Iron-copper alloy-based friction plate and preparation method thereof

Abstract

The invention discloses an iron-copper alloy-based friction plate and a preparation method thereof. The iron-copper alloy-based friction plate comprises the following raw materials in percentage by weight: 70-80% of iron-copper alloy powder, 7-15% of a friction reinforced phase composite material, 2-7% of a friction auxiliary material, 8-15% of a solid solution strengthening material, 0.7-1.5% of graphite and 0.5-1% of a lubricant, the friction reinforced phase composite material is a mixture of silicon dioxide, silicon carbide and aluminum oxide; the friction auxiliary material is a mixture of silicon-aluminum whiskers, calcium silicate whiskers, manganese-zinc alloy powder and carbon fiber powder; the solid solution strengthening material is zinc-tin-phosphorus alloy powder. The preparation method comprises the following steps: preparing materials; performing compression molding; sintering is performed; and machining and surface treatment. According to the invention, the raw material formulas cooperate with each other and cooperate with each step of the preparation method, so that the prepared product is good in wear resistance and stable in friction coefficient.

Description

Technical Field

[0001] This invention relates to the field of metal friction materials technology, specifically to an iron-copper alloy-based friction pad and its preparation method. Background Technology

[0002] Friction materials, as key materials that achieve kinetic energy transfer or absorption through friction, are widely used in brake linings and clutch plates of various mechanical equipment, vehicles, and rail transit. An ideal friction material needs to possess a stable coefficient of friction, good wear resistance, high-temperature resistance, and high mechanical strength.

[0003] Currently, friction materials on the market are generally divided into paper-based friction plates, rubber-based friction plates, and iron-based friction plates. Paper-based and rubber-based friction plates have the following main drawbacks during use: They shed excessive lint, which can easily clog the drive shaft clearance over time, causing jamming and rendering the motorcycle unable to run; their load-bearing capacity cannot fully meet the operating conditions of large-displacement, heavy-duty motorcycles, and prolonged loading (such as uphill driving) can lead to burnout and render the friction plate unusable; their service life is short, typically less than 30,000 km (light load) for paper-based friction plates and less than 15,000 km (heavy load) for rubber-based friction plates; and their high-temperature resistance is very poor. Due to their material composition, instantaneous temperatures exceeding 400℃ are extremely dangerous, and normal use should not involve prolonged exposure to or above 200℃, as excessively high operating temperatures pose a safety hazard and may lead to accidents. While existing iron-based friction plates have high hardness and wear resistance, their coefficient of friction is unstable.

[0004] Based on the above problems, the inventors proposed an iron-copper alloy-based friction plate, which has good wear resistance and a stable coefficient of friction, and can meet the requirements of heavy-duty motorcycles and other high-performance braking or transmission systems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide an iron-copper alloy-based friction pad and its preparation method. This invention uses an iron-copper alloy as the base material, selecting a reasonable ratio of silicon dioxide, silicon carbide, and alumina as the friction-reinforcing composite material to achieve a high dynamic and static coefficient of friction. A reasonable ratio of silicon-aluminum whiskers, calcium silicate whiskers, manganese-zinc alloy powder, and carbon fiber powder are selected as friction-aiding materials, working in conjunction with the friction-reinforcing composite material to improve the product's wear resistance and enhance the stability of the friction coefficient. Zinc-tin-phosphorus alloy powder is selected as the solid solution strengthening material, and the ratio of zinc, tin, and phosphorus is reasonably controlled. Combined with a sintering method, it fully dissolves with other components to form a stable solid solution, further improving wear resistance and product performance stability. Through the synergistic effect of the raw material formulation and the various steps of the preparation method, this invention produces a product with good wear resistance and a stable coefficient of friction, meeting the requirements of heavy-duty motorcycles and other high-performance braking or transmission systems.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides an iron-copper alloy-based friction pad, wherein the raw materials comprise by weight ratio: 70-80% iron-copper alloy powder, 7-15% friction-reinforcing phase composite material, 2-7% friction-aiding material, 8-15% solid solution-strengthening material, 0.7-1.5% graphite, and 0.5-1% lubricant;

[0008] The friction-reinforced phase composite material is a mixture of silicon dioxide, silicon carbide, and aluminum oxide;

[0009] The friction-aiding material is a mixture of silicon-aluminum whiskers, calcium silicate whiskers, manganese-zinc alloy powder, and carbon fiber powder;

[0010] The solid solution strengthening material is zinc-tin-phosphorus alloy powder.

[0011] Preferably, the copper content in the iron-copper alloy powder is 8-20%.

[0012] Preferably, the mass ratio of silicon dioxide, silicon carbide, and alumina in the friction-reinforced phase composite material is 2:2:1.

[0013] Preferably, the mass ratio of silicon-aluminum whiskers, calcium silicate whiskers, manganese-zinc alloy powder, and carbon fiber powder in the friction-aiding material is 3:1:4:2.

[0014] Preferably, the mass ratio of zinc, tin, and phosphorus in the zinc-tin-phosphorus alloy powder is 6:1:3.

[0015] Preferably, the graphite is layered graphite, which enhances the sintering mechanical strength of the product.

[0016] Preferably, the lubricant is any one of zinc stearate, magnesium stearate, lithium stearate, and paraffin powder.

[0017] This invention uses an iron-copper alloy as the base material, fundamentally ensuring the product's high-temperature resistance and good mechanical strength. The formulation and proportions of the friction-reinforced composite material guarantee a high coefficient of dynamic and static friction. By rationally selecting solid solution strengthening materials and controlling the proportions of each component, and through sintering diffusion, the materials fully dissolve with other components, achieving better metallurgical bonding and forming a stable solid solution. This avoids the flaking and shedding defects of the high-melting-point friction-reinforced composite material during use. The selection of friction auxiliary materials and the control of their proportions effectively enhance the wear resistance and friction coefficient stability of the friction-reinforced composite material, while also protecting the mating parts and improving the product's stability. The addition of manganese-zinc alloy powder to the friction auxiliary materials further stabilizes the friction coefficient during use, overcoming the effects of temperature changes and fatigue on the friction coefficient.

[0018] In a second aspect, the present invention provides a method for preparing the above-mentioned iron-copper alloy-based friction pad, comprising the following steps:

[0019] (1) Ingredients: Mix iron-copper alloy powder, friction-enhancing phase composite material, friction-aiding material, solid solution strengthening material, graphite and lubricant in proportion;

[0020] (2) Press molding: The evenly mixed raw materials are added into the mold and pressed into a green blank;

[0021] (3) Sintering: The pressed green body is placed in a heating furnace for three-stage sintering treatment: low temperature, medium temperature and medium-high temperature.

[0022] (4) Machining and surface treatment.

[0023] Preferably, in step (2), the vertical axial pressure of the pressing is 350-480 MPa.

[0024] Preferably, in step (3), the furnace temperature is controlled at 400℃-580℃ in the low temperature stage, 850-900℃ in the medium temperature stage, and 950-1020℃ in the medium-high temperature stage.

[0025] Preferably, the heat preservation time for the low temperature stage, the medium temperature stage, and the medium-high temperature stage is 30-60 minutes.

[0026] Sintering involves three stages: low-temperature debinding, medium-temperature solution treatment, and medium-high-temperature sintering and holding. This process allows the raw material components to fully diffuse and combine within their physicochemical properties, without damaging the physical properties of some components due to excessively high temperatures. By controlling the temperature and holding time, the product acquires sufficient strength, tensile strength, and wear resistance.

[0027] Preferably, the machining is double-sided grinding.

[0028] Preferably, the surface treatment is mold finishing.

[0029] The beneficial effects of this invention are:

[0030] 1. This invention uses an iron-copper alloy as the base material and selects a reasonable ratio of silicon dioxide, silicon carbide, and alumina as the friction-reinforcing phase composite material to give the product a high dynamic and static friction coefficient. A reasonable ratio of silicon-aluminum whiskers, calcium silicate whiskers, manganese-zinc alloy powder, and carbon fiber powder are selected as friction-aiding materials to work in conjunction with the friction-reinforcing phase composite material, improving the product's wear resistance and enhancing the stability of the friction coefficient. Zinc-tin-phosphorus alloy powder is selected as the solid solution strengthening material, and the ratio of zinc, tin, and phosphorus is reasonably controlled. Combined with a sintering method, it fully dissolves with other components to form a stable solid solution, further improving wear resistance and the product's performance stability.

[0031] 2. This invention, through the synergistic interaction between raw material formulations and the coordination of various steps in the preparation method, enables the prepared product to have good wear resistance and a stable coefficient of friction, which can meet the requirements of heavy-duty motorcycles and other high-performance braking or transmission systems. Attached Figure Description

[0032] Figure 1 This is a photograph of the product prepared in Example 1 of the present invention.

[0033] Figure 2 This is a photograph of the product prepared in Example 2 of the present invention.

[0034] Figure 3 This is a torque-time curve of the iron-copper alloy friction plate of the present invention;

[0035] Figure 4 This is a torque-time curve for a paper-based friction pad.

[0036] Figure 5 This is a torque-time curve for a rubber-cork based friction pad.

[0037] Figure 6 This is a torque-time curve for an iron-based friction plate. Detailed Implementation

[0038] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0039] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments.

[0040] Example 1:

[0041] A friction pad based on an iron-copper alloy comprises the following raw materials by weight ratio: 70% iron-copper alloy powder, 15% friction-reinforcing phase composite material, 2.5% friction-aiding material, 10% zinc-tin-phosphorus alloy powder, 1.5% layered graphite, and 1% magnesium stearate.

[0042] The copper content in the iron-copper alloy powder is 8%.

[0043] The friction-reinforced phase composite material is a mixture of silicon dioxide, silicon carbide, and aluminum oxide, with a mass ratio of silicon dioxide, silicon carbide, and aluminum oxide of 2:2:1.

[0044] The friction-aiding material is a mixture of silicon-aluminum whiskers, calcium silicate whiskers, manganese-zinc alloy powder, and carbon fiber powder; the mass ratio of silicon-aluminum whiskers, calcium silicate whiskers, manganese-zinc alloy powder, and carbon fiber powder is 3:1:4:2.

[0045] The mass ratio of zinc, tin, and phosphorus in zinc-tin-phosphorus alloy powder is 6:1:3.

[0046] The preparation method of the above-mentioned iron-copper alloy-based friction pad includes the following steps:

[0047] (1) Ingredients: Mix iron-copper alloy powder, friction-reinforced phase composite material, friction-aiding material, zinc-tin-phosphorus alloy powder, layered graphite and magnesium stearate in proportion;

[0048] (2) Press molding: The uniformly mixed raw materials are added into the mold and pressed into a green body. The vertical axial pressure of the pressing molding is 380 MPa.

[0049] (3) Sintering: The pressed green body is placed in a heating furnace for three stages of sintering: low temperature, medium temperature and medium-high temperature. The furnace temperature is controlled at 400℃ in the low temperature stage, 850℃ in the medium temperature stage and 950℃ in the medium-high temperature stage. The holding time for the low temperature stage, medium temperature stage and medium-high temperature stage is 40min.

[0050] (4) Double-sided grinding and mold finishing.

[0051] Example 2:

[0052] A type of iron-copper alloy-based friction pad, the raw materials of which, by weight ratio, comprise: 80% iron-copper alloy powder, 7% friction-reinforcing phase composite material, 3% friction-aiding material, 8% zinc-tin-phosphorus alloy powder, 1.2% layered graphite, and 0.8% zinc stearate;

[0053] The copper content in the iron-copper alloy powder is 20%.

[0054] The friction-reinforced phase composite material is a mixture of silicon dioxide, silicon carbide, and aluminum oxide, with a mass ratio of silicon dioxide, silicon carbide, and aluminum oxide of 2:2:1.

[0055] The friction-aiding material is a mixture of silicon-aluminum whiskers, calcium silicate whiskers, manganese-zinc alloy powder, and carbon fiber powder; the mass ratio of silicon-aluminum whiskers, calcium silicate whiskers, manganese-zinc alloy powder, and carbon fiber powder is 3:1:4:2.

[0056] The mass ratio of zinc, tin, and phosphorus in zinc-tin-phosphorus alloy powder is 6:1:3.

[0057] The preparation method of the above-mentioned iron-copper alloy-based friction pad includes the following steps:

[0058] (1) Ingredients: Mix iron-copper alloy powder, friction-reinforced phase composite material, friction-aiding material, zinc-tin-phosphorus alloy powder, layered graphite and zinc stearate in proportion;

[0059] (2) Press molding: The uniformly mixed raw materials are added into the mold and pressed into a green body. The vertical axial pressure of the pressing molding is 480 MPa.

[0060] (3) Sintering: The pressed green body is placed in a heating furnace for three stages of sintering: low temperature, medium temperature and medium-high temperature. The furnace temperature is controlled at 580℃ in the low temperature stage, 900℃ in the medium temperature stage and 1020℃ in the medium-high temperature stage. The holding time for the low temperature stage, medium temperature stage and medium-high temperature stage is 50min.

[0061] (4) Double-sided grinding and mold finishing.

[0062] A comparative experiment was conducted on the torque variation over time of the iron-copper alloy-based friction pad prepared in Example 1 of this invention, as well as existing paper-based friction pads, rubber-cork-based friction pads, and iron-based friction pads. The test results are as follows: Figures 3-6 As shown.

[0063] pass Figures 3-6 It can be seen that after the torque of the iron-copper alloy-based friction plate of the present invention is rapidly established, it remains highly stable within a very narrow range with minimal fluctuations. It can maintain the good wear resistance of the metal material and obtain a more stable coefficient of friction. Its performance is significantly better than that of paper-based friction plates, rubber-cork-based friction plates and iron-based friction plates.

[0064] The iron-copper alloy-based friction plates prepared in Examples 1 and 2 were subjected to performance testing. The test conditions and results are shown in Tables 1-5.

[0065] Table 1:

[0066]

[0067] Table 2: Measurement Record of Dynamic Friction Torque

[0068]

[0069] Table 3: Test Results of Dynamic Friction Torque

[0070]

[0071] Table 4: Static Friction Torque Measurement Record

[0072]

[0073] Table 5: Results of Static Friction Torque Test

[0074]

[0075] The above experimental data shows that the iron-copper alloy friction pad of this invention exhibits high consistency and stability in both dynamic and static friction torques at a test temperature of 100°C. Especially after a short break-in period, the dynamic friction torque shows no signs of decay, indicating excellent resistance to thermal degradation and meeting the requirements of continuous operation, demonstrating superior and stable performance. The static friction coefficient is greater than the dynamic friction coefficient (positive static-to-dynamic ratio), ensuring a smooth and powerful start for the transmission system while guaranteeing smooth operation during work, avoiding "jamming" or "vibration." In 10 repeated tests, the fluctuation range of braking torque and residual torque was very small, indicating high consistency and reliability in mass production of this friction pad.

[0076] In summary, the iron-copper alloy friction plate prepared by this invention is an excellent product with stable and reliable performance, which can be applied to mechanical systems that require smooth transmission and good durability (such as motorcycle clutches).

[0077] The performance of the iron-copper alloy-based friction plates prepared in Examples 1 and 2 of this invention was compared with that of existing rubber-cork-based friction plates. The experimental results are shown in Table 6.

[0078] Table 6. Experimental Results Comparing the Performance of Iron-Copper Alloy-Based Friction Plates and Rubber-Cork-Based Friction Plates

[0079]

[0080] As can be seen from the table above, the performance of the iron-copper alloy-based friction pad prepared by this invention is significantly better than that of the existing rubber-cork-based friction pad.

[0081] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An iron-copper alloy based friction plate, characterized in that, The raw materials include, by weight ratio, iron-copper alloy powder 70-80%, friction-enhancing phase composite 7-15%, friction auxiliary material 2-7%, solid solution strengthening material 8-15%, graphite 0.7-1.5%, and lubricant 0.5-1%. The friction-enhancing phase composite is a mixture of silicon dioxide, silicon carbide, and aluminum oxide. The friction auxiliary material is a mixture of silicon-aluminum whisker, calcium silicate whisker, manganese-zinc alloy powder, and carbon fiber powder. The solid solution strengthening material is zinc-tin-phosphorus alloy powder.

2. The friction plate of claim 1, wherein: The copper content in the iron-copper alloy powder is 8-20%.

3. The friction plate of claim 1, wherein: The mass ratio of silicon dioxide, silicon carbide, and aluminum oxide in the friction-enhancing phase composite is 2:2:

1.

4. The friction plate of claim 1, wherein: The mass ratio of silicon-aluminum whisker, calcium silicate whisker, manganese-zinc alloy powder, and carbon fiber powder in the friction auxiliary material is 3:1:4:

2.

5. The friction plate of claim 1, wherein: The mass ratio of zinc, tin, and phosphorus in the zinc-tin-phosphorus alloy powder is 6:1:

3.

6. The friction plate of claim 1, wherein: The lubricant is any one of zinc stearate, magnesium stearate, lithium stearate, and paraffin powder.

7. The method of producing an iron-copper alloy base friction plate according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: (1) batching: uniformly mix the iron-copper alloy powder, friction-enhancing phase composite, friction auxiliary material, solid solution strengthening material, graphite, and lubricant in proportion; (2) compression molding: add the uniformly mixed raw materials into a mold to form a green body; (3) sintering: place the compression-molded green body into a heating furnace for three-stage sintering treatment at low, medium, and medium-high temperatures; (4) mechanical processing and surface treatment.

8. The method of claim 7, wherein: In step (2), the vertical axial pressure for compression molding is 350-480 MPa.

9. The method of claim 7, wherein: In step (3), the furnace temperature is controlled at 400-580℃ in the low-temperature stage, 850-900℃ in the medium-temperature stage, and 950-1020℃ in the medium-high-temperature stage.

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