CN113201202A - High-damping resin-based friction material and preparation method thereof - Google Patents

Abstract

The invention relates to a high-damping resin-based friction material and a preparation method thereof. The high-damping silicone rubber modified resin-based friction material disclosed by the invention has the advantages that the damping loss factor is improved, the impact can be alleviated, the vibration is weakened, the noise level in the braking process is reduced, the riding comfort is improved, and the environmental noise pollution is reduced. Meanwhile, the friction material has the advantages of low wear rate, high and stable friction coefficient and the like.

Description

High-damping resin-based friction material and preparation method thereof

Technical Field

The invention belongs to the field of friction materials, and relates to a high-damping resin-based friction material and a preparation method thereof.

Background

The friction material is a key part of a braking device or a carrying mechanical transmission, and has the main function of absorbing the kinetic energy of the automobile by friction and converting the kinetic energy into energy in other forms so as to achieve the effects of braking and speed reduction. The resin-based friction material mainly comprises components such as a resin binder, reinforcing fibers, a friction performance regulator, a filler and the like and other accessory ingredients, has good friction coefficient, wear resistance, certain heat resistance and mechanical strength, and is widely applied to various engineering machines and equipment such as motorcycles, trucks, automobiles, petroleum drilling machines, mining machines, agricultural vehicles and the like.

With the continuous progress of the automobile industry, people put higher demands on the safety, the smoothness and the comfort of the brake lining. Vibration and noise generated in the braking process are important factors influencing the service life of parts and the braking comfort, and solving the vibration and noise of the braking is always one of the important points of attention of researchers.

Document 1, "chinese patent publication No. CN 104109342 a," discloses a resin-based friction material having low noise and resistance to heat fading. The invention selects coke, expanded frogstones and diatomite as mixed fillers, and utilizes the special porous and layered structure as noise reduction modifier. The results show that the noise level is reduced with the increase of the three fillers, but the friction coefficient is reduced to different degrees due to the introduction of the lamellar materials, the braking efficiency is reduced, and the strength of the composite material is easily reduced due to the porous structure.

Document 2, "chinese patent with patent publication No. CN 109707773B", prepares a three-layer low-noise drum friction plate, which includes a precoat, a damping layer, and a primer layer; the damping layer comprises, by weight, 3-5 parts of phenolic resin, 70-80 parts of noise reduction particles, 5-10 parts of fibrilia and 5-10 parts of nitrile rubber. The vibration energy is effectively absorbed through the action of the middle vibration damping layer, the excitation source of the system is reduced, and the noise reduction effect is good. The preparation steps of the invention are that the premixed materials of the mixed primer layer, the damping layer and the fabric layer are put into a hot-pressing mould in sequence according to the weight ratio for hot-pressing forming, but the preparation steps are relatively complex, the uniformity of the materials is difficult to control and the like.

The current vibration and noise reduction thought of the friction material mainly has two aspects: firstly, sound absorption filler is added, but most sound absorption materials are porous structures, and influence is caused on the mechanical property of the composite material; and secondly, an external component is added or the structure of the device is changed, so that the preparation process is relatively complex and the manufacturing cost is increased. Therefore, there is a need to reduce vibration and noise during braking of friction materials from a new perspective. The damping technology is an effective means for vibration and noise reduction commonly used in the engineering field, and the damping characteristic of the material can be utilized to convert the energy of mechanical vibration and sound vibration into heat energy or other energy which can be consumed, thereby achieving the purpose of vibration and noise reduction. Therefore, it is one of the development directions of high performance friction materials to simultaneously improve the damping and frictional wear performance of the friction materials.

Disclosure of Invention

Technical problem to be solved

In order to avoid the defects of the prior art, the invention provides a high-damping resin-based friction material and a preparation method thereof.

Technical scheme

A high-damping resin-based friction material is characterized by comprising the following raw material components in parts by weight: 13 to 18 percent of phenolic resin, 15 to 20 percent of polyacrylonitrile carbon fiber, 40 to 60 percent of friction performance regulator and 3 to 17 percent of damping silicon rubber; the damping silicon rubber is high-temperature vulcanized silicon rubber, and the rubber hydrocarbon content is more than 40%. The sum of the weight percentages of the components is 100 percent.

The length of the polyacrylonitrile-based carbon fiber is 100 μm.

The phenolic resins include, but are not limited to: cashew nut oil modified phenolic resin, boron modified phenolic resin or barium phenolic resin.

The friction performance modifiers include, but are not limited to: one or more of calcium sulfate whisker, alumina, barium sulfate, chromite, diatomite and fluorite powder.

The friction performance regulator is a particle material with the particle size of 100-300 meshes.

The friction performance regulator is a mixture of a 100-300-mesh particle material, a 500-1500-mesh particle material and friction performance regulators with different particle sizes.

A method for preparing the high-damping resin-based friction material is characterized by comprising the following steps:

step 1: stirring and mixing 13-18% of phenolic resin, 15-20% of polyacrylonitrile carbon fiber, 40-60% of friction performance regulator and 3-17% of damping silicone rubber, and then putting the mixture into a mold;

the damping silicon rubber is high-temperature vulcanized silicon rubber, and the rubber hydrocarbon content is more than 40%;

the length of the fiber is 100 mu m after the polyacrylonitrile-based carbon fiber is cut by a high-speed mixer;

step 2: preheating a pressing die to 150-160 ℃ to prepare pressing;

and step 3: pressing is carried out, and the process conditions are as follows: pressing at 160-180 ℃, pressing at 5-6 Mpa, keeping the temperature and pressure for 600-900 s, and deflating every 50 s;

and 4, step 4: putting the pressed product sample into an oven, heating to 120-130 ℃, and keeping the temperature for 60-80 min; heating to 140-150 ℃, and keeping the temperature for 90-100 min; heating to 160-170 ℃, and keeping the temperature for 120-130 min; heating to 180-200 ℃, and keeping the temperature for 50-60 min; and cooling to room temperature to obtain the high-damping resin-based friction material.

Advantageous effects

The invention provides a high-damping resin-based friction material and a preparation method thereof. The high-damping silicone rubber modified resin-based friction material disclosed by the invention has the advantages that the damping loss factor is improved, the impact can be alleviated, the vibration is weakened, the noise level in the braking process is reduced, the riding comfort is improved, and the environmental noise pollution is reduced. Meanwhile, the friction material has the advantages of low wear rate, high and stable friction coefficient and the like.

The addition of the bonding phenolic resin can increase the surface fitting property of the friction material, and is beneficial to reducing vibration in the braking process. The friction performance regulator has the characteristics of good stability and moderate hardness, can keep the matching property of the friction material and the dual, reduces the damage of the friction material in the braking process, and avoids various noises generated by braking seizure, slipping and the like.

Particularly, the damping silicon rubber is high-temperature vulcanized silicon rubber, rubber molecules generate a crosslinking reaction by heating after compounding agents such as vulcanizing agents and the like are added into the silicon rubber, and the damping silicon rubber has good damping characteristic and excellent high and low temperature resistance and can work for a long time at the temperature of between 90 ℃ below zero and 350 ℃.

According to the invention, by a simple and efficient blending method, damping silicon rubber is introduced into a resin-based friction material, so that on one hand, the high damping characteristic of the silicon rubber is utilized, the damping loss factor of the friction material is improved, the energy dissipation capability is enhanced, the vibration and noise level in the braking process is reduced, the vibration stability is improved by 39% at most, and the noise is reduced by 2-3 dB; on the other hand, the material toughness has been strengthened after the silicon rubber is modified, and the combined material shear fracture mode is changed into toughness from fragility gradually, has reduced the production and the extension of crazing line in the braking process, has alleviateed friction material's fatigue wear, has promoted braking stability, and the frictional wear performance reinforcing: the friction coefficient is 0.36-0.39, the stability coefficient reaches more than 80%, and the volume wear rate is optimally reduced by 28.6%.

Drawings

FIG. 1 is a graph of different example shear performance;

FIG. 2 is a surface micro-topography of milled material of various examples (where a is a comparative example and b, c, d are examples 1,2,3, respectively).

Detailed Description

The invention will now be further described with reference to the following examples and drawings:

example 1:

a high-damping resin-based friction material comprises the following components in percentage by mass: phenolic resin: 13% -18%, polyacrylonitrile carbon fiber: 15% -20%, friction performance regulator: 40% -60%, damping silicone rubber content: 3 to 6 percent.

Step 1, weighing phenolic resin, fiber, friction performance regulator and damping silicone rubber according to mass percent, putting into a high-speed mixer for stirring, and putting into a die after uniform mixing;

step 2, preheating a pressing die to 150-160 ℃ to prepare pressing;

step 3, the pressing process conditions are as follows: the pressing temperature is 160 ℃, the pressing pressure is 5Mpa, the heat preservation and pressure maintaining time is 600s, and the air is discharged once every 50 s;

step 4, putting the pressed product sample into an oven, heating to 120 ℃, and preserving heat for 60 min; heating to 140 deg.C, and maintaining the temperature for 90 min; heating to 160 deg.C, and maintaining the temperature for 120 min; heating to 180 deg.C, and maintaining for 60 min; and cooling to room temperature.

Example 2:

a high-damping resin-based friction material comprises the following components in percentage by mass: phenolic resin: 13% -18%, polyacrylonitrile carbon fiber: 15% -20%, friction performance regulator: 40% -55%, damping silicon rubber content: 9% -12%; the material was prepared as described in example 1.

Example 3:

a high-damping resin-based friction material comprises the following components in percentage by mass: phenolic resin: 13% -18%, polyacrylonitrile carbon fiber: 15% -20%, friction performance regulator: 40% -50%, damping silicone rubber content: 13% -16%; the material was prepared as described in example 1.

Comparative example:

the comparative example is not added with damping silicon rubber and comprises the following components in percentage by mass: phenolic resin: 13% -20%, polyacrylonitrile carbon fiber: 15% -20%, friction performance regulator: 40% -65%; for comparison, comparative examples were prepared as in the above examples.

In order to verify the effect of the invention, the friction material prepared in the example and the comparative sample are subjected to shear performance test, frictional wear test, dynamic thermomechanical analysis and microscopic morphology observation, an acceleration sensing device is used for recording the change of normal acceleration in the braking process to reflect the vibration level, and a sound level meter is used for recording the sound pressure level reaction noise level.

The results of the experimental comparison of the frictional wear properties of the high damping resin-based friction material of the present invention are shown in table 1 below:

TABLE 1 comparative experimental results for friction properties

The results of the friction and wear performance comparison experiments show that the friction material provided by the invention has obviously improved friction coefficient stability, and examples 1 and 2 show higher friction coefficient and lower wear rate, and have excellent tribological performance.

The damping loss factor comparison experiment results of the high-damping resin-based friction material disclosed by the invention are shown in the following table 2:

TABLE 2 damping characteristics comparative test results

According to the test result of the damping loss factor, the loss factor can be improved by increasing the content of the damping silicon rubber, and the energy dissipation in the braking process is facilitated.

The vibration level of the high damping resin-based friction material is quantitatively characterized by the variance of normal acceleration change in the braking process, the noise level is quantitatively characterized by the mean value of sound pressure level, and the experimental results are shown in the following table 3:

TABLE 3 comparative test results of vibration and noise levels

According to the test results of vibration and noise tests, after the damping silicon rubber is added, the vibration and noise level in the braking process is improved to a certain extent.

Claims (7)

1. A high-damping resin-based friction material is characterized by comprising the following raw material components in parts by weight: 13 to 18 percent of phenolic resin, 15 to 20 percent of polyacrylonitrile carbon fiber, 40 to 60 percent of friction performance regulator and 3 to 17 percent of damping silicon rubber; the damping silicon rubber is high-temperature vulcanized silicon rubber, and the rubber hydrocarbon content is more than 40%.

2. The high damping resin-based friction material according to claim 1, wherein: the length of the polyacrylonitrile-based carbon fiber is 100 μm.

3. The high damping resin-based friction material according to claim 1, wherein: the phenolic resins include, but are not limited to: cashew nut oil modified phenolic resin, boron modified phenolic resin or barium phenolic resin.

4. The high damping resin-based friction material according to claim 1, wherein: the friction performance modifiers include, but are not limited to: one or more of calcium sulfate whisker, alumina, barium sulfate, chromite, diatomite and fluorite powder.

5. The high damping resin-based friction material according to claim 1 or 4, wherein: the friction performance regulator is a particle material with the particle size of 100-300 meshes.

6. The high damping resin-based friction material according to claim 1 or 4, wherein: the friction performance regulator is a mixture of a 100-300-mesh particle material, a 500-1500-mesh particle material and friction performance regulators with different particle sizes.

7. A method for preparing the high damping resin-based friction material as defined in any one of claims 1 to 6, characterized by the steps of:

step 1: stirring and mixing 13-18% of phenolic resin, 15-20% of polyacrylonitrile carbon fiber, 40-60% of friction performance regulator and 3-17% of damping silicone rubber, and then putting the mixture into a mold;

the damping silicon rubber is high-temperature vulcanized silicon rubber, and the rubber hydrocarbon content is more than 40%;

the length of the fiber is 100 mu m after the polyacrylonitrile-based carbon fiber is cut by a high-speed mixer;

step 2: preheating a pressing die to 150-160 ℃ to prepare pressing;

and step 3: pressing is carried out, and the process conditions are as follows: pressing at 160-180 ℃, pressing at 5-6 Mpa, keeping the temperature and pressure for 600-900 s, and deflating every 50 s;

and 4, step 4: putting the pressed product sample into an oven, heating to 120-130 ℃, and keeping the temperature for 60-80 min; heating to 140-150 ℃, and keeping the temperature for 90-100 min; heating to 160-170 ℃, and keeping the temperature for 120-130 min; heating to 180-200 ℃, and keeping the temperature for 50-60 min; and cooling to room temperature to obtain the high-damping resin-based friction material.

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