Brake disc with surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating, preparation method of brake disc and automobile

Abstract

The invention provides a brake disc with a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating, a preparation method of the brake disc and an automobile, and relates to the field of brake discs. The brake disc is pretreated to obtain a to-be-cladded brake disc; the angle of the brake disc to be cladded is adjusted, so that the included angle 1 between the surface to be cladded and the axis of the cladding head and the included angle 2 between the edge of the cladding head and the axis of the cladding head meet the condition that the sum of angle 1 and angle 2 is smaller than 90 degrees; and the brake disc to be cladded is sequentially subjected to bottoming layer ultra-high-speed laser cladding and hard surface layer ultra-high-speed laser cladding, and the brake disc with the ultra-high-speed laser cladding abrasion-resistant and corrosion-resistant coating on the surface is obtained. The to-be-cladded surface and the axis of the cladding head are placed at a certain included angle, so that the damage of high-power laser reflection to the cladding head assembly is avoided; during ultrahigh-speed laser cladding, the rotary table is cooperatively regulated and controlled, so that the rotating speed of the brake disc and the moving speed of the cladding head are synchronously changed along with time, and the linear speed and the lap joint rate are kept uniform in the cladding process.

Description

Technical Field

[0001] The present application relates to the field of brake discs, and in particular to a brake disc having a wear-resistant and corrosion-resistant coating formed by ultra-high-speed laser cladding on the surface, a preparation method thereof, and an automobile. Background Art

[0002] Particulate matter emissions from vehicle braking systems have a localized effect and cause significant harm to the human body. Unlike carbon dioxide emissions, which have a global impact on the atmosphere, particulate matter emissions generated by the friction between brake pads and brake discs during vehicle braking have a localized effect, meaning they cause the greatest harm to people and the environment near the emission source (such as intersections and busy roads). Studies have shown that ingesting these particles can cause respiratory problems, cancer, and other physical harm, and increase the risk of Alzheimer's disease. The EU's newly released Euro 7 standard, for the first time, includes controls on particulate matter emissions from braking systems. To meet this stringent standard, the most fundamental solution is to improve the wear resistance of brake discs and reduce particulate matter emissions caused by wear at the source.

[0003] Ultra-high-speed laser cladding technology is a process in which powder and a laser beam converge above a workpiece to melt the powder, which is then evenly deposited on the workpiece surface and solidified to form a protective coating. The cladding rate can be as high as 20m / min-200m / min. The coating surface quality is high and usually only requires simple grinding or polishing for application. The coating is metallurgically bonded and has high performance reliability. Compared with conventional surface protection technologies, it has irreplaceable application advantages in cost, efficiency, and automation, and is particularly suitable for the preparation of wear-resistant and corrosion-resistant coatings for brake discs.

[0004] However, the high-power laser reflection required in the ultra-high-speed laser cladding process can damage the cladding head components, and the coating formed by ultra-high-speed laser cladding has problems such as unevenness and poor wear resistance. Summary of the Invention

[0005] The purpose of this application is to provide a brake disc with a wear-resistant and corrosion-resistant coating on the surface by ultra-high-speed laser cladding, a preparation method thereof, and a vehicle to solve the above-mentioned problems.

[0006] To achieve the above objectives, the present application provides, in a first aspect, a method for preparing a brake disc having a wear-resistant and corrosion-resistant coating on its surface by ultra-high-speed laser cladding, comprising: Pre-treating the brake disc to obtain the brake disc to be clad; Adjust the angle of the brake disc to be clad so that the angle ∠1 between the surface to be clad and the axis of the cladding head and the angle ∠2 between the edge of the cladding head and the axis of the cladding head meet the following conditions: ∠1+0.5∠2<90°; The brake disc to be clad is subjected to sequential base layer ultra-high speed laser cladding and hard surface layer ultra-high speed laser cladding to obtain the brake disc having the ultra-high speed laser cladding wear-resistant and corrosion-resistant coating on the surface; The ultra-high-speed laser cladding of the base layer comprises: rotating the brake disc to be clad, and performing ultra-high-speed laser cladding of the base layer from the inside to the outside to obtain a brake disc with a base layer; The ultra-high-speed laser cladding of the hard surface layer comprises: performing ultra-high-speed laser cladding of the hard surface layer on the brake disc with the primer layer from the outside to the inside to obtain the brake disc with the ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface; During the ultra-high-speed laser cladding of the base layer and the ultra-high-speed laser cladding of the hard surface layer, ∠1 remains unchanged; During the ultra-high-speed laser cladding of the base layer, the initial rotation speed of the brake disc to be clad satisfies: ; During the ultra-high-speed laser cladding of the base layer, the initial moving speed of the cladding head satisfies: ; During the ultra-high-speed laser cladding process of the base layer, the rotation speed of the brake disc to be clad is gradually reduced, satisfying: ; During the ultra-high-speed laser cladding process of the base layer, the moving speed of the cladding head gradually decreases, satisfying: ; During the ultra-high-speed laser cladding of the hard surface layer, the initial rotation speed of the brake disc with the base layer satisfies: ; During the ultra-high-speed laser cladding of the hard surface layer, the initial moving speed of the cladding head satisfies: ; During the ultra-high-speed laser cladding of the hard surface layer, the rotation speed of the brake disc with the base layer is gradually increased to meet the following requirements: ; During the ultra-high-speed laser cladding of the hard surface layer, the moving speed of the cladding head gradually increases, satisfying: ; Wherein, W1 is the initial rotation speed of the brake disc to be clad when preparing the brake disc with the base layer, W1 ’ is the real-time rotation speed during the preparation of the brake disc with a base layer, W2 is the starting rotation speed of the brake disc with a base layer when preparing the brake disc with a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating, and W2 ’ is the real-time rotation speed during the preparation of the brake disc with the surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating, M1 is the starting moving speed of the cladding head during the ultra-high-speed laser cladding of the base layer, and M1 ...’ M2 is the moving speed of the cladding head during the ultra-high-speed laser cladding of the base layer, M3 is the starting moving speed of the cladding head during the ultra-high-speed laser cladding of the hard surface layer, and M4 is the starting moving speed of the cladding head during the ultra-high-speed laser cladding of the hard surface layer. ’ is the moving speed of the cladding head during the ultra-high-speed laser cladding of the hard surface layer, V is the linear speed, L is the laser spot diameter, η is the overlap rate, D1 is the inner diameter of the brake disc, D2 is the outer diameter of the brake disc, t1 and t2 are the cladding times of the ultra-high-speed laser cladding of the base layer and the ultra-high-speed laser cladding of the hard surface layer, respectively.

[0007] Optionally, the preprocessing includes: The surface oil stains of the brake disc are cleaned with alcohol and / or acetone to obtain the brake disc to be clad.

[0008] Optionally, the raw material of the base layer prepared by ultra-high-speed laser cladding with a base layer includes 316L stainless steel.

[0009] Optionally, the raw materials of the hard surface layer prepared by ultra-high-speed laser cladding include iron-based alloy and hard particles.

[0010] Optionally, the iron-based alloy, calculated with the total mass as 100%, includes: C<0.02wt%, Cr16wt%-18wt%, Ni11wt%-13wt%, Mo2wt%-3wt%, Si0.5wt%-1wt%, Mn0.1wt%-0.5wt%, and the balance is Fe.

[0011] Optionally, the hard particles include one or more of tungsten carbide, titanium carbide, chromium carbide and silicon carbide.

[0012] Optionally, the method for preparing the brake disc having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating satisfies at least one of the following conditions: A. The particle size of the iron-based alloy and / or the hard particles is 15 μm-53 μm; B. The mass content of the hard particles in the hard surface layer is 20wt%-50wt%.

[0013] Optionally, the method for preparing the brake disc having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating satisfies at least one of the following conditions: A. The linear speed is 100m / min-200m / min; B. The laser spot diameter is 3mm-5mm; C. The overlap rate is 70%-90%; D. The power of the base layer ultra-high speed laser cladding and the hard surface layer ultra-high speed laser cladding is 6000W-12000W; E. The powder feeding rate of the cladding head is 2g / s-5g / s.

[0014] A second aspect of the present application provides a brake disc having a wear-resistant and corrosion-resistant coating on its surface by ultra-high-speed laser cladding, which is prepared by the method for preparing a brake disc having a wear-resistant and corrosion-resistant coating on its surface by ultra-high-speed laser cladding.

[0015] A third aspect of the present application provides an automobile, comprising the brake disc having the wear-resistant and corrosion-resistant coating formed by ultra-high-speed laser cladding on the surface.

[0016] Compared with the prior art, the advantages of this application include: The present application provides a method for preparing a brake disc with a wear-resistant and corrosion-resistant coating by ultra-high-speed laser cladding on the surface. First, by placing the surface to be clad at a certain angle to the axis of the cladding head, damage to the cladding head assembly caused by the reflection of the high-power laser that must be used in ultra-high-speed laser cladding is avoided; secondly, during ultra-high-speed laser cladding, the turntable is coordinated and regulated so that the rotation speed of the brake disc to be clad or the brake disc with a base layer and the moving speed of the cladding head change synchronously with time, thereby ensuring that the linear speed and overlap rate remain uniform during the cladding process, thereby improving the uniformity of the thickness, structure and performance of the cladding layer; then, in order to reduce the amount of deformation, the two cladding layers (base layer and hard surface layer) adopt different cladding directions; the base layer is clad from the inner diameter to the outer diameter of the brake disc to be processed. During this process, the diameter of the brake disc to be clad continues to increase. In order to keep the cladding linear speed V unchanged, the rotation speed W1 of the brake disc to be clad is adjusted. ’ Should be continuously reduced and the corresponding formula needs to be satisfied; at the same time, due to the rotation speed W1 of the brake disc to be clad ’ In order to keep the overlap rate of the melt track constant, the cladding head M1 ’ The moving speed should also be continuously reduced, and the corresponding formula needs to be satisfied. Accordingly, the hard surface layer is clad from the outer diameter to the inner diameter of the brake disc with the base layer. During this process, the diameter of the brake disc with the base layer is continuously reduced. In order to keep the cladding linear speed V unchanged, the rotation speed W2 of the brake disc with the base layer is ’ Should continue to increase, need to meet the corresponding another set of formulas, at the same time, because the bottom layer of the brake disc rotation speed continues to increase, in order to keep the melt overlap rate unchanged, the moving speed of the cladding head M2 ’ It should also continue to increase and needs to satisfy another set of corresponding formulas.

[0017] The brake disc provided in this application has a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating, and the preparation efficiency of the wear-resistant and corrosion-resistant coating of the brake disc can reach 7.2m 2 / h, reaching the highest level reported abroad so far. The cladding time of a single layer of coating on a brake disc (outer diameter 288mm, inner diameter 135mm) is less than 30s, which greatly improves production efficiency. The cladding head is at a specific angle to the brake disc, which effectively avoids damage to the optical components of the cladding equipment due to laser reflection. The powder utilization rate reaches more than 90%, which greatly reduces costs. The cladding parameters are adjusted dynamically to improve the uniformity of the coating structure. The double-layer structure bottom layer provides good corrosion resistance, and the surface layer has excellent wear resistance. It not only avoids the brake disc from being corroded in rainy, snowy and humid weather or long-term parking, resulting in unstable braking performance and affecting the safety of life and property, but also reduces corrosion and wear, greatly extends the service life of the brake disc, and reduces solid particulate matter emissions from the brake system, which is of great significance for promoting the construction of a green and environmentally friendly society.

[0018] The automobile provided in this application reduces particulate matter emissions caused by brake disc wear. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0020] Figure 1 A schematic diagram of the cladding process in a method for preparing a brake disc having a wear-resistant and corrosion-resistant coating on the surface by ultra-high-speed laser cladding is provided for this application; Figure 2 Schematic diagram of coating prepared by existing cladding method; Figure 3 This is a macroscopic morphology of the brake disc with a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating prepared in Example 1; Figure 4 This is a microstructural diagram of the brake disc with a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating prepared in Example 1. DETAILED DESCRIPTION

[0021] As used herein: "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0022] The conjunction "consisting of" excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed, excluding materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim, rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0023] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed alone. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including the range "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0024] In these examples, parts and percentages are by mass unless otherwise indicated.

[0025] "Parts by mass" refers to the basic unit of measurement used to express the mass ratio of multiple components. One part can represent any unit of mass, such as 1g or 2.689g. For example, if we say that the parts by mass of component A are a parts and the parts by mass of component B are b parts, this means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, we could say that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number representing a multiplication factor). It's important to note that, unlike parts by mass, the sum of the parts by mass of all components is not limited to 100 parts.

[0026] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0027] In a first aspect, the present application provides a method for preparing a brake disc having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating, comprising: Pre-treating the brake disc to obtain the brake disc to be clad; Adjust the angle of the brake disc to be clad so that the angle ∠1 between the surface to be clad and the axis of the cladding head and the angle ∠2 between the edge of the cladding head and the axis of the cladding head meet the following conditions: ∠1+0.5∠2<90°; It should be noted that in the actual production process, the workpiece is usually placed horizontally during laser cladding to allow the powder to better converge on the workpiece surface and improve the powder utilization rate. However, for ultra-high-speed laser cladding, the laser power is large and the laser reflection on the workpiece surface can easily cause damage to the cladding head. Therefore, if Figure 1 As shown, the present application deflects the workpiece at a certain angle to reduce the impact of reflection on the cladding head. At the same time, since the convergence position of the ultra-high-speed laser cladding laser and powder is above the workpiece rather than on the workpiece surface, the powder is pre-melted and reaches the workpiece surface in a semi-molten state, which can adhere to the workpiece surface. Therefore, at this deflection angle, the powder utilization rate will not be greatly affected. The brake disc to be clad is subjected to sequential base layer ultra-high speed laser cladding and hard surface layer ultra-high speed laser cladding to obtain the brake disc having the ultra-high speed laser cladding wear-resistant and corrosion-resistant coating on the surface; The ultra-high-speed laser cladding of the base layer comprises: rotating the brake disc to be clad, and performing ultra-high-speed laser cladding of the base layer from the inside to the outside to obtain a brake disc with a base layer; The ultra-high-speed laser cladding of the hard surface layer comprises: performing ultra-high-speed laser cladding of the hard surface layer on the brake disc with the primer layer from the outside to the inside to obtain the brake disc with the ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface; During the ultra-high-speed laser cladding of the base layer and the ultra-high-speed laser cladding of the hard surface layer, ∠1 remains unchanged; During the ultra-high-speed laser cladding of the base layer, the initial rotation speed of the brake disc to be clad satisfies: ; During the ultra-high-speed laser cladding of the base layer, the initial moving speed of the cladding head satisfies: ; During the ultra-high-speed laser cladding process of the base layer, the rotation speed of the brake disc to be clad is gradually reduced, satisfying: ; During the ultra-high-speed laser cladding process of the base layer, the moving speed of the cladding head gradually decreases, satisfying: ; During the ultra-high-speed laser cladding of the hard surface layer, the initial rotation speed of the brake disc with the base layer satisfies: ; During the ultra-high-speed laser cladding of the hard surface layer, the initial moving speed of the cladding head satisfies: ; During the ultra-high-speed laser cladding of the hard surface layer, the rotation speed of the brake disc with the base layer is gradually increased to meet the following requirements: ; During the ultra-high-speed laser cladding of the hard surface layer, the moving speed of the cladding head gradually increases, satisfying: ; It should be noted that if Figure 2 As shown in the figure, the speed of the cladding head during ultra-high-speed laser cladding should be coordinated with the rotation speed of the brake disc. When preparing the base layer, the cladding head moves from the inside to the outside. If it is not adjusted, the linear speed will become larger and larger, resulting in inconsistent coating thickness and performance inside and outside the brake disc, which will appear. Figure 2 The coating in the middle picture is thick inside and thin outside. If you only adjust the rotation speed of the brake disc without adjusting the moving speed of the cladding head, the linear speed can remain consistent, but the overlap rate between each cladding layer will change, which will also lead to inconsistent coating thickness and performance inside and outside the brake disc. Figure 2 The middle right image shows a coating that is thin inside and thick outside. Similarly, when preparing the hard surface layer, the rotation speeds of the cladding head and the brake disc need to be coordinated according to the formula to ensure consistency and stability in coating thickness and performance. Wherein, W1 is the initial rotation speed of the brake disc to be clad when preparing the brake disc with the base layer, W1 ’ is the real-time rotation speed during the preparation of the brake disc with a base layer, W2 is the starting rotation speed of the brake disc with a base layer when preparing the brake disc with a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating, and W2 ’ is the real-time rotation speed during the preparation of the brake disc with the surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating, M1 is the starting moving speed of the cladding head during the ultra-high-speed laser cladding of the base layer, and M1 ... ’ M2 is the moving speed of the cladding head during the ultra-high-speed laser cladding of the base layer, M3 is the starting moving speed of the cladding head during the ultra-high-speed laser cladding of the hard surface layer, and M4 is the starting moving speed of the cladding head during the ultra-high-speed laser cladding of the hard surface layer. ’ is the moving speed of the cladding head during the ultra-high-speed laser cladding of the hard surface layer, V is the linear speed, L is the laser spot diameter, η is the overlap rate, D1 is the inner diameter of the brake disc, D2 is the outer diameter of the brake disc, t1 and t2 are the cladding times of the ultra-high-speed laser cladding of the base layer and the ultra-high-speed laser cladding of the hard surface layer, respectively.

[0028] It is important to understand that ultra-high-speed laser cladding changes the intersection of the powder and the laser beam from the workpiece surface to above the workpiece, allowing approximately 80% of the laser energy to act directly on the powder, causing it to pre-melt. This is then deposited onto the workpiece surface to form a micro-molten pool, which rapidly solidifies to form a coating that is metallurgically bonded to the workpiece surface. Furthermore, due to the unique micro-molten pool characteristics of ultra-high-speed laser cladding, its heat input is low, the thermal impact on the substrate is minimal, and the coating surface quality is high. Typically, simple grinding or polishing is all that is required for application. The coating is metallurgically bonded and has high performance reliability. Compared to conventional surface protection technologies, it has irreplaceable application advantages in terms of cost, efficiency, and automation, making it particularly suitable for the preparation of wear-resistant coatings for brake discs.

[0029] In some embodiments, the pre-processing comprises: The surface oil stains of the brake disc are cleaned with alcohol and / or acetone to obtain the brake disc to be clad.

[0030] In some embodiments, the raw material of the base layer prepared by the ultra-high-speed laser cladding with a base layer includes 316L stainless steel.

[0031] It should be noted that the base material is stainless steel, which not only plays a role in composition transition, but also has an anti-corrosion effect, reducing the emission of particulate matter such as Fe3O4 caused by the wear of the gray cast iron matrix after corrosion.

[0032] In some embodiments, the raw materials of the hard surface layer prepared by ultra-high-speed laser cladding include iron-based alloy and hard particles.

[0033] It is important to note that when the raw materials for the hardfacing layer include an iron-based alloy and hard particles, the iron-based alloy has an austenitic structure, which has a face-centered cubic structure. Because face-centered cubic crystals have 12 slip systems, they can adopt multiple spatial orientations during slip, making slip easy, resulting in good plasticity for the austenite. The hard particles are characterized by high hardness and wear resistance. The plasticity of the austenitic iron-based alloy in the coating acts as a binder, securing the hard particles within the coating without causing cracking. The hard particles increase strength and wear resistance, resulting in a coating with wear resistance over eight times that of the gray cast iron substrate, significantly reducing particulate emissions caused by wear.

[0034] In some embodiments, the iron-based alloy, calculated with the total mass as 100%, comprises: C<0.02wt%, Cr16wt%-18wt%, Ni11wt%-13wt%, Mo2wt%-3wt%, Si0.5wt%-1wt%, Mn0.1wt%-0.5wt%, and the balance is Fe.

[0035] Optionally, the iron-based alloy is calculated with the total mass as 100%, C can be 0.001wt%, 0.01wt%, 0.015wt% or any value <0.02wt%, Cr can be 16wt%, 17wt%, 18wt% or any value between 16wt% and 18wt%, Ni can be 11wt%, 12wt%, 13wt% or any value between 11wt% and 13wt%, Mo can be 2wt%, 2.5wt%, 3wt% or any value between 2wt% and 3wt%, Si can be 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt% or any value between 0.5wt% and 1wt%, Mn can be 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt% or any value between 0.1wt% and 0.5wt%, and the balance is Fe.

[0036] It should be noted that this iron-based alloy is an ultra-low carbon austenitic stainless steel. The austenite has a face-centered cubic structure and good toughness. On the one hand, it provides a toughening effect for the composite coating, and on the other hand, it has better bonding with hard particles (tungsten carbide, titanium carbide, chromium carbide and silicon carbide, etc.); compared with martensitic steel and duplex steel, although martensitic stainless steel has high hardness, lattice distortion and volume collision will occur during the martensitic transformation, causing large internal stress, and cracks are prone to occur when too many ceramic particles are added; in addition, multiple temperature increases during braking will also cause the martensite to undergo tempering transformation, resulting in unstable performance; the martensite content in duplex stainless steel is about half, and it will also have similar disadvantages; and the other half of the ferrite phase has good toughness, but the strength is too low to fix the hard particles, and it has poor heat resistance and is prone to softening and deformation at high temperatures. On the one hand, the austenite phase of this alloy can better accommodate the hard particles in the cladding layer. The austenite with good toughness can firmly fix the hard particles in the cladding layer, so that even if the hard particles are added to 30wt%, no cracks will occur. On the other hand, it also has better thermal stability, avoiding performance degradation caused by multiple temperature increases during braking.

[0037] It should also be noted that the high Cr and Ni contents are intended, on the one hand, to form a separate austenite phase in the steel, inhibiting ferrite formation during the cladding process. Furthermore, these two elements significantly enhance the alloy's corrosion resistance, preventing rust from occurring in complex environments such as rain and snow, which could affect braking performance. The addition of Mo improves the steel's resistance to high-temperature deformation and creep, contributing to improved brake stability during emergency braking. Mo also enhances the steel's resistance to pitting and crevice corrosion, further enhancing the brake disc's environmental adaptability. However, when the Mo content exceeds 3.5%, the corrosion rate in oxidizing media (such as HNO3) increases dramatically. Furthermore, Mo is relatively expensive, so its addition should not exceed 3.5%. Si acts as a deoxidizer and slag-forming agent during ultra-high-speed laser cladding, improving the performance of the cladding layer. Mn forms a stable austenite with N and a certain amount of Ni. Manganese also has a strong affinity with sulfur, forming MnS, which helps eliminate the harmful effects of residual sulfur in the steel.

[0038] In some embodiments, the hard particles include one or more of tungsten carbide, titanium carbide, chromium carbide, and silicon carbide.

[0039] It should be noted that hard particles include one or more of tungsten carbide, titanium carbide, chromium carbide and silicon carbide. These hard particles have the characteristics of high hardness and high wear resistance, low price and high cost performance.

[0040] In some embodiments, the method for preparing a brake disc having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating satisfies at least one of the following conditions: A. The particle size of the iron-based alloy and / or the hard particles is 15 μm-53 μm; Optionally, the particle size of the iron-based alloy and / or the hard particles may be 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 53 μm or any value between 15 μm and 53 μm; B. The mass content of the hard particles in the hard surface layer is 20wt%-50wt%.

[0041] Optionally, the mass content of the hard particles in the hard surface layer can be 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt% or any value between 20wt% and 50wt%.

[0042] It should be noted that when the mass content of hard particles in the hard surface layer is 20wt%-50wt%, when the content of hard particles is less than 20%, the content is too small, and the effect of increasing strength and wear resistance is not obvious; when it exceeds 50%, the content of hard particles is too high, and the bonding phase in the coating is insufficient, which easily causes cracking; in addition, during the braking process, the coating expands due to heat, and the thermal expansion coefficients of the iron-based alloy and the hard particles are different. Too many hard particles will cause thermal cracks.

[0043] In some embodiments, the method for preparing a brake disc having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating satisfies at least one of the following conditions: A. The linear speed is 100m / min-200m / min; Optionally, the line speed may be 100 m / min, 120 m / min, 140 m / min, 160 m / min, 180 m / min, 200 m / min or any value between 100 m / min and 200 m / min; It should be noted that the line speed can reach 100m / min-200m / min, which is a great improvement compared to the 0.6m / min-1m / min of traditional laser cladding, thereby significantly improving the cladding efficiency.

[0044] B. The laser spot diameter is 3mm-5mm; Optionally, the laser spot diameter may be 3 mm, 4 mm, 5 mm, or any value between 3 mm and 5 mm; C. The overlap rate is 70%-90%; Optionally, the overlap ratio may be 70%, 75%, 80%, 85%, 90%, or any value between 70% and 90%; D. The power of the base layer ultra-high speed laser cladding and the hard surface layer ultra-high speed laser cladding is 6000W-12000W; Optionally, the power of the ultra-high-speed laser cladding of the base layer and the ultra-high-speed laser cladding of the hard surface layer can be 6000W, 7000W, 8000W, 9000W, 10000W, 11000W, 12000W or any value between 6000W and 12000W; E. The powder feeding rate of the cladding head is 2g / s-5g / s.

[0045] Optionally, the powder feeding rate of the cladding head may be 2 g / s, 3 g / s, 4 g / s, 5 g / s or any value between 2 g / s and 5 g / s.

[0046] A second aspect of the present application provides a brake disc having a wear-resistant and corrosion-resistant coating on its surface by ultra-high-speed laser cladding, which is prepared by the method for preparing a brake disc having a wear-resistant and corrosion-resistant coating on its surface by ultra-high-speed laser cladding.

[0047] A third aspect of the present application provides an automobile, comprising the brake disc having the wear-resistant and corrosion-resistant coating formed by ultra-high-speed laser cladding on the surface.

[0048] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, the conditions are carried out according to conventional conditions or manufacturer recommendations. The reagents or instruments used are not specified by the manufacturer and are conventional products that can be purchased commercially.

[0049] Example 1 A first aspect of this embodiment provides a method for preparing a brake disc having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating, comprising: S1: Brake disc surface pretreatment: Use alcohol or acetone to clean the oil stains on the brake disc surface to obtain the brake disc to be clad; S2: Preparation of ultra-high-speed laser cladding iron-based composite powder for hard surface layer: 70% by mass of iron-based alloy and 30% by mass of hard particle TiC powder were mixed in a mixer for 120 minutes. After mixing evenly, the mixture was dried at 80°C for 2 hours to obtain ultra-high-speed laser cladding iron-based composite powder for hard surface layer; wherein, the mass percentage of each element in the iron-based alloy powder is C0.01wt%, Cr16.8wt%, Ni12.1wt%, Mo2.6wt%, Si0.8wt%, Mn0.3wt%, and the balance is Fe. The particle size of the base alloy powder and TiC is 15μm-53μm.

[0050] S3: Angle adjustment: adjust the angle of the brake disc to be clad so that the angle ∠1 between the surface to be clad and the axis of the cladding head and the angle ∠2 between the edge of the cladding head and the axis of the cladding head meet the conditions: ∠1+0.5∠2<90°; S4: performing ultra-high-speed laser cladding on the base layer and ultra-high-speed laser cladding on the hard surface layer of the brake disc to be clad in sequence, to obtain a brake disc with an ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface; The base layer ultra-high speed laser cladding includes: rotating the brake disc to be clad, and performing ultra-high speed laser cladding of the base layer from the inside to the outside to obtain a brake disc with a base layer; wherein, the initial rotation speed of the brake disc to be clad at the beginning satisfies , calculated W1 = 353.68r / min; the initial moving speed of the cladding head satisfies , calculated M1 = 0.2829m / min; during the ultra-high-speed laser cladding process of the base layer, the rotation speed of the brake disc to be clad gradually decreases and meets , put the parameters into the formula and get: ; The moving speed of the cladding head gradually decreases and meets the , put the parameters into the formula and get: ; Ultra-high-speed laser cladding of the hard surface layer includes: ultra-high-speed laser cladding of the hard surface layer of the brake disc with the base layer from the outside to the inside to obtain a brake disc with an ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface; wherein, the initial rotation speed of the brake disc with the base layer at the beginning meets , calculated W2 = 165.79r / min, the initial moving speed of the cladding head satisfies , calculated M2 = 0.1326m / min; the rotation speed of the brake disc with the base layer gradually increases during the ultra-high-speed laser cladding process of the hard surface layer, and meets , put the parameters into the formula and get: , the moving speed of the cladding head gradually increases and satisfies , put the parameters into the formula and get: ; The process parameters of ultra-high-speed laser cladding are as follows: D1 is the inner diameter of the brake disc 0.135m, D2 is the outer diameter of the brake disc 0.288m, linear speed V = 150m / min, laser spot diameter L = 4mm, overlap rate η = 80%, ultra-high-speed laser cladding power is 9000W, and the powder feeding rate of the cladding head is 3.5g / s.

[0051] A second aspect of the present application provides a brake disc having a surface ultra-high-speed laser-clad wear-resistant and corrosion-resistant coating, which is prepared by the above-mentioned preparation method.

[0052] The macroscopic morphology of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating is as follows: Figure 3 shown.

[0053] The coating microstructure of the brake disc with the surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating is as follows: Figure 4 shown.

[0054] After friction and wear testing, the wear resistance test result of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface was 2.75×10 -6 The wear resistance test result of the brake disc is 3.03×10 -5 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface is 11 times that of the brake disc.

[0055] Example 2 A first aspect of this embodiment provides a method for preparing a brake disc having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating, comprising: S1: Brake disc surface pretreatment: Use alcohol or acetone to clean the oil stains on the brake disc surface to obtain the brake disc to be clad; S2: Preparation of ultra-high-speed laser cladding iron-based composite powder for hard surface layer: 70% by mass of iron-based alloy and 20% by mass of hard particle TiC powder were mixed in a mixer for 120 minutes. After mixing evenly, the mixture was dried at 80°C for 2 hours to obtain ultra-high-speed laser cladding iron-based composite powder for hard surface layer; wherein, the mass percentage of each element in the iron-based alloy powder is C0.01wt%, Cr16.8wt%, Ni12.1wt%, Mo2.6wt%, Si0.8wt%, Mn0.3wt%, and the balance is Fe. The particle sizes of the base alloy powder and TiC are both 15μm-53μm.

[0056] S3: Angle adjustment: adjust the angle of the brake disc to be clad so that the angle ∠1 between the surface to be clad and the axis of the cladding head and the angle ∠2 between the edge of the cladding head and the axis of the cladding head meet the conditions: ∠1+0.5∠2<90°; S4: performing ultra-high-speed laser cladding on the base layer and ultra-high-speed laser cladding on the hard surface layer of the brake disc to be clad in sequence, to obtain a brake disc with an ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface; The base layer ultra-high speed laser cladding includes: rotating the brake disc to be clad, and performing ultra-high speed laser cladding of the base layer from the inside to the outside to obtain a brake disc with a base layer; wherein, the initial rotation speed of the brake disc to be clad at the beginning satisfies , calculated W1=353.68 r / min; the initial moving speed of the cladding head satisfies , calculated M1 = 0.2829m / min; during the ultra-high-speed laser cladding process of the base layer, the rotation speed of the brake disc to be clad gradually decreases and meets , put the parameters into the formula and get: / 0.0032 ; The moving speed of the cladding head gradually decreases and meets the , put the parameters into the formula and get: ; Ultra-high-speed laser cladding of the hard surface layer includes: ultra-high-speed laser cladding of the hard surface layer of the brake disc with the base layer from the outside to the inside to obtain a brake disc with an ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface; wherein, the initial rotation speed of the brake disc with the base layer at the beginning meets , calculated W2 = 165.79r / min, the initial moving speed of the cladding head satisfies , calculated M2 = 0.1326m / min; the rotation speed of the brake disc with the base layer gradually increases during the ultra-high-speed laser cladding process of the hard surface layer, and meets , put the parameters into the formula and get: , the moving speed of the cladding head gradually increases and satisfies , put the parameters into the formula and get: ; The process parameters of ultra-high-speed laser cladding are as follows: D1 is the inner diameter of the brake disc 0.135m, D2 is the outer diameter of the brake disc 0.288m, linear speed V = 150m / min, laser spot diameter L = 4mm, overlap rate η = 80%, ultra-high-speed laser cladding power is 9200W, and the powder feeding rate of the cladding head is 3.6g / s.

[0057] After friction and wear testing, the wear resistance test result of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface was 3.80×10 -6 The wear resistance test result of the brake disc is 3.03×10 -5 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface is 8 times that of the brake disc.

[0058] Example 3 A first aspect of this embodiment provides a method for preparing a brake disc having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating, comprising: S1: Brake disc surface pretreatment: Use alcohol or acetone to clean the oil stains on the brake disc surface to obtain the brake disc to be clad; S2: Preparation of ultra-high-speed laser cladding iron-based composite powder for hard surface layer: 70% by mass of iron-based alloy and 50% of hard particle TiC powder were mixed in a mixer for 120 minutes. After mixing evenly, the mixture was dried at 80°C for 2 hours to obtain ultra-high-speed laser cladding iron-based composite powder for hard surface layer; wherein, the mass percentage of each element in the iron-based alloy powder is C0.01wt%, Cr16.8wt%, Ni12.1wt%, Mo2.6wt%, Si0.8wt%, Mn0.3wt%, and the balance is Fe. The particle size of the base alloy powder and TiC is 15μm-53μm.

[0059] S3: Angle adjustment: adjust the angle of the brake disc to be clad so that the angle ∠1 between the surface to be clad and the axis of the cladding head and the angle ∠2 between the edge of the cladding head and the axis of the cladding head meet the conditions: ∠1+0.5∠2<90°; S4: performing ultra-high-speed laser cladding on the base layer and ultra-high-speed laser cladding on the hard surface layer of the brake disc to be clad in sequence, to obtain a brake disc with an ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface; The base layer ultra-high speed laser cladding includes: rotating the brake disc to be clad, and performing ultra-high speed laser cladding of the base layer from the inside to the outside to obtain a brake disc with a base layer; wherein, the initial rotation speed of the brake disc to be clad at the beginning satisfies , calculated W1=353.68 r / min; the initial moving speed of the cladding head satisfies , calculated M1 = 0.2829m / min; during the ultra-high-speed laser cladding process of the base layer, the rotation speed of the brake disc to be clad gradually decreases and meets , put the parameters into the formula and get: , the moving speed of the cladding head gradually decreases, and meets the , put the parameters into the formula and get: ; Ultra-high-speed laser cladding of the hard surface layer includes: ultra-high-speed laser cladding of the hard surface layer of the brake disc with the base layer from the outside to the inside to obtain a brake disc with an ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface; wherein, the initial rotation speed of the brake disc with the base layer at the beginning meets , calculated W2 = 165.79r / min, the initial moving speed of the cladding head satisfies , calculated M2 = 0.1326m / min; the rotation speed of the brake disc with the base layer gradually increases during the ultra-high-speed laser cladding process of the hard surface layer, and meets , put the parameters into the formula and get: , the moving speed of the cladding head gradually increases and satisfies , put the parameters into the formula and get: ; The process parameters of ultra-high-speed laser cladding are as follows: D1 is the inner diameter of the brake disc 0.135m, D2 is the outer diameter of the brake disc 0.288m, linear speed V = 150m / min, laser spot diameter L = 4mm, overlap rate η = 80%, ultra-high-speed laser cladding power is 8600W, and the powder feeding rate of the cladding head is 3.3g / s.

[0060] After friction and wear testing, the wear resistance test result of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface was 2.92×10 -6 The wear resistance test result of the brake disc is 3.03×10 -5 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface is 10.4 times that of the brake disc.

[0061] Comparative Example 1 This comparative example provides a method for preparing a brake disc having an ultra-high-speed laser cladding coating on the surface. The difference from Example 1 is that this comparative example does not perform the angle adjustment in step S3 of Example 1, so that the surface to be clad in this comparative example is perpendicular to the cladding head.

[0062] After friction and wear testing, the wear resistance of the surface ultra-high-speed laser cladding coating prepared in this comparative example is not greatly affected, but it will damage the equipment.

[0063] Comparative Example 2 This comparative example provides a method for preparing a brake disc having an ultra-high-speed laser cladding coating on the surface, which differs from Example 1 in that: The initial rotation speed of the brake disc to be clad during the base layer ultra-high-speed laser cladding does not meet the following requirements: ; That is, W1=400r / min.

[0064] After friction and wear test, the wear resistance test result of the ultra-high-speed laser cladding coating prepared in this comparative example is 4.46×10 -6 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface is 6.8 times that of the brake disc.

[0065] Comparative Example 3 This comparative example provides a method for preparing a brake disc having an ultra-high-speed laser cladding coating on the surface, which differs from Example 1 in that: The initial moving speed of the cladding head during ultra-high-speed laser cladding of the base layer does not meet the following requirements: ; That is, M1=0.35m / min.

[0066] After friction and wear test, the wear resistance test result of the ultra-high-speed laser cladding coating prepared in this comparative example is 7.73×10 -6 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface is 3.9 times that of the brake disc.

[0067] Comparative Example 4 This comparative example provides a method for preparing a brake disc having an ultra-high-speed laser cladding coating on the surface, which differs from Example 1 in that: The rotation speed of the brake disc to be clad during the ultra-high-speed laser cladding process does not meet the following requirements: .

[0068] The friction and wear test showed that the wear resistance test results of the ultra-high-speed laser cladding coating prepared in this comparative example showed that the coating performance was uneven, with a coating wear rate of 4.81×10 -6 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating is 6.3 times that of the brake disc; the wear rate of the coating near the outer edge is 6.31×10 -6 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface is 4.8 times that of the brake disc.

[0069] Comparative Example 5 This comparative example provides a method for preparing a brake disc having an ultra-high-speed laser cladding coating on the surface, which differs from Example 1 in that: The moving speed of the cladding head during the ultra-high-speed laser cladding process of the base layer does not meet the following requirements: .

[0070] The friction and wear test showed that the wear resistance test results of the surface ultra-high-speed laser cladding coating prepared in this comparative example showed that the coating performance was uneven, with a coating wear rate of 4.97×10 -6 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating is 6.1 times that of the brake disc; the wear rate of the coating near the outer edge is 7.21×10 -6 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface is 4.2 times that of the brake disc.

[0071] Comparative Example 6 This comparative example provides a method for preparing a brake disc having an ultra-high-speed laser cladding coating on the surface, which differs from Example 1 in that: The initial rotation speed of the brake disc with the base layer during ultra-high-speed laser cladding of the hard surface layer does not meet the following requirements: ; That is, W2=120 r / min.

[0072] After friction and wear test, the wear resistance test result of the ultra-high-speed laser cladding coating prepared in this comparative example is 5.32×10 -6 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface is 5.7 times that of the brake disc.

[0073] Comparative Example 7 This comparative example provides a method for preparing a brake disc having an ultra-high-speed laser cladding coating on the surface, which differs from Example 1 in that: The initial moving speed of the cladding head during ultra-high-speed laser cladding of the hard surface layer does not meet the following requirements: ; That is, M2=0.1m / min.

[0074] After friction and wear test, the wear resistance test result of the ultra-high-speed laser cladding coating prepared in this comparative example is 5.94×10 -6 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface is 5.1 times that of the brake disc.

[0075] Comparative Example 8 This comparative example provides a method for preparing a brake disc having an ultra-high-speed laser cladding coating on the surface, which differs from Example 1 in that: The rotation speed of the brake disc with the base layer during the ultra-high-speed laser cladding process of the hard surface layer does not meet the following requirements: .

[0076] After friction and wear tests, the wear resistance test results of the surface ultra-high-speed laser cladding coating prepared in this comparative example showed that the coating performance was uneven, with a coating wear rate of 5.51×10 -6 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating is 5.5 times that of the brake disc; the wear rate of the coating near the outer edge is 4.52×10 -6 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface is 6.7 times that of the brake disc.

[0077] Comparative Example 9 This comparative example provides a method for preparing a brake disc having an ultra-high-speed laser cladding coating on the surface, which differs from Example 1 in that: The moving speed of the cladding head during ultra-high-speed laser cladding of the hard surface layer does not meet the following requirements: .

[0078] The friction and wear test showed that the wear resistance test results of the ultra-high-speed laser cladding coating prepared in this comparative example showed that the coating performance was uneven, with a coating wear rate of 5.22×10 -6 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating is 5.8 times that of the brake disc; the wear rate of the coating near the outer edge is 4.27×10 -6 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface is 7.1 times that of the brake disc.

[0079] Comparative Example 10 This comparative example provides a method for preparing a brake disc having an ultra-high-speed laser cladding coating on the surface. The difference from Example 1 is that the raw material of the hard surface layer in this comparative example is only an iron-based alloy.

[0080] After friction and wear test, the wear resistance test result of the ultra-high-speed laser cladding coating prepared in this comparative example is that the coating wear rate is 1.59×10 -5 The wear resistance of the brake disc with ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface is 1.9 times that of the brake disc.

[0081] Comparative Example 11 This comparative example provides a method for preparing a brake disc having an ultra-high-speed laser cladding coating on the surface. The difference from Example 1 is that the raw material of the hard surface layer in this comparative example is only hard particles.

[0082] After friction and wear testing, the wear resistance test result of the surface ultra-high-speed laser cladding coating prepared in this comparative example showed that only hard particles could not be clad and formed.

[0083] Comparative Example 12 This comparative example provides a method for preparing a brake disc having an ultra-high-speed laser cladding coating on the surface. The difference from Example 1 is that the mass content of hard particles in the hard surface layer raw material of this comparative example is 55 wt%.

[0084] After friction and wear testing, the wear resistance test result of the ultra-high-speed laser cladding coating prepared in this comparative example was that macro cracks appeared in the hard surface layer and the cladding layer could not be used.

[0085] Comparative Example 13 This comparative example provides a method for preparing a brake disc having an ultra-high-speed laser cladding coating on the surface. The difference from Example 1 is that the iron-based alloy in this comparative example, calculated with the total mass as 100%, includes: C0.05wt%, Cr15wt%, Ni10wt%, Mo5wt%, Si2wt%, Mn0.5wt%, and the balance is Fe.

[0086] After friction and wear testing, the wear resistance test result of the surface ultra-high-speed laser cladding coating prepared in this comparative example was that micro cracks appeared in the cladding layer and it could not be used.

[0087] Friction and wear test: reciprocating friction and wear, contact mode is plane, the grinding pair is SiN ball with a diameter of 7.938mm, load is 120N, time is 30min, and the reciprocating speed of the steel ball is 10mm / s).

[0088] It can be seen from the above embodiments and comparative examples that the cladding at a certain angle adopted in the present invention can protect the optical components of the equipment from damage on the basis of ensuring the performance of the cladding layer. The double-layer structure of the base layer and the hard surface layer can achieve the effect of corrosion resistance and wear resistance. Through the dynamic coordinated adjustment of the rotation speed and the moving speed of the cladding head, the performance of the cladding layer can be made uniform, thereby ensuring the stability of the brake disc performance. The wear resistance of the brake disc after cladding can reach 11 times that of the unclad brake disc.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

[0090] Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and to form distinct embodiments. For example, in the claims above, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is intended solely to enhance understanding of the overall background of this application and should not be construed as an admission or any implication that such information constitutes prior art known to those skilled in the art.

Claims

1. A method for preparing a brake disc having a wear-resistant and corrosion-resistant coating by ultra-high-speed laser cladding on the surface, characterized in that: include: Pre-treating the brake disc to obtain the brake disc to be clad; The angle of the brake disc to be clad is adjusted so that the angle ∠1 between the surface to be clad and the axis of the cladding head and the angle ∠2 between the edge of the cladding head and the axis of the cladding head meet the conditions: ∠1+0.5∠2＜90°； The brake disc to be clad is subjected to ultra-high speed laser cladding of a base layer and ultra-high speed laser cladding of a hard surface layer in sequence to obtain the brake disc having the ultra-high speed laser cladding wear-resistant and corrosion-resistant coating on the surface; The ultra-high-speed laser cladding of the base layer comprises: rotating the brake disc to be clad, and performing ultra-high-speed laser cladding of the base layer from the inside to the outside to obtain a brake disc with a base layer; The ultra-high-speed laser cladding of the hard surface layer comprises: performing ultra-high-speed laser cladding of the hard surface layer on the brake disc with the base layer from the outside to the inside to obtain the brake disc with the ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating on the surface; During the ultra-high-speed laser cladding of the base layer and the ultra-high-speed laser cladding of the hard surface layer, ∠1 remains unchanged; During the ultra-high-speed laser cladding of the base layer, the initial rotation speed of the brake disc to be clad satisfies: ； During the ultra-high-speed laser cladding of the base layer, the initial moving speed of the cladding head satisfies: ； During the ultra-high-speed laser cladding process of the base layer, the rotation speed of the brake disc to be clad is gradually reduced, satisfying: ； During the ultra-high-speed laser cladding process of the base layer, the moving speed of the cladding head gradually decreases, satisfying: ； During the ultra-high-speed laser cladding of the hard surface layer, the initial rotation speed of the brake disc with the base layer satisfies: ； During the ultra-high-speed laser cladding of the hard surface layer, the initial moving speed of the cladding head satisfies: ； During the ultra-high-speed laser cladding of the hard surface layer, the rotation speed of the brake disc with the base layer gradually increases, satisfying: ； During the ultra-high-speed laser cladding of the hard surface layer, the moving speed of the cladding head gradually increases, satisfying: ； Wherein, W1 is the starting rotation speed of the brake disc to be clad when preparing the brake disc with the base layer, W1 ’ is the real-time rotation speed during the preparation of the brake disc with the base layer, W2 is the starting rotation speed of the brake disc with the base layer when preparing the brake disc with the surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating, and W2 ’ is the real-time rotation speed in the process of preparing the brake disc with the surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating, M1 is the starting moving speed of the cladding head during the ultra-high-speed laser cladding of the base layer, and M1 ’ M2 is the moving speed of the cladding head during the ultra-high-speed laser cladding of the base layer, M3 is the starting moving speed of the cladding head during the ultra-high-speed laser cladding of the hard surface layer, and M4 is the starting moving speed of the cladding head during the ultra-high-speed laser cladding of the hard surface layer. ’ is the moving speed of the cladding head during the ultra-high-speed laser cladding of the hard surface layer, V is the linear speed, L is the laser spot diameter, η is the overlap rate, D1 is the inner diameter of the brake disc, D2 is the outer diameter of the brake disc, t1 and t2 are the cladding times of the ultra-high-speed laser cladding of the base layer or the ultra-high-speed laser cladding of the hard surface layer, respectively.

2. The method for preparing a brake disc having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating according to claim 1, characterized in that: The pre-processing comprises: The surface oil stains of the brake disc are cleaned by using alcohol and / or acetone to obtain the brake disc to be clad.

3. The method for preparing a brake disc having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating according to claim 1, characterized in that: The raw material of the base layer prepared by the base layer ultra-high-speed laser cladding includes 316L stainless steel.

4. The method for preparing a brake disc having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating according to claim 1, characterized in that: The raw materials of the hard surface layer prepared by ultra-high-speed laser cladding of the hard surface layer include iron-based alloy and hard particles.

5. The method for preparing a brake disc having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating according to claim 4, characterized in that: The iron-based alloy, calculated with the total mass as 100%, includes: C<0.02wt%, Cr16wt%-18wt%, Ni11wt%-13wt%, Mo2wt%-3wt%, Si0.5wt%-1wt%, Mn0.1wt%-0.5wt%, and the balance is Fe.

6. The method for preparing a brake disc having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating according to claim 4, characterized in that: The hard particles include one or more of tungsten carbide, titanium carbide, chromium carbide and silicon carbide.

7. The method for preparing a brake disc having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating according to claim 4, characterized in that: At least one of the following conditions is met: A. The particle size of the iron-based alloy and / or the hard particles is 15 μm-53 μm; B. The mass content of the hard particles in the hard surface layer is 20wt%-50wt%.

8. The method for preparing a brake disc having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating according to any one of claims 1 to 7, characterized in that: At least one of the following conditions is met: A. The line speed is 100m / min-200m / min; B. The laser spot diameter is 3mm-5mm; C. The overlap rate is 70%-90%; D. The power of the base layer ultra-high speed laser cladding and the hard surface layer ultra-high speed laser cladding is 6000W-12000W; E. The powder feeding rate of the cladding head is 2g / s-5g / s.

9. A brake disc with a wear-resistant and corrosion-resistant coating clad on the surface by ultra-high-speed laser cladding, characterized in that: The brake disc is prepared by the preparation method of any one of claims 1 to 8 having a surface ultra-high-speed laser cladding wear-resistant and corrosion-resistant coating.

10. An automobile, characterized in that: The invention comprises a brake disc having a surface ultra-high-speed laser-clad wear-resistant and corrosion-resistant coating as described in claim 9.

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