CN117904482B - A ceramic-containing copper-based powder metallurgy friction material and its preparation method and application - Google Patents

Abstract

The invention relates to a copper-based powder metallurgy friction material containing ceramics, belonging to the technical field of design and preparation of powder metallurgy friction materials. The raw materials used by the method comprise the following components in percentage by mass; 52-58% of electrolytic copper powder; 2-6% of electrolytic nickel powder; 10-20% of reduced iron powder; 1-6% of tungsten powder; 8-15% of graphite powder; 1-5% of boron carbide powder; 7-10% of zirconia-titanium nitride ceramic powder, wherein the ratio of zirconia to titanium nitride is 8:0.5 to 0.5:8, 8; the grain size of the boron carbide is 1-10 microns, the grain size of the zirconia is 1-10 microns, the grain size of the titanium nitride powder is 10-20 microns, and the grain size of the titanium nitride powder minus the grain size of the boron carbide is more than or equal to 4 microns. The preparation method comprises the following steps: and (5) taking all the raw materials according to the design components, uniformly mixing, and then pressurizing and sintering to obtain the product. The invention has reasonable component design and simple and controllable preparation process, and the obtained product has excellent performance when being used as a friction material.

Description

A ceramic-containing copper-based powder metallurgy friction material and its preparation method and application

Technical Field

The invention relates to the field of design and preparation of powder metallurgy friction materials, and specifically comprises a three-ceramic component composite modified copper-based powder metallurgy friction material containing a nitride component, and a preparation method and application thereof.

Background technique

Copper-based friction materials are widely used in the braking systems of automobiles, high-speed railways, aviation and engineering equipment due to their high mechanical strength, good thermal conductivity and strong heat resistance. However, as the operating speed of vehicles and engineering equipment continues to increase, the heat energy generated during braking increases. Under extreme conditions of high load and strong heat, the original copper-based powder metallurgy friction materials will still show a series of thermal decay behaviors such as thermal cracks, increased wear and large fluctuations in friction coefficient. Therefore, optimizing and improving the existing copper-based powder metallurgy friction material formula is a feasible strategy to expand the application scope of copper-based friction materials.

So far, copper-based powder metallurgy friction materials, in addition to copper as the base component, also include reinforcing components such as iron and nickel, lubricating components such as graphite and molybdenum disulfide, and friction components such as zirconium oxide and aluminum oxide. Among them, the friction component is mainly used to increase the friction coefficient between the friction pairs. However, under normal circumstances, the friction component has poor wettability with the copper matrix and weak bonding force, and it is very easy to fall off during the intense friction process, which on the one hand causes the friction coefficient to fluctuate and the friction performance to decrease; on the other hand, it is very likely to damage the wear parts and cause unnecessary economic losses.

In view of the above problems, the main solution at present is to use the synergistic effect between dual ceramic components to further improve the tribological properties of copper-based materials. Chinese patent application CN107012358A discloses a powder metallurgy friction material and preparation process for brake pads. The patent application uses zirconium oxide and silicon carbide composite ceramics as friction components to improve the friction coefficient and friction stability of copper-based materials, so that the copper-based materials show higher friction stability during the friction process. However, the patent application does not involve the specific performance parameters of the product. Patent CN112593112A also discloses a formula for enhancing the friction coefficient of copper-based friction materials using zirconium carbide and silicon oxide as dual friction components, but its invention mainly involves the use of high-energy laser beams to promote the in-situ reaction of _ZrSiO4 and carbon materials to generate dual friction components of zirconium carbide and silicon oxide, and the production cost is relatively high. Chinese patent application CN116377279A discloses a copper-based powder metallurgy brake pad containing multiple ceramic components and its preparation method. This patent application is based on improving the heat resistance of copper-based powder metallurgy brake pads, using the characteristic parameters of various reinforcing phases to synergistically enhance, give full play to the advantages and coupling effects of each component, and obtain a copper-based composite material with excellent comprehensive performance. This patent application first attempted to use dual ceramic powder B ₄ C-TiC with hexagonal boron nitride powder and metal matrix to improve the friction stability and heat resistance of the brake pad. The wear loss of the product obtained in this patent application is 0.05~0.15cm ³ /MJ, and the friction stability coefficient is 0.74~0.86.

Summary of the invention

Based on Chinese patent application CN 116377279A, the present invention attempts to use boron carbide, zirconium oxide and titanium nitride three-component composite ceramics to synergistically reinforce copper-based powder metallurgy friction materials in order to further reduce wear. By optimizing the components, the invention objective is achieved, and the present invention is formed.

The copper-based powder metallurgy friction material developed and designed by the present invention fully utilizes the complementary advantages among the friction components, and through the reaction synergy between the components of the three friction components and the appropriate matching of the friction component particle sizes, the purpose of further effectively improving the friction and wear properties of the copper-based powder metallurgy friction material is achieved, while ensuring that the wear rate of the brake disc dual material is at a low level.

In view of the problems existing in the existing single- and double-ceramic component modified copper-based powder metallurgy friction materials, the present invention provides a three-ceramic component composite modified copper-based powder metallurgy friction material containing a nitride component and a preparation method thereof. By utilizing the synergistic effect between the three friction components of appropriately sized boron carbide, zirconium oxide and titanium nitride, especially the diffusion enhancement reaction between appropriately sized boron carbide and titanium nitride, the friction performance of the copper-based friction material, especially the friction stability in high-temperature service environment, can be improved to a certain extent.

The present invention discloses a ceramic-containing copper-based powder metallurgy friction material, wherein the raw materials used include the following components by mass percentage:

Electrolytic copper powder 52-58%, preferably 55-58%;

Electrolytic nickel powder 2~6%, preferably 2~5%;

Reduced iron powder 10-20%, preferably 11-16%;

Tungsten powder 1~6%, preferably 2~4%;

Graphite powder 8-15%, preferably 10-14%;

Boron carbide powder 1~5%, preferably 2~4%;

7-10% zirconium oxide-titanium nitride (ZrO ₂ -TiN) ceramic powder, preferably 7.5-8.5%, more preferably 8%, wherein the mass ratio of zirconium oxide to titanium nitride is 8:0.5-0.5:8, more preferably 3:5-5:3;

The boron carbide particles used have a size of 1-10 microns, the zirconium oxide particles have a size of 1-10 microns, the titanium nitride powder particles have a size of 10-20 microns, and the titanium nitride powder particle size minus the boron carbide particle size is greater than or equal to 4 microns.

As a further preference, the particle size of the boron carbide particles is 2-5 microns, the particle size of the zirconium oxide ceramic particles is 3-5 microns, and the particle size of the titanium nitride ceramic particles is 10-15 microns. Alternatively, the particle size of the boron carbide particles is 5-8 microns, the particle size of the zirconium oxide ceramic particles is 4-8 microns, and the particle size of the titanium nitride ceramic particles is 12-15 microns.

As a preferred embodiment, the present invention provides a ceramic-containing copper-based powder metallurgy friction material, wherein the raw materials used are composed of the following components by mass percentage: 56-58% electrolytic copper powder, 11-15% reduced iron powder, 3-5% electrolytic nickel, 2-5% tungsten powder, 9-14% graphite powder, 2-4% boron carbide powder; 8% zirconium oxide-titanium nitride powder, wherein the mass ratio of zirconium oxide to titanium nitride is 3:5-5:3.

As one of the further preferred schemes, the present invention is a ceramic-containing copper-based powder metallurgy friction material, wherein the raw materials used are composed of the following components by mass percentage: 56% electrolytic copper powder, 15% reduced iron powder, 3% electrolytic nickel, 2% tungsten powder, 14% graphite powder, 2% boron carbide powder; 8% zirconium oxide-titanium nitride powder, wherein the mass ratio of zirconium oxide to titanium nitride is 3:5. This scheme can achieve the goal of reducing the wear rate of the copper-based material as much as possible when the average friction coefficient and the stable friction coefficient are both high.

As one of the further preferred schemes, the present invention is a ceramic-containing copper-based powder metallurgy friction material, the raw materials used for which are composed of the following components by mass percentage: 58% electrolytic copper powder, 11% reduced iron powder, 5% electrolytic nickel, 4% tungsten powder, 10% graphite powder, 4% boron carbide powder; 8% zirconium oxide-titanium nitride powder, wherein the mass ratio of zirconium oxide to titanium nitride is 5:3. This scheme can achieve the goal of increasing the stable friction coefficient of the copper-based material as much as possible when the average friction coefficient is high and the wear rate of the copper-based material is low.

The present invention discloses a copper-based powder metallurgy friction material containing ceramics, wherein electrolytic copper powder is used as the main material, and the particle size is 60 to 80 microns, and more preferably 65 to 75 microns. Reduced iron powder is used as the main reinforcing component to synergistically enhance the mechanical properties of the copper-based friction material, and the particle size is 60 to 80 microns, and more preferably 65 to 75 microns. Electrolytic nickel powder and tungsten powder are used as secondary reinforcing components to achieve the purpose of dispersion strengthening, and the particle size is 60 to 80 microns, and more preferably 65 to 75 microns. Graphite powder is preferably flaky graphite powder, and flaky graphite powder is used as a lubricating component, and its main function is to promote the formation of friction film to achieve the purpose of reducing wear and friction. The particle size is 120 to 180 microns, and more preferably 130 to 170 microns.

In the present invention, the ternary composite ceramic powder includes boron carbide powder, zirconium oxide powder and titanium nitride powder as friction components, which are used to increase the friction coefficient between the friction pairs, wherein the boron carbide particle size is 2 to 8 microns; the zirconium oxide particle size is 3 to 5 microns; the titanium nitride powder particle size is 10 to 20 microns, preferably 10 to 15 microns, and the titanium nitride powder particle size-boron carbide particle size is greater than or equal to 4 microns. As a further preference, the particle size of the boron carbide particles is 2 to 5 microns, the particle size of the zirconium oxide ceramic particles is 3 to 5 microns, and the particle size of the titanium nitride ceramic particles is 10 to 15 microns. Or, the particle size of the boron carbide particles is 5 to 8 microns, the particle size of the zirconium oxide ceramic particles is 4 to 8 microns, and the particle size of the titanium nitride ceramic particles is 12 to 15 microns.

On the one hand, the present invention utilizes the composite reaction and synergistic effect between three friction components of appropriate size and appropriate amount, especially boron carbide and titanium nitride, to enhance the tribological properties of copper-based powder metallurgy friction materials through lubrication-friction coupling. On the other hand, zirconium oxide particles with smaller particle size are used to cooperate with titanium nitride ceramics with larger particle size to increase the friction balance on the basis of improving the friction coefficient. Compared with existing copper-based friction materials, the copper-based powder metallurgy friction material described in the present invention has a high friction coefficient and high friction stability. Especially in the case of high temperature generated by high-speed braking, the copper-based powder metallurgy friction material containing ceramics designed and prepared by the present invention has the advantages of high friction stability, low wear rate and low damage rate of the mating parts.

The present invention provides a method for preparing a ceramic-containing copper-based powder metallurgy friction material, comprising the following steps:

step one

Dispense each raw material according to the designed composition;

Step 2

The prepared raw material powders are mixed to obtain a uniformly mixed powder; when mixing, the powders are first mixed by stirring, and then mixed by a V-type mixer;

When mixing, add 2-3% of the raw material powder mass of aviation kerosene, and when mixing in a V-type mixer, control the speed to 80-120 rpm and the time to 45min-5h;

Step 3

The uniformly mixed powder is added into a mold for pressing to obtain a pressed green body, wherein the process parameters of the pressing process are: pressure 500-600 MPa, and holding time 20-30 seconds.

Step 4

The green body is placed in a pressure furnace for sintering to obtain a product; the parameters of the sintering process are: sintering pressure 1.5-2.5MPa, temperature 500-600℃, heat preservation and pressure holding for 1-2 hours, sintering pressure 2.5-3.5MPa, temperature 600-700℃, heat preservation and pressure holding for 1-3 hours, sintering pressure 3.5-5MPa, temperature 700-940℃, heat preservation and pressure holding for 2-3 hours.

The invention discloses an application of a ceramic-containing copper-based powder metallurgy friction material, which includes using it as a friction material, such as a brake system of automobiles, high-speed railways, aviation, and engineering equipment.

Beneficial Effects

The fine-grained boron carbide ceramic particles used in the present invention are hard in texture, which can improve the friction coefficient of copper-based materials. At the same time, a boron oxide friction film can be quickly and evenly generated in a high-temperature environment, thereby improving the high-temperature stability of the substrate. The fine-grained zirconium oxide ceramic used in the present invention is used as a small-grained hard phase; but if used alone, its bonding strength with the copper substrate is small and it falls off during the friction process. The titanium nitride ceramic selected in the present invention is used as a large-grained hard phase, which can greatly increase the friction coefficient of the substrate during the friction process. However, if used alone, it will cause the friction stability of the copper-based material to decrease. Starting from the complex service conditions of the material, the present invention adjusts the proportion of three friction components of boron carbide, zirconium oxide and titanium nitride of appropriate sizes, utilizes the composite reaction between large-grained titanium nitride and fine-grained boron carbide, and the synergistic cooperation of small-grained zirconium oxide ceramic and large-grained titanium nitride ceramic, to achieve the synergistic enhancement of the ceramic component to the copper-based friction material, improve the problem of unstable bonding between the ceramic particles and the substrate interface, reduce the shedding of components, and further improve the comprehensive friction and wear performance of the material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a microscopic morphology of the product obtained in Example 1;

FIG2 is a microscopic morphology of the product obtained in Example 2;

FIG3 is a friction curve diagram of the product obtained in Example 1;

FIG4 is a friction curve diagram of the product obtained in Example 2;

FIG5 is a friction curve diagram of the product obtained in Comparative Example 1;

FIG6 is a friction curve diagram of the product obtained in Comparative Example 2;

FIG7 is a graph showing the average friction coefficient of the product obtained in Example 1;

FIG8 is a graph showing the friction stability coefficient of the product obtained in Example 1.

It can be seen from FIG. 1 that the components in the product obtained in Example 1 are evenly distributed, wherein the ceramic particles are mainly dispersed in the matrix composed of copper and iron, and the matrix has good continuity because the zirconium oxide content is relatively high and the particles are small.

As can be seen from FIG. 2 , in the product obtained in Example 2, each component is evenly distributed, but the matrix continuity is poor, which is mainly due to the high content and large particle size of titanium nitride, and the fact that titanium nitride is easily agglomerated with boron carbide.

As can be seen from FIG. 3 , the friction coefficient of the product obtained in Example 1 is maintained at around 0.35, and the friction curve is relatively flat. This is because the zirconium oxide and titanium nitride content are highly matched with the particle size and the content of large-particle titanium nitride ceramic components is relatively high.

It can be seen from FIG. 4 that the friction coefficient of the product obtained in Example 2 is slightly lower than 0.35 and the friction coefficient fluctuates less. This is because the zirconium oxide and titanium nitride content are well matched with the particle size and the content of small-particle zirconium oxide ceramic components is relatively high.

It can be seen from FIG. 5 that the product obtained in Comparative Example 1 has a lower friction coefficient and a high friction curve stability, which is due to the absence of large particles of titanium nitride ceramic components in the example.

As can be seen from FIG. 6 , the friction coefficient of the product obtained in Comparative Example 2 is very high and fluctuates greatly. This is because the product obtained in Comparative Example 2 does not contain small particles of zirconia ceramic components.

As can be seen from FIG. 7 , the friction coefficient of the product obtained in Example 1 is basically maintained above 0.35, which is related to the composition ratio and particle size of the ternary ceramic powder of boron carbide, zirconium oxide and titanium nitride.

As can be seen from Figure 8, the friction stability coefficient of the product obtained in Example 1 is basically maintained above 0.8 or even close to 0.9, indicating that the friction stability of the product obtained in Example 1 is relatively high. Combined with Figure 7, it can be concluded that the product obtained in Example 1 can also ensure relatively high friction stability on the basis of a relatively high friction coefficient.

Detailed ways

In the embodiments and comparative examples of the present invention, the paired carbon-ceramic discs used are made of carbon/carbon-silicon carbide composite materials (carbon fiber reinforced silicon carbide-carbon-based composite materials). The material preparation process mainly includes: preparing carbon/carbon materials by prefabricating and pyrolytic carbon deposition, and then infiltrating liquid silicon into the carbon/carbon material matrix by molten silicon infiltration, so that it reacts with pyrolytic carbon to form silicon carbide, and finally obtaining carbon/carbon-silicon carbide composite materials. The carbon/carbon-silicon carbide composite material has the characteristics of low density (2.35g/cm ³ ), low porosity (2.9%) and high hardness (120.7 HRL).

In the embodiments and comparative examples, the friction simulation experiment of the product is: using the MM-3000 scaled test machine, the obtained product is paired with a carbon ceramic disc to form a friction pair to complete the braking experiment. The experimental parameters are: braking pressure 0.5 MPa, braking inertia 0.45kg·m ² , speed 24 m/s. Each experimental data is obtained by taking the average value after the braking experiment is repeated 10 times.

Example 1

Step 1: Weighing the proportions. Weigh the raw materials in order according to the formula. By mass percentage, electrolytic copper powder is 56%, reduced iron powder is 15%, electrolytic nickel is 3%, tungsten powder is 2%, graphite powder is 14%, boron carbide powder is 2%, and zirconium oxide and titanium nitride powder are 8% in total.

Among them: the particle size of electrolytic copper powder is 65~70 microns, the particle size of reduced iron powder is 65~70 microns, the particle size of electrolytic nickel is 65~70 microns, the particle size of tungsten powder is 65~70 microns, the particle size of graphite powder is 130~150 microns, the particle size of boron carbide particles is 2~5 microns, the particle size of zirconium oxide ceramic particles is 3~5 microns, and the particle size of titanium nitride ceramic particles is 10~15 microns.

The mass ratio of the zirconium oxide to titanium nitride ceramic powders used is 3:5.

Step 2: Mix the raw materials. Mix the raw material powders weighed in the first step to obtain a uniformly mixed powder; when mixing, first mix by stirring, and then mix by a V-type mixer;

When mixing, add 3% of the mass of the raw material powder into aviation kerosene, and when mixing in a V-type mixer, control the speed to 100 rpm and the time to 3 hours;

Step 3: Pressing the green body. Pour the fully mixed raw material powder into the mold and press it into shape. The pressing parameters are: pressing pressure 500MPa, holding time 15 seconds.

Step 4: Sample sintering. The green body is placed in a bell-type pressure furnace for sintering. The sintering process is: sintering pressure 2MPa, temperature 600℃, heat preservation and pressure holding for 1 hour, sintering pressure 3MPa, temperature 700℃, heat preservation and pressure holding for 1 hour, sintering pressure 5MPa, temperature 940℃, heat preservation and pressure holding for 3 hours.

Example 2

Step 1: Weighing the proportions. Weigh the raw materials in order according to the formula. By mass percentage, electrolytic copper powder is 58%, reduced iron powder is 11%, electrolytic nickel is 5%, tungsten powder is 4%, graphite powder is 10%, boron carbide powder is 4%, and zirconium oxide and titanium nitride powder are 8% in total.

Among them: the particle size of electrolytic copper powder is 70~75 microns, the particle size of reduced iron powder is 70~75 microns, the particle size of electrolytic nickel is 70~75 microns, the particle size of tungsten powder is 70~75 microns, the particle size of graphite powder is 150~170 microns, the particle size of boron carbide particles is 5~8 microns, the particle size of zirconium oxide ceramic particles is 4~8 microns, and the particle size of titanium nitride ceramic particles is 12~15 microns.

The mass ratio of the zirconium oxide to titanium nitride ceramic powders used is 5:3.

Step 2: Mixing raw materials. Mix the raw material powders weighed in the first step to obtain a uniformly mixed powder; when mixing, first mix by stirring, and then use a V-type mixer to mix;

When mixing, add 3% of the raw material powder mass of aviation kerosene, and when mixing in a V-type mixer, control the speed to 150 rpm and the time to 4 hours;

Step 3: Pressing the green body. Pour the fully mixed raw material powder into the mold and press it into shape. The pressing parameters are: pressing pressure 500MPa, holding time 15 seconds.

Step 4: Sample sintering. The green body is placed in a bell-type pressure furnace for sintering. The sintering process is: sintering pressure 2MPa, temperature 600℃, heat preservation and pressure maintenance for 1 hour, sintering pressure 3MPa, temperature 900℃, heat preservation and pressure maintenance for 1 hour, sintering pressure 5MPa, temperature 960℃, heat preservation and pressure maintenance for 3 hours.

Example 3

The preparation method and experimental parameters are basically the same as those in Example 1, except that the raw material content ratio is, by mass percentage, 54% electrolytic copper powder, 14% reduced iron powder, 3% electrolytic nickel, 5% tungsten powder, 9% graphite powder, 5% boron carbide powder, and 10% zirconium oxide and titanium nitride powder in total.

The mass ratio of the zirconium oxide to titanium nitride ceramic powders used is 1:1.

The particle size of zirconium oxide ceramic particles is 4~8 microns, and the particle size of titanium nitride ceramic particles is 12~15 microns.

Example 4

The preparation method and experimental parameters are basically the same as those in Example 1, except that:

1. The raw material content ratio, calculated by mass percentage, is 52% electrolytic copper powder, 15% reduced iron powder, 4% electrolytic nickel, 6% tungsten powder, 10% graphite powder, 5% boron carbide powder, and 8% zirconium oxide and titanium nitride powder in total.

The mass ratio of zirconium oxide to titanium nitride ceramic powder used is 5:3;

2. During the mixing of step 2, add 3% aviation kerosene by weight of the raw material powder, and when mixing in a V-type mixer, control the speed to 50 rpm and the mixing time to 1 hour.

Comparative Example 1

The preparation method and experimental parameters are basically the same as those in Example 1, except that titanium nitride is not added as a friction component in the formula of this example. By mass percentage, the electrolytic copper powder is 56%, the reduced iron powder is 15%, the electrolytic nickel is 3%, the tungsten powder is 2%, the graphite powder is 14%, the boron carbide powder is 2%, and the zirconium oxide powder is 8%, and the particle size of the zirconium oxide ceramic particles is 4 to 8 microns.

Comparative Example 2

The preparation method and experimental parameters are basically the same as those of Example 2, except that zirconium oxide is not added as a friction component in this example; by mass percentage, the electrolytic copper powder is 58%, the reduced iron powder is 11%, the electrolytic nickel is 5%, the tungsten powder is 4%, the graphite powder is 10%, the boron carbide powder is 4%, and the titanium nitride powder is 8%, and the particle size of the titanium nitride ceramic particles is about 12~15 microns.

Comparative Example 3

The preparation method and experimental parameters are basically the same as those in Example 1, except that the raw materials are weighed in sequence according to the formula, and by mass percentage, the electrolytic copper powder is 54%, the reduced iron powder is 15%, the electrolytic nickel is 3%, the tungsten powder is 2%, the graphite powder is 14%, the boron carbide powder is 2%, and the zirconium oxide and titanium nitride powders total 10%.

The mass ratio of zirconium oxide to titanium nitride ceramic powder is 1:1. The particle size of zirconium oxide ceramic particles is less than about 4 microns, and the particle size of titanium nitride ceramic particles is about 25-30 microns.

Comparative Example 4

The preparation method is basically the same as that of Example 4, except that: during mixing in step 2, 5% of the mass of the raw material powder is added with aviation kerosene, and when mixing in a V-type mixer, the speed is controlled to be 300 rpm and the time is 8 hours.

Comparative Example 5

Other conditions are the same as those in Example 1, except that the particle size of the boron carbide particles is 3-5 microns, the particle size of the zirconium oxide ceramic particles is 3-5 microns, and the particle size of the titanium nitride ceramic particles is 3-5 microns.

Comparative Example 6

The other conditions were the same as those in Example 1, except that the sintering system was one-step sintering, and the sintering process was as follows: sintering pressure 5 MPa, temperature 960° C., and heat and pressure holding for 5 hours.

In the embodiments and comparative examples, the friction simulation test results of the products are shown in Table 1.

As shown in Table 1, the average friction coefficients of Example 1 and Example 2 are both over 0.32, and the friction stability coefficients are both over 0.8. At the same time, both the lower wear rate (copper-based material) and the damage rate of the friction disc of the mating part are taken into account. This shows that Example 1 and Example 2 have moderate and stable friction coefficients, and the comprehensive friction performance can also meet the actual application requirements. The friction coefficient of Example 3 exceeds 0.40, but the friction stability is lower than 0.8. This is because the content of the composite ceramic particles of zirconium oxide and titanium nitride is too high, which leads to an increase in the friction coefficient of the copper-based material, but a decrease in stability. Comparative Example 1 contains only zirconium oxide ceramics, resulting in poor bonding with the matrix. The friction coefficient is small. Comparative Example 2 contains only titanium nitride ceramics, resulting in a high degree of bonding with the matrix, and at the same time, excessive titanium nitride will form a chemical diffusion bond with boron carbide, so the average friction coefficient is higher. However, all comparative examples have problems such as poor friction stability, high wear rate and greater damage to the mating parts. At the same time, in Comparative Example 3, the particle size of the zirconium oxide ceramic particles is too small and the particle size of the titanium nitride ceramic is too large, and the particle size of the ceramic components is mismatched. Although the overall content of the composite ceramic increases, resulting in an increase in the friction coefficient, the too small zirconium oxide ceramic particles cannot achieve abrasive wear during the friction process, resulting in a low friction stability coefficient. In Comparative Example 4, the particle breakage caused by the long ball milling time and the high ball milling rate may be the main reason for the reduction in the friction coefficient. It can be seen from Comparative Example 5 that although the particle size that is too close can improve the friction stability coefficient to a certain extent, it will also cause a decrease in the friction coefficient, which further illustrates that the single composition of different components and the appropriate particle size ratio can improve the friction performance of copper-based materials. The main reason for the reduction in the friction coefficient of Comparative Example 6 is that the sintering system is a one-step sintering, and the excessively fast temperature rise rate causes the copper-based material to have problems such as excessive grain growth and increased defects during the sintering process. These conditions will cause the mechanical properties of the copper-based material to decrease, thereby reducing its friction and wear performance.

Claims (8)

1. A copper-based powder metallurgy friction material containing ceramics, characterized in that: the raw materials used include the following components by mass percentage; Electrolytic copper powder 52~58%; Electrolytic nickel powder 2~6%; Reduced iron powder 10~20%; Tungsten powder 1~6%; Graphite powder 8~15%; Boron carbide powder 1~5%; Zirconia-titanium nitride ceramic powder 7-10%, wherein the mass ratio of zirconium oxide to titanium nitride is 8:0.5-0.5:8; The boron carbide particles used have a size of 1 to 10 microns, the zirconium oxide particles have a size of 1 to 10 microns, the titanium nitride powder particles have a size of 10 to 20 microns, and the titanium nitride powder particle size minus the boron carbide particle size is greater than or equal to 4 microns; The ceramic-containing copper-based powder metallurgy friction material is prepared by the following steps: step one Dispense each raw material according to the designed composition; Step 2 The prepared raw material powders are mixed to obtain a uniformly mixed powder; when mixing, the powders are first mixed by stirring, and then mixed by a V-type mixer; When mixing, add 2-3% of the raw material powder mass of aviation kerosene, and when mixing in a V-type mixer, control the speed to 80-120 rpm and the time to 45min-5h; Step 3 The uniformly mixed powder is added into a mold for pressing to obtain a pressed green body, wherein the process parameters of the pressing process are: pressure 500-600 MPa, holding time 20-30 seconds; Step 4 The green body is placed in a pressure furnace for sintering to obtain a product; the parameters of the sintering process are: sintering pressure 1.5-2.5MPa, temperature 500~600℃, heat preservation and pressure holding for 1~2 hours, sintering pressure 2.5~3.5MPa, temperature 600~700℃, heat preservation and pressure holding for 1~3 hours, sintering pressure 3.5~5MPa, temperature 700~940℃, heat preservation and pressure holding for 2~3 hours. 2. A ceramic copper-based powder metallurgy friction material according to claim 1, characterized in that: the raw materials used include the following components by mass percentage; Electrolytic copper powder 55~58%; Electrolytic nickel powder 2~5%; Reduced iron powder 11~16%; Tungsten powder 2~4%; Graphite powder 10~14%; Boron carbide powder 2~4%; Zirconia-titanium nitride ceramic powder 7.5~8.5%, wherein the mass ratio of zirconium oxide to titanium nitride is 3:5~5:3. 3. The ceramic-containing copper-based powder metallurgy friction material according to claim 1, characterized in that: The particle size of boron carbide particles is 2~5 microns, the particle size of zirconium oxide ceramic particles is 3~5 microns, and the particle size of titanium nitride ceramic particles is 10~15 microns. 4. The ceramic-containing copper-based powder metallurgy friction material according to claim 1, characterized in that: The particle size of boron carbide particles is 5~8 microns, the particle size of zirconium oxide ceramic particles is 4~8 microns, and the particle size of titanium nitride ceramic particles is 12~15 microns. 5. The ceramic-containing copper-based powder metallurgy friction material according to claim 2, characterized in that: The raw materials used are composed of the following components by mass percentage: 56-58% electrolytic copper powder, 11-15% reduced iron powder, 3-5% electrolytic nickel, 2-5% tungsten powder, 9-14% graphite powder, 2-4% boron carbide powder; 8% zirconium oxide-titanium nitride powder, wherein the mass ratio of zirconium oxide to titanium nitride is 3:5-5:3. 6. The ceramic-containing copper-based powder metallurgy friction material according to claim 5, characterized in that: The raw materials used are composed of the following components by mass percentage: 56% electrolytic copper powder, 15% reduced iron powder, 3% electrolytic nickel, 2% tungsten powder, 14% graphite powder, 2% boron carbide powder; 8% zirconium oxide-titanium nitride powder, wherein the mass ratio of zirconium oxide to titanium nitride is 3:5; Or, the raw materials used are composed of the following components by mass percentage: 58% electrolytic copper powder, 11% reduced iron powder, 5% electrolytic nickel, 4% tungsten powder, 10% graphite powder, 4% boron carbide powder; 8% zirconium oxide-titanium nitride powder, wherein the mass ratio of zirconium oxide to titanium nitride is 5:3. 7. The ceramic-containing copper-based powder metallurgy friction material according to claim 1, characterized in that: The particle size of electrolytic copper powder is 60~80 microns, the particle size of reduced iron powder is 60~80 microns, the particle size of electrolytic nickel powder is 60~80 microns, the particle size of tungsten powder is 60~80 microns, and the particle size of graphite powder is 120~180 microns. 8. An application of the ceramic-containing copper-based powder metallurgy friction material according to any one of claims 1 to 7, characterized in that the ceramic-containing copper-based powder metallurgy friction material is used as a friction material.