LIGHT METAL STRUCTURE-FUNCTION DUAL-GRADIENT COMPOSITE BRAKE DISC (BRAKE DRUM)

Abstract

The present disclosure provides a light metal structure-function dual-gradient composite brake disc or brake drum. The light metal structure-function dual-gradient composite brake disc or brake drum is made of a light metal/graded ceramic skeleton composite friction layer bearing friction and wear functions and having function (performance) gradient characteristics and a light metal bearing connection and structure functions and having structure gradient characteristics with the light metal/graded ceramic skeleton composite friction layer by integrated composite casting. Such a dual-gradient brake disc or brake drum can exert the advantages of large thermal capacity, rapid thermal dissipation, and insensitivity to cracks of the light metal, and high hardness, high shear resistance, high elastic modulus, and excellent thermal shock resistance of the graded ceramic skeleton. In addition, the light metal/graded ceramic skeleton composite friction layer can withstand higher temperatures without softening and deformation, such that a temperature during friction braking is more uniform.

Claims

1. A light metal structure-function dual-gradient composite brake disc or brake drum, wherein a ceramic skeleton with gradient change characteristics and a light metal form the light metal structure-function dual-gradient composite brake disc or brake drum with structure-function (performance) dual-gradient composite performance characteristics by integrated composite casting, wherein a light metal/graded ceramic skeleton composite friction layer formed by the ceramic skeleton and bearing friction and wear functions has function (performance) gradient characteristics, and the light metal bearing connection and structure functions has structure gradient characteristics with the light metal/graded ceramic skeleton composite friction layer.

2. The light metal structure-function dual-gradient composite brake disc or brake drum according to claim 1, wherein a ceramic skeleton in the light metal/graded ceramic skeleton composite friction layer bearing friction and wear functions is a continuous structural phase graded ceramic skeleton with gradient change characteristics in pore size and structure form that is made of ceramic with excellent thermal shock resistance and wear resistance and high thermal conductivity.

3. The light metal structure-function dual-gradient composite brake disc or brake drum according to claim 1, wherein a pore diameter of a continuous structural phase graded ceramic skeleton in the light metal/graded ceramic skeleton composite friction layer bearing friction and wear functions shows a gradient change when the continuous structural phase graded ceramic skeleton extends from a position perpendicular to a friction surface to a disc body.

4. The light metal structure-function dual-gradient composite brake disc or brake drum according to claim 1, wherein an interface of a continuous structural phase graded ceramic skeleton in the light metal/graded ceramic skeleton composite friction layer bearing friction and wear functions and the light metal bearing connection and structure functions is not perpendicular to a friction surface.

5. The light metal structure-function dual-gradient composite brake disc or brake drum according to claim 1, wherein the light metal/graded ceramic skeleton composite friction layer bearing friction and wear functions has a thickness 1-5 mm greater than a wear limit-reaching size of the brake disc or brake drum.

6. The light metal structure-function dual-gradient composite brake disc or brake drum according to claim 1, wherein the light metal bearing connection and structure functions is strengthened and toughened by nano-materials; and a continuous structural phase graded ceramic skeleton in the light metal/graded ceramic skeleton composite friction layer bearing friction and wear functions is strengthened and toughened by nano-ceramic particles or ceramic fibers.

7. The light metal structure-function dual-gradient composite brake drum according to claim 1, wherein the light metal structure-function dual-gradient composite brake drum is further provided with a ferrous metal mesh enhancing strength of the light metal as a matrix in the light metal structure-function dual-gradient composite brake drum, limiting expansion and deformation of the light metal and preventing the brake drum from cracking under an action of a braking pressure (radial tension) by integrated composite casting.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG. 1 is a sectional diagram of a light metal structure-function dual-gradient composite brake disc (brake drum);

[0020] FIG. 2 shows photos of the light metal structure-function dual-gradient composite brake disc (brake drum);

[0021] FIG. 3 is a schematic diagram of an inclined ceramic skeleton in a binding part of a composite friction layer and a light metal;

[0022] FIG. 4 is a schematic diagram of a convex ceramic skeleton in the binding part of the composite friction layer and the light metal;

[0023] FIG. 5 is a schematic diagram of a concave ceramic skeleton in the binding part of the composite friction layer and the light metal;

[0024] FIG. 6 is a schematic diagram of a sawtooth ceramic skeleton in the binding part of a composite friction surface and the light metal;

[0025] FIG. 7 is a schematic diagram of a pore of the ceramic skeleton changing from small to large when the ceramic skeleton extends to the light metal matrix;

[0026] FIG. 8A to 8D show curves in a 1:1 bench test of a subway with the brake disc of the present disclosure;

[0027] FIG. 9A and FIG. 9B show a comparison of cyclic braking times in 1:1 bench tests with the brake disc of the present disclosure and the cast steel brake disc;

[0028] FIG. 10A and FIG. 10B show a comparison of temperature rises in the 1:1 bench tests with the brake disc of the present disclosure and the cast steel brake disc;

[0029] FIG. 11A and FIG. 11B show a comparison of friction coefficients in the 1:1 bench tests with the brake disc of the present disclosure and the cast steel brake disc;

[0030] FIG. 12A and FIG. 12B show a comparison of temperatures at six temperature measuring points in the 1:1 bench tests with the brake disc of the present disclosure and the cast steel brake disc;

[0031] FIG. 13A and FIG. 13B show a friction coefficient in a 1:1 bench test with the brake disc of the present disclosure at 400 km/h;

[0032] FIG. 14 shows photos before the 1:1 bench test with the brake disc of the present disclosure at 400 km/h, after running-in, and after the test;

[0033] FIG. 15 shows data of a 1:1 bench test of a passenger vehicle with the brake disc of the present disclosure; and

[0034] FIG. 16 shows photos before and after the 1:1 bench test of a passenger vehicle with the brake disc of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Example 1

[0035] Example 1 shows curves of partial data of a bench test of a subway vehicle with a BD2500/15000 brake power 1:1 test bench conducted by a third party in accordance with CZJS/T 0012-2016 Technical specification of brake pads for urban rail vehicles by using a brake disc of the present disclosure.

[0036] It can be seen from curves of all test data (FIG. 8A), friction coefficient curves at different speeds (FIG. 8B) and test data curves under simulated conditions (FIG. 8C) and (FIG. 8D) that the friction coefficient is uniform and stable, and the temperature rise is low.

Example 2

[0037] Example 2 shows curves of partial data of a bench test of a motor train set at 250 km/h with a BD2500/15000 brake power 1:1 test bench conducted by a third party in accordance with TB/T2980-2014 Brake disc rolling stock by using a brake disc of the present disclosure and a cast steel brake disc.

[0038] It can be seen from FIG. 9A and FIG. 9B that the cooling time of the brake disc of the present disclosure (FIG. 9A) is nearly 50% less than that of the cast steel brake disc (FIG. 9B) under the same braking conditions.

[0039] It can be seen from FIG. 10A and FIG. 10B that the temperature rise of the brake disc of the present disclosure (FIG. 10A) is 20% lower than that of the cast steel brake disc (FIG. 10B) under the same braking conditions.

[0040] It can be seen from FIG. 11A and FIG. 11B that the curve of the friction coefficient of the brake disc of the present disclosure (FIG. 11A) is smoother than that of the friction coefficient of the cast steel brake disc (FIG. 11B) under the same braking conditions.

[0041] It can be seen from FIG. 12A and FIG. 12B that the temperatures of the six temperature measuring points of the brake disc of the present disclosure (FIG. 12A) are lower, more uniform and more regular than those of the six temperature measuring points of the cast steel brake disc (FIG. 12B) under the same braking conditions.

Example 3

[0042] Example 3 shows curves of partial data of a bench test of a high-speed train at 400 km/h with a BD2500/15000 brake power 1:1 test bench conducted by a third party in accordance with TB/T2980-2014 Brake disc rolling stock by using a brake disc of the present disclosure.

[0043] It can be seen from the test data in FIG. 13A and FIG. 13B that the light metal structure-function dual-gradient composite brake disc can meet the braking requirements of high-speed trains running at 400 km/h, and can maintain a stable friction coefficient at the maximum temperature of 520° C. on the friction surface.

[0044] It can be seen from the photos of the friction surface before the 400 km/h test, after running-in and after the test (FIG. 14) that the light metal structure-function dual-gradient composite brake disc can meet the maximum temperature requirement of 520° C., and due to the support of the continuous phase ceramic skeleton on the composite friction layer, the friction surface does not soften and deform, and there is no furrow on the friction surface. All properties meet the use requirements of the brake disc. Safe and effective clutch and braking for all kinds of rotating machinery can be implemented, and obvious weight reduction, energy saving and emission reduction effect is achieved.

Example 4

[0045] Example 4 shows curves of partial data of a 1:1 bench test of a passenger vehicle conducted by a third party according to the AK MASTER test outline using a brake disc of the present disclosure.

[0046] It can be seen from the test data in FIG. 15 that the brake disc of the present disclosure can fully meet the use requirements of passenger vehicles.

[0047] It can be seen from the photos after the test that the friction surface of the brake disc of the present disclosure is intact without scratches (FIG. 16).