METHOD OF SURFACE FRICTION TREATMENT OF CERAMIC-REINFORCED ALUMINUM MATRIX COMPOSITE BRAKE DISC

Abstract

The present invention relates to a method of surface friction treatment of a ceramic-reinforced aluminum matrix composite brake disc. By means of the surface friction treatment, a layer of restructured film is formed on a friction surface of the ceramic-reinforced aluminum matrix composite brake disc. Surface friction will form abrasive particles comprising aluminum alloy abrasive particles and ceramic abrasive particles on the friction surface, and an instantaneous high temperature generated during friction melts part of the aluminum alloy abrasive particles and oxidizes a surface of part of the ceramic abrasive particles and the aluminum alloy abrasive particles, and meanwhile under friction force and pressure, the abrasive particles comprising the molten and softened aluminum alloy abrasive particles, ceramic abrasive particles, and their surface oxidation products are broken, mixed, extruded, and bonded to form a layer of restructured film.

Claims

1. A method of surface friction treatment of a ceramic-reinforced aluminum matrix composite brake disc, characterized by comprising the following steps: forming a layer of restructured film on a friction surface of the ceramic-reinforced aluminum matrix composite brake disc by means of the surface friction treatment by using an abrasive tool as a tool, wherein an abrasive hardness of the selected abrasive tool is less than or equal to a Mohs hardness of a ceramic in the ceramic-reinforced aluminum matrix composite brake disc; the surface friction treatment comprises the following steps: (1) rough grinding: during the rough grinding, controlling a rotational speed of the abrasive tool at 1000-3500 r/min, upper and lower blade feeding amount of 0.01-0.03 mm, and the friction surface of the ceramic-reinforced aluminum matrix composite brake disc after the rough grinding having a surface roughness Ra2.000 m; (2) precision grinding: during the precision grinding, controlling a rotational speed of the abrasive tool at 1000-3500 r/min, upper and lower blade feeding amount of 0.001-0.01 mm, and the friction surface of the ceramic-reinforced aluminum matrix composite brake disc after the precision grinding having a surface roughness Ra1.000 m; (3) surface friction: repeating axial blade travel 2-10 times without blade feeding; and through the above 3 steps, the restructured film is obtained; wherein the surface friction will form abrasive particles comprising aluminum alloy abrasive particles and ceramic abrasive particles on the friction surface, and an instantaneous high temperature generated during friction melts part of the aluminum alloy abrasive particles and oxidizes a surface of part of the ceramic abrasive particles and the aluminum alloy abrasive particles, and meanwhile under friction force and pressure, the abrasive particles comprising the molten and softened aluminum alloy abrasive particles, the ceramic abrasive particles, and their surface oxidation products are broken, mixed, extruded, and bonded to form the restructured film which covers the entire surface of the ceramic-reinforced aluminum matrix composite brake disc to replace an original surface of the ceramic-reinforced aluminum matrix composite brake disc; a thickness of the restructured film is 1-5 m; wherein during friction between the ceramic-reinforced aluminum matrix composite brake disc and a brake pad, the restructured film directly rubs against the brake pad, a chemical substance in the brake pad will generate a layer of stable and firm friction film on a surface of the restructured film.

2. The method of surface friction treatment of the ceramic-reinforced aluminum matrix composite brake disc according to claim 1, characterized in that the ceramic is selected from one or more of silicon carbide, titanium carbide, corundum, boron carbide, tungsten carbide, tantalum carbide, vanadium carbide or niobium carbide.

3. The method of surface friction treatment of the ceramic-reinforced aluminum matrix composite brake disc according to claim 2, characterized in that the ceramic is selected from silicon carbide.

4. The method of surface friction treatment of the ceramic-reinforced aluminum matrix composite brake disc according to claim 1, characterized in that a volume of the ceramic in the ceramic-reinforced aluminum matrix composite accounts for 10%-75%.

5. (canceled)

6. The method of surface friction treatment of the ceramic-reinforced aluminum matrix composite brake disc according to claim 1, characterized in that a material of the brake pad to coordinate with the ceramic-reinforced aluminum matrix composite brake disc is selected to be an organically synthesized brake pad; the material of the organically synthesized brake pad is selected from unmodified phenolic resins, modified phenolic resins, epoxy resins, bismaleimide resins, polyimide resins, amino resins, and nitrile-butadiene rubber modified resins; and the modified phenolic resins are selected from cashew nutshell oil-modified phenolic resins, cashew nutshell oil-melamine-modified phenolic resins, boron-modified phenolic resins.

7-10. (canceled)

11. A ceramic-reinforced aluminum matrix composite brake disc, characterized in that a friction surface of the ceramic-reinforced aluminum matrix composite brake disc forms a layer of restructured film, the restructured film is formed by breaking, mixing, extruding and bonding abrasive particles comprising molten and softened aluminum alloy abrasive particles, ceramic abrasive particles, and their surface oxidation products, and the layer of restructured film covers the entire surface of the ceramic-reinforced aluminum matrix composite brake disc to replace an original surface of the ceramic-reinforced aluminum matrix composite brake disc, wherein a thickness of the restructured film is 1-5 m; the restructured film is obtained by the method of surface friction treatment of the ceramic-reinforced aluminum matrix composite brake disc according to claim 1; wherein during friction between the ceramic-reinforced aluminum matrix composite brake disc and a brake pad, the restructured film directly rubs against the rage/brake pad, a chemical substance in the brake pad will generate a layer of stable and firm friction film on a surface of the restructured film, and a thickness of the friction film is 2-10 m, and a material of the brake pad to coordinate with the ceramic-reinforced aluminum matrix composite brake disc is selected to be an organically synthesized brake pad.

12. The ceramic-reinforced aluminum matrix composite brake disc according to claim 11, characterized in that the ceramic in the ceramic-reinforced aluminum matrix composite brake disc is selected from one or more of silicon carbide, titanium carbide, corundum, boron carbide, tungsten carbide, tantalum carbide, vanadium carbide or niobium carbide.

13. The ceramic-reinforced aluminum matrix composite brake disc according to claim 12, characterized in that the ceramic is selected from silicon carbide.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The surface of the aluminum disc (i.e., a ceramic-reinforced aluminum matrix composite brake disc for short) was observed for its surface morphology with a high power microscope attached to a Vickers hardness tester with a magnification of 1200 times, as shown in FIGS. 1-10.

[0061] FIG. 1 is a surface topography of an aluminum disk after processing by the method of Comparative Example 2;

[0062] FIG. 2 is a surface topography of an aluminum disk after treating by the method of Example 1;

[0063] FIG. 3 is a surface topography of an aluminum disk after processing by the method of Comparative Example 2;

[0064] FIG. 4 is a surface topography of an aluminum disk after treating by the method of Example 1;

[0065] FIG. 5 is a surface topography of the aluminum disc after processing by the method of Comparative Example 2 and the brake pad after friction testing on MM-1000 scale inertia dynamometer;

[0066] FIG. 6 is a surface topography of the aluminum disc after treating by the method of Example 1 and the brake pad after friction testing on MM-1000 scale inertia dynamometer;

[0067] FIG. 7 is a surface topography 1 of the aluminum disc after processing by the method of Comparative Example 2 and the brake pad after friction testing on MM-1000 scale inertia dynamometer;

[0068] FIG. 8 is a surface topography 2 of the aluminum disc after processing by the method of Comparative Example 2 and the brake pad after friction testing on MM-1000 scale inertia dynamometer;

[0069] FIG. 9 is a surface topography 1 of the aluminum disc after treating by the method of Example 1 and the brake pad after friction testing on MM-1000 scale inertia dynamometer; and

[0070] FIG. 10 is a surface topography 2 of the aluminum disc after treating by the method of Example 1 and the brake pad after friction testing on MM-1000 scale inertia dynamometer.

DESCRIPTION OF THE EMBODIMENTS

[0071] The invention is described in detail below in combination with the accompanying drawings and specific embodiments.

Example 1

[0072] The example provides a method of surface friction treatment of an aluminum disc, comprising the following steps: [0073] (1) rough grinding: fixing the aluminum disc to a workbench, selecting a white corundum grinding wheel as an abrasive tool, during the rough grinding, controlling a rotational speed thereof at 2800 r/min, upper and lower blade feeding amount of 0.02 mm, and the aluminum disc after the rough grinding having a surface roughness Ra0.802 m. [0074] (2) precision grinding: fixing the aluminum disc to a workbench, controlling a rotational speed thereof at 2800 r/min, upper and lower blade feeding amount of 0.01 mm, and the aluminum disc after the precision grinding having a surface roughness Ra0.365 m. [0075] (3) surface friction: repeating axial blade travel 2 times without blade feeding.

[0076] Through the above 3 steps, the restructured film is obtained.

Example 2

[0077] The example provides a method of surface friction treatment of an aluminum disc, comprising the following steps: [0078] (1) rough grinding: fixing the aluminum disc to a workbench, selecting a brown corundum grinding wheel as an abrasive tool, during the rough grinding, controlling a rotational speed thereof at 3200 r/min, upper and lower blade feeding amount of 0.02 mm, and the aluminum disc after the rough grinding having a surface roughness Ra0.864 m. [0079] (2) precision grinding: fixing the aluminum disc to a workbench, controlling a rotational speed thereof at 3200 r/min, upper and lower blade feeding amount of 0.008 mm, and the aluminum disc after the precision grinding having a surface roughness Ra0.330 m. [0080] (3) surface friction: repeating axial blade travel 4 times without blade feeding.

[0081] Through the above 3 steps, the restructured film is obtained.

Example 3

[0082] The example provides a method of surface friction treatment of an aluminum disc, comprising the following steps: [0083] (1) rough grinding: fixing the aluminum disc to a workbench, selecting a green silicon carbide grinding wheel as an abrasive tool, during the rough grinding, controlling a rotational speed thereof at 1400/min, upper and lower blade feeding amount of 0.01 mm, and the aluminum disc after the rough grinding having a surface roughness Ra1.012 m. [0084] (2) precision grinding: fixing the aluminum disc to a workbench, controlling a rotational speed thereof at 1400 r/min, upper and lower blade feeding amount of 0.005 mm, and the aluminum disc after the precision grinding having a surface roughness Ra 0.452 m. [0085] (3) surface friction: repeating axial blade travel 3 times without blade feeding.

[0086] Through the above 3 steps, the restructured film is obtained.

Example 4

[0087] The example provides a method of surface friction treatment of an aluminum disc, comprising the following steps: [0088] (1) rough grinding: fixing the aluminum disc to a workbench, selecting a black silicon carbide grinding wheel as an abrasive tool, during the rough grinding, controlling a rotational speed thereof at 3500 r/min, upper and lower blade feeding amount of 0.03 mm, and the aluminum disc after the rough grinding having a surface roughness Ra0.911 m. [0089] (2) precision grinding: fixing the aluminum disc to a workbench, controlling a rotational speed thereof at 3500 r/min, upper and lower blade feeding amount of 0.001 mm, and the aluminum disc after the precision grinding having a surface roughness Ra 0.501 m. [0090] (3) surface friction: repeating axial blade travel 5 times without blade feeding.

[0091] Through the above 3 steps, the restructured film is obtained.

Comparative Example 1

[0092] The comparative example provides a method of surface friction treatment of an aluminum disc, comprising the following steps: [0093] (1) rough grinding: fixing the aluminum disc to a workbench, selecting an artificial diamond grinding wheel as an abrasive tool, during the rough grinding, controlling a rotational speed thereof at 3500 r/min, upper and lower blade feeding amount of 0.03 mm, and the aluminum disc after the rough grinding having a surface roughness Ra 1.206 m. [0094] (2) precision grinding: fixing the aluminum disc to a workbench, controlling a rotational speed thereof at 3500 r/min, upper and lower blade feeding amount of 0.005 mm, and the aluminum disc after the precision grinding having a surface roughness Ra 0.766 m. [0095] (3) Surface friction: repeating axial blade travel 5 times without blade feeding, no restructured film forming.

Comparative Example 2

[0096] The comparative example provides a method of lathe processing a surface of an aluminum disc, comprising the following steps: [0097] (1) rough lathing: fixing the aluminum disc to a workbench, selecting an artificial diamond cutting tool as a processing tool, during rough processing, controlling a rotational speed thereof at 900 r/min, a blade feeding amount of 0.05 mm, and the aluminum disc after the rough grinding having a surface roughness Ra2.116 m. [0098] (2) precision lathing: fixing the aluminum disc to a workbench, controlling a rotational speed thereof at 900 r/min, a blade feeding amount of 0.005 mm, and the aluminum disc after the precision lathing having a surface roughness Ra 1.676 m.

[0099] In the above examples and comparative examples, the composition of the aluminum disc comprises an aluminum alloy matrix and silicon carbide, by volume percentage, having the components and contents as follows: 25% silicon carbide particles, 75% aluminum alloy, in which by mass percentage, the components of the aluminum alloy are 9.0% silicon, 0.25% copper, 0.30% manganese, 0.20% magnesium, 0.6% iron, 0.30% nickel, 0.2% zinc, 0.02% lead, 0.005% tin, and the rest being aluminum. The aluminum disc was prepared by a stir casting method.

[0100] The aluminum discs were processed or treated by two different methods of lathing and surface friction, and the thickness, roughness and hardness of the surface films of the aluminum discs were tested respectively after processing or treatment, as shown in Table 1.

TABLE-US-00001 TABLE 1 Testing Data of the Surfaces of the Aluminum Discs after Processing or Treating Lathing Surface Friction Treatment Processing Example Example Example Example Comparative Comparative 1 2 3 4 Example 1 Example 2 Measurements/m 10.6 10.4 10.1 9.9 7.5 7.2 Thickness of 3.4 3.2 2.9 2.7 / / Restructured Film/m Surface Roughness Ra 0.342 0.327 0.480 0.312 0.726 2.711 Vickers Hardness/HV 199 235 257 248 107 124

[0101] From the data, it can be seen that the surface of the aluminum disc through lathing processing is relatively rough and the surface of the aluminum disc through the surface friction treatment is relatively flat. The increase in film thickness after the surface friction treatment indicates the presence of a layer of restructured film on the surface of the aluminum disc after the treatment.

[0102] Therein, the testing methods for the restructured film thickness, surface roughness, Vickers hardness are: [0103] the thickness of the restructured film, was measured with Model FMP40 film thickness gauge, during measuring, holding the probe sleeve, in the measurement, to maintain the vertical, stable, constant force of the probe to contact the surface of the aluminum disk, followed by a tick sound of the instrument, finishing the measurement to read out the measurement results.

[0104] Surface roughness, was measured with Model TR200 surface roughness instrument, correctly and stably placing the instrument on the surface of the aluminum disc, positioning the contact probein the center line for measurement, pressing the start measurement key for measurement, and reading out the measurement results at the end of measurement.

[0105] Vickers hardness, was measured with Model HV-1000Z automatic turret microhardness tester, during measurement pressing the top two opposing surfaces with a specified angle (136) of the positive four-pronged cone diamond indenter with a certain test force into the surface of the aluminum disk, holding for a specified period of time, after removal of the test force, the surface of the sample being pressed out an indentation having a square base and the same angle as the indenter, based on the surface area of the indentation, and calculating the Vickers hardness.

[0106] Aluminum discs were processed or treated by using two different methods of lathing (as in Comparative Example 2) and surface friction (as in Example 1), and after processing or treatment, and were respectively friction tested with automobile brake pads on an MM-1000 scale inertia dynamometer, and before and after the tests, the surface morphology thereof was observed by using a high power microscope attached to a Vickers hardness tester with a magnification of 1200 times, and the results were shown in FIGS. 1 and 2. As can be seen from FIG. 1 and FIG. 2, the surface of the aluminum disk through lathing processing has obvious grooves, the surface is uneven and relatively rough, without a restructured film; the surface of the aluminum disk after surface friction treatment has no groove, the surface is even and relatively flat and smooth, and forms a layer of restructured film.

[0107] The hardness of the local position of the surfaces of the aluminum disks by lathing processing and surface friction treatment is shown in FIG. 3 and FIG. 4. A brighter region of the surface of the aluminum disk by lathing processing in FIG. 3 was selected to test the hardness with a Vickers hardness tester, the bright region had a plastic lathing pattern and softer HV124, which should be an aluminum alloy; the dark region was presumed to be a dimple left after peeling off brittle silicon carbide particles. As can be seen from FIG. 4, the surface friction treatment of the surface of the aluminum disk formed a layer of relatively even restructured film, which having a roughness significantly lower than that of the surface of the aluminum disk by lathing processing, a restructured film hardness of HV199, a moderate hardness, beneficial to the formation of friction film.

[0108] Aluminum discs were processed or treated by using two different methods of lathing (as in Comparative Example 2) and surface friction (as in Example 1), with which the matched automobile brake pads having exactly the same formulation process, the material of the brake pads being an organically synthesized brake pad of phenolic resins, the friction test was performed on an MM-1000 scale inertia dynamometer, after the test, the film thickness, roughness and hardness of the surface of the aluminum disc were determined, as shown in Table 2.

TABLE-US-00002 TABLE 2 Testing Data of the Aluminum Discs after Surface Friction Surface Friction Lathing Processing Treatment Comparative Example 1 Example 2 Measurements/m 14.2 7.9 Thickness of Restructured 3.4 / Film/m Thickness of Friction Film/m 3.6 / Surface Roughness Ra/m 0.389 1.025 Vickers Hardness/HV 267/252 184/2950

[0109] As can be seen from Table 2, after the test, the surface friction treatment of the surface of the aluminum disk increased the film thickness, indicating that after the friction reaction a layer of thick friction film was indeed generated; while the surface film of the aluminum disk by lathing processing was very thin and almost non-existent, and during friction between the aluminum disk by lathing processing and the automobile brake pad, the surface could not form a layer of continuous friction film and the friction film was very thin.

[0110] The surface of the aluminum disk was observe at the end of the test. The results, as shown in FIGS. 5 and 6, showed that the bright white region and the dark region on the surface of the aluminum disk by lathing processing were more different, and there was a large bright white region. After the surface friction treatment, the microscopic bright white region of the friction surface was more scattered and mixed more evenly with the dark region. It was indicated that an even friction film was generated, after friction between the restructured film on the surface of the aluminum disc and the brake pad.

[0111] After testing the brake pads and the aluminum discs by lathing processing, the brighter region and the dark region in FIGS. 7 and 8 of the surface of the aluminum disc were selected to test the hardness of the large bright region of HV2950 with a Vickers hardness tester, the hardness being extremely high, presumably the bright region should be silicon carbide of a higher hardness, and the periphery of the indentation was clear and crackless, indicating that the region of silicon carbide was quite thick and large particles, and was the native silicon carbide particles of the surface of the aluminum disc, after the softer aluminum alloy at the periphery was worn, protruding from the friction surface, to form a large bright white region. The dark region had a hardness of HV184, which was supposed to be the aluminum alloy matrix and friction material of lower hardness. This indicated that the surface of Comparative Example 2 was still a discontinuous film layer after friction, with silicon carbide protruding to be the contact point with the brake pad, and thus the coefficient of friction was lower and unstable.

[0112] After testing automobile brake pads and the aluminum disc through surface friction treatment, the brighter region and the dark region of the surface of the aluminum disc in FIGS. 9 and 10 were selected to test the hardness with a Vickers hardness tester, for the bright region HV267 and the dark region HV252, the hardness was relatively close, indicating that after the friction reaction, on the surface of the aluminum disc has been formed a continuous layer of friction, which can also confirm that the restructured film after surface friction treatment can form a friction film during friction.

[0113] The surface of the aluminum disc used a method of surface friction treatment, as described in Examples 1-4 and Comparative Example 1, with which the matched automobile brake pads having exactly the same formulation process, the material of the brake pads being an organically synthesized brake pad of phenolic resins, the surface of the aluminum disc used a method of lathing processing with an artificial diamond cutting tool, as described in Comparative Example 2, and the friction test was performed on an MM-1000 scale inertia dynamometer, after processing, respectively with the brake pads, at a test pressure 90 bar. The testing results were shown in Table 3.

TABLE-US-00003 TABLE 3 Testing Data of the Surfaces of the Aluminum Discs on an MM-1000 Scale Inertia Dynamometer Example Example Example Example Comparative Comparative Speed/km/h 1 2 3 4 Example 1 Example 2 90 0.410 0.376 0.371 0.385 0.371 0.341 160 0.357 0.366 0.339 0.401 0.358 0.301 200 0.344 0.362 0.332 0.341 0.329 0.236 90 0.585 0.562 0.521 0.447 0.390 0.235 160 0.463 0.420 0.412 0.381 0.390 0.239 200 0.329 0.359 0.314 0.304 0.315 0.218 90 0.583 0.490 0.529 0.473 0.333 0.223 Mass Wear of 0.329 0.431 0.401 0.387 0.653 1.029 Brake Pad/g Thickness Wear 0.685 0.655 0.955 0.740 1.335 1.521 of Brake Pad/mm Mass Wear of 0 0 0 0 0.001 0.001 Aluminum Disc/g Surface of Crackless Crackless Crackless Crackless Crackless Crackless Brake Pad After Testing Surface of Smooth, Smooth, Smooth, Smooth, Smooth, Smooth, Aluminum Disc Crackless Crackless Crackless Crackless Crackless Crackless After Testing

[0114] In Table 3, the data corresponding to the rows following the speeds (km/h) of 90, 160, 200, 90, 160, 200, 90 are the coefficients of friction of the corresponding examples and comparative examples. In Table 3, the coefficients of friction of the examples and the comparative examples were measured multiple times at speeds (km/h) of 90, 160, 200, 90, 160, 200, 90, respectively, and these are set testing procedures, wherein a second group of 90 km/h, 160 km/h, 200 km/h and a third group of 90 km/h were tested for the recovery performance of the surface of the aluminum disk after high-speed friction. The second 90 km/h, 160 km/h, 200 km/h and the third 90 km/h were used to check the recovery performance of the aluminum disc surface after high speed friction.

[0115] The surface of the aluminum disc used a method of surface friction treatment, as described in Examples 1-4, and after the aluminum disc was tested with an automobile brake pad, the brake pad had a high and stable coefficient of friction and good recovery performance. Comparative Example 1 (surface friction treatment with an artificial diamond grinding wheel), the brake pad had a low coefficient of friction and poor recovery performance, as can be seen, after the aluminum disc through surface friction treatment with an abrasive tool having an abrasive hardness less than or equal to that of silicon carbide, the brake pad had a high coefficient of friction and better recovery after testing. Comparative Example 2 (lathing processing with an artificial diamond cutting tool), the brake pad had a low coefficient of friction and very poor recovery performance. The surface of the brake pads in both processing methods was crackless, and the aluminum discs were smooth and crackless.

[0116] In view of the relatively ideal results of the MM-1000 scale inertia dynamometer test, the AK-MASTER (SAE-J2522) 1:1 bench test was carried out for verification. The surface of the aluminum disc used a method of surface friction treatment with a white corundum grinding wheel, as described in Example 1, with which the matched automobile brake pads having exactly the same formulation process, the material of the brake pads being an organically synthesized brake pad of phenolic resins, the surface of the aluminum disc used a method of lathing processing with an artificial diamond cutting tool, as described in Comparative Example 2, and the friction test was performed on an AK-MASTER (SAE-J2522) 1:1 bench, after processing, respectively with the brake pads, the testing results being shown in Tables 4 and 5.

TABLE-US-00004 TABLE 4 Data of the Aluminum Discs in 1:1 Bench Coefficient of Friction Testing AK-Master Example 1 Comparative Example 2 Chapter No. of Testing Avg. Min. Avg. Min. 6.1 0.34 0.31 6.2 0.35 0.35 6.3 0.37 0.34 6.4.1 0.42 0.33 6.4.2 0.36 0.35 6.4.3 0.33 0.33 6.4.4 0.32 0.27 6.4.5 0.32 0.22 6.5 0.33 0.27 6.6 0.37 0.33 6.7 0.34 0.26 6.8 0.35 0.29 6.9 0.34 0.26 0.27 0.22 6.10 0.32 0.24 6.11 0.34 0.25 6.12.1 0.34 0.21 6.12.2 0.23 0.18 0.17 0.14 6.13 0.34 0.26 6.14 0.27 0.21 0.15 0.10 6.15 0.34 0.26

[0117] In Table 4, 6.1, 6.2, 6.3, etc. in the first column indicate the different testing chapter numbers of the AK-MASTER (SAE-J2522) 1:1 bench, and different testing chapter numbers correspond to slightly different testing standards, the coefficients of friction of the aluminum discs were measured under different testing chapter numbers, and the minimum coefficients of friction were not required under some testing chapter numbers, and therefore under some testing chapter numbers the minimum coefficient of friction (Min.) is empty.

TABLE-US-00005 TABLE 5 Testing Data of Aluminum Disc 1:1 Bench Test Item Example 1 Comparative Example 2 Mass Wear of Brake Internal 3.5 External 3.5 Internal 6.2 External 8.3 Pad/g Test Test Test Test Thickness Wear of Internal 0.270 External 0.282 Internal 0.492 External 0.735 Brake Pad/m Test Test Test Test Mass Wear of 0 0.8 Aluminum Disc/g Surface of Brake Crackless Crackless Pad After Testing Surface of Smooth, Crackless Smooth, Crackless Aluminum Disc After Testing Thickness of 3.2 / Restructured Film/m Thickness of 5.2 / Friction Film/m Before Testing 0.325 2.643 Aluminum Disc Surface Roughness Ra/m After Testing 0.354 1.230 Aluminum Disc Surface Roughness Ra/m

[0118] As can be seen from Table 4, the surface of the aluminum disc used a method of surface friction treatment, as described in Examples 1, and after the aluminum disc was tested with an automobile brake pad, the brake pad had a high and stable coefficient of friction and good recovery performance. The surface of the aluminum disc used a method of lathing processing, as described in Comparative Example 2, and after the aluminum disc was tested with an automobile brake pad, the brake pad had a low coefficient of friction and very poor recovery performance. As can be seen from Table 5, the surface of the aluminum disc used a method of surface friction treatment, there exists a layer of restructured film on the surface of the aluminum disc, and a layer of friction film was generated on the surface of the aluminum disc after 1:1 bench test. The surface of the aluminum disc used a method of lathing processing, the surface of the aluminum disc could not form a layer of restructured film, and after 1:1 bench test, the surface of the aluminum disc could not form a layer of continuous friction film and the friction film was very thin. The surface of the aluminum disc used a method of surface friction treatment, the wear of the brake pad was low, and the aluminum disc had no wear. The surface of the brake pads in both processing methods was crackless, and the aluminum discs were smooth and crackless.

[0119] It should be noted that the above examples and comparative examples are given only for the treatment of aluminum discs of a specific composition, and the method using the present invention can also be applied to a variety of other silicon carbide-reinforced aluminum matrix composite brake discs, in addition to the specific disc composition given in the examples and comparative examples. e.g., the composition of the silicon carbide-reinforced aluminum matrix composite brake disc comprises an aluminum alloy matrix and silicon carbide, by volume percentage, having the components and contents as follows: 20-30% silicon carbide particles, 70-80% aluminum alloy, in which by mass percentage, the components of the aluminum alloy are: silicon 8.0-10.5%, copper0.3%, manganese0.2-0.5%, magnesium 0.17-0.30%, iron1.0%, nickel0.50%, zinc0.40%, lead0.05%, tin0.01%, and the rest being aluminum.

[0120] Furthermore, in addition that the method of the present invention can be applied to a ceramic-reinforced aluminum matrix composite brake disc having silicon carbide as the ceramic material, according to the technical solution of the present application, for the ceramic-reinforced aluminum matrix composite brake disc, a layer of restructured film can be likewise formed on the surface of the ceramic-reinforced aluminum matrix composite brake disc by adopting the method of surface friction treatment provided by the present invention when the ceramic is selected from corundum or other materials.

[0121] The foregoing description of examples is intended to facilitate the understanding and use of the invention by persons of ordinary skill in the art. A person skilled in the art can obviously easily make various modifications to these examples and apply the general principles illustrated herein to other examples without having to go through creative labor. Therefore, the present invention is not limited to the above examples, and improvements and modifications made by persons skilled in the art in accordance with the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.