A kind of automobile disc brake free-burnout running-in coating and its production process

Abstract

This invention discloses a non-ablation break-in coating for automotive disc brakes and its manufacturing process, belonging to the technical field of automotive braking systems. By weight percentage, the coating formulation includes: 12-20% water-based liquid phenolic resin, 40-50% 400-800 mesh alumina, 8-12% 3000 mesh zirconium silicate, 25-35% calcium carbonate, and 3-5% iron oxide red pigment. This allows for the replacement of high-temperature ablation processes above 400℃, reducing coating preparation energy consumption by over 60%, eliminating toxic gas emissions, avoiding the use of toxic components such as acetone and nitrocellulose varnish, and ensuring a VOC release concentration of ≤50mg / m³. 3 It complies with environmental regulations, optimizes the coating curing process, adopts low-temperature drying at 80-100℃ to shorten the curing time to 10 minutes, and ensures coating adhesion. Through the synergistic design of wear-resistant components with specific mesh size, the initial friction coefficient of the brake pads is increased to above 0.35, the occurrence rate of brake noise is reduced, and the break-in period is shortened.

Description

Technical Field

[0001] This invention relates to a non-abrasion break-in coating for automotive disc brakes and its manufacturing process, belonging to the technical field of automotive braking systems. Background Technology

[0002] As a core safety component of the braking system, the performance of automotive brake pads directly determines the reliability and safety of vehicle braking. After replacing brake pads, the friction surface of the new brake pads cannot fully adhere to the old brake discs, requiring a break-in period of 100-300 kilometers to achieve optimal braking performance. During this period, there are safety hazards such as insufficient initial braking force and excessive braking noise. To solve this problem, the traditional industry solution uses a high-temperature ablation process: placing the brake pad friction material in a high-temperature environment above 400°C to ablate and loosen the friction surface, thereby accelerating adhesion to the brake disc. However, this process has significant drawbacks: High-temperature ablation requires a large amount of electrical energy, and during the ablation process, the organic binder in the friction material decomposes to produce toxic gases such as formaldehyde and phenol, which pollute the workshop environment and endanger the health of operators. High-temperature ablation can cause a loss of 0.5-1mm in the surface thickness of the friction material, resulting in a waste of raw materials. Furthermore, microcracks are easily generated inside the friction material after ablation, which shortens the service life of the brake pads. High-temperature ablation requires specialized kiln equipment, and the ablation parameters for different friction materials need to be adjusted separately, making it difficult to adapt to the mass production of various brake pads.

[0003] To replace traditional ablation processes, the industry has gradually developed ablation-free coating technologies, but existing technologies still have many shortcomings: For example, the non-ablation friction coating disclosed in Chinese patent CN104482087B uses nitrocellulose lacquer as a binder and acetone as a diluent. Acetone is highly volatile and toxic; long-term exposure can inhibit the central nervous system, and it is classified as a Class A flammable substance, posing a fire risk, which does not meet the environmental and safety requirements for modern automotive parts. For example, the brake pad coating disclosed in Chinese patent CN109099082B needs to be cured at 180°C for 45 minutes. The curing energy consumption accounts for more than 40% of the total production energy consumption. Moreover, high temperature can easily cause the coating and the friction material substrate to have a mismatch in thermal expansion coefficient, which can lead to coating peeling. For example, Chinese patent CN110903731B uses a composite system of phenolic resin, epoxy resin and composite mineral fiber. Although it improves the coating strength, the cost of composite mineral fiber raw materials is high, which leads to an increase in the total cost of the coating. It is more than twice the cost of traditional ablation process, making it difficult to promote on a large scale. To address the aforementioned issues, there is an urgent need in this field for a non-ablative break-in coating technology that employs non-toxic solvents, operates at low temperatures and low energy consumption, exhibits balanced performance, and possesses visual inspection capabilities. This technology is designed to meet the stringent requirements of new energy vehicles regarding braking noise and environmental friendliness, while also satisfying the cost and efficiency demands of industrial production. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a non-ablation break-in coating for automotive disc brakes and its manufacturing process. This replaces the high-temperature ablation process above 400℃, reduces coating preparation energy consumption by over 60%, eliminates toxic gas emissions, avoids the use of toxic components such as acetone and nitrocellulose lacquer, and ensures the coating's VOC release concentration is ≤50mg / m³. 3 It complies with environmental regulations, optimizes the coating curing process, adopts low-temperature drying at 80-100℃ to shorten the curing time to 10 minutes, and ensures coating adhesion. Through the synergistic design of wear-resistant components with specific mesh size, the initial friction coefficient of the brake pads is increased to above 0.35, the occurrence rate of brake noise is reduced, and the break-in period is shortened.

[0005] The technical solution adopted by this invention to solve its technical problem is: A non-abrasion break-in coating for automotive disc brakes, the coating formulation comprising, by weight percentage: 12-20% water-based liquid phenolic resin, 40-50% 400-800 mesh alumina, 8-12% 3000 mesh zirconium silicate, 25-35% calcium carbonate, and 3-5% iron oxide red pigment.

[0006] Preferably, the water-based liquid phenolic resin is an industrial-grade water-based liquid phenolic resin with a solid content of 50±2% and a gel time of 10-15s at 165℃.

[0007] Preferably, the 400-800 mesh alumina is α-type alumina with a purity ≥99%.

[0008] Preferably, the purity of the 3000 mesh zirconium silicate is ≥98%.

[0009] Preferably, the calcium carbonate is heavy calcium carbonate with a particle size of 2000 mesh.

[0010] Preferably, the iron oxide red pigment is an iron oxide red pigment with a temperature resistance of >200℃.

[0011] A manufacturing process for preparing an ablation-free break-in coating for automotive disc brakes includes the following steps: S1. Pre-treat 400-800 mesh alumina, 3000 mesh zirconium silicate, calcium carbonate and iron oxide red pigment, and then sieve them through the corresponding mesh screens respectively; S2. Add the sieved 400-800 mesh alumina, 3000 mesh zirconium silicate, calcium carbonate, and iron oxide red pigment to the plow-type mixer in sequence to obtain a dry mixture. Add water-based liquid phenolic resin to the dry mixture to obtain a coating slurry. S3. Pre-treat the brake pads by applying a coating slurry to the pre-treated brake pads using a fully automatic roller coating machine, and then drying the coated brake pads in a hot air circulating oven with a conveyor belt for 10±1 minutes. S4. Place the dried brake pads on a cooling rack for natural cooling, and test the coating adhesion, initial coefficient of friction, the occurrence rate of brake noise of 70dB or above, and the VOC release concentration of the coating.

[0012] Preferably, the pretreatment in S1 includes: placing 400-800 mesh alumina, 3000 mesh zirconium silicate, calcium carbonate, and iron oxide red pigment in a hot air circulating oven at 60±5℃ and drying for 2±0.5 hours, controlling the moisture content to be ≤0.3%.

[0013] Preferably, in step S2, the water-based liquid phenolic resin is added to the dry mixture in three portions, with each portion being 1 / 3 of the total amount added and stirred for 3 ± 0.5 minutes. Finally, the mixture is stirred at a speed of 200 ± 10 rpm for 5 ± 1 minutes to obtain a coating slurry with a viscosity of 5000-8000 mPa·s and a solid content of 60 ± 5%.

[0014] Preferably, in step S3, the brake pad pretreatment specifically includes: The friction material of the brake lining was ground using a CNC grinding machine with a grinding depth of 0.1 ± 0.02 mm, and the surface roughness Ra of the friction material was controlled to be ≤ 2.0 μm. First, use a high-pressure air gun with a pressure of 0.6±0.1MPa to blow away the floating dust on the surface of the friction material, and then use a vacuum cleaner with a suction power of ≥20kPa to adsorb the dust in the gaps. Wipe the surface of the friction material twice with a lint-free cloth soaked in industrial-grade anhydrous ethanol, and let it air dry naturally at 25±5℃ for 5±1 minutes, controlling the water contact angle of the friction material surface to be ≤60°.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This method replaces high-temperature ablation processes above 400℃, reducing coating preparation energy consumption by over 60%, eliminating toxic gas emissions, and avoiding the use of toxic components such as acetone and nitrocellulose varnish, resulting in a VOC emission concentration of ≤50mg / m³ for the coating. 3 It complies with environmental regulations and optimizes the coating curing process; Low-temperature drying at 80-100℃ shortens the curing time to 10 minutes while ensuring coating adhesion. Through the synergistic design of wear-resistant components with specific mesh sizes, the initial friction coefficient of the brake pads is increased to above 0.35, the brake noise rate is reduced to below 5%, and the break-in period is shortened to within 50 kilometers. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a data table showing the effect of different contents of water-based liquid phenolic resin on coating performance according to the present invention; Figure 2 This is a test table of grinding performance of alumina with different mesh sizes according to the present invention; Figure 3 The table below shows the effect of different calcium carbonate contents on frictional stability according to the present invention. Figure 4 This is a test table for the non-abrasion break-in coating of automotive disc brakes, as described in Embodiment 1 of the present invention. Figure 5 This is a test table for the non-abrasion break-in coating of automotive disc brakes according to Embodiment 2 of the present invention; Figure 6 This is a test table for the non-abrasion break-in coating of automotive disc brakes according to Embodiment 3 of the present invention; Figure 7 Performance test tables for the products prepared according to Embodiment 1, Embodiment 2, Embodiment 3, Comparative Example 1, and Comparative Example 2 of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] A non-abrasion break-in coating for automotive disc brakes, the coating formulation by weight percentage includes: 12-20% water-based liquid phenolic resin, 40-50% 400-800 mesh alumina, 8-12% 3000 mesh zirconium silicate, 25-35% calcium carbonate, and 3-5% iron oxide red pigment.

[0020] The water-based liquid phenolic resin uses water as the dispersion medium, has no volatile toxic solvents, and its molecular chain contains hydroxyl groups (-OH), which can form hydrogen bonds with the brake pad friction material substrate, improving adhesion. In this embodiment, the water-based liquid phenolic resin is an industrial-grade water-based liquid phenolic resin with a solid content of 50±2%, a gel time of 10-15s / 165℃ at 165℃, and ensures rapid curing when dried at 80-100℃. Figure 1 The table shows the effect of different contents on coating performance verified through orthogonal experiments: When the content is <12%: insufficient binder leads to weak bonding between the coating and the substrate. Adhesion test shows that the adhesion is <4MPa, and the coating is easy to peel off during the break-in process. When the content is >20%, too much binder will make the coating brittle after curing, and microcracks will easily be generated during braking, increasing the noise rate to over 15%. The optimal range is 12-20%: at this point, the coating adhesion is ≥5MPa and the elongation at break is 8-10%, balancing strength and flexibility.

[0021] Furthermore, 400-800 mesh alumina is α-type alumina with a purity ≥99% and stable wear resistance. Avoid using industrial-grade alumina containing impurities, such as... Figure 2 The table shows that the grinding performance of alumina with different mesh sizes was tested and found that: Mesh count < 400 mesh: The particles are too coarse, the grinding force is too strong, resulting in scratches on the brake disc surface depth > 0.1mm; Mesh count > 800 mesh: The particles are too fine, resulting in insufficient initial grinding force and extending the break-in period to over 150 kilometers; The optimal mesh size is 400-800 mesh: 400 mesh particles are responsible for rough grinding, and 800 mesh particles are responsible for fine grinding. When the two are mixed at a mass ratio of 1:1, the scratch depth of the brake disc is <0.03mm, and the break-in period is shortened to less than 50 kilometers.

[0022] The purity of 3000 mesh zirconium silicate is ≥98%.

[0023] The calcium carbonate is heavy calcium carbonate with a particle size of 2000 mesh. As a low-cost filler, calcium carbonate can replace some of the high-cost alumina. Its soft properties can also regulate the stability of the friction coefficient, preventing excessive fluctuations during braking. Specifically, for example… Figure 3 As shown in the table, the results are verified through tests comparing the total cost of the coating with its frictional stability. When the content is <25%: the cost reduction is less than 20%, and the economic target cannot be achieved; When the content is >35%, excessive soft components lead to a decrease in the coefficient of friction and a weakening of the coating's wear resistance. The optimal range is 25-35%: at this point, the total cost of the coating is reduced by more than 30%, and the friction coefficient fluctuation is ≤0.03, balancing cost and performance.

[0024] Furthermore, in order to create a sharp contrast with the black / gray of the brake pad body, areas with missed or thin coatings can be quickly identified visually after application, improving inspection efficiency. Iron oxide red pigment is an iron oxide red pigment with a temperature resistance of >200℃ and a Mohs hardness of 4-5, which can assist alumina in initial grinding. At the same time, its red particles fall off during the break-in process, allowing for a direct assessment of the break-in progress.

[0025] A manufacturing process for preparing an ablation-free break-in coating for automotive disc brakes includes the following steps: S1. Pre-treat 400-800 mesh alumina, 3000 mesh zirconium silicate, calcium carbonate and iron oxide red pigment, and then sieve them through the corresponding mesh screens respectively; S2. Add the sieved 400-800 mesh alumina, 3000 mesh zirconium silicate, calcium carbonate, and iron oxide red pigment to the plow-type mixer in sequence to obtain a dry mixture. Add water-based liquid phenolic resin to the dry mixture to obtain a coating slurry. S3. Pre-treat the brake pads by applying a coating slurry to the pre-treated brake pads using a fully automatic roller coating machine, and then drying the coated brake pads in a hot air circulating oven with a conveyor belt for 10±1 minutes. S4. Place the dried brake pads on a cooling rack for natural cooling, and test the coating adhesion, initial coefficient of friction, the occurrence rate of brake noise of 70dB or above, and the VOC release concentration of the coating.

[0026] The pretreatment in S1 includes: placing 400-800 mesh alumina, 3000 mesh zirconium silicate, calcium carbonate, and iron oxide red pigment in a hot air circulating oven at 60±5℃ and drying for 2±0.5 hours, controlling the moisture content to ≤0.3%.

[0027] In S2, water-based liquid phenolic resin is added to the dry mixture in three portions, with each portion being 1 / 3 of the total amount added and stirred for 3±0.5 minutes. Finally, the mixture is stirred at a speed of 200±10 rpm for 5±1 minutes to obtain a coating slurry with a viscosity of 5000-8000 mPa·s and a solid content of 60±5%.

[0028] Furthermore, in S2, the coating slurry is subjected to vacuum degassing at an environment of -0.095±0.005MPa for 3±0.5 minutes.

[0029] In S3, the brake pad pretreatment specifically includes: The friction material of the brake lining was ground using a CNC grinding machine with a grinding depth of 0.1 ± 0.02 mm, and the surface roughness Ra of the friction material was controlled to be ≤ 2.0 μm. First, use a high-pressure air gun with a pressure of 0.6±0.1MPa to blow away the floating dust on the surface of the friction material, and then use a vacuum cleaner with a suction power of ≥20kPa to adsorb the dust in the gaps. Wipe the surface of the friction material twice with a lint-free cloth soaked in industrial-grade anhydrous ethanol, and let it air dry naturally at 25±5℃ for 5±1 minutes, controlling the water contact angle of the friction material surface to be ≤60°.

[0030] Example 1: A non-abrasion break-in coating for automotive disc brakes, the coating formulation by weight percentage includes: 14% water-based liquid phenolic resin, 40% alumina, 10% zirconium silicate, 31% calcium carbonate, and 5% iron oxide red pigment.

[0031] A manufacturing process for preparing an ablation-free break-in coating for automotive disc brakes includes the following steps: S1. Place 400-800 mesh alumina, 3000 mesh zirconium silicate, calcium carbonate and iron oxide red pigment at 60℃ and dry for 2 hours to make the moisture content of the raw materials ≤0.3%, and then sieve them through the corresponding mesh screens respectively. S2. Add the sieved 400-800 mesh alumina, 3000 mesh zirconium silicate, calcium carbonate, and iron oxide red pigment to a plow-type mixer in sequence, and stir at 100 rpm for 10 minutes to obtain a dry mixture. Add the water-based liquid phenolic resin to the dry mixture in 3 portions, and stir at 200 rpm for 5 minutes. The slurry viscosity is 7000 mPa·s, and the solid content is 60%. Then, vacuum degassing is performed at -0.095±0.005 MPa for 3±0.5 minutes to obtain the coating slurry. S3. The brake pads are ground, dusted, and activated. A fully automatic roller coating machine is then used to apply a coating slurry to the pretreated brake pads. The coating roller operates at 10 rpm, the scraper roller gap is 0.15 mm, the conveyor belt speed is 3 m / min, and the friction material area is 150 cm². 2 Apply 9.4g of slurry to a thickness of 0.15mm. Use a hot air circulating oven with a conveyor belt to dry the brake pads coated with the slurry. The oven has three temperature zones: 80℃, 90℃ and 100℃. The conveyor belt speed is 0.5m / min and the drying time is 10 minutes. S4. Place the dried brake pads on a cooling rack for natural cooling, i.e., air dry at 25°C for 15 minutes. Test the coating adhesion, initial coefficient of friction, incidence of braking noise of 70dB or higher, and VOC emission concentration. In this embodiment, the test results are: adhesion 5.5MPa, initial coefficient of friction 0.38, incidence of noise of 70dB or higher 4.8%, break-in period 48 km, VOC emission 45mg / m³. 3 .

[0032] Specifically, such as Figure 4 The table shows the performance of the non-abrasion break-in coating for automotive disc brakes prepared in this embodiment in real driving scenarios, especially the test data in terms of friction coefficient and noise percentage.

[0033] Example 2: A non-abrasion break-in coating for automotive disc brakes, the coating formulation by weight percentage includes: 17% water-based liquid phenolic resin, 40% alumina, 10% zirconium silicate, 28% calcium carbonate, and 5% iron oxide red pigment.

[0034] A production process for preparing an ablation-free break-in coating for automotive disc brakes is consistent with Example 1, except that the coating amount is adjusted to 140 cm² on the friction material area. 2 Apply 8.8g of slurry to a thickness of 0.15mm. Performance test results: Adhesion: 5.3 MPa; Initial friction coefficient: 0.39; Noise level above 70 dB: 3.2%; Break-in period: 50 km; VOC emission: 42 mg / m³ 3 .

[0035] Specifically, such as Figure 5 The table shows the performance of the non-abrasion break-in coating for automotive disc brakes prepared in this embodiment in real driving scenarios, especially the test data in terms of friction coefficient and noise percentage.

[0036] Example 3: A non-abrasion break-in coating for automotive disc brakes, the coating formulation by weight percentage includes: 20% water-based liquid phenolic resin, 40% alumina, 10% zirconium silicate, 25% calcium carbonate, and 5% iron oxide red pigment.

[0037] A production process for preparing an ablation-free break-in coating for automotive disc brakes differs from Example 1 in that the coating amount is adjusted, specifically, the friction material area is 200 cm². 2 Apply 12.5g of slurry to a thickness of 0.15mm, dry for 11 minutes, and the performance test results are as follows: Adhesion: 5.1 MPa; Initial friction coefficient: 0.40; Noise level above 70 dB: 2.8%; Break-in period: 55 km; VOC emission: 48 mg / m³ 3 .

[0038] Specifically, such as Figure 6 The table shows the performance of the non-abrasion break-in coating for automotive disc brakes prepared in this embodiment in real driving scenarios, especially the test data in terms of friction coefficient and noise percentage.

[0039] Comparative Example 1: Process parameters Ablation temperature: 450℃, ablation time: 30 minutes; Friction material: Same as in Example 1.

[0040] Performance test results: Initial friction coefficient: 0.30, 1st braking; Occurrence rate of noise levels above 70dB: 15.2%; Break-in period: 100 kilometers; Energy consumption: 100kWh / 1000 units; VOC emissions: 2000 mg / m³ 3 ; Friction material thickness loss: 0.8 mm.

[0041] Comparative Example 2: Formula composition Nitrocellulose varnish: 35 parts by weight; Acetone: 10 parts by weight; Iron oxide red: 20 parts by weight; Antimony sulfide: 8 parts by weight; Brown fused alumina: 6 parts by weight; Zirconium silicate: 6 parts by weight.

[0042] Preparation process Mixing: Stir at 600 rpm for 20 minutes; Coating: 0.15mm thickness; Drying: Dry at 180℃ for 20 minutes.

[0043] Performance test results: Initial friction coefficient: 0.32, 1st braking; Occurrence rate of noise levels above 70dB: 8.5%; Break-in period: 150 kilometers; Energy consumption: 80kWh / 1000 units; VOC emissions: 2500 mg / m³ 3 (Acetone volatilization); Adhesion: 3.8 MPa.

[0044] Specifically, such as Figure 7 The table shows the performance test results of the products manufactured in Embodiment 1, Embodiment 2, Embodiment 3, Comparative Example 1, and Comparative Example 2 of the present invention. Analysis shows that... Compared with Comparative Example 1, Examples 1 to 3 of the present invention, while maintaining excellent braking performance, significantly reduced VOC emissions and energy consumption. Furthermore, the thickness loss of the friction material was controlled at 0.10-0.15 mm, far lower than the 0.8 mm of Comparative Example 1, greatly reducing raw material waste. Regarding braking performance, the initial friction coefficient of the embodiments of the present invention all reached above 0.38, superior to 0.30 of Comparative Example 1 and 0.32 of Comparative Example 2; the incidence of braking noise above 70 dB was reduced to below 5%, significantly superior to 15.2% of Comparative Example 1 and 8.5% of Comparative Example 2; and the break-in period was shortened to within 55 kilometers, significantly superior to 100 kilometers of Comparative Example 1 and 150 kilometers of Comparative Example 2.

[0045] Compared with Comparative Example 2, the embodiments of the present invention not only reduce VOC emissions by more than 98%, meeting environmental protection requirements, but also maintain a stable coating adhesion of over 5.1 MPa, superior to the 3.8 MPa of Comparative Example 2. It is particularly noteworthy that Comparative Example 2 requires the use of toxic diluents such as acetone during preparation, posing a risk of flammability and explosion, while the present invention uses water-based liquid phenolic resin, completely eliminating safety hazards.

[0046] In summary, this invention, through the synergistic design of wear-resistant components with specific ratios and mesh sizes, combined with a low-temperature rapid curing process, achieves environmentally friendly, energy-saving, and efficient ablation-free running-in coating preparation while ensuring coating adhesion and braking performance. This overcomes many shortcomings of existing technologies and achieves unexpected technical results.

[0047] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A non-abrasion break-in coating for automotive disc brakes, characterized in that, The coating formulation, by weight percentage, comprises: 12-20% water-based liquid phenolic resin, 40-50% 400-800 mesh alumina, 8-12% 3000 mesh zirconium silicate, 25-35% calcium carbonate, and 3-5% iron oxide red pigment.

2. The non-abrasion break-in coating for automotive disc brakes according to claim 1, characterized in that, The water-based liquid phenolic resin is an industrial-grade water-based liquid phenolic resin with a solid content of 50±2% and a gel time of 10-15s at 165℃.

3. The non-abrasion break-in coating for automotive disc brakes according to claim 1, characterized in that, The 400-800 mesh alumina is α-type alumina with a purity ≥99%.

4. The non-abrasion break-in coating for automotive disc brakes according to claim 1, characterized in that, The purity of the 3000 mesh zirconium silicate is ≥98%.

5. The non-abrasion break-in coating for automotive disc brakes according to claim 1, characterized in that, The calcium carbonate is heavy calcium carbonate with a particle size of 2000 mesh.

6. The non-abrasion break-in coating for automotive disc brakes according to claim 1, characterized in that, The iron oxide red pigment is an iron oxide red pigment with a temperature resistance of >200℃.

7. A manufacturing process for preparing the non-ablation break-in coating for automotive disc brakes as described in claim 1, characterized in that, The specific steps include: S1, 400-800 mesh alumina, 3000 mesh zirconium silicate, calcium carbonate and iron oxide red pigment are pretreated and then sieved through the corresponding mesh screens respectively; S2, add the sieved 400-800 mesh alumina, 3000 mesh zirconium silicate, calcium carbonate, and iron oxide red pigment to the plow-type mixer in sequence to obtain a dry mixture, and add water-based liquid phenolic resin to the dry mixture to obtain a coating slurry. S3. The brake pads are pretreated by using a fully automatic roller coater to apply a coating slurry to the pretreated brake pads. The brake pads coated with the coating slurry are then dried in a hot air circulating oven with a conveyor belt for 10 ± 1 minutes. S4. Place the dried brake pads on a cooling rack for natural cooling, and test the coating adhesion, initial coefficient of friction, the incidence of brake noise of 70dB and above, and the VOC release concentration of the coating.

8. The non-abrasion break-in coating for automotive disc brakes according to claim 7, characterized in that, The pretreatment in S1 includes: placing 400-800 mesh alumina, 3000 mesh zirconium silicate, calcium carbonate, and iron oxide red pigment in a hot air circulating oven at 60±5℃ and drying for 2±0.5 hours, controlling the moisture content to ≤0.3%.

9. The non-abrasion break-in coating for automotive disc brakes according to claim 7, characterized in that, In step S2, water-based liquid phenolic resin is added to the dry mixture in three portions. Each time, 1 / 3 of the total amount is added and the mixture is stirred for 3 ± 0.5 minutes. Finally, the mixture is stirred at a speed of 200 ± 10 rpm for 5 ± 1 minutes to obtain a coating slurry with a viscosity of 5000-8000 mPa·s and a solid content of 60 ± 5%.

10. The non-abrasion break-in coating for automotive disc brakes according to claim 7, characterized in that, In S3, the brake pad pretreatment specifically includes: The friction material of the brake lining was ground using a CNC grinding machine with a grinding depth of 0.1 ± 0.02 mm, and the surface roughness Ra of the friction material was controlled to be ≤ 2.0 μm. First, use a high-pressure air gun with a pressure of 0.6±0.1MPa to blow away the floating dust on the surface of the friction material, and then use a vacuum cleaner with a suction power of ≥20kPa to adsorb the dust in the gaps. Wipe the surface of the friction material twice with a lint-free cloth soaked in industrial-grade anhydrous ethanol, and let it air dry naturally at 25±5℃ for 5±1 minutes, controlling the water contact angle of the friction material surface to be ≤60°.

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