阅读说明：本技术 含碱土金属氧化物铝合金制动盘汽车刹车片及其制备方法 (Automobile brake pad containing alkaline earth metal oxide aluminum alloy brake disc and preparation method thereof ) 是由 张定权 于 2021-10-11 设计创作，主要内容包括：本发明涉及汽车刹车片技术领域,尤其是涉及含碱土金属氧化物铝合金制动盘汽车刹车片及其制备方法。本发明将双马来酰亚胺改性酚醛树脂、氯醇橡胶、硼酸铝晶须、聚丙烯网状纤维、叶蛇纹石、水滑石、碱土金属氧化物、菱镁矿、膨润土、软木粉按比例放入混料机,混合后得到混合料；然后将钢背、混合料置于模具中进行模压成型,得到毛坯；最后将毛坯加热固化,加工制得汽车刹车片。本发明的汽车刹车片具有高的摩擦系数,比重轻,硬度低,噪声小,磨耗低,对偶表面无裂纹,有效保护对偶,延长汽车刹车片使用寿命。(The invention relates to the technical field of automobile brake pads, in particular to an automobile brake pad containing an alkaline earth metal oxide aluminum alloy brake disc and a preparation method thereof. The bismaleimide modified phenolic resin, the chlorohydrin rubber, the aluminum borate whisker, the polypropylene reticular fiber, the antigorite, the hydrotalcite, the alkaline earth metal oxide, the magnesite, the bentonite and the cork powder are proportionally put into a mixer and mixed to obtain a mixture; then placing the steel backing and the mixture in a mold for compression molding to obtain a blank; and finally, heating and curing the blank, and processing to obtain the automobile brake pad. The automobile brake pad has the advantages of high friction coefficient, light specific gravity, low hardness, low noise, low abrasion, no crack on the dual surface, effective dual protection and prolonged service life.)

1. The automobile brake pad material containing the alkaline earth metal oxide aluminum alloy brake disc is characterized by comprising the following components in percentage by mass:

2. the method for preparing the automobile brake pad by using the alkaline earth metal oxide-containing aluminum alloy brake disc automobile brake pad material as claimed in claim 1, which comprises the following steps:

(1) mixing raw materials: putting the components of the alkaline earth metal oxide-containing aluminum alloy brake disc automobile brake pad material into a mixer in proportion, and mixing to obtain a mixture;

(2) compression molding: placing the steel backing and the mixture in a die for compression molding to obtain a blank;

(2) curing heat treatment: and heating and curing the blank, and processing to obtain the automobile brake pad.

3. The method for preparing the automobile brake pad from the alkaline-earth metal oxide-containing aluminum alloy brake disc and the automobile brake pad material as claimed in claim 2, wherein in the step (1), the raw material mixing is to proportionally add the bismaleimide modified phenolic resin, the epichlorohydrin rubber, the antigorite, the hydrotalcite, the alkaline-earth metal oxide, the magnesite, the bentonite and the cork powder into a mixer for first mixing stirring, proportionally add the aluminum borate whisker and the polypropylene reticular fiber, and perform second mixing stirring until a uniform mixture is obtained.

4. The method for preparing the automobile brake pad by using the alkaline earth metal oxide aluminum alloy brake disc automobile brake pad material as recited in claim 3, wherein the stirring speed during the first mixing and stirring process and the second mixing and stirring process is 3500-4000r/min, the time for the first mixing and stirring process is 30-40min, and the time for the second mixing and stirring process is 4-8 min.

5. The method for preparing the automobile brake pad from the alkaline-earth metal oxide aluminum alloy brake disc and the automobile brake pad material as claimed in claim 2, wherein in the step (2), the compression molding is to put the steel backing and the mixture into a mold, and apply pressure to compress and mold the mixture.

6. The method for preparing the automobile brake pad from the alkaline earth metal oxide-containing aluminum alloy brake disc and the automobile brake pad material as claimed in claim 5, wherein in the compression molding process, the mold temperature is 30-95 ℃, the molding pressure is 30-45MPa, the air is released for 3-5 times within 6 minutes, and the pressure holding time is 120-240 s.

7. The method for preparing the automobile brake pad from the alkaline earth metal oxide aluminum alloy brake disc and automobile brake pad material as claimed in claim 2, wherein in the step (3), the heating curing is a temperature-programmed curing heat treatment.

8. The method for preparing the automobile brake pad from the alkaline earth metal oxide aluminum alloy brake disc and the automobile brake pad material as claimed in claim 7, wherein the curing temperature in the temperature-programmed curing heat treatment process is 110 ℃, 130 ℃, 150 ℃ and 180 ℃.

9. The method for preparing the automobile brake pad from the alkaline earth metal oxide-containing aluminum alloy brake disc and automobile brake pad material as claimed in claim 7, wherein the curing time in the curing process is a constant temperature curing time.

10. The method for preparing the automobile brake pad from the alkaline-earth metal oxide-containing aluminum alloy brake disc and automobile brake pad material as claimed in claim 7, wherein the curing temperature is 110 ℃ and the curing time is 2-3 h;

when the curing temperature is 130 ℃, the curing time is 5-6 h;

when the curing temperature is 150 ℃, the curing time is 6-7 h;

the curing time is 10-12h when the curing temperature is 180 ℃.

Technical Field

The invention relates to the technical field of automobile brake pads, in particular to an automobile brake pad containing an alkaline earth metal oxide aluminum alloy brake disc and a preparation method thereof.

Background

The lightweight is the development trend of global automobiles, and it is crucial to lighten vehicle weight, and the brake disc is as a part of vehicle unsprung mass, and the weight that reduces car brake disc can not only reduce the emission, reduces the pollution, can also further alleviate vibration, reduce the noise, improve riding comfort level etc.. At present, the existing automobile brake disc is a cast iron disc, the weight of the existing automobile brake disc is large, the silicon carbide reinforced aluminum alloy brake disc has the advantages of small density, light weight, fast heat dissipation and the like, and the requirements of automobiles on energy conservation and emission reduction are not relaxed along with the continuous increase of environmental pressure, so that the automobile light weight is a development trend, and once large-scale commercialization is successful, the existing automobile brake disc is a cast iron disc which is completely replaced. The developed countries in the western world have started the research and development of silicon carbide reinforced aluminum alloy from the last 90 th century, and only German KNORR company has a small amount of application on urban rail vehicles so far, but has not been applied to automobiles. Many research institutes have chosen to give up, for the most part because aluminum alloys have low hardness, low melting points, and do not have suitable automotive brake pads to match. Therefore, the development of automobile brake pads matched with aluminum alloy discs is urgent.

Patent CN 112594308A discloses a preparation method of high performance automobile brake block, through the electrostatic adsorption phenomenon that exists in the difference and the mixing process of each component density of fully considering the brake block, to the influence of automobile brake block quality, adopt the multistep compounding method, fully guaranteed the homodisperse of each component, this patent emphasizes that the brake block defective rate of its preparation is low, product property can be stable, long service life, wear resistance is good, coefficient of friction is stable, the brake is sensitive, the braking is steady, there is not brake scream, the comfort performance is better, and the dual disk is not damaged. The patent does not show whether the brake disc is an aluminum alloy disc or a cast iron disc, and the performance of the aluminum alloy disc is completely different from that of the cast iron disc, so that the production process and the formula composition of the corresponding automobile brake pad are completely different. In addition, the patent adopts a hot-press forming process at 110-180 ℃, and hot-press forming generally enables the product density to be higher and is difficult to realize light weight.

Disclosure of Invention

In view of the above problems, the present invention provides an alkaline earth metal oxide-containing aluminum alloy brake disc for an automobile and a method for manufacturing the same. The automobile brake pad has the advantages of high friction coefficient, light specific gravity, low hardness, low noise, low abrasion, no crack on the dual surface, effective dual protection and prolonged service life.

The purpose of the invention can be realized by the following technical scheme:

the invention aims to provide an alkaline earth metal oxide-containing aluminum alloy brake disc automobile brake pad material which comprises the following components in percentage by mass:

the second purpose of the invention is to provide a method for preparing an automobile brake pad by using an alkaline earth metal oxide-containing aluminum alloy brake disc and an automobile brake pad material, which comprises the following steps:

(1) mixing raw materials: putting the components of the alkaline earth metal oxide-containing aluminum alloy brake disc automobile brake pad material into a mixer in proportion, and mixing to obtain a mixture;

(2) compression molding: placing the steel backing and the mixture in a die for compression molding to obtain a blank;

(2) curing heat treatment: and heating and curing the blank, and processing to obtain the automobile brake pad.

In one embodiment of the present invention, in the step (1), the raw material mixing is to proportionally add the bismaleimide modified phenolic resin, the epichlorohydrin rubber, the antigorite, the hydrotalcite, the alkaline earth metal oxide, the magnesite, the bentonite and the cork powder into a mixer to be mixed and stirred for the first time, then proportionally add the aluminum borate whisker and the polypropylene reticular fiber, and perform the second mixing and stirring to obtain a uniform mixture.

In one embodiment of the present invention, the stirring speed during the first mixing and stirring and the second mixing and stirring is 3500-.

In one embodiment of the invention, in the step (2), the compression molding is to put the steel backing and the mixture into a mold, and apply pressure to compress and mold the mixture.

In one embodiment of the invention, in the compression molding process, the temperature of the mold is 30-95 ℃, the molding pressure is 30-45MPa, the air is released for 3-5 times within 6 minutes, and the pressure maintaining time is 120-240 s.

In one embodiment of the present invention, in the step (3), the heat curing is a temperature-programmed curing heat treatment.

In one embodiment of the present invention, the curing temperatures during the temperature-programmed curing heat treatment are 110 ℃, 130 ℃, 150 ℃ and 180 ℃, respectively.

In one embodiment of the present invention, the curing time in the curing process is a constant temperature curing time.

In one embodiment of the invention, the curing time is 2-3h at a curing temperature of 110 ℃;

when the curing temperature is 130 ℃, the curing time is 5-6 h;

when the curing temperature is 150 ℃, the curing time is 6-7 h;

the curing time is 10-12h when the curing temperature is 180 ℃.

The third purpose of the invention is to provide the automobile brake pad prepared on the basis of the automobile brake pad material containing the alkaline earth metal oxide aluminum alloy brake disc obtained by the method.

The functions of the raw materials are as follows:

the bismaleimide modified phenolic resin has the advantages that the thermal decomposition temperature is greatly increased after modification, and the phenomenon of high-temperature heat fading is avoided.

The chlorohydrin rubber is a copolymer of epoxy chloropropane and ethylene oxide, has good elasticity, good flexibility of a molecular chain, and contains chloromethyl polar groups, so that the chlorohydrin rubber has good cold resistance and heat resistance, and the use temperature range is-40-135 ℃.

The polypropylene reticular fiber is a reticular structure formed by mutually crosslinking a plurality of fiber monofilaments which are prepared by taking polypropylene as a raw material through special processing and treatment, and the bonding strength of the fiber and a friction material is enhanced.

Aluminum borate whisker with the density of 2.93g/cm³The melting point is 1440-1460 ℃, the heat-resistant temperature is 1200 ℃, the Mohs hardness is 7, the tensile strength is 7.84GPa, and the tensile elastic modulus is 392 GPa. Has high elastic modulus, good mechanical strength, heat resistance, acid resistance and electric insulation. The aluminum borate whisker and the polypropylene reticular fiber achieve the purpose of hybrid reinforcement and are used as a reinforcing material in a friction material.

The antigorite exhibits good lubricating properties due to its layered structure and weak interlayer bonding force. Has good performance at low temperature and high temperature, is an excellent friction regulator, and has the effects of enhancing and reducing friction.

Hydrotalcite is decomposed by heat to release a large amount of water and carbon dioxide, can reduce the system temperature, and can be used as a flame retardant.

Alkaline earth metal oxide: high melting point and high hardness, and are used as friction enhancing materials in this application. Comprises a mixture of one or more of magnesium oxide, calcium oxide, beryllium oxide, strontium oxide, barium oxide or radium oxide. Preferably beryllium oxide, strontium oxide, barium oxide or radium oxide.

Magnesite has Mohs hardness of 3.5-4.5 and specific gravity of 2.9-3.1, and resistance-increasing mineral raw materials mainly play a role in adjusting friction coefficient, hardness and density in a friction material, improving brake noise of a product and reducing cost.

Bentonite, white, 1-2 Mohs hardness, 2-3 g/cm density³It can be used as antifriction material. Can absorb the friction heat of the friction material in the braking process and effectively slow down the overheating failure degree of the material. The bentonite has loose and porous structure, and can reduce the hardness and noise of the friction material.

The brake pad is formed by pressing at the temperature of 30-95 ℃, belongs to a cold press forming process, and the density of the brake pad prepared by cold press forming is as low as 1.4-1.6g/cm³The method can realize light weight, and the cold press molding process product has the advantages of high friction coefficient, high porosity, low hardness, low noise, low abrasion, low manufacturing cost and the like.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention relates to an automobile brake pad matched with an aluminum alloy disc, which fills the blank in the field and has the density as low as 1.4-1.6g/cm³Thereby realizing light weight.

(2) The friction material is added with alkaline earth metal oxide which has high hardness, meanwhile, the bismaleimide modified phenolic resin is added into a formula system, so that the heat resistance of the brake pad is improved, and the chlorohydrin rubber is added, so that the properties of the chlorohydrin rubber and the bismaleimide modified phenolic resin are cooperated, and the defects of high brittleness and poor heat resistance of the pure phenolic resin are overcome. The heat resistance and the shearing strength of the automobile brake pad are higher, and the brake pad has higher friction coefficient.

(3) By optimizing the raw material combination, reasonably setting the proportion and the cold pressing production process, the formed automobile brake pad has high friction coefficient, light specific gravity, low hardness, small noise, low abrasion, no crack on the dual surface, effective protection of the dual and prolonged service life.

Detailed Description

The purpose of the invention can be realized by the following technical scheme:

the invention aims to provide an alkaline earth metal oxide-containing aluminum alloy brake disc automobile brake pad material which comprises the following components in percentage by mass:

the second purpose of the invention is to provide a method for preparing an automobile brake pad by using an alkaline earth metal oxide-containing aluminum alloy brake disc and an automobile brake pad material, which comprises the following steps:

(1) mixing raw materials: putting the components of the alkaline earth metal oxide-containing aluminum alloy brake disc automobile brake pad material into a mixer in proportion, and mixing to obtain a mixture;

(2) compression molding: placing the steel backing and the mixture in a die for compression molding to obtain a blank;

(2) curing heat treatment: and heating and curing the blank, and processing to obtain the automobile brake pad.

In one embodiment of the present invention, in the step (1), the raw material mixing is to proportionally add the bismaleimide modified phenolic resin, the epichlorohydrin rubber, the antigorite, the hydrotalcite, the alkaline earth metal oxide, the magnesite, the bentonite and the cork powder into a mixer to be mixed and stirred for the first time, then proportionally add the aluminum borate whisker and the polypropylene reticular fiber, and perform the second mixing and stirring to obtain a uniform mixture.

In one embodiment of the present invention, the stirring speed during the first mixing and stirring and the second mixing and stirring is 3500-.

In one embodiment of the invention, in the step (2), the compression molding is to put the steel backing and the mixture into a mold, and apply pressure to compress and mold the mixture.

In one embodiment of the invention, in the compression molding process, the temperature of the mold is 30-95 ℃, the molding pressure is 30-45MPa, the air is released for 3-5 times within 6 minutes, and the pressure maintaining time is 120-240 s.

In one embodiment of the present invention, in the step (3), the heat curing is a temperature-programmed curing heat treatment.

In one embodiment of the present invention, the curing temperatures during the temperature-programmed curing heat treatment are 110 ℃, 130 ℃, 150 ℃ and 180 ℃, respectively.

In one embodiment of the present invention, the curing time in the curing process is a constant temperature curing time.

In one embodiment of the invention, the curing time is 2-3h at a curing temperature of 110 ℃;

when the curing temperature is 130 ℃, the curing time is 5-6 h;

when the curing temperature is 150 ℃, the curing time is 6-7 h;

the curing time is 10-12h when the curing temperature is 180 ℃.

The invention also provides an automobile brake pad prepared on the basis of the automobile brake pad material containing the alkaline earth metal oxide aluminum alloy brake disc obtained by the method.

The present invention will be described in detail with reference to specific examples.

In the following examples, epichlorohydrin rubber, aluminum borate whisker, polypropylene mesh fiber, antigorite, hydrotalcite, alkaline earth metal oxide (beryllium oxide, strontium oxide, barium oxide, radium oxide), magnesite, bentonite, cork powder are all conventional raw materials in the art.

Example 1

The embodiment provides an alkaline earth metal oxide-containing aluminum alloy brake disc automobile brake pad, which comprises the following steps:

(1) preparation of raw materials:

the alkaline earth metal oxide in this example is selected from a mixture of beryllium oxide and strontium oxide in a mass ratio of 1: 1.

Wherein the preparation of the bismaleimide modified phenolic resin comprises the following steps: adding phenolic resin into a three-neck flask, adding N, N-dimethylformamide (as a solvent), heating for dissolving, adding a NaOH solution with the mass fraction of 25%, and finally dropwise adding a bromopropylene liquid with a certain proportion, wherein the molar ratio of the phenolic resin to the NaOH to the bromopropylene is as follows: 1: 1.2: 1.5, keeping the reaction at 50 ℃ for 6 to 6.5 hours to finally obtain the allyl etherified phenolic resin. Mixing allyl etherified phenolic resin and bismaleimide according to a mass ratio of 1.4: 1, adding the mixture into a three-neck flask, stirring and dissolving the mixture, adding 1 mass percent of dicumyl peroxide (serving as a catalyst), reacting the mixture for 1 to 1.5 hours at the temperature of 160 ℃, and cooling the reaction product to obtain the bismaleimide modified phenolic resin.

(2) Preparation:

adding bismaleimide modified phenolic resin, chlorohydrin rubber, antigorite, hydrotalcite, alkaline earth metal oxide, magnesite, bentonite and cork powder into a high-speed plow-rake mixer according to a proportion, mixing and stirring at a rotating speed of 3500r/min for 30min, adding aluminum borate whisker and polypropylene reticular fiber according to a proportion, mixing and stirring for 4min to be uniform. And (3) placing the prepared mixture and the steel backing into a die, wherein the temperature of the die is 30 ℃, the forming pressure is 30MPa, the air is released for 5 times within 6 minutes, and then the pressure is maintained for 120 s.

The conditions for heat curing are: placing into an oven, performing programmed heating curing heat treatment, wherein the temperature is increased from room temperature to 110 deg.C for 90min, and the temperature is increased from 110 deg.C to 180 deg.C for 60min,

the curing time is 2h when the curing temperature is 110 ℃, 5h when the curing temperature is 130 ℃, 6h when the curing temperature is 150 ℃ and 10h when the curing temperature is 180 ℃.

Example 2

The embodiment provides an alkaline earth metal oxide-containing aluminum alloy brake disc automobile brake pad, which comprises the following steps:

(1) preparation of raw materials:

the alkaline earth metal oxide in this example is selected from a mixture of barium oxide and strontium oxide in a mass ratio of 1: 1.

Wherein the preparation of the bismaleimide modified phenolic resin comprises the following steps: adding phenolic resin into a three-neck flask, adding N, N-dimethylformamide (as a solvent), heating for dissolving, adding a NaOH solution with the mass fraction of 25%, and finally dropwise adding a bromopropylene liquid with a certain proportion, wherein the molar ratio of the phenolic resin to the NaOH to the bromopropylene is as follows: 1: 1.2: 1.5, keeping the reaction at 50 ℃ for 6 to 6.5 hours to finally obtain the allyl etherified phenolic resin. Mixing allyl etherified phenolic resin and bismaleimide according to a mass ratio of 1.4: 1, adding the mixture into a three-neck flask, stirring and dissolving the mixture, adding 1 mass percent of dicumyl peroxide (serving as a catalyst), reacting the mixture for 1 to 1.5 hours at the temperature of 160 ℃, and cooling the reaction product to obtain the bismaleimide modified phenolic resin.

(2) Preparation:

adding bismaleimide modified phenolic resin, chlorohydrin rubber, antigorite, hydrotalcite, alkaline earth metal oxide, magnesite, bentonite and cork powder into a high-speed plow-rake mixer according to a proportion, mixing and stirring at the rotating speed of 4000r/min for 35min, adding aluminum borate whiskers and polypropylene reticular fibers according to a proportion, mixing and stirring for 6min to be uniform. And (3) placing the prepared mixture and the steel backing into a die, wherein the temperature of the die is 65 ℃, the forming pressure is 35MPa, the air is released for 4 times within 6 minutes, and then the pressure is maintained for 200 s.

The curing time is 2h when the curing temperature is 110 ℃, 6h when the curing temperature is 130 ℃, 6h when the curing temperature is 150 ℃, and 11h when the curing temperature is 180 ℃.

Example 3

The embodiment provides an alkaline earth metal oxide-containing aluminum alloy brake disc automobile brake pad, which comprises the following steps:

(1) preparation of raw materials:

the alkaline earth metal oxide in this embodiment is selected from radium oxide.

Wherein the preparation of the bismaleimide modified phenolic resin comprises the following steps: adding phenolic resin into a three-neck flask, adding N, N-dimethylformamide (as a solvent), heating for dissolving, adding a NaOH solution with the mass fraction of 25%, and finally dropwise adding a bromopropylene liquid with a certain proportion, wherein the molar ratio of the phenolic resin to the NaOH to the bromopropylene is as follows: 1: 1.2: 1.5, keeping the reaction at 50 ℃ for 6 to 6.5 hours to finally obtain the allyl etherified phenolic resin. Mixing allyl etherified phenolic resin and bismaleimide according to a mass ratio of 1.4: 1, adding the mixture into a three-neck flask, stirring and dissolving the mixture, adding 1 mass percent of dicumyl peroxide (serving as a catalyst), reacting the mixture for 1 to 1.5 hours at the temperature of 160 ℃, and cooling the reaction product to obtain the bismaleimide modified phenolic resin.

(2) Preparation:

adding bismaleimide modified phenolic resin, chlorohydrin rubber, antigorite, hydrotalcite, alkaline earth metal oxide, magnesite, bentonite and cork powder into a high-speed plow-rake type mixer according to a proportion, mixing and stirring at the rotating speed of 3750r/min for 33min, then adding aluminum borate whiskers and polypropylene reticular fibers according to a proportion, mixing and stirring for 7min to be uniform. And (3) placing the prepared mixture and the steel backing into a die, wherein the temperature of the die is 85 ℃, the forming pressure is 45MPa, the air is released for 3 times within 6 minutes, and then the pressure is maintained for 240 s.

The curing time is 3h when the curing temperature is 110 ℃, 5h when the curing temperature is 130 ℃, 6h when the curing temperature is 150 ℃ and 11h when the curing temperature is 180 ℃.

Example 4

The embodiment provides an alkaline earth metal oxide-containing aluminum alloy brake disc automobile brake pad, which comprises the following steps:

(1) preparation of raw materials:

the alkaline earth metal oxide in this embodiment is selected from barium oxide.

Wherein the preparation of the bismaleimide modified phenolic resin comprises the following steps: adding phenolic resin into a three-neck flask, adding N, N-dimethylformamide (as a solvent), heating for dissolving, adding a NaOH solution with the mass fraction of 25%, and finally dropwise adding a bromopropylene liquid with a certain proportion, wherein the molar ratio of the phenolic resin to the NaOH to the bromopropylene is as follows: 1: 1.2: 1.5, keeping the reaction at 50 ℃ for 6 to 6.5 hours to finally obtain the allyl etherified phenolic resin. Mixing allyl etherified phenolic resin and bismaleimide according to a mass ratio of 1.4: 1, adding the mixture into a three-neck flask, stirring and dissolving the mixture, adding 1 mass percent of dicumyl peroxide (serving as a catalyst), reacting the mixture for 1 to 1.5 hours at the temperature of 160 ℃, and cooling the reaction product to obtain the bismaleimide modified phenolic resin.

(2) Preparation:

adding bismaleimide modified phenolic resin, chlorohydrin rubber, antigorite, hydrotalcite, alkaline earth metal oxide, magnesite, bentonite and cork powder into a high-speed plow-rake mixer according to a proportion, mixing and stirring at a rotating speed of 3500r/min for 40min, adding aluminum borate whisker and polypropylene reticular fiber according to a proportion, mixing and stirring for 8min to be uniform. And (3) placing the prepared mixture and the steel backing into a die, wherein the temperature of the die is 95 ℃, the forming pressure is 40MPa, the air is released for 4 times within 6 minutes, and then the pressure is maintained for 180 s.

The curing time is 3h when the curing temperature is 110 ℃, 6h when the curing temperature is 130 ℃, 7h when the curing temperature is 150 ℃ and 12h when the curing temperature is 180 ℃.

The alkaline earth metal oxide is not added, the other formula components and the production process are the same as those of the example 1, and the prepared automobile brake pad is marked as X. The results of the AK-MASTER test and the physical mechanical test performed on the automobile brake pads and the automobile brake pad X prepared in the examples are shown in table 1:

TABLE 1 automobile brake pad Performance test data

	Example 1	Example 2	Example 3	Example 4	X
						Density (g/cm)3)	1.40	1.55	1.45	1.60	1.62
Hardness (HRR)	66	55	60	70	80
						Noise (dB (A))	70	65	60	62	88
Shear strength (MPa)	6.0	7.5	6.8	8.5	3.5
						Coefficient of friction	0.44	0.45	0.43	0.46	0.32
Wear rate (cm) after test3/MJ)	0.15	0.12	0.14	0.16	0.30
						The surface of the brake pad has cracks after the test	Is free of	Is free of	Is free of	Is free of	Is free of
The surface of the aluminum alloy plate after the test has cracks	Is free of	Is free of	Is free of	Is free of	Is provided with

According to performance test data, the automobile brake pad prepared by the embodiment added with the alkaline earth metal oxide has the advantages of high friction coefficient, light specific gravity, low hardness, low noise, low abrasion, no crack on the dual surface, effective protection of the dual and prolonged service life of the automobile brake pad.

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.