WO2004081405A1

WO2004081405A1 - Friction material and process of manufacturing thereof

Info

Publication number: WO2004081405A1
Application number: PCT/SI2004/000015
Authority: WO
Inventors: Srecko Secnik; Zmago Stadler
Original assignee: MS PRODUCTION MIKLAVZ ZORNIK SP
Current assignee: MS PRODUCTION MIKLAVZ ZORNIK SP
Priority date: 2003-03-10
Filing date: 2004-03-05
Publication date: 2004-09-23
Anticipated expiration: 2005-09-10
Also published as: SI21465A

Abstract

The invention relates to a sintered friction material and process of manufacturing thereof, and moreover also to friction elements like brake linings and/or brake shoes for motor vehicles, incluiding the process of manufacturing such products. Such friction elements excel by low rate of wear and also by high and thermal stable friction coefficient. These materials are suitable for all kinds of brake linings used in combination with brake discs of steel or grey casting, and especially with new generation of discs, which is based on C/C-SiC and CiC composites.

Description

FRICTION MATERIAL ANB PROCESS OF MANUFACTURING THEREOF

The invention belongs to the field of chemistry, and more particularly to that, dealing with materials for particular purposes, i.e. wear-resistant friction materials. On the other hand, the invention can also be ranged, within the branch of machine building, into the field of brakes and clutches, and more particularly of brake pads. Furthermore, the invention can also be ranged into the field of processing of powder substances, i.e. of making of objects and semi-products by means of sintering. .

The present invention deals, in the first place, with sintered friction materials for manufacture of brake elements such as brake pads for passenger cars, motorcycles, industrial machines and other devices. Due to constantly increasing demands concerning friction characteristics of brake pads in modern brake systems and to their exposition to constantly increasing temperatures at braking, to constantly increasing demands concerning low wear and also to new available materials for the manufacture of brake disks, sintered brake materials are again introduced in the production of brake linings, and especially of brake pads. Yet, the newest available materials for brake disks, such as composite materials based on aluminium with addition of ceramic powders (so called Al- MMC materials), composite materials based on C/C composite with ceramic coating based on SiC and composite materials based on C/SiC, owing to their specifically and unlikeness to classical materials for the manufacture of disks, such as grey cast and steel cast require the development of new friction materials for production of brake pads. Hitherto, namely, there was available no material suitable for usage in brake elements, e. g. brake pads, and particularly brake lining of disk brakes, which would excel by low wear and high friction coefficient at high temperatures (over 650° C) and at the loadings at high sliding speed, which all represent the parameters of regular use of disk brakes of e.g. a modern motorcycle or also any other motor vehicle. The aim of the present invention is therefore creation of a sintered friction material, which would have a high friction coefficient at least within the domain of regular use, which would be independent with respect to temperature, speed and surface pressure at braking.

It is generally known that sintered friction materials, too, are used for production of friction linings, i.e. brake pads for passenger cars, industrial machines and of friction elements for clutches, and also for motorcycles. Sintered friction materials are based on a metal matrix composed of sintered powders of copper and/or brass; it can also- consist of powdered iron and copper where, however, iron powder prevails as the basis. Beside the metal component sintered friction materials can also contain additives of friction modification, such as abrasive substances, metal sulphides or coke powder, as well as lubricants, such as graphite.

Sintered friction materials generally consist, of:

1. Metal powders (e. g. copper, brass, bronze, iron),

2. Friction modifiers (e.g. alumina, silicon carbide, silicon nitride, boron carbide, boron nitride, chrome oxide, silica, metal sulphides), and

3. Lubricants (e. g. graphite, molybdenum sulphide, calcium fluoride, kryolite).

Considering expected properties of each particular friction material merely all sintered friction materials consist of components ranged in the above quoted groups.

Basic proportions of the components in sintered friction materials are the following (by weight %):

70 to 80 % of metal components,

10 to 20 % of friction modifiers, and

5 to 15 % of lubricants.

According to US Patent No. 3,731,776 adding of metal borides is foreseen, which should results in smaller wear of sintered friction materials based on iron, graphite, molybdenum sulphide, silicon nitride and ferro ungsten. Measured values of the friction coefficient are, in average, 0.30 to 0.35, which are essentially lower than those required for ^"modern friction materials. Sintered friction materials are also described in the US Patents 3,703,224 and 3,449,774, where it is the presentation of synergistic influence of graphite and silicon nitrides on the characteristics of friction materials on the basis of iron (85 %). The acquired friction coefficients are only 0.26 to 0.19, and thus again smaller than those required by modern friction materials.

Furthermore, the US Patent 3,191,278 deals with friction materials based on copper with the addition of titanium, iron, SiO , molybdenum sulphide, graphite and lead. Their friction characteristics are not quoted. It only mentions the impact of the additives (Ti) on sintering as well as on the final mechanical characteristics of sintered linings.

From the publication »Friction Materials (Recent Advances, Louis B, Newman, Noyes Data Corporation, 1987) it is known several compositions of sintered friction materials based on iron and on the combination of copper and iron. The compositions contain additives of molybdenum sulphide and graphite and SiO₂, silicon carbide and boron nitride are suggested as abrasive additives. This material can be used for the manufacture of brake pads and clutch lining, its friction characteristics, however, are not quoted.

The use of carbon fibres in combination with a ceramic or glass matrix with a smaller addition of metallic fibres is mentioned in the US Patent 4,019,912. The aim of this solution is to get heat resistant brake linings, enabling smooth and noiseless braking at the smallest possible wear of the surfaces cooperating with the brake linings, e.g. brake discs. This composition contains the essentially longer carbon fibres (10 mm), and also their share in the composition is very high (30 to 40 %). In this case the carbon fibres, e.g. of pyrolised carbohydrates, are relatively long, and their impact on the friction characteristic is different from that being the base of the present invention.

The subject of the here provided present invention are sintered friction materials having a high friction coefficient regardless of temperature, speed and surface pressure at braking, which enables their use for the manufacture of friction elements, such as e. g. brake pads, and primarily of disc brake linings excelling by their low wear and high friction coefficient at high temperatures (over 650°C) and loadings at high sliding speed. Sintered friction materials dealt with in the present invention contain a new combination of materials representing a basic metallic matrix based on copper, iron with the addition of powdered steel, alloyed by the carbides of tungsten, vanadium and/or chrome, with the addition of abrasive substances resistant in a neutral/reductive atmosphere as well as of mechanical and temperature resistant carbon fibres (0.2 to 1.0 mm long) in the here below quoted proportions. Substances for sintering and friction modifiers shall be added to the basic metallic matrix, and all this shall be bonded into a solid friction composite by way of sintering in a protective atmosphere.

The subject of the present invention is also friction material composed of (by weight percents of the total quantity of material):

5 to 15 % of friction modifiers, e.g. graphite, molybdenum sulphide, calcium fluoride; 1 to 10 % of friction additives, e.g. abrasive substances such as silicon carbide, alumina, silicon nitride; 30 to 45 % of copper powder and copper chips; 15 to 25 % of iron powder containing 0.02 to 0.05 % of carbon or copper alloyed steel powder; 10 to 20 % of steel powder, alloyed with carbides of W, V, Co and Cr, 1 to 5 % of bronze powder CuSn 10; and

1 to 10 % of carbon fibres, especially of 0.2 to 1.0 mm length.

Preferential sintered friction material consists of (by weight %):

5 to 15 % of friction modifiers, e.g. graphite, molybdenum sulphide, calcium fluoride;

1 to 15 % of friction additives, e.g. abrasive substances, such as silicon carbide, alumina, silicon nitride, aluminium nitride; 30 to 45 % of copper powder and copper chips; 15 to 25 % of iron powder containing 0.02 to 0.05 % of carbon or copper alloyed steel powder; 10 to 20 % of steel powder, alloyed with carbides of W, V, Co and Cr;

1 to 5 % of bronze powder CuSn 10; and

1 to 10 % of carbon fibres, especially of 0.2 to 1.0 mm length. A further possible composition of the friction material is (again by weight percents of the total quantity of material):

10 to 15 % of graphite having the size of particles 0.15 to 0.60 mm;

1 to 5 % of calcium fluoride;

4 to 8 % of silicon carbide having average particles size 25 μm;

40 to 45 % of copper powder having the size of particles smaller than 0.075 mm;

5 to 8 % of copper chips having the size of particles: 60 μm thick and 3 mm long;

18 to 22% of iron powder containing 0.02 to 0.03% of carbon having the size of particles less than 0.15 mm, or of steel (A) powder, preferably iron powder, containing 0.02 to 0.03% of carbon, and of 5% of copper, whose particle size is less than 0.15 mm;

12 to 17% of (B) steel powder containing 1.2% of carbon, 4% of chrome, 5% of molybdenum, 3% of vanadium, 6% of tungsten, whose particle size is less than 0.15 mm;

2 to 4% of bronze powder CuSnl 0 with 90 % of particles not exceeding

0.25 mm; and 2 to 5% carbon fibres being 0.2 to 1.0 mm long.

All these components are known and commercially available.

The mostly preferred sintered friction material consists of (again by weight percents of the total quantity of the material):

10 to 15 % of graphite, size of particles 0.15 to 0.60 mm;

1 to 5 % of calcium fluoride;

4 to 8 % of silicon carbide having average particles size 25 μm;

1 to 5 % of aluminium nitride having average particle size of 45 μm;

40 to 45 % of copper powder having the size of particles smaller than 0.075 mm;

1 to 3 % of copper chips having the size of particles at least approximately 60 μm thick and 3 mm long; 18 to 22 % of iron powder containing 0.02 to 0.03% of carbon having the size of particles less than 0.15 mm, or of steel (A) powder, preferably iron powder, containing 0.02 to 0.03% of carbon, and of 5% of copper, whose particle size is less than 0.15 mm; 10 to 15 % of steel powder (B) containing 1.2% of carbon, 4% of chrome, 5% of molybdenum, 3% of vanadium, 6% of tungsten; whose particle size is less than 0.15 mm;

2 to 4 % of bronze powder CuSnlO with 90% of particles not exceeding 0.25 mm; and

2 to 5 % of carbon fibres being 0.2 to 1.0 mm long.

All these components are known and commercially available.

A further subject of the proposed invention is the process of preparing a sintered friction material. Such process consists of mixing the above quoted components according to the invention in a mixer with the purpose of mixing of powdered components in dry condition. The time of mixing depends on the evenness of distribution of light components in the mixture. Mixing takes place until a desired evenness of the distribution of graphite particles is achieved, which is visually estimated by means of a stereo-microscope.

A still further subject of the invention are fiiction elements prepared of the friction mixture according to the present invention, and their use at high friction loadings on brake disks, made of grey cast iron, cast steel and on disks made of composite materials on the basis of C/C-SiC and C/SiC.

A friction mixture prepared according to the hereinabove described procedure and in the hereinabove described proportions of particular components is ready for manufacturing appropriate friction elements, especially brake linings, and more particularly brake pads, which are intended for cooperation with the disc in a disc brake. For this purpose, the process of shaping and sintering of the mixture into the brake lining together with the backing plate is applied. The process of manufacturing of the break pad consists of several consecutive phases, where:

- During the first phase a 10 to 15 μm thick layer of copper is applied, by way of galvanization, to the backing plate made of a steel plate;

- After that, the step of pressing and applying of the mixture to the backing plate in special tools at a specific pressure of 350 to 450 Mpa is executed;

- Upon that, the brake pads with the applied friction lining are stacked and pressed in special frames of heat resistant steel and/or inconel or graphite and sintered approximately one hour in the protective atmosphere consisting of argon or in a gas mixture of argon, nitrogen and hydrogen or endo-gas at temperatures of 900 to 1200°C;

- Finally, sintered pads are finished in consecutive phases of grinding, painting and assembling.

Brake pads manufactured in this way are ready for testing and for installing into the brake system.

Now, several embodiments of the invention and particular examples on the basis of the invention will be described without any limitation with respect to the scope of patent protection.

Example 1

In a laboratory mixer, the so-called V-type mixer, a mixture was prepared, consisting of 45 g of graphite - particle size 0.15 to 0.6 mm, 12 g of silicon carbide - average particle size 25 μm, 129 g of powdered copper - particle size below 0.075 mm, 60 g of iron powder containing 0.02 to 0.03 % and which particle size is below 0.15 mm, 45 g of steel powder (B) containing 1.2 % of carbon, 4% of chrome, 5% of molybdenum, 3% of vanadium and 6 % of tungsten - particle size below 0.15 mm, 9 g of bronze powder CuSnlO - the size of 90 % of particles below 0.25 mm, and 6 g of carbon fibres, 0.2 to 1.0 mm long. Brake pads, intended for cooperation with the discs of the disc brakes of the rear wheel of the motorcycle, whose dimension was 40 x 40 mm and fiiction area of 10.2 cm², have been made of this blend according to the hereinabove described procedure.

Friction characteristics of sintered brake pads manufactured of the friction mixture according to the present invention are tested on the automatic friction testing machine type Krauss RWS 75B according to our own test programs. The results of testing the embodiment of the invention obtained in accordance with this example are given in Table 1 and Table 2. Example 2

Proceeding was the same as described in Example 1, with the exception, that 30 g of graphite - particle size 0.15 to 0.6 mm, 15 g of calcium fluoride and 60 g of steel powder (A) containing 0.02 to 0.03 % of carbon were applied, and, instead of iron powder, 5% of copper - particle size below 0.15 mm were applied.

The results of testing with respect to friction characteristics of the brake pads manufactured according to the invention are also for this embodiment obtained- according the Example 2, in the Table 1 and Table 2.

Example 3

Proceeding was the same as in Example 1 with the exception that 18 g of silicon carbide - average particle size 25 μm, 99 g of copper powder - particle size below 0.075 mm and 30 g of copper fibres of the size 60 μm x 3 mm, 39 g of steel powder (B) containing 1.2 % of carbon, 4 % of chrome, 5 % of molybdenum, 3% of vanadium and 6 % of tungsten - particle size below 0.15 mm were applied.

Appropriate results of testing with respect to friction characteristics of brake pads manufactured according to the Example 3 according to the invention are given in Table 1.

Example 4

Proceeding was the same as in Example 1, with the exception, that 32 g of graphite - particle size 0.15 to 0.6 mm, 20 g of silicon carbide - average particle size 25 μm, 9 g of aluminium nitride - average particle size 45 μm, 134 g of powdered copper - particle size below 0.075 mm, 36 g of steel powder (B) containing 1.2% of carbon, 4% of chrome, 5% of molybdenum, 3% of vanadium and 6% of tungsten - particle size below 0.15 mm were applied.

The results of testing with respect to friction characteristics of the brake pads manufactured according to this Example 4 of the invention are given in Table 1. In Table 1 the friction characteristics of sintered brake linings manufactured on the basis of the friction mixture according to the proposed invention (brake disc: C/C- SiC composite) are shown. Testing was performed at the constant speed of rotation 660 min^"1. The friction coefficient is marked with μ, and SICOM™ is a registered trademark owned by MS PRODUCTION and related to material on the basis of silicon infiltrated carbon/carbon composite.

Table 1

CHARACTERISTICS Example 1 Example 2 Example 3 Example 4 μ 200 0.66 0.60 0.63 0.72 μ 300 0.66 0.60 0.62 0.70 μ 400 0.57 0.58 0.63 0.66 μ (average) 0.62 0.59 0.63 0.69

Work done (MJ) 3.0 2.8 2.9 4.1

Specific Wear:

By weight (g/MJ) 0.21 0.26 0.10 0.05

By volume (mm³ /MJ) 51.7 70.0 30.1 16.6

Testing conditions:

Disc: 0 190 x 5.2 mm. C/C-SiC composite (SICOM™)

Brake pad: 40 x 40 mm

Brake system: Brembo

Effective radius: 81.4 mm

Pad area: 10.2 cm ²

Specific pressure on the pad: 120.4 N/cm²

Hydraulic pressure: 19.8 bar

Testing procedure

30 braking at a constant temperature of 200°C 30 braking at a constant temperature of 300°C 30 braking at a constant temperature of 400°C Total: 90 braking Table 2 shows friction characteristics of sintered brake linings manufactured of the friction mixture according to the proposed invention as well as a commercial specimen (brake disc: cast steel). Again, testing was performed at the constant speed of rotation 660 min^" , the and friction coefficient is also marked with μ.

Table 2

CHARACTERISTICS Example 1 Example 2 Ferrode I/D450 μ 100 0.52 0.49 0.45- μ 200 0.52 0.49 0.52 μ 300 0.54 0.52 0.51 μ (average) 0.53 0.49 0.49

Work done (MJ) 1.9 1.84 1.48

Specific wear:

By weight (g/MJ) 0.23 ^' 0.38 0.21

Bv volume (mm ³ / MJ) 60.6 84.5 61.3

Testing Conditions: Disc: 0 190 x 3.7 mm., cast steel

Brake plate: 40 x 40 mm Brake system: Brembo Effective radius: 81.4 mm Pad area: 10.2 cm²

Specific pressure on the pad: 120.4 N/cm² Hydraulic pressure : 19.8 bar

Testing procedure:

30 braking at a constant temperature of 100°C 30 braking at a constant temperature of 200°C 30 braking at a constant temperature of 300°C Total: 90 braking Friction characteristics of sintered materials of the Examples 1, 2, 3 and 4 (Table 1), as measured on the brake discs manufactured of the composite C/C having a SiC ceramic sliding surface show that all four of them excel by a high and constant friction coefficient μ and by low specific wear. The material of the Example 4 has the highest measured and also the most temperature - stable friction coefficient μ at 400°C. The lowest specific wear has been measured in this material, as well. The material of the Example 1 has a high friction coefficient μ at lower temperatures (100 to 300°C), which, however, is less constant. Low specific wear of the friction material, too, was observed in the Example 1. Sintered material of the Example 2 contains friction modifiers showing effects at higher temperatures, so good characteristic can be expected at very high temperatures of braking (over 600°C).

A comparison of friction the characteristics on classic brake discs manufactured of steel cast (Table 2) and of friction materials of the Examples 1 and 2 and of the commercial specimen Ferrodo I/C459 shows that friction characteristics (fiiction coefficient μ and specific wear) are comparable to those of the commercial specimen. Average fiiction coefficients μ of the materials of the examples 1 and 2 are even higher than those of the material Ferrodo.

The measured friction characteristics show that sintered fiiction materials according to the proposed invention can be successfully used also in classical brake discs, and they are especially suitable for braking on brake discs of the new generation manufactured of composite materials C/C-SiC and C/SiC.

Claims

PATENT CLAIMS

1. Friction material consisting of at least one metal or metal alloy in powder form and sintered friction material containing at least one friction modifier applicable in brake linings, especially in brake pads, characterized in that it consists of a combination of materials making the basic metal matrix based on copper, iron - with added steel powder, alloyed by the carbides of tungsten, vanadium in/or chrome abrasive substances resistant in neutral/reductive atmosphere, and of mechanically and thermal resistant carbon fibres (0.2 to 1.0 mm long) in actually wanted proportion, where also sintering additives and fiiction modifiers are added to the basic matrix, and all this bonded, by way of sintering in the protection atmosphere into a solid composite.

2. Friction material according to Claim 1 consisting of

5 to 15% of friction modifiers, e.g. graphite, molybdenum sulphide, calcium fluoride;

1 to 10% of friction additives, e.g. abrasive substances such as siliconcarbide, alumina, silicon nitride; 30 to 45% of copper powder and copper chips; 15 to 25% of iron powder containing 0.02 to 0.05% of carbon or copper alloyed steel powder; 10 to 20% of steel powder, alloyed with carbides of W, V, Co and Cr; 1 to 5% of bronze powder CuSn 10;

1 to 10% of carbon fibres, especially of 0.2 to 1.0 mm length; all this by weight percentage of the total quantity of material.

3. Friction material according to Claim 1, consisting of

10 to 15%o of graphite - the size of particles 0.15 to 0.60 mm; 1 to 5% of calcium fluoride;

4 to 8% of silicon carbide with average particles size 25 μm;

40 to 45% of copper powder having particles smaller than 0.075 mm;

5 to 8% of copper chips, where the particles are at least approximately 60 μm thick and 3 mm long; 18 to 22% of iron powder containing 0.02 to 0.03% of carbon and with the size of particles less than 0.15 mm, or of steel (A) powder, preferably iron powder, containing 0.02 to 0.03% of carbon, as well as of 5% of copper, whose particle size is less than 0.15 mm;

12 to 17% of steel (B) powder containing 1.2% of carbon, 4% of chrome, 5% of molybdenum, 3% of vanadium, 6% of tungsten, whose particle size is less than 0.15 mm;

2 to 4% of bronze powder CuSnlO with 90% of particles not exceeding 0.25 mm; and

2 to 5% of carbon fibres, 0.2 to 1.0 mm long; all this by weight percentage of the total quantity of material.

4. Friction material according to Claim 1 consisting of

10 to 15% of graphite having size of particles 0.15 to 0.60 mm;

1 to 5% of calcium fluoride;

4 to 8% of silicon carbide having average particles size 25 μm;

1 to 5% of aluminium nitride having average particle size of 45 μm;

40 to 45% of copper powder having particle size smaller than 0.075 mm;

1 to 3% of copper chips having the size of particles at least approximately 60 μm thick and 3 mm long; 18 to 22% of iron powder containing 0.02 to 0.03 % of carbon having the size of particles less than 0.15 mm, or of steel (A) powder, preferably iron powder, containing 0.02 to 0.03 % of carbon, and of 5 % of copper, whose particle size is less than 0.15 mm, 10 to 15% of steel powder (B), containing 1.2 % of carbon, 4 % of chrome, 5 % of molybdenum, 3 % of vanadium, 6 % of tungsten, whose particle size is less than 0.15 mm;

2 to 4% of bronze powder CuSnlO with 90 % of particles not exceeding 0.25 mm; and 2 to 5% of carbon fibres, 0.2 to 1.0 mm long; all this by weight percentage of the total quantity of material.

5. Process of manufacturing a sintered friction material, characterized in that in the first step the components for preparation of friction material are mixed by a mixer in order to get their even distribution, namely

- a combination of materials making the basic matrix based on copper, iron with addition of steel powder alloyed with carbides of tungsten, vanadium and/or chrome;

- abrasive substances subsistent in a neutral / reductive atmosphere; and

- mechanically and thermal resistance carbon fibres, 0,2 to 1,0 mm long, every time in a wanted proportion, where also sintering aids and friction modifiers are added to the basic metal matrix; whereupon the hereinabove quoted components for preparation of the friction material are applied to the previously prepared backing plate coated with copper, at which pressing and shaping of the mixture to the hereinabove mentioned backing plate is performed in special, for this purpose prepared tools at a specific pressure of 350 to 450 MPa; after that, thus obtained green lining, pressed to the hereinabove quoted backing plate is pressed in tools of heat resistance steel and/or inconel or graphite and sintered, during approximately one hour, in a protective atmosphere, consisting of argon or of a mixture of argon, nitrogen and hydrogen or endo-gas at a temperature of 900 to 1200°C; and finally, the obtained fiiction material is, after selection, submitted to final shaping by subsequent operations of grinding and, if necessary, painting.

6. Process according to Claim 5, characterized in that in the first step the components for preparation of the friction material are mixed in a mixer to achieve their even distribution, namely 5 to 15%) of friction modifiers, e. g. graphite, molybdenum sulphide, calcium fluoride, 1 to 10%) of friction additives, e. g. abrasive substances such as silicon carbide, alumina, silicon nitride, 30 to 45%) of copper powder and copper chips, 15 to 25%) of iron powder containing 0.02 to 0.05 % of carbon or copper alloyed steel powder, 10 to 20%) of steel powder, alloyed with carbides of W, V, Co and Cr, 1 to 5% of bronze powder CuSn 10,

1 to 10% of carbon fibres, especially of 0.2 to 1.0 mm length, all this by weight percentage of the total quantity of material; whereupon the hereinabove quoted components for preparation of the friction material are applied to the formerly prepared backing plate coated with the copper, at which pressing and shaping of the mixture to the hereinabove mentioned backing plate is effectuated in special, for this purpose prepared tools at a specific pressure of 350 to 450 Mpa; after that, thus obtained green lining, pressed to the hereinabove quoted backing plate is pressed in tools of heat resistance steel and/or inconel or graphite and sintered, during one hour, in a protective atmosphere of argon or of a mixture of argon, nitrogen and hydrogen or endo-gas at a temperature of 900 to 1200°C; and finally, the obtained fiiction material is, after selection, submitted to final shaping by subsequent operations of grinding and, if necessary, painting.

7. Process according to Claim 5, characterized in that in the first step the components for preparation of the friction material are mixed in a mixer to achieve their even distribution, namely 10 to 15% of graphite having the size of particles 0.15 to 0.60 mm,

1 to 5% of calcium fluoride;

4 to 8% of silicon carbide having average particles size 25 μm;

40 to 45% of copper powder having the size of particles smaller than 0.075 mm;

5 to 8% of copper chips having the size of particles at least approximately 60 μm thick and 3 mm long; 18 to 22% of iron powder containing 0.02 to 0.03 % of carbon having the size of particles less than 0.15 mm, or of steel (A) powder, preferably iron powder, containing 0.02 to 0.03 % of carbon, and of 5 % of copper, whose particle size is less than 0.15 mm; 12 to 17% of steel (B) powder, containing 1,2 % of carbon, 4 % of chrome, 5 % of molybdenum, 3 % of vanadium, 6 % of. tungsten, whose particle size is less than 0.15 mm;

2 to 4% of bronze powder CuSnlO with 90 % of particles not exceeding

0.25 mm; and 2 to 5%. of carbon fibres, 0.2 to 1.0 mm long; all this by weight percentage of the total quantity of material, whereupon the hereinabove quoted components for preparation of the friction material are applied to the formerly prepared backing plate, coated with the copper, at which pressing and shaping of the mixture to the hereinabove mentioned backing plate is performed in special, for this purpose prepared tools at a specific pressure of 350 to 450 MPa; after that, thus obtained green lining, pressed to the hereinabove quoted backing plate is pressed in tools of heat resistance steel and/or inconel or graphite and sintered, during one hour, in a protective atmosphere of argon or of a mixture of argon, nitrogen and hydrogen or endo-gas at a temperature of 900 to 1200°C; and finally, the obtained friction material is, after selection, submitted to final shaping by subsequent operations of grinding and, if necessary, painting.

8. Process according to Claim 5, characterized in that in the first step the components for preparation of the friction material are mixed in a mixer to achieve their even distribution, namely 10 to 15% of graphite having the size of particles 0.15 to 0.60 mm;

1 to 5% of calcium fluoride;

4 to 8% of silicon carbide having average particle size 25 μm;

1 to 5 % of aluminium nitride having average particle size of 45 μm; 40 to 45% of copper powder having the size of particles smaller than 0.075 mm;

1 to 3% of copper chips having the size of particles at least approximately 60 μm thick and 3 mm long;

18 to 22% of iron powder containing 0.02 to 0.03 % of carbon having the size of particles less than 0.15 mm, or of a steel (A) powder, preferably iron powder, containing 0.02 to 0.03 % of carbon, and of 5 % of copper, whose particle size is less than 0,15 mm - preferentially iron powder;

10 to 15% of steel powder (B) containing 1.2 % of carbon, 4 %_> of chrome, 5 % of molybdenum, 3 % of vanadium, 6 % of tungsten, whose particle size is less than 0.15 mm,

2 to 4% of bronze powder CuSnlO with 90 % of particles not exceeding 0.25 mm, and 2 to 5% of carbon fibres, 0.2 to 1.0 mm long, all this by weight percentage of the total quantity of material; whereupon the hereinabove quoted components for preparation of the friction material are applied to the formerly prepared backing plate coated with the copper, at which pressing and shaping of the mixture to the hereinabove mentioned backing plate is effectuated in special, for this purpose prepared tools at a specific pressure of 350 to 450 MPa; after that, thus obtained green lining, pressed to the hereinabove quoted backing plate is pressed in tools of heat resistance steel and/or inconel or graphite and sintered, during one hour, in a protective atmosphere of argon or of a mixture of argon, nitrogen and hydrogen or endo-gas at a temperature of 900 to 1200° C; and finally, the obtained friction material is, after selection, submitted to final shaping by subsequent operations of grinding and, if necessary, painting.

9. Friction lining, comprising at least one backing plate and at least one layer of appropriate friction material, characterized in that the said friction material consists of a combination of materials making the base metal matrix based on copper, iron with addition of steel powder, alloyed by carbides of tungsten, vanadium and/or chrome, abrasive substances resistant in a neutral / reductive atmosphere, as well as of mechanically and heat resistant carbon fibres (0.2 to 1.0 long) in actually wanted proportion, where also sintering aids and friction modifiers are added to the base matrix, and all this bonded, by way of sintering, in the protection atmosphere into a solid friction composite.

10. Brake lining according to Claim 9, characterized in that the friction material consists of

5 to 15% of friction modifiers, e.g. graphite, molybdenum sulphide, calcium fluoride; 1 to 10% of friction additives, e.g. abrasive substances such as silicon carbide, alumina, silicon nitride; 30 to 45% of copper powder and copper chips; 15 to 25% of iron powder containing 0.02 to 0.05 % of carbon or copper alloyed steel powder; 10 to 20% of steel powder, alloyed with carbides of W, V, Co and Cr; 1 to 5% of bronze powder CuSn 10;

11. Brake lining according to the Claim 9, characterized in that the friction material consists of

10 to 15 % of graphite having the size of particles 0.15 to 0.60 mm;

1 to 5 % of calcium fluoride;

4 to 8 % of silicon carbide having average particles size 25 μm;

40 to 45 % of copper powder having the size of particles smaller than 0.075 mm;

18 to 22 % of iron powder containing 0.02 to 0.03 % of carbon having the size of particles less than 0,15 mm, or of a steel (A) powder, preferably iron powder, containing 0.02 to 0.03 % of carbon, and of 5 % of copper, whose particle size is less than 0.15 mm;

12 to 17 % of steel (B) powder containing 1.2 % of carbon, 4 % of chrome, 5 % of molybdenum, 3 % of vanadium, 6 % of tungsten, whose particle size is less than 0.15 mm;

2 to 4 % of bronze powder CuSnlO with 90 %> of particles not exceeding 0.25 mm; and 2 to 5 % of carbon fibres, 0,2 to 1,0 mm long; all this by weight percentage of the total quantity of material.

12. Brake lining according to Claim 9, characterized in that the friction material consists of

10 to 15% of graphite having the size of particles 0.15 to 0.60 mm;

1 to 5% of calcium fluoride;

4 to 8% of silicon carbide having the average particles size 25 μm;

1 to 5% of aluminium nitride having the average particle size of 45 μm;

40 to 45% of copper powder having the size of particles smaller than 0.075 mm; 1 to 3% of copper chips having the size of particles at least approximately 60 μm thick and 3 mm long; 18 to 22% of iron powder containing 0.02 to 0.03 % of carbon having the size of particles less than 0.15 mm, or of steel (A) powder, preferably iron powder, containing 0.02 to 0.03 % of carbon, and of 5 % of copper, whose particle size is less than 0.15 mm; 10 to 15% of steel powder (B) containing 1.2 % of carbon, 4 %> of chrome, 5 % of molybdenum, 3 % of vanadium, 6 % of tungsten,- whose particle size is less than 0.15 mm;

13. Brake lining, namely a brake pad, consisting of at least one backing plate, which is, on one hand, adapted for reliable fixing to the available place in the brake complex of the backing plate, and on the other hand for receipt of the available friction lining, which is foreseen for cooperation with a corresponding part of each belonging brake assembly, especially' with a brake disc of a disc brake, characterized in that the friction layer is placed on the previously coated metal matrix on the basis of copper, an especially a 10 - 15 μm thick surface layer of copper, and that the friction layer consists of a combination of materials making the base metal matrix based on copper, iron with addition of steel powder, alloyed by carbides of tungsten, vanadium and/or chrome; abrasive substances resistant in a neutral / reductive atmosphere; as well as of mechanically and heat resistant carbon fibres (0.2 to 1.0 long); every time in a required proportion, where also sintering additives and friction modifiers are added to the base metal matrix, and all this is, by way of sintering in the protective atmosphere, bonded into a solid friction composite.

14. Brake lining according to Claim 13, characterized in that the friction layer consists of

5 to 15%> of friction modifiers, e, g, graphite, molybdenum sulphide, calcium fluoride; 1 to 10%) of friction additives, e. g. abrasive substances such as silicon carbide, alumina, silicon nitride; 30 to 45% of copper powder and copper chips; 15 to 25% of iron powder containing 0.02 to 0.05 % of carbon or copper alloyed steel powder; 10 to 20% of steel powder, alloyed with carbides of W, V, Co and Cr; 1 to 5%) of bronze powder CuSn 10;

15. Brake lining according to Claim 13, characterized in that the friction layer consists of

10 to 15 % of graphite having the size of particles 0.15 to 0.60 mm;

1 to 5 % of calcium fluoride;

4 to 8 % of silicon carbide having average particles size 25 μm;

40 to 45 % of copper powder having the size of particles smaller than 0.075 mm;

5 to 8 % of copper chips having the size of particles at least approximately 60 μm thick and 3 mm long; 18 to 22 % of iron powder containing 0.02 to 0.03% of carbon having the size of particles less than 0,15 mm, or of s steel (A) powder, preferably iron powder, containing 0.02 to 0.03% of carbon, and of 5% of copper, whose particle size is less than 0.15 mm; 12 to 17 % of steel (B) powder containing 1.2% of carbon, 4% of chrome, 5% of molybdenum, 3% of vanadium, 6% of tungsten, whose particle size is less than 0.15 mm;

2 to 5 % of carbon fibres, 0,2 to 1,0 mm long; all this by weight percentage of the total quantity of material.

16. Brake lining according to Claim 13, characterized in that the friction layer consists of

10 to 15 % of graphite having the size of particles 0.15 to 0.60 mm; 1 to 5 % of calcium fluoride;

4 to 8 % of silicon carbide having average particles size 25 μm;

1 to 5 % of aluminium nitride having average particle size of 45 μm;

40 to 45 % of copper powder having the size of particles smaller than 0.075 mm;

1 to 3 % of copper chips having the size of particles: 60 μm thick and 3 mm long;

18 to 22 % of iron powder containing 0.02 to 0.03 % of carbon having the size of particles less than 0.15 mm, or of steel (A) powder, preferably iron powder, containing 0.02 to 0.03 % of carbon, and of 5 %^"of copper, whose particle size is less than 0.15 mm;

10 to 15 % of steel powder (B) containing 1.2 % of carbon, 4 % of chrome, 5 % of molybdenum, 3 % of vanadium, 6 %> of tungsten, whose particle size is less than 0.15 mm;

2 to 4 % of bronze powder CuSnlO with 90 % of particles not exceeding 0.25 mm; and 2 to 5 % of carbon fibres, 0.2 to 1.0 mm long; all this by weight percentage of the total quantity of material.

17. Process of manufacturing a brake lining, especially a brake pad, which consists of at least one backing plate, which is on the one hand adapted for reliable fixation to the available place in the brake assembly, and on the other hand for acceptance of the available friction lining, which is adapted for cooperation with a corresponding part of the brake assembly, especially with a brake disc of a disc brake, preferentially with a disc, which is made of grey cast, cast steel or with a disc made of composite materials based on C/C-SiC and C/SiC, characterized in that in the first step, a 10 to 15 μm thick layer of copper is galvanically applied to the formerly prepared backing plate made of a steel sheet; in the next step appropriate pressing and forming mass to the hereinabove mentioned backing plate is carried out in a particular, for this purpose prepared tool at the specific pressure of 350 to 450 MPa; whereupon after appropriate piling and pressing of the brake . pads with green pressed friction lining in specially prepared frames of heat resistance steel and/or inconel or graphite, and sintering during approximately one hour, in the protective atmosphere of argon, or in a mixture of argon, nitrogen and hydrogen or endo-gas at temperatures 900 to 1200°C is applied; whereupon the sintered pads are finally shaped by additional operations of grinding, painting and final assembling, where the hereinabove mentioned friction mass consists of a combination of materials making the base metal matrix on the basis of copper, iron with the addition of steel powder, alloyed by the carbides of tungsten, vanadium and/or chrome; abrasive substances, resistant in a neutral /reduction atmosphere, as well as of mechanically and heat resistant carbon fibres (0.2 to 1.0 mm long) - every time in required proportions.

18. Process of manufacturing a brake lining according to Claim 17, characterized in that in the first step a 10 to 15 μm thick layer of copper is galvanically applied to the formerly prepared backing plate made of a steel sheet, after that, the step of pressing and forming friction mixture to the hereinabove mentioned backing plate is carried out in a particular, for this purpose prepared tool at the specific pressure of 350 to 450 MPa, whereupon appropriate piling and pressing of the brake pads with green pressed friction lining in specially prepared frames of heat resistance steel and/or inconel or graphite, and sintering, during one hour, in the protective atmosphere of argon, or in a mixture of argon, nitrogen and hydrogen or endo-gas at temperatures 900 to 1200°C, whereupon sintered pads are finally shaped by additional operations of grinding, painting and final assembling, where the friction mixture consists of 5 to 15% of friction modifiers, e, g, graphite, molybdenum sulphide, calcium fluoride;

1 to 10% of friction additives, e. g. abrasive substances such as silicon carbide, alumina, silicon nitride; 30 to 45%> of copper powder and copper chips; 15 to 25% of iron powder containing 0.02 to 0.05 % of carbon or copper alloyed steel

10 to 20%) of steel powder, alloyed with carbides of W, V, Co and Cr, 1 to 5% of bronze powder CuSn 10; 1 to 10% of carbon fibres, especially of 0.2 to 1.0 mm length, all this by weight percentage of the total quantity of material.

19. Process of manufacturing a brake lining according to Claim 17, characterized in that in the first step a 10 to 15 μm thick layer of copper is galvanically applied to the formerly prepared backing plate made of a steel sheet, during the next step appropriate pressing and forming friction mixture to the hereinabove mentioned backing plate is carried out in a particular, for this purpose prepared tool at the specific pressure of 350 to 450 MPa, whereupon appropriate piling and pressing of the brake pads with green pressed friction lining in specially prepared frames of heat resistance steel and/or inconel or graphite, and sintering, during one hour, in the protective atmosphere of argon, or in a mixture of argon, nitrogen and hydrogen or endo-gas at temperatures 900 to 1200°C, whereupon sintered pads are finally shaped by additional operations of grinding, painting and final assembling, where the fiiction mixture consists of 10 to 15% of graphite having the size of particles 0.15 to 0.60 mm;

1 to 5% of calcium fluoride;

4 to 8% of silicon carbide having the average particle size 25 μm;

40 to 45% of copper powder having the size of particles smaller than 0.075 mm;

5 to 8% of copper chips having the size of particles at least approximately 60 μm thick and 3 mm long; 18 to 22% of iron powder containing 0.02 to 0.03 % of carbon having the of particles less than 0,15 mm, or of a steel (A) powder, preferably iron powder, containing 0.02 to 0.03 % of carbon, and of 5 % of copper, whose particle size is less than 0.15 mm; 12 to 17% of a steel (B) powder containing 1,2 % of carbon, 4 % of chrome, 5 % of molybdenum, 3 %> of vanadium, 6 % of tungsten, whose particle size is less than 0.15 mm;

2 to 4% of bronze powder CuSnlO with 90 % of particles not exceeding 0.25 mm; and 2 to 5% of carbon fibres, which are 0.2 to 1.0 mm long; all this by weight percentage of the total quantity of material.

20. Process of manufacturing a brake lining according to Claim 17, characterized in that in the first step a 10 to 15 μm thick layer of copper is galvanically applied to the formerly prepared backing plate made of a steel sheet; during the next step appropriate pressing and forming friction mixture to the hereinabove mentioned backing plate is carried out in a particular, for this purpose prepared tool at the specific pressure of 350 to 450 MPa; whereupon appropriate piling and pressing of the brake pads with green pressed friction lining in specially prepared frames of heat resistance steel and/or inconel or graphite is applied, and also sintering, during approximately one hour, in the protective atmosphere of argon, or in a mixture of argon, nitrogen and hydrogen or endo-gas at temperatures 900 to 1200°C, whereupon sintered pads are finally shaped by additional operations of grinding, painting and final assembling, where the said fiiction mixture consists of 10 to 15 % of graphite having the size of particles 0.15 to 0.60 mm; 1 to 5 % of calcium fluoride;

4 to 8 % of silicon carbide having the average particle size 25 μm;

1 to 5 % of aluminium nitride having the average particle size of 45 μm; 40 to 45 % , of copper powder having the size of particles smaller than 0.075 mm;

1 to 3 % of copper chips having the size of particles at least approximately 60 μm thick and 3 mm long; 18 to 22 % of iron powder containing 0.02 to 0.03 % of carbon having the size of particles less than 0.15 mm, or of a steel (A) powder, preferably iron powder, containing 0.02 to 0.03 % of carbon, and of 5 % of copper, whose particle size is less than 0.15 mm; 10 to 15 % of a steel (B) powder containing 1.2 % of carbon; 4 %> of chrome, 5 % of molybdenum, 3 % of vanadium, 6 % of tungsten; whose particle size is less than 0.15 mm;

2 to 4 % of bronze powder CuSnlO with 90 % of particles not exceeding 0.25 mm; and 2 to 5 % of carbon fibres, which are 0.2 to 1.0 mm long; all this by weight percentage of the total quantity of material.