Copper-based friction plate of wind power high-speed shaft brake and manufacturing method

Abstract

The invention discloses a copper-based friction plate of a wind power high-speed shaft brake and a manufacturing method, the friction plate comprises a friction material, the friction material comprises a friction layer and a friction layer, the friction layer comprises the following raw materials in percentage by weight: 65-72% of copper powder, 1-6% of iron powder, 3-10% of high-carbon ferrochrome powder, 8-15% of copper-tin-titanium powder and 15-20% of graphite powder; 1 to 5% of TiB2; and the transition layer comprises the following raw materials in percentage by weight: 70-75.4% of iron powder, 23-28% of copper powder, 1-3% of graphite powder and 0.6-1.2% of copper welding powder. The friction plate in the technical scheme is low in cost, does not contain harmful elements such as lead, meets the environmental protection requirement, integrates the advantages of a copper-based friction plate and an iron-based friction plate, has a stable friction factor and good wear resistance, and has the friction performance superior to that of an imported friction plate.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power brake materials, and in particular to a copper-based friction plate for a wind power high-speed shaft brake and a manufacturing method thereof. Background Art

[0002] High-speed shaft brake pads are an essential component of wind turbines, and their performance directly impacts the reliability and safety of the turbine. With the rapid development of the wind power industry, wind turbines are moving towards higher speeds and higher loads. Damage to wind turbine brake pads is one of the main causes of wind turbine failure.

[0003] The main performance drawbacks of current friction materials include poor compressive strength, easy deformation at high temperatures, unstable friction coefficients, and severe noise pollution. Furthermore, the heavy metal lead (Pb) commonly found in friction materials poses a significant environmental risk, failing to meet the demands of modern industrial development and environmental protection. Currently, commercially available wind turbine friction pads are expensive. Therefore, developing a wind turbine friction material with superior performance, environmental friendliness, and reasonable cost is crucial. This could improve the overall performance and safety of wind turbines. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a copper-based friction plate for a wind power high-speed shaft brake and a manufacturing method thereof, wherein the friction plate has a stable friction coefficient, high energy density and good wear resistance.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions: A copper-based friction plate for a wind turbine high-speed shaft brake comprises a friction material, wherein the friction material comprises: Friction layer: includes the following raw materials by weight percentage: copper powder 65-72%, iron powder 1-6%, high carbon ferrochrome powder 3-10%, copper tin titanium powder 8-15%, graphite powder 15-20%; TiB2 1-5%; The transition layer comprises the following raw materials in weight percentage: iron powder 70-75.4%, copper powder 23-28%, graphite powder 1-3%, and brazing powder 0.6-1.2%.

[0006] Preferably, the graphite powder in the friction layer includes: artificial graphite powder: 60-80%, natural graphite powder: 20-40%; the graphite in the transition layer is natural graphite.

[0007] Preferably, the particle size of copper powder is -200 mesh, the particle size of iron powder is -100 mesh, the particle size of high carbon ferrochrome powder is -100 mesh, the particle size of copper tin titanium powder is -200 mesh, the particle size of TiB2 is 5-10 microns, and the particle size of graphite powder is -80 mesh.

[0008] Preferably, the friction layer comprises the following raw materials in weight percentage: copper powder 57%, iron powder 5%, high carbon ferrochrome powder 8%, copper tin titanium powder 10%, artificial graphite powder 12%, natural graphite powder 5%, TiB23%; The transition layer includes the following raw materials in weight percentage: iron powder 72.2%, copper powder 25%, graphite 2%, and brazing powder 0.8%.

[0009] Preferably, a back plate is further included, the friction material is arranged on one side of the back plate, and the friction layer is connected to the back plate through a transition layer.

[0010] A method for manufacturing the copper-based friction plate for a wind turbine high-speed shaft brake as described above comprises the following steps: 1) Ingredients: Weigh the raw materials of the friction layer and transition layer of the above friction material according to the proportion; 2) Mixing: Friction layer mixing: Pour copper powder, iron powder, high carbon ferrochrome powder and copper tin titanium powder into a mixer and mix for 10 to 20 minutes; add binder and mix for 10 to 20 minutes; add TiB2 and graphite powder and mix for 60 to 90 minutes.

[0011] Mixing of transition layer: Pour iron powder, copper powder, graphite powder and brazing powder into a mixer, add binder and mix for 60-90 minutes; 3) Pressing: Place the transition layer mixture prepared in step 2) into a mold, then place the friction layer mixture on top of the transition layer mixture, and press on a press at a pressure of 200-350 MPa. De-molding is performed to obtain a compact; 4) Sintering: The compact prepared in step 3) is combined with the backing plate and placed in a bell-shaped furnace for pressure sintering; the backing plate is a copper-plated backing plate, and the transition layer in the compact is located between the friction layer and the backing plate; 5) Coining: Place the friction plate sintered in step 4) on a flat die and coining it using a press at a pressure of 150-280 MPa.

[0012] Preferably, in step 2), the binder is paraffin oil, and the amount of paraffin oil added is 75 ml per 100 kg.

[0013] Preferably, in step 4), the pressure sintering pressure is 1.0-2.0 MPa, the sintering temperature is 940-1020° C., the sintering time is 1.5-2.5 hours, and the sintering atmosphere is ammonia decomposition gas.

[0014] Preferably, in step 4), the coating thickness of the back plate is 0.005-0.01 mm.

[0015] Preferably, in step 4), the green compact and the back plate are combined through positioning holes; a height limiting block is placed on the surface of the back plate without the green compact, and the height of the height limiting block is 0.1-0.15 mm lower than the thickness of the green compact.

[0016] The present invention has the following beneficial effects due to the adoption of the above technical solution: 1. The present invention uses copper powder as the base component, iron powder, high-carbon ferrochrome powder, and copper-tin-titanium powder as reinforcing components, graphite powder as the lubricating component, and TiB2 as the friction component. The addition of iron powder, high-carbon ferrochrome powder, and copper-tin-titanium powder improves the wettability of the base and lubricating components, enhancing the bonding between the lubricating and base components, thereby increasing the strength, hardness, and wear resistance of the friction material. The graphite powder in the lubricating component is composed of natural graphite and artificial graphite in a proportional manner, ensuring the stability of the friction coefficient and wear resistance of the friction plate at different braking speeds and reducing wear. TiB2 has a hardness second only to diamond and cubic boron nitride and exhibits excellent high-temperature properties. The addition of TiB2 improves the high-temperature strength of the base, while reinforcing the friction component enhances the friction performance of the friction material.

[0017] 2. In the present invention, the addition of a transition layer increases the bonding strength between the friction layer and the backing plate, thereby improving the wear resistance of the friction material. The friction plate provided by the present invention is low-cost, does not contain harmful elements such as lead, and meets environmental requirements. It combines the advantages of copper-based and iron-based friction plates, has a stable friction coefficient, good wear resistance, and superior friction performance to imported friction plates. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a physical picture of the friction plate in the present invention. DETAILED DESCRIPTION

[0019] The embodiments of the present invention described in detail below are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention. Example 1

[0020] A copper-based friction plate for a wind turbine high-speed shaft brake comprises a back plate and a friction material, wherein the friction material comprises: Friction layer: includes the following raw materials in weight percentage: copper powder 55%, iron powder 5%, high carbon ferrochrome powder 8%, copper tin titanium powder 12%, artificial graphite powder 12%, natural graphite powder 5%, TiB23%; Transition layer: comprising the following raw materials in weight percentage: iron powder 72.2%, copper powder 25%, graphite powder 2%, and brazing powder 0.8%.

[0021] A method for manufacturing a copper-based friction plate for a wind turbine high-speed shaft brake comprises the following steps: 1) Ingredients: Weigh the raw materials of the friction layer and transition layer of the above friction material according to the proportion; 2) Mixing: Friction layer mixing: Pour copper powder, iron powder, high carbon ferrochrome powder and copper tin titanium powder into a mixer and mix for 10 minutes; then add paraffin oil according to the total weight of the powder and mix for 20 minutes; finally, add TiB2 and graphite powder and mix for 90 minutes; Transition layer mixing: Pour iron powder, copper powder, graphite powder and brazing powder into a mixer, then add paraffin oil according to the total weight of the powder and mix for 90 minutes; the amount of paraffin oil added is 75 ml per 100 kg; 3) Pressing: Place the transition layer mixture prepared in step 2) into a mold, then place the friction layer mixture on top of the transition layer mixture, and press the mixture on a press at a pressure of 300 MPa. Demolding is then performed to obtain a compact; 4) Sintering: The compact pressed in step 3) is combined with the back plate through the positioning holes and placed in a bell-shaped furnace for pressure sintering. A height limiter is placed on the surface of the back plate without the compact. The height of the limiter is 0.1-0.15 mm lower than the thickness of the compact. The limiter prevents warping of the back plate and ensures the density of the friction plate, thereby ensuring friction performance. The sintering temperature is 940°C, the heat preservation is 2.0 hours, the pressure is 2.0 MPa, and the sintering atmosphere is ammonia decomposition gas.

[0022] 5) Precision pressing: Place the friction plate sintered in step 4) on a flat die and use a press to precision press it at a pressure of 150 MPa. During precision pressing, a thickness limit block consistent with the final size of the friction plate is used to ensure the size of the friction plate.

[0023] In this embodiment, the backplane is copper-plated and can be plated with copper using electroplating. Prior to electroplating, the backplane must be degreased and derusted. The backplane is hung on the cathode, and the copper plate is hung on the anode. A plating solution containing copper ions is added to the electroplating tank, and direct current is applied. The electroplating time is adjusted according to the thickness of the coating. The thickness of the coating on the backplane is 0.005-0.01 mm. Example 2

[0024] A copper-based friction plate for a wind turbine high-speed shaft brake comprises a back plate and a friction material, wherein the friction material comprises: Friction layer: includes the following raw materials in weight percentage: copper powder 57%, iron powder 5%, high carbon ferrochrome powder 6%, copper tin titanium powder 12%, artificial graphite powder 11%, natural graphite powder 6%, TiB23%; Transition layer: comprising the following raw materials in weight percentage: iron powder 72%, copper powder 26%, graphite powder 1%, and brazing powder 1%.

[0025] A method for manufacturing a copper-based friction plate for a wind turbine high-speed shaft brake comprises the following steps: 1) Ingredients: Weigh the raw materials of the friction layer and transition layer of the above friction material according to the proportion; 2) Mixing: Friction layer mixing: Pour copper powder, iron powder, high carbon ferrochrome powder and copper tin titanium powder into a mixer and mix for 10 minutes; then add paraffin oil according to the total weight of the powder and mix for 20 minutes; finally, add TiB2 and graphite powder and mix for 90 minutes; Transition layer mixing: Pour iron powder, copper powder, graphite powder and brazing powder into a mixer, then add paraffin oil according to the total weight of the powder and mix for 90 minutes; the amount of paraffin oil added is 75 ml per 100 kg; 3) Pressing: Place the transition layer mixture prepared in step 2) into a mold, then place the friction layer mixture on top of the transition layer mixture, and press the mixture on a press at a pressure of 300 MPa. Demolding is then performed to obtain a compact; 4) Sintering: The compact pressed in step 3) is combined with the back plate through the positioning holes and placed in a bell-shaped furnace for pressure sintering. A height limiter is placed on the surface of the back plate without the compact. The height of the height limiter is 0.1-0.15 mm lower than the thickness of the compact. The height limiter prevents warping of the back plate and ensures the density of the friction plate, thereby ensuring friction performance. The sintering temperature is 960°C, the heat preservation is 2.0 hours, the pressure is 1.5 MPa, and the sintering atmosphere is: ammonia decomposition gas.

[0026] 5) Precision pressing: Place the friction plate sintered in step 4) on a flat die and use a press to precision press it at a pressure of 200 MPa. During precision pressing, a thickness limit block consistent with the final size of the friction plate is used to ensure the size of the friction plate. Example 3

[0027] A copper-based friction plate for a wind turbine high-speed shaft brake comprises a back plate and a friction material, wherein the friction material comprises: Friction layer: includes the following raw materials in weight percentage: copper powder 57%, iron powder 5%, high carbon ferrochrome powder 10%, copper tin titanium powder 8%, artificial graphite powder 13%, natural graphite powder 3%, TiB 24%; Transition layer: comprising the following raw materials in weight percentage: iron powder 72.2%, copper powder 25%, graphite powder 2%, and brazing powder 0.8%.

[0028] A method for manufacturing a copper-based friction plate for a wind turbine high-speed shaft brake comprises the following steps: 1) Ingredients: Weigh the raw materials of the friction layer and transition layer of the above friction material according to the proportion; 2) Mixing: Friction layer mixing: Pour copper powder, iron powder, high carbon ferrochrome powder and copper tin titanium powder into a mixer and mix for 10 minutes; then add paraffin oil according to the total weight of the powder and mix for 20 minutes; finally, add TiB2 and graphite powder and mix for 90 minutes; Transition layer mixing: Pour iron powder, copper powder, graphite powder and brazing powder into a mixer, then add paraffin oil according to the total weight of the powder and mix for 90 minutes; the amount of paraffin oil added is 75 ml per 100 kg; 3) Pressing: Place the transition layer mixture prepared in step 2) into a mold, then place the friction layer mixture on top of the transition layer mixture, and press the mixture on a press at a pressure of 300 MPa. Demolding is then performed to obtain a compact; 4) Sintering: After the compact pressed in step 3) is combined with the back plate through the positioning hole, it is placed in a bell-shaped furnace for pressure sintering. A height limit block is placed on the surface of the back plate without the compact. The height of the height limit block is 0.1~0.15mm lower than the thickness of the compact. The height limit block prevents the back plate from warping on the one hand, and ensures the density of the friction plate, thereby ensuring friction performance on the other hand. The sintering temperature is 1020℃, the heat preservation is 2.0 hours, the pressure is 1.0MPa, and the sintering atmosphere is: ammonia decomposition gas.

[0029] 5) Precision pressing: Place the friction plate sintered in step 4) on a flat die and use a press to precision press it at a pressure of 250 MPa. During precision pressing, a thickness limit block that matches the final size of the friction plate is used to ensure the size of the friction plate.

[0030] Comparative Example 1: Commercially available imported KTR STOP M DB453000041100 friction plate.

[0031] Comparative Example 2: The friction layer comprises the following raw materials by weight: 51% copper powder, 7% iron powder, 12% high-carbon ferrochrome powder, 7% copper-tin-titanium powder, 11% artificial graphite powder, 6% natural graphite powder, and 26% TiB. The transition layer comprises the following raw materials by weight: 72.2% iron powder, 25% copper powder, 2% graphite powder, and 0.8% brazing powder. The production process and process parameters are the same as those in Example 1.

[0032] Comparative Example 3: The components of the friction layer and the transition layer are the same as those in Example 1; the sintering temperature is 920° C., and the other process parameters are the same as those in Example 1.

[0033] According to the friction performance test method of dry sintered metal friction plate JB / T 7269, friction tests were performed on the friction plate samples of Examples 1-3 and Comparative Examples 1-3 using an MM3000 friction and wear performance tester.

[0034] The test parameters are as follows: Net friction area 18cm 2 ; Moment of inertia 1.4 kg·m 2 The mating material was 45# steel. The engagement speeds were 3500, 5000, and 6000 r / min. The braking pressure was 2.7 MPa. The brakes were braked five times continuously, and the average dynamic friction coefficient was measured. A pressure of 2.7 MPa was applied until the automatic disc slipped three times, and the average static friction coefficient was measured. Each sample was braked 10 times at 2.7 MPa pressure, with speeds of 3500, 5000, and 6000 r / min and a moment of inertia of 1.4 kg·m. 2Three evenly distributed points were taken on the specimen. The thickness at each point was measured with a high-precision digital micrometer before and after the friction performance test, with an accuracy of 0.001mm. The thickness change at each location after the experiment, i.e. the thickness wear of the specimen, was calculated. The wear rate was then calculated based on the thickness wear.

[0035] Table 1: Friction performance test results of friction plate samples of Examples 1-3 and Comparative Examples 1-3

[0036] Results analysis: As shown in Table 1, the friction plates prepared in Examples 1-3 of the present invention have comparable static friction coefficients, dynamic friction coefficients, and energy densities to those of currently used imported friction plates when braking at different engagement speeds, and their wear rates are significantly lower than those of currently used imported friction plates (Comparative Example 1). Among them, the friction plate sample prepared in Example 3 has the best performance, with a wear rate of only 0.17×10 -7 cm 3 / J, and only 0.83×10 at 5000rpm -7 cm 3 / J, and only 1.64×10 -7 cm 3 / J, with better wear resistance and significantly reduced cost of use. The ingredients in Comparative Example 2 are outside the scope of this document, and the friction performance is lower than that of the examples. Comparative Example 3 has the same ingredients as Example 1. Due to the low sintering temperature (920°C), the friction performance is significantly lower than that of Example 1. This is primarily because as the sintering temperature increases, the interatomic diffusion coefficient increases, reducing the number of pores in the material, significantly reducing the pore size and porosity, and increasing the material's density and hardness. This strengthens the bonding ability of the material's Cu matrix with Sn, Fe, Cr, and C, forming copper-tin-iron alloys and copper-iron-chromium-carbon alloys. Due to the alloy strengthening effect, the compressive strength and shear strength of the sintered body are significantly improved.

[0037] The copper-based friction plate for a wind turbine high-speed shaft brake provided by the present invention has a friction material prepared by studying the action mechanism of each component, making a reasonable proportion, optimizing process parameters, and adjusting and controlling the content and existence form of each component, so that the friction plate has a reasonable load-bearing capacity and good heat dissipation performance. The obtained friction material for the brake friction plate has a stable and appropriate friction factor, high strength, good wear resistance, large specific heat capacity and density, can absorb more friction heat per unit volume, can effectively bear peak loads in operating conditions, has good thermal conductivity, is resistant to high temperatures during service, has high working reliability, and has a long material service life, reducing the number of maintenance times, and significantly improving the power generation efficiency of the wind turbine set.

Claims

1. A copper-based friction plate for a wind turbine high-speed shaft brake, characterized in that: The invention comprises a friction material and a transition layer, wherein the friction material comprises: Friction layer: includes the following raw materials in weight percentage: copper powder 65-72%, iron powder 1-6%, high carbon ferrochrome powder 3-10%, copper tin titanium powder 8-15%, graphite powder 15-20%; TiB2 1-5%; The transition layer comprises the following raw materials in weight percentage: iron powder 70-75.4%, copper powder 23-28%, graphite powder 1-3%, and brazing powder 0.6-1.2%.

2. The copper-based friction plate for a wind turbine high-speed shaft brake according to claim 1, characterized in that: In the friction layer, the graphite powder includes: artificial graphite powder: 60-80%, natural graphite powder: 20-40%; the graphite in the transition layer is natural graphite.

3. The copper-based friction plate for a wind turbine high-speed shaft brake according to claim 1, characterized in that: The particle size of copper powder is -200 mesh, the particle size of iron powder is -100 mesh, the particle size of high carbon ferrochrome powder is -100 mesh, the particle size of copper tin titanium powder is -200 mesh, the particle size of TiB2 is 5-10 microns, and the particle size of graphite powder is -80 mesh.

4. The copper-based friction plate for a wind turbine high-speed shaft brake according to claim 1, characterized in that: The friction layer includes the following raw materials in weight percentage: copper powder 57%, iron powder 5%, high carbon ferrochrome powder 8%, copper tin titanium powder 10%, artificial graphite powder 12%, natural graphite powder 5%, TiB2 3%; The transition layer includes the following raw materials in weight percentage: iron powder 72.2%, copper powder 25%, graphite 2%, and brazing powder 0.8%.

5. The copper-based friction plate for a wind turbine high-speed shaft brake according to claim 1, characterized in that: It also includes a back plate, the friction material is arranged on one side of the back plate, and the friction layer is connected to the back plate through a transition layer.

6. A method for manufacturing a copper-based friction plate for a wind turbine high-speed shaft brake according to any one of claims 1 to 5, characterized in that: The steps include: 1) Ingredients: Weigh the raw materials of the friction layer and transition layer of the above friction material according to the proportion; 2) Mixing: Friction layer mixing: Pour copper powder, iron powder, high carbon ferrochrome powder and copper tin titanium powder into a mixer and mix for 10 to 20 minutes; add binder and mix for 10 to 20 minutes; add TiB2 and graphite powder and mix for 60 to 90 minutes; Mixing of transition layer: Pour iron powder, copper powder, graphite powder and brazing powder into a mixer, add binder and mix for 60-90 minutes; 3) Pressing: Place the transition layer mixture prepared in step 2) into a mold, then place the friction layer mixture on top of the transition layer mixture, and press on a press at a pressure of 200-350 MPa. De-molding is performed to obtain a compact; 4) Sintering: The compact prepared in step 3) is combined with the backing plate and placed in a bell-shaped furnace for pressure sintering; the backing plate is a copper-plated backing plate, and the transition layer in the compact is located between the friction layer and the backing plate; 5) Coining: Place the friction plate sintered in step 4) on a flat die and coining it using a press at a pressure of 150-280 MPa.

7. The method for manufacturing a copper-based friction plate for a wind turbine high-speed shaft brake according to claim 6, characterized in that: In step 2), the binder is paraffin oil, and the amount of paraffin oil added is 75 ml per 100 kg.

8. The method for manufacturing a copper-based friction plate for a wind turbine high-speed shaft brake according to claim 6, characterized in that: In step 4), the pressure sintering pressure is 1.0-2.0 MPa, the sintering temperature is 940-1020° C., the sintering time is 1.5-2.5 hours, and the sintering atmosphere is ammonia decomposition gas.

9. The method for manufacturing a copper-based friction plate for a wind turbine high-speed shaft brake according to claim 6, characterized in that: In step 4), the coating thickness of the back plate is 0.005-0.01 mm.

10. The method for manufacturing a copper-based friction plate for a wind turbine high-speed shaft brake according to claim 6, characterized in that: In step 4), the compact and the back plate are combined through the positioning hole; a height limiting block is placed on the surface of the back plate without the compact, and the height of the height limiting block is 0.1-0.15 mm lower than the thickness of the compact.

Images