阅读说明：本技术 一种碳陶制动盘用碳纤维预制体及其制备方法和应用 (Carbon fiber preform for carbon ceramic brake disc and preparation method and application thereof ) 是由 朱苏华 颜兵 刘翼君 于 2020-12-30 设计创作，主要内容包括：本发明公开了一种碳纤维预制体及其制备方法和应用,首先根据制动盘结构尺寸将碳布(无纬布)和网胎进行仿形裁剪；接着将碳布(无纬布)和网胎交替叠层并逐层针刺并辅助加工得到含通风槽结构的预制体中间层,同时加工出通风槽结构的仿形填充物并填充于中间层内；然后将碳布(无纬布)和网胎交替叠层并逐层针刺制得预制体底层和上层；最后对制得的预制体毛坯进一步加工获得制动盘预制体成品。本发明的碳纤维制动盘预制体能够实现承载、散热、近尺寸一体化制备,提高了原材料利用率、缩短了碳陶制动盘后续生产加工周期,能够大幅度降低碳陶制动盘制造成本,有效推动碳陶材料在航空、轨道交通和汽车制动领域的应用。(The invention discloses a carbon fiber preform and a preparation method and application thereof, wherein firstly, carbon cloth (non-woven cloth) and a net tire are subjected to profile cutting according to the structural size of a brake disc; then alternately laminating carbon cloth (non-woven cloth) and net tires, needling layer by layer and performing auxiliary processing to obtain a prefabricated body middle layer containing a ventilation groove structure, and simultaneously processing a profiling filler of the ventilation groove structure and filling the profiling filler in the middle layer; then alternately laminating carbon cloth (non-woven cloth) and the net tire and needling layer by layer to prepare a bottom layer and an upper layer of the prefabricated body; and finally, further processing the prepared preform blank to obtain a brake disc preform finished product. The carbon fiber brake disc preform disclosed by the invention can realize integrated preparation of bearing, heat dissipation and near size, the utilization rate of raw materials is improved, the subsequent production and processing period of the carbon ceramic brake disc is shortened, the manufacturing cost of the carbon ceramic brake disc can be greatly reduced, and the application of the carbon ceramic material in the fields of aviation, rail transit and automobile braking is effectively promoted.)

1. A preparation method of a carbon fiber preform for a carbon ceramic brake disc is characterized by comprising the following steps: the method comprises the following steps:

step 1: preparation of intermediate layer of preform

Firstly, alternately laminating a layer of carbon cloth or non-woven cloth and a layer of net tire and needling layer by layer to prepare a rough blank of the intermediate layer of the preform, then processing a ventilation groove on the rough blank of the intermediate layer of the preform according to a drawing, simultaneously filling fillers with the sizes matched with those of the upper ventilation groove in the ventilation groove to obtain the intermediate layer of the preform,

step 2 preparation of carbon fiber preform

And (2) alternately laminating a layer of carbon cloth or non-woven cloth and a layer of net tire on the middle layer of the preform obtained in the step (1) and needling layer by layer to obtain a bottom layer of the preform, turning over the obtained preform, continuously laminating a layer of carbon cloth or non-woven cloth and a layer of net tire on the other surface of the middle layer of the preform alternately and needling layer by layer to obtain an upper layer of the preform, and processing according to a drawing to obtain the carbon fiber preform.

2. The preparation method of the carbon fiber preform for the carbon-ceramic brake disc as claimed in claim 1, wherein the preparation method comprises the following steps: in the step 1, the filler is made of at least one of PE/PU/PS foam, a pearl cotton plate and an EVA plate.

3. The preparation method of the carbon fiber preform for the carbon-ceramic brake disc as claimed in claim 2, wherein the preparation method comprises the following steps: in the step 1 and the step 2, the surface densities of the carbon cloth and the non-woven cloth are 280-360 g/m²；

In the step 1 and the step 2, the density of the net tread is 80-120 g/m²；

In the step 1 and the step 2, the needling density is 30-40 needles/cm²。

4. The preparation method of the carbon fiber preform for the carbon-ceramic brake disc as claimed in claim 2, wherein the preparation method comprises the following steps: in the steps 1 and 2, the carbon cloth or the non-woven cloth is laid in the lamination process in the following way: in the first mode, the long carbon fibers in two adjacent layers of carbon cloth or non-woven cloth are laid according to the orientation of 0 degree/90 degrees, and the long carbon fibers in two adjacent layers of carbon cloth or non-woven cloth are laid according to the orientation of-45 degrees/0 degrees/45 degrees/90 degrees.

5. The preparation method of the carbon fiber preform for the carbon-ceramic brake disc as claimed in claim 2, wherein the preparation method comprises the following steps: in the step 2, the density of the carbon fiber preform is 0.50-0.60 g/cm³。

6. The carbon fiber preform for a carbon-ceramic brake disc prepared by the preparation method according to any one of claims 1 to 5.

7. The application of the carbon fiber preform for the carbon-ceramic brake disc prepared by the preparation method according to any one of claims 1 to 5 is characterized in that: the carbon fiber preform is used for preparing a carbon ceramic brake disc.

8. The application of the carbon fiber preform for the carbon-ceramic brake disc prepared by the preparation method according to claim 7 is characterized in that: the preparation process of the carbon ceramic brake disc comprises the following step of carrying out chemical vapor deposition on a carbon fiber preform to obtain the carbon fiber preform with the density of 1.45-1.55 g/cm³And (3) carrying out melting siliconizing on the carbon-carbon prefabricated body to obtain the carbon-ceramic brake disc.

9. The application of the carbon fiber preform for the carbon-ceramic brake disc as claimed in claim 8, is characterized in that:

in the chemical vapor deposition process, the deposition temperature is 920-1050 ℃, the deposition pressure is 3-5 kPa, and the deposition time is 100-150 h.

10. The application of the carbon fiber preform for the carbon-ceramic brake disc as claimed in claim 8, is characterized in that: the melting siliconizing is carried out in a vacuum atmosphere, the temperature of the melting siliconizing is 1600-1900 ℃, the time of the melting siliconizing is 1-3 h, and the density of the carbon ceramic brake disc is 2.0-2.3 g/cm³。

Technical Field

The invention relates to a carbon fiber preform and a preparation method and application thereof, belonging to the technical field of carbon ceramic composite material preparation.

Background

The carbon-ceramic composite material has low density, high strength, stable friction coefficient and small abrasion loss, and is considered as a new generation of brake material following the carbon-carbon composite material. Compared with a steel brake disc, the carbon-ceramic brake disc has the advantages that the weight is reduced by about two thirds, the loading level is doubled, the service life is prolonged by 1-2 times, and the carbon-ceramic brake disc has wide application prospect in brake systems of high-speed trains, racing heavy-duty vehicles, special vehicles, high-grade cars and the like.

At present, the preparation methods of carbon-ceramic brake disc preforms can be divided into two main categories: firstly, short fiber hot-press forming is adopted, and secondly, long fiber needling forming is adopted. Chinese patent CN 103553695A discloses a brake disc made of carbon-ceramic composite material and a preparation method thereof, wherein short carbon fibers, silicon powder, a bonding agent, absolute ethyl alcohol and the like are uniformly mixed according to a ratio, then the mixture is pressed and cured in a grinding tool to form a brake disc preform blank, heat dissipation structures such as ventilation grooves and the like can be processed after the blank is densified, the heat dissipation structure is simple, designability is poor, processing difficulty is increased, and in addition, the brake disc prepared by the method has lower mechanical property. U.S. Pat. No. 5,5184387 discloses a preparation method of a ring-assembled carbon fiber preform, which comprises the steps of firstly needling carbon fiber unidirectional cloth to a certain thickness, then dividing the carbon fiber unidirectional cloth into a plurality of fan-shaped structural units, then splicing the fan-shaped structural units into a ring-shaped structure, designing the fiber orientation among the units, and connecting an upper unit layer and a lower unit layer through needling; the method can effectively improve the utilization rate of raw materials, and is used for preparing high-performance C/C and C/C-SiC brake discs, but the heat dissipation structure of the brake disc still needs subsequent processing.

Disclosure of Invention

The invention aims at overcoming the technical defects, and a first object of the invention is to provide a preparation method of a carbon fiber preform for a carbon ceramic brake disc.

The second purpose of the invention is to provide the carbon fiber preform for the carbon ceramic brake disc prepared by the preparation method.

The third purpose of the invention is to provide the application of the carbon fiber preform for the carbon ceramic brake disc prepared by the preparation method, and the carbon fiber preform can be used for preparing the carbon ceramic brake disc and can realize the integrated molding of the carbon ceramic brake disc with the functions of bearing and heat dissipation in a near-size manner.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention relates to a preparation method of a carbon fiber preform for a carbon ceramic brake disc, which comprises the following steps:

step 1: preparation of intermediate layer of preform

Firstly, alternately laminating a layer of carbon cloth or non-woven cloth and a layer of net tire and needling layer by layer to prepare a rough blank of the intermediate layer of the preform, then processing a ventilation groove on the rough blank of the intermediate layer of the preform according to a drawing, simultaneously filling fillers with the sizes matched with those of the upper ventilation groove in the ventilation groove to obtain the intermediate layer of the preform,

step 2 preparation of carbon fiber preform

And (2) alternately laminating a layer of carbon cloth or non-woven cloth and a layer of net tire on the middle layer of the preform obtained in the step (1) and needling layer by layer to obtain a bottom layer of the preform, turning over the obtained preform, continuously laminating a layer of carbon cloth or non-woven cloth and a layer of net tire on the other surface of the middle layer of the preform alternately and needling layer by layer to obtain an upper layer of the preform, and processing according to a drawing to obtain the carbon fiber preform.

In the actual operation process, before the preparation of the preform, the carbon cloth, the non-woven cloth and the net tire which are required to be used are cut into the corresponding annular blank of the brake disc. In the invention, the carbon cloth, the non-woven cloth and the carbon fiber in the net tire are T700 grade. In the actual operation process, Dongli T700-12K or other models of the same grade are adopted.

In addition, in the actual operation process, after the carbon fiber preform is processed, if the part with loose connection is checked, manual thorn repairing is carried out.

According to the invention, the carbon fiber preform is prepared in a layered manner, and the intermediate layer of the preform with the ventilation grooves is prefabricated, so that the ventilation grooves with special shapes and complex patterns can be prepared, and the carbon ceramic brake disc prepared by using the carbon fiber preform has better heat dissipation performance.

Preferably, in step 1, the filler is made of one selected from PE/PU/PS foam, pearl wool board and EVA board

Preferably, in the step 1 and the step 2, the surface densities of the carbon cloth and the non-woven cloth are 280-360 g/m²。

Preferably, in the step 1 and the step 2, the density of the tread surface is 80 to 120g/m²。

Preferably, in the step 1 and the step 2, the needling density is 30-40 needles/cm²。

Preferably, in the steps 1 and 2, the carbon cloth or the non-woven cloth is laid in the lamination process in the following way: in the first mode, the long carbon fiber orientation in two adjacent layers of carbon cloth or non-woven cloth is laid according to 0 degree/90 degrees, the long carbon fiber orientation in two adjacent layers of carbon cloth or non-woven cloth is laid according to-45 degrees/0 degrees/45 degrees/90 degrees,

preferably, in the step 2, the density of the carbon fiber preform is 0.50-0.60 g/cm³。

The invention also provides the carbon fiber preform for the carbon ceramic brake disc prepared by the preparation method.

The invention also provides application of the carbon fiber preform for the carbon ceramic brake disc prepared by the preparation method, and the carbon fiber preform is used for preparing the carbon ceramic brake disc.

According to the preferable scheme, the carbon ceramic brake disc is prepared by carrying out chemical vapor deposition on a carbon fiber preform to obtain the carbon fiber preform with the density of 1.45-1.55 g/cm³And (3) carrying out melting siliconizing on the carbon-carbon prefabricated body to obtain the carbon-ceramic brake disc.

Further preferably, the carbon source gas is selected from methane, argon,At least one of propylene and natural gas, and diluent gas selected from H₂、Ar、N₂At least one of (1).

Further preferably, in the chemical vapor deposition process, the deposition temperature is 920-1050 ℃, the deposition pressure is 3-5 kPa, and the deposition time is 100-150 h.

The inventor finds that after the heat dissipation groove is machined in advance, a gas diffusion path is shortened during gas deposition, deposition efficiency is remarkably improved, and deposition time is shortened by 30-50 hours.

Further preferably, the melt siliconizing is carried out in a vacuum atmosphere, the temperature of the melt siliconizing is 1600-1850 ℃, and the time of the melt siliconizing is 1-3 hours.

Further preferably, the density of the carbon ceramic brake disc is 2.0-2.3 g/cm³

In the actual operation process, the brake disc after the melting siliconizing is subjected to end face fine grinding to obtain a finished carbon ceramic brake disc product.

Drawings

FIG. 1 is a schematic view of the intermediate layer of the preform after cutting the vent grooves in example 1;

FIG. 2 is a schematic view of a preform after preparing a primer layer in example 1;

FIG. 3 is a schematic view of a preform after the preparation of an upper layer in example 1;

FIG. 4 is a schematic diagram of the finished preform of example 1, wherein 1 is the intermediate layer of the preform, 2 is the filler, 3 is the bottom layer of the preform, and 4 is the upper layer of the preform.

FIG. 5 example 2 schematic representation of the preform intermediate layer after cutting the vent slots.

FIG. 6 is a real object diagram of the middle layer of the preform after the ventilation slots are cut in the embodiment 2.

Figure 7 is a schematic representation of the intermediate layer of the preform after cutting the vent slots in comparative example 1.

The invention is further described with reference to the following figures and detailed description.

Detailed Description

Example 1

Preparation of carbon fiber preform for brake disc

Step 1: profile cutting of weftless fabric and net tyre

The outer diameter of the carbon-ceramic brake disc is 680mm, the inner diameter of the carbon-ceramic brake disc is 420mm, the thickness of the carbon-ceramic brake disc is 55mm, and the outer diameter of a prefabricated body is 720mm, the inner diameter of the prefabricated body is 400mm, and the thickness of the prefabricated body is 59 mm; the density is 80g/m²And a carbon fiber web of 300g/m²The non-woven cloth is cut into a circular ring with the outer diameter of 740mm and the inner diameter of 380mm for standby.

Step 2: preparation of intermediate layer of preform

The rings in the step 1 are sequentially laminated alternately according to a layer of non-woven fabric and a layer of net tire and needled layer by layer, the fibers of the non-woven fabric in two adjacent times are distributed according to the angle of 0 degree/90 degrees, and the needling density is 40 needles/cm²(ii) a The thickness of the middle layer is 25mm, and a ventilation groove structure is processed after the thickness is reached (figure 1); meanwhile, PU foam board filler of the ventilation groove is processed in a copying mode and filled in the ventilation groove.

And step 3: preparation of bottom layer and upper layer of prefabricated body

Sequentially laying non-woven cloth and a net tire on the middle layer of the prefabricated body by the same process as the step 2, and needling layer by layer to prepare a bottom layer of the prefabricated body, wherein the thickness of the bottom layer of the prefabricated body is 20mm (figure 2); then, the preform is turned over, and then the upper layer of the preform is prepared by the same method, wherein the thickness of the upper layer of the preform is 14 mm.

And 4, step 4: processing of preforms

And (3) processing the preform blank (figure 3) obtained in the step (3) to an outer diameter of 720mm and an inner diameter of 400mm to obtain a finished preform for the brake disc (figure 4).

The density of the prepared carbon fiber preform was 0.45g/cm³。

Preparation of carbon-ceramic brake disc

Carrying out chemical vapor deposition on the carbon fiber preform, wherein in the chemical vapor deposition process, propylene (12L/min) is introduced: the deposition temperature of nitrogen (10L/min) is 1000 ℃, the deposition pressure is 3-5 kPa, and the deposition time is 120 h. A density of 1.48g/cm was obtained³And performing melt siliconizing on the carbon-carbon preform to obtain a carbon-ceramic brake disc, wherein the melt siliconizing is performed in a vacuum atmosphere, the melt siliconizing temperature is 1720 ℃, and the melt siliconizing time is 2 hours. The density of the carbon ceramic brake disc is 2.1g/cm³And finely grinding the obtained finished product.

In the preparation process of the embodiment 1 of the invention, the same density is achieved in the chemical vapor deposition process, compared with the carbon fiber preform without a processing groove, the same density is obtained by deposition, 30-50h can be saved, and the subsequent processing time is reduced by 4 hours.

A1: 1 rack examination rack is adopted to examine and simulate the emergency braking condition of the passenger car at the speed of 120 kilometers per hour, and the temperature of the carbon-ceramic brake disc prepared in the embodiment 1 is 120 ℃ during braking.

Example 2:

step 1: carbon cloth and net tyre profiling cutting

The outer diameter of the carbon-ceramic brake disc is 680mm, the inner diameter of the carbon-ceramic brake disc is 420mm, the thickness of the carbon-ceramic brake disc is 55mm, and the outer diameter of a prefabricated body is 720mm, the inner diameter of the prefabricated body is 400mm, and the thickness of the prefabricated body is 59 mm; the density is 80g/m²And a carbon fiber web of 360g/m²The carbon cloth is cut into rings with the outer diameter of 740mm and the inner diameter of 380mm for standby.

Step 2: preparation of intermediate layer of preform

The rings in the step 1 are sequentially alternately laminated according to a layer of carbon cloth and a layer of net tire and needled layer by layer, wherein the needling density is 40 needles/cm²(ii) a The thickness of the middle layer is 25mm, and after the middle layer reaches the thickness, a ventilation groove structure with a complex pattern is processed according to a design drawing (as shown in figure 5); simultaneously, the EVA board filler of the ventilation groove is processed by profiling and is filled in the ventilation groove.

And step 3: preparation of bottom layer and upper layer of prefabricated body

Sequentially laying carbon cloth and a net tire on the middle layer of the prefabricated body by the same process as the step 2, and needling layer by layer to prepare a bottom layer of the prefabricated body, wherein the thickness of the bottom layer of the prefabricated body is 20 mm; then, the preform is turned over, and then the upper layer of the preform is prepared by the same method, wherein the thickness of the upper layer of the preform is 14 mm.

And 4, step 4: processing of preforms

And (4) processing the preform blank obtained in the step (3) to an outer diameter of 720mm and an inner diameter of 400mm to obtain a finished preform for the brake disc.

The density of the prepared carbon fiber preform was 0.55g/cm³。

Preparation of carbon-ceramic brake disc

Carrying out chemical vapor deposition on the carbon fiber preform, and introducing the carbon fiber preform into the reactor during the chemical vapor depositionThe temperature of deposition of propylene (7L/min) and nitrogen (10L/min) is 1050 ℃, the pressure of deposition is 3-5 kPa, and the deposition time is 140 h. A density of 1.55g/cm was obtained³And carrying out melt siliconizing on the carbon-carbon preform to obtain the carbon-ceramic brake disc, wherein the melt siliconizing is carried out in a vacuum atmosphere, the melt siliconizing temperature is 1820 ℃, and the melt siliconizing time is 2 hours. The density of the carbon ceramic brake disc is 2.3g/cm³And finely grinding the obtained finished product.

A1: 1 rack examination rack is adopted to examine and simulate the emergency braking condition of the passenger car at the speed of 120 kilometers per hour, and the temperature of the carbon-ceramic brake disc prepared in the embodiment 1 is 110 ℃ during braking.

Example 3

Step 1: profile cutting of weftless fabric and net tyre

The outer diameter of the carbon-ceramic brake disc is 680mm, the inner diameter of the carbon-ceramic brake disc is 420mm, the thickness of the carbon-ceramic brake disc is 55mm, and the outer diameter of a prefabricated body is 720mm, the inner diameter of the prefabricated body is 400mm, and the thickness of the prefabricated body is 59 mm; the density is 120g/m²And a carbon fiber web of 320g/m²The non-woven cloth is cut into a circular ring with the outer diameter of 740mm and the inner diameter of 380mm for standby.

Step 2: preparation of intermediate layer of preform

The rings in the step 1 are sequentially laminated alternately according to a layer of weftless fabric and a layer of net tire and needled layer by layer, the adjacent four layers of weftless fabric fibers are distributed according to-45 degrees/0 degrees/45 degrees/90 degrees, and the needling density is 40 needles/cm²(ii) a The thickness of the middle layer is 25mm, and a ventilation groove structure is processed after the thickness is reached; meanwhile, PU foam board filler of the ventilation groove is processed in a copying mode and filled in the ventilation groove.

And step 3: preparation of bottom layer and upper layer of prefabricated body

Sequentially laying non-woven cloth and a net tire on the middle layer of the prefabricated body by the same process as the step 2, and needling layer by layer to prepare a bottom layer of the prefabricated body, wherein the thickness of the bottom layer of the prefabricated body is 20 mm; then, the preform is turned over, and then the upper layer of the preform is prepared by the same method, wherein the thickness of the upper layer of the preform is 14 mm.

And 4, step 4: processing of preforms

And (4) processing the blank obtained in the step (3) to a prefabricated finished product with the outer diameter of 720mm and the inner diameter of 400 mm.

The density of the prepared carbon fiber preform was 0.55g/cm³。

Preparation of carbon-ceramic brake disc

And (3) carrying out chemical vapor deposition on the carbon fiber preform, wherein in the chemical vapor deposition process, the temperature of introducing propylene (20L/min) and nitrogen (10L/min) for deposition is 960 ℃, the deposition pressure is 3-5 kPa, and the deposition time is 130 h. A density of 1.53g/cm was obtained³And performing melt siliconizing on the carbon-carbon preform to obtain a carbon-ceramic brake disc, wherein the melt siliconizing is performed in a vacuum atmosphere, the temperature of the melt siliconizing is 1680 ℃, and the time of the melt siliconizing is 2 hours. The density of the carbon ceramic brake disc is 2.2g/cm³And finely grinding the obtained finished product.

A1: 1 rack examination rack is adopted to examine and simulate the emergency braking condition of the passenger car at the speed of 120 kilometers per hour, and the temperature of the carbon-ceramic brake disc prepared in the embodiment 1 is 118 ℃ during braking.

Comparative example 1

The other conditions are the same as the example 2, only after the carbon-carbon composite material is prepared, the ventilating groove is processed into the ventilating groove instead of the ventilating groove arranged in the middle of the carbon fiber prefabricated body, only the linear ventilating groove can be processed into the ventilating groove (figure 7), and the processing time is to densify the prepared carbon fiber prefabricated body to 1.5g/m by adopting chemical vapor deposition²And the time is 180 hours.

A1: 1 rack examination rack is adopted to examine and simulate the emergency braking condition of the passenger car at the speed of 120 kilometers per hour, and the temperature of the carbon-ceramic brake disc prepared in the embodiment 1 is 145 ℃ during braking.