Polyether-ether-ketone surface modified coating material as well as preparation method and application thereof

Abstract

The invention discloses a polyether-ether-ketone surface modified coating material as well as a preparation method and application thereof, the coating material sequentially comprises a polyether-ether-ketone matrix, a transition layer zinc layer and a surface layer CuSn6 layer, and the zinc layer and the CuSn6 layer are sprayed on the matrix polyether-ether-ketone through an electric arc spraying technology; the preparation method comprises the steps that after corners are polished, cleaning is conducted, sand blasting roughening is conducted, and the zinc transition layer and the CuSn6 layer are sequentially sprayed through the electric arc spraying technology. The transition layer zinc layer and the surface layer CuSn6 layer are introduced on the PEEK, the zinc transition layer not only avoids thermal damage of high-temperature molten metal to a PEEK matrix in the spraying process of high-melting-point CuSn6, but also effectively inhibits generation of cracks on a coating / matrix interface, and the composite material enables the PEEK to have both a lightweight matrix and a functional conductive surface, so that the composite material can be applied to the field of electroconductive materials. The method has great application potential in electromagnetic shielding, electric contact and electrostatic discharge (wings of unmanned aerial vehicles).

Description

Technical Field

[0001] This invention relates to the field of polymer surface modification, and particularly to a polyether ether ketone (PEEK) surface-modified coating material, its preparation method, and its application. Background Technology

[0002] Conductive slip rings achieve power and signal transmission between rotating components through sliding friction and electrical contact, and are widely used in aerospace equipment, such as satellite solar panel drive mechanisms, space station docking mechanisms, aircraft optoelectronic pod rotation mechanisms, airborne radar, helicopter main rotor de-icing systems, and space robotic arm rotary joints. With the trend towards higher power density in spacecraft, the demand for lightweight, high-performance conductive contact devices is becoming increasingly urgent. While traditional metal conductive contact components (such as gold, silver, copper, and aluminum) possess excellent conductivity and mechanical properties, their high density significantly increases the overall weight of the system, limiting the improvement of energy efficiency and dynamic response capabilities. Against this backdrop, replacing metals with special engineering plastics to achieve structural-functional integration has become an important technical path to solve the lightweighting problem. Among them, polyetheretherketone (PEEK) has a higher specific strength than other engineering plastics such as nylon (PA66), polyoxymethylene (POM), and polyester (PBT), and a density (1.32 g / cm³). 3 Its density is greater than that of gold (19.32 g / cm³). 3 With its low temperature and excellent high-temperature resistance, chemical corrosion resistance, and wear resistance, PEEK is considered a highly promising lightweight matrix material. However, pure PEEK itself is not conductive and cannot be directly applied to scenarios requiring current conduction (such as electromagnetic shielding, electrical contact, and electrostatic discharge). Therefore, achieving surface metallization of PEEK to construct a composite structure that combines a lightweight matrix with a functional conductive surface is key to overcoming these limitations. Summary of the Invention

[0003] Objectives of the Invention: The first objective of this invention is to provide a polyetheretherketone (PEEK) surface-modified coating material with a composite structure that combines a lightweight substrate and a functional conductive surface; the second objective of this invention is to provide a method for preparing the PEEK surface-modified coating material; and the third objective of this invention is to provide applications of the PEEK surface-modified coating material.

[0004] Technical solution: The polyetheretherketone (PEEK) surface-modified coating material of the present invention comprises, in sequence, a PEEK matrix, a zinc transition layer, and a CuSn6 surface layer, wherein the zinc layer and the CuSn6 layer are sprayed onto the PEEK matrix using an arc spraying technique.

[0005] Preferably, the thickness of the zinc layer is 150~250 μm. The Zn intermediate (transition) layer not only avoids the thermal damage to the PEEK substrate caused by the high-temperature molten metal during the high-melting-point CuSn6 spraying process, but also effectively suppresses the generation of cracks at the coating / substrate interface, thereby improving the overall performance of the coating.

[0006] Preferably, the thickness of the CuSn6 is 30~70 μm.

[0007] Preferably, the thickness of the polyetheretherketone matrix is ​​5-10 mm.

[0008] Preferably, the wear resistance current of the polyether ether ketone surface-modified coating material is 0~60A.

[0009] The method for preparing the polyether ether ketone surface-modified coating material of the present invention includes the following steps:

[0010] (1) Edge grinding: Grind the edges and corners of the polyetheretherketone matrix;

[0011] (2) Surface cleaning: Clean the surface of the polyetheretherketone matrix to remove grease and stains;

[0012] (3) Sandblasting roughening: The PEEK matrix is ​​roughened by sandblasting with white corundum sand;

[0013] (4) Zinc coating: The zinc coating is applied using arc spraying technology;

[0014] (5) Spraying CuSn6 layer: The CuSn6 layer is sprayed using arc spraying technology.

[0015] Preferably, the conditions for applying the zinc layer using arc spraying technology are: spraying working voltage of 20~30 V, spraying working current of 200~300 A, and spraying gas pressure greater than 0.55 MPa.

[0016] Preferably, the conditions for applying the CuSn6 layer using arc spraying technology are: spraying working voltage of 20~50 V, spraying working current of 100~300 A, and spraying gas pressure greater than 0.55 MPa.

[0017] Preferably, in the sandblasting roughening process, the white corundum abrasive is 40-50 mesh.

[0018] The application of the polyetheretherketone surface-modified coating material described in this invention in electromagnetic shielding, electrical contact, and electrostatic discharge (wings of drones).

[0019] Invention Mechanism:

[0020] Pure PEEK itself is not conductive and cannot be directly applied to scenarios requiring current conduction. Therefore, metallizing the PEEK surface can create composite structures with functional conductive surfaces.

[0021] As conductive contact devices, coatings are frequently subjected to sliding friction and wear under current-carrying conditions. Their current-carrying tribological properties and the coating's own mechanical load-bearing capacity (such as hardness, bonding strength, and toughness) directly determine the device's functional reliability and service life.

[0022] Tin bronze (CuSn6) not only possesses excellent electrical and thermal conductivity, but also exhibits good wear resistance potential under current-carrying friction conditions due to its moderate hardness and self-lubricating properties, making it an ideal functional coating material to replace traditional metal conductive devices. Therefore, this invention utilizes arc spraying technology to prepare a high-performance CuSn6 conductive coating layer on the surface of a PEEK substrate, aiming to systematically solve the performance problems in the development of lightweight conductive devices. However, it was found that due to the thermal sensitivity of PEEK, high-melting-temperature arc-sprayed particles deposited on the PEEK substrate undergo localized degradation, leading to a significant decrease in the bonding strength between the coating and the substrate.

[0023] This invention achieves a high-strength bond between the arc-sprayed current-carrying layer and the polyetheretherketone (PEEK) matrix by introducing a Zn transition layer. Utilizing low-melting-point Zn as the transition layer avoids the thermal damage to the PEEK matrix caused by the high-temperature molten metal during the high-melting-point CuSn6 spraying process, and effectively suppresses crack formation at the coating / substrate interface, thus improving the overall performance of the coating. This is because the melting point of zinc (419.5℃) is much lower than that of tin bronze (850~1000℃). Pre-spraying Zn onto the PEEK as a transition layer allows it to undergo a phase transformation under the subsequent impact of high-temperature molten tin bronze droplets, absorbing and dissipating a large amount of heat energy, thereby suppressing thermal damage to the PEEK matrix. Furthermore, the zinc layer, as a soft metal transition layer, can buffer the mechanical impact of high-speed particles and alleviate interfacial thermal stress caused by differences in thermal expansion coefficients. This ensures a high-quality tin bronze coating with good bonding to the substrate and no thermal damage, even under high-heat-input arc-spraying processes.

[0024] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) By introducing a transition layer of zinc and a surface layer of CuSn6 on PEEK, the present invention enables both the Zn / PEEK interface and the CuSn6 / Zn interface to form a good bonding form, thereby improving the bonding strength between the metal coating and the PEEK substrate, making PEEK both a lightweight substrate and a functional conductive surface; (2) The density of the polyether ether ketone surface-modified coating material of the present invention is only 1.72 g / cm³. 3(2) The overall weight of the material is only about 30% higher than that of pure PEEK substrate; (3) The coating effect of the present invention is 55% higher than that of the existing PEEK cold spray Al coating technology; (4) The preparation method is simple and easy to industrialize; (5) The polyether ether ketone surface modified coating material of the present invention has great application potential in electromagnetic shielding, electrical contact, and electrostatic discharge (wings of UAVs). Attached Figure Description

[0025] Figure 1 Cross-sectional topography of the coatings in Example 1 (left) and Comparative Example 1 (right);

[0026] Figure 2 The graph shows the change in microhardness of the material prepared in Example 1.

[0027] Figure 3 The bonding strength diagrams are for the materials prepared in Example 1 and Comparative Example 1.

[0028] Figure 4 The diagram shows the mechanical interlock between the metal coating and the PEEK substrate prepared in Example 1.

[0029] Figure 5 The diffusion analysis diagrams for the Zn / PEEK interface and CuSn6 / Zn interface contact regions of the materials prepared in Example 1 are shown, where (a) is an elemental variation curve from the CuSn6 coating to the PEEK substrate; (b) is a magnified view of a portion of the elemental variation curve; (c) is a schematic diagram of the bonding mechanism of the CuSn6 / Zn alloy interface; and (d) are XRD patterns of the CuSn6 coating and at a distance of 5 pm from the Zn coating.

[0030] Figure 6 (a) Schematic diagram of the bonding analysis of the Zn / PEEK interface of the material prepared in Example 1; (b) Schematic diagram of the bonding mechanism of the PEEK / Zn interface; (c) FTIR spectrum of the untreated PEEK surface; (d) 0.1 ...

[0031] Figure 7 The wear rate of the CuSn6 coating prepared in Example 1 under different currents is shown in the graph.

[0032] Figure 8 The friction coefficient diagram of the CuSn6 coating prepared in Example 1 under different currents;

[0033] Figure 9 The current-carrying performance of the CuSn6 coating prepared in Example 1 under different currents is shown in the diagrams: (a) contact resistance diagram; (b) average contact resistance diagram; and (c) current-carrying efficiency and current-carrying stability diagram. Detailed Implementation

[0034] The technical solution of the present invention will be further described below with reference to the embodiments.

[0035] Example 1

[0036] (1) Before arc spraying, use an MS3325A dust-collecting grinder to pre-grind the edges and corners of the substrate to reduce the phenomenon of cracking and peeling of the coating after spraying;

[0037] (2) Use a JP-040S ultrasonic cleaner to clean the surface of the substrate and remove grease and stains from the substrate surface to reduce their impact on the bonding between the coating and the substrate.

[0038] (3) Use 46-mesh white corundum sand to roughen the PEEK substrate by sandblasting at an air pressure of 0.9 MPa. After sandblasting, in order to prevent oxidation of the substrate surface due to prolonged exposure, which would affect the bonding between the substrate and the coating, the substrate should be immediately subjected to arc spraying.

[0039] (4) First, a Zn transition layer is sprayed onto the polyetheretherketone surface: the spraying working voltage is 29 V, the spraying working current is 220 A, the spraying gas pressure is greater than 0.55 MPa, and the spraying thickness is 200 μm;

[0040] (5) Next, a CuSn6 coating is sprayed on the surface of the transition layer: the spraying working voltage is 36 V, the spraying working current is 175 A, the spraying gas pressure is greater than 0.55 MPa, and the spraying thickness is 50 μm.

[0041] Table 1. Composition and content of powder core filament (mass fraction, %)

[0042]

[0043] Example 2

[0044] Based on Example 1, the coating thickness of the zinc layer was changed to 150 μm; all other conditions remained the same.

[0045] Example 3

[0046] Based on Example 1, the coating thickness of the zinc layer was changed to 250 μm; all other conditions remained the same.

[0047] Comparative Example 1

[0048] Based on Example 1, no zinc layer was sprayed, and all other conditions remained the same.

[0049] Structural characterization

[0050] The samples prepared in Example 1 and Comparative Example 1 were cut into 10×10×6 mm pieces using a diamond wire cutter (STX-202AQ, Shenyang Kejing, China). The samples were then polished with 240, 400, 800, 1000, 1200, 1500, and 2000 grit sandpaper. (When polishing with the above sandpapers, the ink marks of the next grit disappear when switching to the next grit. Polishing is stopped when the entire coating surface is covered with the marks from the next grit, and then the next grit can be changed. Each grit is polished in only one direction, so the ink marks are all in the same direction after polishing with that grit.) After polishing, metallographic specimens were prepared, thus completing the coating preparation process. The cross-sectional microstructure of the coating was observed using a scanning electron microscope (SEM). The cross-sectional morphology of the coating was observed using a metallographic specimen that had undergone gold sputtering treatment. The SEM observation results are as follows: Figure 1 As shown.

[0051] Figure 1 (Left) The cross-sectional morphology of the metal coating on the PEEK surface-modified coating prepared in Example 1 can be observed. The metal coating can be divided into two layers: an upper CuSn6 coating with a thickness of 50 μm and a lower Zn transition layer with a thickness of 200 μm. The CuSn6 / Zn interface and the Zn / PEEK interface are well bonded. This is because the melting point of zinc (419.5℃) is much lower than that of tin bronze (850~1000℃). By pre-spraying Zn onto PEEK as a transition layer, it undergoes a phase transformation under the subsequent impact of high-temperature tin bronze droplets, absorbing and dissipating a large amount of heat energy, thereby suppressing the thermal damage to the PEEK substrate caused by high temperature. Furthermore, the zinc layer, as a soft metal transition layer, can buffer the mechanical impact of high-speed particles and alleviate the interfacial thermal stress caused by the difference in thermal expansion coefficients. This ensures that a high-quality tin bronze coating with good bonding to the substrate and no thermal damage is obtained under the high-heat-input arc spraying process.

[0052] Figure 1(Right) This shows the cross-sectional morphology of the PEEK surface-modified coating prepared in Comparative Example 1. It can be observed that the PEEK substrate suffers severe thermal damage, resulting in numerous pores at the interface. This is because PEEK and tin bronze have significantly different coefficients of thermal expansion. After arc spraying, the coating and substrate begin to cool and shrink. Due to the large difference in thermal expansion coefficients, the shrinkage of the tin bronze coating is much smaller than that of the PEEK substrate, causing the already weak bonding between the two materials (due to poor wettability) to separate at the interface, forming interfacial pores. Furthermore, the high temperature of the molten tin bronze particles during arc spraying causes the local temperature on the PEEK surface to exceed its thermal decomposition initiation temperature. PEEK decomposition produces small molecule gases, which cannot escape during the rapid solidification of the coating and are trapped at the interface, forming pores. In summary, under the combined effects of shrinkage tension and thermal shock, the already fragile mechanical bonding interface, which is prone to damage due to poor wettability, is easily damaged, resulting in macroscopic pores and microscopic defects that lead to partial PEEK separation and the formation of weak bonding at the coating-substrate interface.

[0053] Therefore, introducing Zn as a transition layer when spraying CuSn6 coating can protect the PEEK substrate from the high temperature effects of CuSn6 deposited particles in arc spraying.

[0054] Performance testing

[0055] 1. Mechanical property testing of the coating

[0056] Test Method: The hardness of the coating was tested using a microhardness tester (FM-ARS 9000), measuring at 5 points in different areas of the coating surface. On the cross-section of the sample, hardness was measured perpendicular to the coating direction from the CuSn6 coating surface to the PEEK substrate, with each measurement point spaced 30 μm apart, for a total of 13 measurement points. The measurement results are shown below. Figure 2 As shown.

[0057] Figure 2 The image shows the microhardness variation curve of the sample from the CuSn6 coating to the PEEK substrate in Example 1. The average microhardness of the CuSn6 coating is 144.5 HV. 0.1 The average microhardness of the Zn transition layer is 21.5 HV. 0.1 The average microhardness of the PEEK matrix is ​​21.3 HV. 0.1 Compared to the PEEK substrate, the hardness of the CuSn6 coating increased by 578.4%, and compared to the Zn transition layer, the hardness of the CuSn6 coating increased by 572.1%. The significant difference in hardness between the CuSn6 coating and the PEEK substrate highlights the effectiveness of introducing the Zn transition layer in mitigating damage to the PEEK substrate from molten metal particles during arc spraying. The presence of the CuSn6 coating significantly enhances the surface hardness of the PEEK substrate.

[0058] 2. Bond strength test of metallized coating

[0059] Test Method: The bond strength of the arc-sprayed metallized coating was determined using a pull-out test according to ASTM-C633. Epoxy resin adhesive (Shanghai Huayi, China) was used to bond both sides of a Φ25 mm diameter coating / substrate sample to a cylindrical tensile bar. After curing at room temperature for 24 hours, the adhesive bond strength was >25 MPa. The pull-out test was conducted on a universal testing machine at a tensile speed of 1 mm / min. Five samples were tested, and the average value was taken. Test results are as follows: Figure 3 As shown.

[0060] The bonding strength between the coating and the substrate reflects the degree of adhesion between them. During the bonding strength test, the stress-displacement curves of the CuSn6 / Zn coating on the PEEK substrate surface in Example 1 and the CuSn6 coating in Comparative Example 1 are shown below. Figure 3 As shown, the bonding strength of the CuSn6 coating without a Zn transition layer on the PEEK substrate is approximately 3.75 MPa, while the bonding strength of the CuSn6 coating with a Zn transition layer is approximately 7.13 MPa. The results indicate that, compared to the coating without a transition layer, the bonding strength between the CuSn6 coating and the PEEK substrate is increased by 90.13% after introducing the Zn transition layer. Compared to the bonding strength of 4.6 MPa achieved by cold-spraying an Al coating onto PEEK using existing techniques, the bonding strength is increased by 55%.

[0061] 3. Interface integration mechanism testing

[0062] Scanning electron microscopy (SEM) was used to observe the surface and cross-sectional microstructure of the coating, and EDS was used to observe elemental diffusion at the interface. Sample preparation was required before XRD and XPS testing. A block sample (sample from Example 1) cut to 10×10×6 mm was placed in a mounting mold and cold-mounted with epoxy resin. The mounted sample was then polished sequentially using 240#~2000# sandpaper according to standard metallographic preparation procedures, starting from the surface coating side. SEM observation was continuously used during polishing until the CuSn6 coating was polished to a distance of 5 μm from the interface to be tested. The sample was then polished using 2.5 μm diamond polishing paste and 80 nm SiO2 polishing solution. X-ray diffraction (XRD) was used to analyze the phase composition of the surface CuSn6 coating and the CuSn6 / Zn interface. X-ray photoelectron spectroscopy (XPS) was used to analyze the chemical valence state and existing forms of elements in materials using chemical shifts, collecting information on potential chemical bonds between Zn / PEEK. The sample surface was sputtered with an Ar ion beam before testing. The test results are as follows: Figure 4 , 5 As shown in Figure 6.

[0063] like Figure 4 As shown, both the CuSn6 coating / Zn transition layer interface and the Zn transition layer / PEEK substrate interface exhibit typical wavy interface morphology. The four types of interlocking phenomena mentioned above are present at both the CuSn6 / Zn interface and the Zn / PEEK interface: embedding, anchoring, interlocking, and spreading. The extensive occurrence of these four mechanical interlocking phenomena ensures sufficient bonding strength for the mechanically bonded coating, which is also an important step in ensuring the formation of the arc-sprayed coating base layer on the PEEK substrate. Furthermore, the mechanical interlocking between the coating and the substrate can withstand a certain shear force, thereby improving the wear resistance of the coating.

[0064] To investigate the diffusion (chemical bonding) at the Zn / PEEK and CuSn6 / Zn interface contact regions, EDS analysis was performed on the cross-sections of the PEEK-based metallized samples, such as... Figure 5 As shown in (a) and 5(b). Figure 5(b) is a magnified view of a region with elemental content close to 0%. The elemental content in the coating region fluctuates along the line scan direction from the CuSn6 coating to the PEEK substrate. At the CuSn6 / Zn interface, Cu and Zn elements form a cross-distribution gradient transition region with a width of approximately 5 μm. Similarly, a cross-distribution transition region with a width of approximately 5 μm is also formed at the interface of the Zn transition layer / PEEK substrate. This is because the high temperature during arc spraying creates a molten pool at the spraying interface, allowing elements to diffuse into each other and form good chemical bonds. The above EDS analysis indicates the existence of a transition region of approximately 5 μm at the CuSn6 / Zn interface. XRD analysis was performed on the CuSn6 coating and a plane 5 μm away from the CuSn6 / Zn interface, as shown... Figure 5 As shown in (c), the main phases of the CuSn6 coating are Cu, Cu2O, and ZnO, while the main phases of the transition zone are Zn, CuZn, and ZnO. Comparing the CuSn6 coating and the transition zone, and comparing the original phases of the CuSn6 coating, it can be seen that the reaction product at the CuSn6 / Zn interface is CuZn. The chemical bonding at the CuSn6 / Zn interface contributes to the formation of a high bonding strength between the coatings. In summary, the chemical bonding at the CuSn6 / Zn interface is as follows... Figure 5 As shown in (d), Cu elements diffuse toward the Zn coating at the CuSn6 / Zn interface, and Zn elements diffuse toward the CuSn6 coating, and a chemical reaction occurs at the interface to form the metal compound CuZn.

[0065] Figure 6 (a) shows the chemical bonding reaction occurring at the Zn / PEEK interface. It can be seen that ZnO in the Zn transition layer undergoes a redox reaction with C=O in the PEEK chain segment to generate CO-Zn chemical bonds. This conclusion was obtained through combined FTIR and XPS analysis. Figure 6 (b) and (c) show a comparison of the FTIR spectra of the untreated PEEK and Zn / PEEK interface, revealing the C=O peak (1647 cm⁻¹) in the interface region. -1 The height of ) is relative to COC (1219 cm) -1 ) and phenyl (1484 cm) -1 The absorption intensity of C=O decreased significantly (the height of the decrease in absorption intensity of C=O shown in the figure is H). This phenomenon indicates that the number of C=O in the interfacial region is reduced due to the breaking of chemical bonds, proving that C=O undergoes selective breaking and participates in chemical reactions in metal-polymer interfacial reactions. XPS analysis further revealed this chemical reaction. Figure 6(d) and (e) are XPS spectra of O 1s and Zn 2p obtained from the Zn / PEEK interface samples. Zn 2p orbital convolution analysis detected two chemical states: Zn-O bonds (834.8 eV, 941.7 eV) and Zn-OC bonds (816.3 eV, 909.8 eV). Furthermore, the interfacial oxygen elemental spectrum (O 1s) was resolved by Gaussian fitting to reveal four characteristic peaks: Zn-O peak (1086.2 eV), C=O peak (2354.8 eV), OH peak (1757.3 eV), and CO-Zn peak (2409.2 eV). Combined with the FTIR results, the Zn-OC bonds at the Zn and PEEK interface are generated by the Zn in zinc oxide. 2+ It is related to the reaction of C=O in PEEK.

[0066] At the CuSn6 / Zn interface, Cu and Zn elements interdiffusion and chemical reaction occur, forming CuZn compounds, confirming the presence of chemical bonding at the CuSn6 / Zn interface. At the Zn / PEEK interface, the C=O in PEEK reacts with the Zn in the oxide film on the Zn powder surface. 2+ A reaction occurs, forming a metal-polymer coordination compound at the interface. These results indicate that, in addition to mechanical interlocking, chemical bonding exists at both the CuSn6 / Zn and Zn / PEEK interfaces, which helps improve the bonding strength between the coating and the substrate. The presence of chemical bonding can form a dense interface, reducing microcracks and porosity, thereby improving the wear resistance of the coating.

[0067] 4. Coating-borne friction and wear test

[0068] A copper wire was welded to the CuSn6 coating surface using an electric welding machine. The other end of the copper wire was connected to the positive terminal of the friction and wear testing machine, forming a conductive circuit on the PEEK metallized sample. The current-carrying friction and wear experiment used a reciprocating current-carrying friction and wear testing machine. The CuSn6 coating and the graphite disk formed a friction pair, simulating the current-carrying friction and wear process of a conductive slip ring. The pre-prepared coating sample and the graphite disk were fixed in a designated area. The graphite disk was mounted on the rotating end and driven by a servo motor to achieve high-speed rotation. A stable and controllable DC current was supplied between the coating and the graphite disk. During the experiment, the applied voltage, current, and contact resistance were transmitted in real time to the data acquisition system via a return cable for convenient data collection. Multiple sets of experiments were conducted on the CuSn6 coating sample using this equipment. Under no-current conditions, the applied normal load was set to 10 N, the sliding speed to 900 mm / s, and the wear time to 60 min. The samples before and after the experiment were cleaned and dried in an ultrasonic machine and weighed using a high-precision balance to measure the wear amount of the coating. The wear amount is as follows: Figure 7As shown. The coefficient of friction, contact resistance, current-carrying efficiency, and current-carrying stability during the current-carrying friction and wear process are as follows. Figure 8 and Figure 9 As shown.

[0069] Wear amount of CuSn6 coating after 60 min of wear under different currents is as follows Figure 7 As shown, the wear of the coating is positively correlated with the increase of current. The wear is minimal at 0 A, at 9.4 mg. When the current increases to 10 A and 20 A, the wear increases to 20.1 mg and 43.6 mg, respectively, which are 2.1 times and 4.6 times that under no-current conditions. When the current increases to 30 A, the wear reaches 87.9 mg, which is 9.4 times that under no-current conditions. This is because the high current leads to a significant increase in contact temperature, which exacerbates the softening and adhesive wear of the contact materials between the friction pairs, damages the wear surface, and significantly increases the wear of the CuSn6 coating.

[0070] Figure 8 (a) is a graph showing the change of the friction coefficient of the CuSn6 coating with time under different currents. When there is no current, the friction coefficient of the CuSn6 coating first increases and then tends to stabilize with time. When there is current, the wear of the sample fluctuates greatly in the early stage. As friction continues, the friction coefficient gradually decreases, then fluctuates occasionally, and finally reaches a stable state.

[0071] Figure 8 (b) shows the average friction coefficient of the CuSn6 coating under different currents. It can be seen that the average friction coefficient first decreases and then increases with increasing current, dropping from 0.43 at 0 A to 0.28 at 10 A, and then slowly increasing to 0.39 at 30 A. The main reason for this phenomenon is that as the current increases, the temperature of the worn surface rises, leading to increased surface oxidation. The formed oxides usually have high hardness, which can suppress the adhesion tendency between friction pairs, reduce frictional resistance, and help reduce the friction coefficient. However, as the degree of oxidation further increases, oxides accumulate on the worn surface, thereby increasing the hardness of the worn surface. This is not conducive to the function of the surface lubricating film and also causes the friction coefficient to show an upward trend under high current conditions.

[0072] The current-carrying capacity of the CuSn6 coating changes over time under different currents, as follows: Figure 9 As shown, the average contact resistance of the coating decreases with increasing current, from 0.4 Ω at 10 A to 0.064 Ω at 30 A. Figure 9 (a and 9b); the current-carrying efficiency increases with increasing current, rising from 90.60% for 10 A to 92.79% for 30 A. Figure 9c); Current-carrying stability first decreases and then increases with increasing current, decreasing from 6.97% at 10 A to 5.33% at 20 A, and then increasing to 7.02% at 30 A. Figure 9 c).

[0073] 5. Material density test

[0074] Test Method: Due to the thin thickness of the coating adhering to the substrate, direct measurement of its bulk density is difficult. This study employs the "regular sample drainage method" for indirect determination, the specific steps of which are as follows:

[0075] First, a square sample with dimensions of approximately 10mm × 10mm was prepared from the sprayed sample. Then, the mass of the sample in its dry state was weighed using an electronic analytical balance with an accuracy of 0.1mg, and recorded as [mass]. Next, the sample was completely immersed in a beaker containing deionized water and treated in an ultrasonic cleaner for 5 minutes to thoroughly remove coating pores and air bubbles from the adhesion surface. After removal, the sample was suspended by a thin metal wire with a diameter of less than 0.2 mm, ensuring it was completely submerged in water without contacting the container wall. Its apparent mass in water was measured and recorded as _____. Finally, according to Archimedes' principle, the volume of the coating-substrate composite sample... ,in The density of water at the experimental temperature (recorded as 20℃) was 0.9982 g / cm³. 3 The volume of the PEEK matrix is ​​known. and quality The volume of the coating can then be calculated. and quality The formula for calculating the bulk density of the coating is as follows:

[0076] .

[0077] Three parallel samples were prepared for each set of parameters, and the average value of the results was taken.

[0078] In engineering applications, greater emphasis is placed on the overall equivalent density of composite materials. Based on the principle of "mixing ratio" in composite materials, its equivalent density... It can be calculated using the density and volume fraction of each component, as shown in the following formula:

[0079]

[0080] in, and These represent the volume fractions of the PEEK substrate and the coating, respectively. The volume fraction is determined by the average coating thickness d and the substrate thickness H, i.e. .

[0081] The measurement results are shown in Table 2 below.

[0082] Table 2. Densities of different materials (density, g / cm³) 3 )

[0083] Material PEEK Tin bronze Composite sample <![CDATA[Density, g / cm 3 > 1.32 8.80 1.72

[0084] In the context of the pursuit of extreme lightweighting in high-end equipment, the "PEEK matrix arc sprayed metal coating" composite material system proposed in this invention exhibits significant weight reduction advantages. Through actual measurement, the density of the PEEK matrix is ​​1.32 g / cm³. 3 Solid tin bronze has a density as high as 8.80 g / cm³. 3 The two materials have a density difference of nearly 6.7 times, which constitutes the fundamental premise for lightweight design. Measurements show that the overall density of the composite coating material prepared in Example 1 is only 1.72 g / cm³. 3 This figure means that while achieving the functional properties of a metal surface (conductivity and wear resistance), the overall weight of the material increases by only about 30% compared to a pure PEEK substrate, but is far lower than that of traditional all-metal structures, with a weight reduction of over 80%. Therefore, this invention successfully overcomes the performance contradiction between "conductivity and wear resistance" and "lightweighting" in traditional materials by using a low-density PEEK matrix to support the main structure and achieving functionality only on the most critical surfaces with a thin layer of metal, providing a highly promising solution for lightweight current-carrying friction components.

Claims

1. A polyetheretherketone (PEEK) surface-modified coating material, characterized in that, It comprises a polyetheretherketone (PEEK) matrix, a zinc transition layer, and a CuSn6 surface layer, wherein the zinc layer and CuSn6 layer are applied to the PEEK matrix using an arc spraying technique.

2. The polyetheretherketone surface-modified coating material according to claim 1, characterized in that, The thickness of the zinc layer is 150~250 μm.

3. The polyetheretherketone surface-modified coating material according to claim 1, characterized in that, The thickness of the CuSn6 is 30~70 μm.

4. The polyetheretherketone surface-modified coating material according to claim 1, characterized in that, The thickness of the polyetheretherketone matrix is ​​5-10 mm.

5. The polyetheretherketone surface-modified coating material according to claim 1, characterized in that, The wear resistance current of the polyether ether ketone surface-modified coating material is 0~60A.

6. A method for preparing a polyetheretherketone surface-modified coating material according to any one of claims 1 to 5, characterized in that, Includes the following steps: (1) Edge grinding: Grind the edges and corners of the polyetheretherketone matrix; (2) Surface cleaning: Clean the surface of the polyetheretherketone matrix to remove grease and stains; (3) Sandblasting roughening: The PEEK matrix is ​​roughened by sandblasting with white corundum sand; (4) Zinc coating: The zinc coating is applied using arc spraying technology; (5) Spraying CuSn6 layer: The CuSn6 layer is sprayed using arc spraying technology.

7. The method for preparing the polyetheretherketone surface-modified coating material according to claim 6, characterized in that, The conditions for applying the zinc layer using arc spraying technology are: spraying working voltage of 20~30 V, spraying working current of 200~300 A, and spraying gas pressure greater than 0.55 MPa.

8. The method for preparing the polyetheretherketone surface-modified coating material according to claim 6, characterized in that, The conditions for applying the CuSn6 layer using arc spraying technology are: spraying working voltage of 20~50 V, spraying working current of 100~300 A, and spraying gas pressure greater than 0.55 MPa.

9. The method for preparing the polyetheretherketone surface-modified coating material according to claim 6, characterized in that, In the sandblasting roughening process, the white corundum abrasive is 40-50 mesh.

10. The application of a polyetheretherketone surface-modified coating material according to any one of claims 1 to 5 in electromagnetic shielding, electrical contact, and electrostatic discharge.

Images