably one or several of acrylic resin, epoxy resin, polyimide and polyurethane; the first lubricating filler preferably comprises one or several of graphite, molybdenum disulfide, nano-graphene and polytetrafluoroethylene, and the size of the lubricating filler is preferably micro-nano size. In the present application, the first wear-resistant filler preferably comprises one or several of zirconium dioxide, silicon dioxide, carbon fiber and glass fiber, and the size of the wear-resistant filler is preferably micro-nano size. In the present application, in the lubricating wear-resistant layer, the mass of the first lubricating filler is preferably 1-20% of the mass of the first resin matrix, more preferably 3-15%, and further preferably 5-10%; the mass of the first wear-resistant filler is preferably 1-20% of the mass of the first resin matrix, more preferably 3-15%, and further preferably 5-10%.

[0046] In the present application, the sensing layer comprises a third resin matrix and conductive core-shell micro-nano particles doped in the third resin matrix. In the present application, the third resin matrix is preferably one or several of acrylic resin, epoxy resin, polyimide and polyurethane. In the present application, the conductive core-shell micro-nano particles are either conductive shell coated insulating core structure or insulating shell coated conductive core structure. In the present application, the conductive core-shell micro-nano particles are preferably prepared by chemical synthesis, and are more preferably prepared by microemulsion polymerization. In the present application, the particle size of the conductive core-shell micro-nano particles is preferably 10 nm-100 μm, and more preferably 100-10 μm, and can be specifically 10 nm, 50 nm, 100 nm, 500 nm, 1 μm, 5 μm, 10 μm, 50 μm or 100 μm.

[0047] In the present application, the components of the conductive shell or conductive core preferably comprise conductive polymers and / or metal micro-nano particles; in the present application, the conductive polymers are preferably one or several of polypyrrole (PPy), polythiophene (Pth), polyaniline (PANi) and poly(3,4-ethylenedioxythiophene) (PEDOT), and the metal micro-nano particles are preferably one or several of gold, silver and copper.

[0048] In the present application, the components of the insulating core or insulating shell preferably include insulating polymers and / or insulating inorganic materials. In the present application, the insulating polymers are preferably one or more of polystyrene (PS), polymethyl methacrylate (PMMA) and polybutyl methacrylate (PBMA), and the insulating inorganic materials are preferably silicon dioxide and / or titanium dioxide.

[0049] In the present application, the thickness of the shell layer in the conductive core-shell micro-nano particle is preferably 1-60% of the diameter of the entire conductive core-shell micro-nano particle, more preferably 5-50%, and specifically can be 1%, 5%, 10%, 20%, 30%, 40% or 50%.

[0050] In the present application, the mass of the electric core-shell micro-nano particle in the sensing layer is preferably 10-60% of the third resin matrix, more preferably 20-50%, and specifically can be 10%, 20%, 30%, 40%, 50% or 60%.

[0051] In the present application, the sensing layer is preferably connected to an electrode, and the electrode is preferably arranged at both ends of the sensing layer. In the present application, the material of the electrode is preferably printed conductive ink, gold, silver, copper, aluminum or indium tin oxide. The present application leads out external contacts through the electrode for measuring the change of the intermediate sensing layer electric signal.

[0052] In the present application, the remaining life layer includes a second resin matrix and a second lubricating filler and a second wear-resistant filler doped in the second resin matrix. In the present application, the second resin matrix is preferably one or more of acrylic resin, epoxy resin, polyimide and polyurethane; the second lubricating filler preferably includes one or more of graphite, molybdenum disulfide, nano-graphene and polytetrafluoroethylene, and the size of the lubricating filler is preferably micro-nano size. In the present application, the second wear-resistant filler preferably includes one or more of zirconium dioxide, silicon dioxide, carbon fiber and glass fiber, and the size of the wear-resistant filler is preferably micro-nano size. In the present application, the mass of the second lubricating filler in the lubricating wear-resistant layer is preferably 1-20% of the mass of the second resin matrix, more preferably 3-15%, and further preferably 5-10%, and the mass of the second wear-resistant filler is preferably 1-20% of the mass of the second resin matrix, more preferably 3-15%, and further preferably 5-10%.

[0053] In the present application, the overall thickness of the wear early warning intelligent material based on the conductive core-shell micro-nano particles is preferably ≤2mm, the thickness of the lubricating wear-resistant layer is preferably 1.5-1.8mm, more preferably 1.6-1.7mm; the thickness of the intermediate sensing layer is preferably 30-100μm, more preferably 50-80μm; the thickness of the remaining life layer is preferably 0.2-0.5mm, more preferably 0.3-0.4mm. In the present application, the thickness of the lubricating wear-resistant layer should be much higher than that of the remaining life layer.

[0054] The present application provides a preparation method of the above-mentioned wear early warning intelligent material based on the conductive core-shell micro-nano particles, comprising the following steps:

[0055] The remaining life layer raw material, the sensing layer raw material and the lubricating wear-resistant layer raw material are sequentially applied on the surface of the substrate, and then cured to obtain the wear early warning intelligent material based on the conductive core-shell micro-nano particles on the surface of the substrate. In the present application, the lubricating wear-resistant layer raw material preferably comprises a first resin matrix, a first lubricating filler, a first wear-resistant filler and a curing agent; the conductive core-shell micro-nano particles comprise a third resin matrix, conductive core-shell micro-nano particles and a curing agent; and the remaining life layer raw material comprises a second resin matrix, a second lubricating filler, a second wear-resistant filler and a curing agent. In the present application, the above-mentioned curing agent is preferably azobisisobutyronitrile, diethylenetriamine, quinoline or zinc neodecanoate, and the specific type of the selected curing agent depends on the type of the resin matrix; in the present application, the amount of the curing agent is preferably 0.05-12% of the mass of the resin matrix, and the specific amount of the curing agent depends on the specific type of the resin matrix and the curing agent.

[0056] In the present application, the substrate is preferably a metal substrate, and the material of the metal substrate is preferably stainless steel, titanium alloy, aluminum alloy or copper alloy. In the present application, before the remaining life layer raw material is applied, the surface of the metal substrate is preferably sandblasted and roughened to improve the interfacial bonding strength of the metal-polymer material. In the present application, the roughness of the surface of the metal substrate after sandblasting and roughening is preferably Ra3-Ra6.

[0057] In the present application, the spraying method is preferably spraying or spin coating. The present application does not have special requirements for the specific operation method of the spraying or spin coating, and the spraying or spin coating method well known to those skilled in the art can be used.

[0058] In the present application, after the sensing layer raw material is applied, the present application preferably applies electrode material on the surface of the obtained sensing layer, and the method for applying the electrode material is preferably one or more of printing conductive ink, physical or chemical vapor deposition of metal or metal oxide, or pasting metal foil.

[0059] In the present application, the curing preferably includes heat curing or photocuring. The present application does not have a special requirement for the mode of the heat curing or photocuring, and a mode of adding curing or photocuring well known to those skilled in the art can be used.

[0060] The present application uses conductive core-shell micro-nano particles as a basic sensing functional unit doped into a polymer matrix to form a sensing layer, and designs a three-layer structure material of a bottom residual life layer, a middle sensing layer and a surface self-lubricating wear-resistant layer. The material is prepared on the surface of a metal pair, and the surface self-lubricating wear-resistant layer is consumed by the wear process to make the wear reach the middle sensing layer, the damage of the conductive micro-nano particles causes a significant change in the resistance of the middle sensing layer to serve as a warning signal, and the warning information that the surface self-lubricating wear-resistant layer has been worn out and the friction pair component needs to be replaced in time is realized.

[0061] In the present application, the overall structure diagram of the wear warning intelligent material based on conductive core-shell micro-nano particles is as shown in Figure 1 . Figure 1 It is indicated that the wear warning intelligent material has a three-layer structure, the top layer and the bottom layer have the effects of lubrication and wear resistance, but the top layer is normally consumed as lubrication and wear resistance, and the bottom layer is the last protection and insurance before the replacement of the friction pair component, so the thickness of the former is greater than that of the latter. The middle layer serves as a sensing layer, and the change in resistance reflects that the wear reaches the layer, and the wear-resistant life of the material is only the bottom layer.

[0062] The component diagram of each layer of the wear warning intelligent material based on conductive core-shell micro-nano particles is as shown in Figure 2 . Figure 2 It is indicated that the material components of each layer are shown, and the main functions of the top layer and the bottom layer are lubrication and wear resistance, so they contain lubricating components and wear-resistant components. The middle layer changes its resistance by containing specific core-shell micro-nano particles to reflect that the wear reaches the middle layer, and reminds that the friction pair component needs to be replaced and maintained in time.

[0063] The wear warning principle diagram of the wear warning intelligent material based on conductive core-shell micro-nano particles is as shown in Figure 3 . Figure 3The working principle of the wear early warning intelligent material is indicated. In the normal working process of the part attached with the wear early warning intelligent material, the self-lubricating wear-resistant layer of the surface layer is normally in contact and mutual sliding with the friction pair, and is continuously worn and consumed. With the increase of the wear depth, the counterpart penetrates the top layer and invades the intermediate layer. With the wear, the conductive micro-nano core-shell particles in the intermediate layer are damaged. For the intermediate functional layer containing the micro-nano particles with the conductive shell covering the insulating core, since the micro-nano particle shell has conductivity, a conductive path has been formed, and the conductivity is high. However, due to wear, the conductive shell is broken, and the insulating core is released, and the conductive path is damaged, and the resistance rises. For the intermediate functional layer containing the micro-nano particles with the insulating shell covering the conductive core, since the micro-nano particle shell and the polymer matrix material are insulating, the resistance is high. However, due to wear, the insulating shell is broken, and the conductive core is released, and the conductive new material is ground and spread on the wear surface, forming a conductive path, and the resistance decreases. Both ways reflect that the surface layer has been worn through, and the wear reaches the intermediate sensing layer, and the change of the resistance can be obtained through the electrodes on both sides of the intermediate layer. When the resistance change signal is obtained, it means that the service life of the bottom layer of the early warning intelligent material is left, and the part should be replaced and maintained in time.

[0064] The preparation process schematic diagram of the wear early warning intelligent material based on the conductive core-shell micro-nano particles is shown in Figure 4 .

[0065] The wear early warning intelligent material based on the conductive core-shell micro-nano particles and the preparation method thereof provided by the present application will be described in detail below in combination with examples, but they cannot be understood as limiting the protection scope of the present application.

[0066] Example 1

[0067] (1) Preparation of conductive core-shell micro-nano particles: polyacrylate (PMMA) insulating shell coated polypyrrole (PPy) conductive core micro-nano particles (PPy@PMMA) were prepared by microemulsion polymerization method, the particle size was about 10 nm, and the shell thickness accounted for about 1% of the diameter.

[0068] (2) Preparation of self-lubricating wear-resistant material: graphite with a particle size of 70 μm and zirconium dioxide (ZrO2) with a particle size of 200 nm were added into the acrylic resin matrix and fully stirred to achieve uniformity. The addition amount of graphite was 5 wt.%, and the addition amount of zirconium dioxide was 5 wt.%. Then 1.2 wt.% of curing agent azobisisobutyronitrile based on the mass of the acrylic resin matrix was added and fully mixed.

[0069] (3) Preparation of intermediate sensing layer material: PPy@PMMA micro-nano particles were doped into the acrylic resin matrix and fully stirred to achieve uniform mixing. The addition amount was 10 wt.%. Then 1.2 wt.% of curing agent azobisisobutyronitrile based on the mass of the acrylic resin matrix was added and fully mixed.

[0070] (4) Metal substrate surface treatment: sandblasting roughening of the stainless steel metal surface to improve the metal-polymer material interface bonding strength, the surface roughness after sandblasting is Ra4;

[0071] (5) Preparation of wear warning intelligent material: the acrylic resin matrix containing graphite and ZrO2 is sprayed on the metal substrate after surface roughening, the thickness is 0.2mm; the acrylic resin matrix containing PPy@PMMA micro-nano particles is sprayed on the last layer of self-lubricating wear-resistant material, the thickness is 30μm, the electrodes are prepared by printing conductive ink at both ends of the polymer material containing PPy@PMMA micro-nano particles; then the acrylic resin matrix containing graphite and ZrO2 fillers is sprayed on it, the thickness is 1.77mm. The overall material is fully cured by heating method, the heating temperature is 50℃, the curing time is 24h, and finally the wear warning intelligent material based on conductive core-shell micro-nano particles is obtained.

[0072] (6) The material wear warning response electrical signal and the friction coefficient change curve are as shown in Figure 5 . The test conditions are load 20N, linear speed 0.2m / s, and reciprocating friction. It can be seen from Figure 5 that when the friction process proceeds to 135-140 minutes, the friction coefficient fluctuates, and at the same time the digital source table detects that the current through the sample material has a change of 0.01μA, which indicates that the friction process reaches the sensing layer, the particles in the sensing layer are ground by the counterpart, the conductive core enters the friction interface, and the interface conductivity is improved. Therefore, it also indicates that the remaining life of the intelligent material is only the bottom layer.

[0073] Example 2

[0074] (1) Preparation of conductive core-shell micro-nano particles: PBMA@PANi micro-nano particles with polystyrene (PANi) conductive shell covering polybutyl methacrylate (PBMA) insulating core are prepared by water emulsion polymerization method, the particle size is about 100μm, and the shell thickness accounts for 60% of the diameter.

[0075] (2) Preparation of self-lubricating wear-resistant material: MoS2 with a particle size of 200nm and SiO2 with a particle size of 100nm are added into the epoxy resin precursor and stirred to achieve uniformity, the addition amount of MoS2 is 1wt.%, the addition amount of SiO2 is 1wt.%, and then 11% of the curing agent diethylene triamine by mass of the epoxy resin precursor is added and mixed thoroughly.

[0076] (3) Preparation of intermediate sensing layer material: PBMA@PANi micro-nano particles are doped into the epoxy resin matrix and stirred to achieve uniformity, the addition amount is 60wt.%, and then 11% of the curing agent diethylene triamine by mass of the epoxy resin precursor is added and mixed thoroughly.

[0077] (4) Metal substrate surface treatment: The surface of the titanium alloy metal was sandblasted to roughen it to improve the metal-polymer material interface bonding strength. The surface roughness after sandblasting was Ra5;

[0078] (5) Preparation of wear warning intelligent material: Epoxy resin composite material containing MoS2 and SiO2 was spin-coated on the metal substrate after surface roughening, with a thickness of 0.5 mm; then the polymer material containing PBMA@PANi micro-nano particles was spin-coated on the last layer of self-lubricating wear-resistant material, with a thickness of 100 μm, and electrodes were prepared by physical vapor deposition of indium tin oxide (ITO) on both ends of the epoxy resin material containing PBMA@PANi core-shell micro-nano particles; then the epoxy resin composite material containing MoS2 and SiO2 was spin-coated on it, with a thickness of 1.4 mm. The overall material was fully cured by heating, with a heating temperature of 90°C and a curing time of 10 h, and finally the wear warning intelligent material based on conductive core-shell micro-nano particles was obtained.

[0079] (6) The material wear warning response electrical signal and the friction coefficient change curve are shown in Figure 6 . The test conditions were a load of 20 N, a linear speed of 0.2 m / s, and reciprocating friction. When the friction process proceeded to 45-90 minutes, the friction coefficient fluctuated, and at the same time, the digital source table detected that the current through the sample material had changed by 15 nA, indicating that the friction process reached the sensing layer, and the particles in the sensing layer were ground by the counter, so that the insulating core entered the friction interface, reducing the interface conductivity. Therefore, it also indicates that the remaining life of the intelligent material is only the bottom layer.

[0080] Example 3

[0081] (1) Preparation of conductive core-shell micro-nano particles: Poly(3,4-ethylenedioxythiophene) (PEDOT) conductive shell-coated polystyrene (PS) insulating core micro-nano particles (PS@PEDOT) were prepared by emulsion polymerization, with a particle size of about 50 μm and a shell thickness of 40% of the diameter.

[0082] (2) Preparation of self-lubricating wear-resistant material: PTFE with a particle size of 100 nm and carbon fibers with a length of 400 μm were added to the polyimide precursor and stirred thoroughly to achieve uniformity. The addition amount of PTFE was 20 wt.%, and the addition amount of carbon fibers was 20 wt.%. Then 1.5 wt.% of quinoline, a curing agent, was added to the polyimide precursor and thoroughly mixed.

[0083] (3) Preparation of intermediate sensing layer material: PS@PEDOT micro-nano particles were doped into the polyimide matrix and thoroughly stirred to achieve uniform mixing. The addition amount was 50 wt.%. Then 1.5 wt.% of quinoline, a curing agent, was added to the polyimide precursor and thoroughly mixed.

[0084] (4) Metal substrate surface treatment: The surface of the aluminum alloy metal was sandblasted and roughened to improve the metal-polymer material interface bonding strength, and the surface roughness after sandblasting was Ra6;

[0085] (5) Preparation of wear warning intelligent material: Polyimide composite material containing PTFE and carbon fiber was sprayed on the metal substrate after surface roughening, with a thickness of 0.3 mm; then polyimide material containing PS@PEDOT micro-nano particles was sprayed on the last layer of self-lubricating wear-resistant material, with a thickness of 80 μm, and electrodes were prepared by chemical vapor deposition of gold at both ends of the polyimide material containing PS@PEDOT core-shell micro-nano particles; then polyimide composite material containing PTFE and carbon fiber was sprayed on it, with a thickness of 1.62 mm. The overall material was fully cured by heating, the heating temperature was 190°C, and the curing time was 20h, and finally the wear warning intelligent material based on conductive core-shell micro-nano particles was obtained.

[0086] (6) The material wear warning response electrical signal and the friction coefficient change curve are shown in Figure 7 . The test conditions were load 20N, linear speed 0.2m / s, and reciprocating friction. When the friction process proceeded to 200-400 minutes, the friction coefficient fluctuated, and the digital source table detected that the current through the sample material had changed by 8nA, indicating that the friction process reached the sensing layer, and the particles in the sensing layer were ground by the counter, making the insulating core enter the friction interface and reducing the interface conductivity. Therefore, it also indicates that the remaining life of the intelligent material is only the bottom layer.

[0087] Example 4

[0088] (1) Preparation of conductive core-shell micro-nano particles: Pth@SiO2 micro-nano particles with a diameter of about 40 μm and a shell thickness of 10% of the diameter were prepared, in which a conductive core of polythiophene (Pth) was coated with a silica (SiO2) insulating shell;

[0089] (2) Preparation of self-lubricating wear-resistant material: Nanometer graphene with a particle size of 500 nm and glass fiber with a length of 100 μm were added to the polyurethane matrix and fully stirred to achieve uniformity, the addition amount of nanometer graphene was 10wt.%, the addition amount of glass fiber was 10wt.%, and then 0.2wt.% of zinc neodecanoate curing agent was added to the polyurethane matrix and fully mixed.

[0090] (3) Preparation of intermediate sensing layer material: A certain amount of Pth@SiO2 micro-nano particles were doped into the polyurethane matrix and fully stirred to achieve uniform mixing, the addition amount was 40wt.%, and then 0.2wt.% of zinc neodecanoate curing agent was added to the polyurethane matrix and fully mixed.

[0091] (4) Metal substrate surface treatment: the surface of the copper alloy substrate is sandblasted to increase the metal-polymer material interface bonding strength, the sand is selected according to the actual preparation process, and the conventional commercially available sand is not specially required, and the surface roughness after sandblasting is Ra3;

[0092] (5) Preparation of wear early warning intelligent material: the polyurethane matrix containing nanographene and glass fiber is spin-coated on the surface roughened metal substrate, and the thickness is 0.4 mm; the polyurethane matrix containing Pth@SiO2 micro-nanoparticles is spin-coated on the last layer of self-lubricating wear-resistant material, and the thickness is 60 μm; electrodes are prepared by pasting copper foil at both ends of the polymeric material containing Pth@SiO2 micro-nanoparticles; the polyurethane matrix containing nanographene and glass fiber is spin-coated thereon, and the thickness is 1.54 mm. The overall material is fully cured by heating, and the curing time is 18 h, and finally the wear early warning intelligent material based on the conductive core-shell micro-nanoparticles is obtained.

[0093] (6) The material wear early warning response electrical signal and the friction coefficient change curve are shown in Figure 8 . The test conditions are load 20 N, linear speed 0.2 m / s, and reciprocating friction. When the friction process proceeds to 75-175 minutes, the friction coefficient fluctuates, and the digital source table detects that the current through the sample material has a change of 1.2 μA, which indicates that the friction process reaches the sensing layer, and the particles in the sensing layer are ground by the counterpart, so that the conductive core enters the friction interface, and the interface conductivity is improved. Therefore, it also indicates that the remaining life of the intelligent material is only the bottom layer.

[0094] The above only describes the preferred embodiments of the present application, and it should be pointed out that for ordinary skilled persons in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. A wear warning intelligent material based on conductive core-shell micro-nano particles, characterized in that: It includes a lubricating and wear-resistant layer on the surface, a sensing layer in the middle layer and a remaining life layer in the bottom layer; The lubricating and wear-resistant layer comprises a first resin matrix and a first lubricating filler and a first wear-resistant filler doped in the first resin matrix; The remaining life layer includes a second resin matrix and a second lubricating filler and a second wear-resistant filler doped in the second resin matrix; The sensing layer includes a third resin matrix and conductive core-shell micro-nano particles doped in the third resin matrix.

2. The wear warning intelligent material based on conductive core-shell micro-nano particles according to claim 1 is characterized in that: The conductive core-shell micro-nano particles are a conductive shell-coated insulating core structure, or an insulating shell-coated conductive core structure; The particle size of the conductive core-shell micro-nano particles is 10 nm to 100 μm.

3. The wear warning intelligent material of conductive core-shell micro-nano particles according to claim 2 is characterized in that: The conductive shell or conductive core comprises conductive polymers and / or metal micro-nanoparticles; The components of the insulating core or insulating shell include insulating polymers and / or insulating inorganic materials; In the conductive core-shell micro-nano particles, the thickness of the shell layer is 1 to 60% of the diameter of the entire conductive core-shell micro-nano particles.

4. The wear warning intelligent material of conductive core-shell micro-nano particles according to claim 1 or 2, characterized in that: The mass of the conductive core-shell micro-nano particles in the sensing layer is 10-60% of the mass of the third resin matrix.

5. The wear warning intelligent material based on conductive core-shell micro-nano particles according to claim 1 is characterized in that: The components of the first resin matrix, the second resin matrix, and the third resin matrix independently include one or more of acrylic resin, epoxy resin, polyimide, and polyurethane; The first lubricating filler and the second lubricating filler independently include one or more of graphite, molybdenum disulfide, nanographene and polytetrafluoroethylene; The first wear-resistant filler and the second wear-resistant filler independently include one or more of zirconium dioxide, silicon dioxide, carbon fiber and glass fiber.

6. The wear warning intelligent material based on conductive core-shell micro-nano particles according to claim 1 or 5, characterized in that: In the lubricating and wear-resistant layer, the mass of the first lubricating filler is 1 to 20% of the mass of the first resin matrix, and the mass of the first wear-resistant filler is 1 to 20% of the mass of the first resin matrix; In the remaining life layer, the mass of the second lubricating filler is 1 to 20% of the mass of the second resin matrix, and the mass of the second wear-resistant filler is 1 to 20% of the mass of the second resin matrix.

7. The wear warning intelligent material based on conductive core-shell micro-nano particles according to claim 1 is characterized in that: The sensing layer is connected to the electrode.

8. The wear warning intelligent material based on conductive core-shell micro-nano particles according to claim 1 is characterized in that: The thickness of the lubricating and wear-resistant layer is 1.5-1.8 mm; the thickness of the intermediate sensing layer is 30-100 μm; and the thickness of the remaining life layer is 0.2-0.5 mm.

9. The method for preparing the wear warning intelligent material based on conductive core-shell micro-nano particles according to any one of claims 1 to 8, characterized in that: The following steps are involved: The remaining life layer material, the sensing layer material, and the lubricating and wear-resistant layer material are sequentially applied to the substrate surface and solidified to obtain a wear warning intelligent material based on conductive core-shell micro-nano particles on the substrate surface; The raw materials of the lubricating and wear-resistant layer include a first resin matrix, a first lubricating filler, a first wear-resistant filler and a curing agent; The conductive core-shell micro-nano particles include a third resin matrix, conductive core-shell micro-nano particles and a curing agent; The remaining life layer raw material includes a second resin matrix, a second lubricating filler, a second wear-resistant filler and a curing agent.

10. The preparation method according to claim 9, characterized in that The curing includes heat curing or light curing.

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