JPH09194821A - Sintered friction material containing manganese - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sintered friction material showing excellent friction characteristics from low to high load, and capable of enhancing vibration damping and chatter reduction. SOLUTION: This friction material comprises a metal and/or an alloy matrix and the rest is mainly an inorg. filler except the matrix. The filler contains 10-60vol.% layered material having a ratio of the thickness (t) in the direction of the layer to the length (h) in the direction of the length of not less than 10(h/t>=10) and not more than 30vol.% (based on Mn) of at least one Mn element contg. compound from among Mn, a Mn alloy, and a Mn compd., of the total friction material.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention comprises a matrix made of a metal and / or an alloy and a filler made of various inorganic substances including a layered substance, and contains a Mn element-containing substance as a matrix and / or a filler. Mn
Regarding the contained sintered friction material, specifically, as means for arbitrarily controlling the rotation or movement of various machines represented by machine tools, construction machines, automobiles, motorcycles (including electric bicycles), railways and aircraft. , A Mn-containing sintered friction material used as a so-called clutch or brake material.

[0002]

BACKGROUND OF THE INVENTION Friction materials conventionally used as clutches or brake materials include organic friction materials in which a filler is bonded with a matrix of an organic substance such as resin or rubber, and fillers made of metal, alloy or It is roughly classified into a sintered friction material bonded by an intermetallic compound matrix.

Among these conventional friction materials, the sintered friction material has a filler of Cu-Sn, Cu-Zn, or Cu.
-Sn-Zn bonded by a matrix is the mainstream, and compared to organic friction materials, the friction coefficient at high temperature is reduced (heat fade phenomenon) and the friction coefficient is reduced due to the inclusion of water (water fade). It has the advantages that the tendency of (phenomenon) is small and wear is small.

However, although this conventional sintered friction material has excellent friction characteristics under high load conditions, it has a large vibration, is liable to cause squeaking during braking, and is resistant to fading.
In addition, the composition of the matrix is examined and proposed as a typical one proposed since it is not satisfactory in the wear resistance, wear resistance and friction coefficient and tends to increase the amount of wear of the mating material. JP-A-3-181628 and JP-A-4-181628 as other organic friction materials.
There is a publication of -114084.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention JP-A-3-181628 and JP-A-4-181628 as prior art of friction materials
Japanese Patent No. 114084 discloses an organic friction material to which an inorganic substance having a plate-like crystal structure of mica, talc, vermiculite, aluminum hydroxide, iron hydroxide, and montmorillonite is added.
The publication discloses a sintered friction material containing mica.

Among these prior art friction materials,
When the former organic friction material is used under a high load condition, the matrix resin is thermally decomposed, resulting in
However, the latter sintered friction material does not adjust the mica of the plate crystal structure and is finely divided because it is crushed during mixing. There is a problem that vibration and squeal are large.

The present invention solves the above-mentioned problems, and specifically, the thickness (t) in the layer direction in the sintered friction material.
A layered material having a ratio of the length to the length (h) in the longitudinal direction of 10 or more,
The present invention aims to provide a sintered friction material capable of exhibiting excellent friction characteristics from a low load condition to a high negative condition, and enhancing vibration damping properties and reduction of squeal by containing a substance containing Mn element and Mn element. To do.

[0008]

DISCLOSURE OF THE INVENTION The inventors of the present invention intend to improve the sintered friction material by further increasing the friction coefficient,
For many years, the requirements are that the coefficient of friction should not drop or fluctuate even under high load conditions such as when the material temperature reaches approximately 500 ° C, that wear resistance should be improved and that squeaking during friction operation should be reduced. For a long time,
Of these, paying particular attention to frictional vibration, and by containing a predetermined amount of a layered substance having a surface area of a predetermined surface or more and having a large surface area in the sintered friction material, it is possible to enhance the vibration damping property and the reduction of squeal. The inclusion of element-containing substances can further enhance the reduction of squeal, and the synergistic effect of both substances provides stable friction characteristics as friction materials (especially friction characteristics at high temperatures).
The present invention has been completed based on the finding that the above can be retained.

That is, the sintered friction material of the present invention is a friction material comprising a matrix made of a metal and / or an alloy, and the rest being a filler mainly made of an inorganic substance excluding the matrix, wherein the filler is , Thickness (t) in the layer direction and length (h) in the length direction with respect to the entire friction material
A layered substance having a ratio of 10 or more (h / t ≧ 10) with respect to the entire friction material is contained in an amount of 10 to 60% by volume,
And at least one Mn among Mn, Mn alloy, and Mn compound
The element-containing substance is 30 in terms of Mn with respect to the entire friction material.
It is characterized by containing less than or equal to volume%.

[0010]

The matrix in the friction material of the present invention is, for example, Cu, Ni, Fe, C.
o, Sn, Ti, Mg, Mn, Si, W, Mo, Zn,
A matrix composed of Al, Ag and their mutual alloys, which is composed mainly of Cu, is preferable because of its high effect. Particularly, at least one of Cu, Ni and Fe has a volume of 50 to the matrix. % Or more is preferably contained.

The filler as another constituent of the matrix includes oxides, carbides, nitrides, fluorides, sulfides, silicides of metals (including semimetals of Si and B) and mutual solid solutions thereof, It contains at least one inorganic substance selected from the group consisting of metal carbonates, mineral substances, intermetallic compounds, graphite, carbon, short fibers and long fibers. Specifically, for example, barium sulfate, talc, diatomaceous earth, serpentine stone, co - _{box, MgO, Fe 2 O 3,} TiO 2, B 2 O 3 in the friction modifier _{typified, SiO 2, AlN, Al 2} O 3, Si 3 N 4,
SiC, B ₄ C, mullite, 4a, 5a, 6 of the periodic table
Ceramics typified by carbides, nitrides, oxides, and silicides of group a metals and their mutual solid solutions, NiSi
₂ , TiSi ₂ , TiAl ₃ , NiAl ₃ , CuAl ₂ , N
i ₃ Al, Co ₃ Al, Zr ₃ Al, Fe ₃ Al, FeAl
Intermetallic compounds represented by ₃ , graphite, MoS ₂ , WS ₂ ,
_{BaF 2, CaF 2, hBN,} PbO, solid lubricant typified fluorinated graphite, the pulp fibers, Le - Yung fibers, Ca -
Various fibers exemplified by Bonn fiber, silica-alumina fiber, potassium titanate fiber, silicon carbide fiber, boron fiber, or at least one selected from reinforcing materials represented by various whiskers. Is.

Further, the layered substance contained as a filler is a plate-shaped substance having individual plate surfaces and thicknesses, and when present in the friction material, the layered substance has a cross section of the friction material. The observed shape is rod-shaped or needle-shaped, and the ratio of the thickness (t) in the layer direction and the length (h) in the length direction of the shape is 10 or more (h / t ≧ 10). is there. In other words, the aspect ratio corresponds to the aspect ratio used for displaying the relationship between the length and the diameter of the whisker, and the aspect ratio is 10 or more. When the aspect ratio of this layered material is less than 10, the vibration damping ability is remarkably reduced and the squeal becomes large during braking, although it depends on the content thereof. In particular, the thickness of the layered material in the layer direction is 30 μm to
It is preferably 2 mm.

When the content of the layered substance is less than 10% by volume with respect to the entire friction material, the effect of internal friction is small, and the vibration damping ability is remarkably deteriorated. On the contrary, when the content exceeds 60% by volume. In addition, the sinterability and strength are significantly reduced. This layered material is preferably one or more of graphite, metal sulfide, boron nitride, mica, vermiculite, talc and kaolin, and particularly graphite and other metal sulfides, boron nitride, mica, Vermiculite,
From the friction material characteristics, it is preferable to use a composite layered material composed of at least one of talc and kaolin. When the composite layered material is used, it is preferable that the layered material graphite is contained in an amount of 50% by volume or more based on the entire layered material from the viewpoint of reduction in vibration damping ability and suppression of squeal.

The graphite contained in this friction material is preferably high-purity graphite having an ash content of 1% by weight or less, and particularly graphite used as a layered material has an ash content of 1% by weight or less, and more preferably. The ash content is to be 0.6% by weight or less of high-purity graphite.

In addition to the above layered material, another Mn element-containing substance which is an active ingredient is at least one of Mn, a Mn-containing alloy and a Mn-containing compound (ceramics).
It may be contained as a seed, and specifically, for example, metal Mn, Cu-Mn alloy, Fe-Mn alloy, Ni-Mn.
Alloy, Co-Mn alloy, manganese oxide (MnO, MnO
₂ ) and Mn-containing ferrites. This Mn element-containing substance should be contained in an amount of 30 vol% or less in terms of Mn with respect to the entire friction material, preferably 2 to 20.
That is, the content is% by volume. When the Mn element-containing substance is more than 30% by volume with respect to the entire friction material, the strength is significantly reduced.

The ratio of the matrix to the filler in the friction material is not particularly limited, but it is preferable that the matrix comprises 20 to 90% by weight of the whole friction material and the balance filler.

[0017]

In the sintered friction material of the present invention, the Mn element-containing substance acts to reduce cohesive wear with the mating material, friction vibration and squeal, and the dispersed layered substance is mainly vibration-damped. It has a function of enhancing the function and a function of reducing the squeaking, and the squeaking is further suppressed by the synergistic effect of both substances. Further, in the sintered friction material of the present invention, fillers other than the layered substance added as necessary contribute to the adjustment of the friction coefficient and the effect of improving the wear resistance, and among them, the friction modifier and the solid lubricant are particularly effective. The material and content contribute to the friction coefficient adjusting action, the ceramics contribute to the wear resistance enhancing action, the reinforcing material contributes to the strength enhancing action, and the matrix mainly contributes to the strength enhancing action, Among them, when at least one of Cu, Ni and Fe is based, it contributes to the effect of enhancing strength and densification, and Fe,
At least one of Co, Cu, Sn and their mutual alloys contributes to the effect of enhancing the sinterability, and the composition of these components as a whole is the main characteristics as a friction material, that is, the friction coefficient and wear resistance. It has the effect of enhancing the sex and the effect of preventing squeaking.

[0018]

Examples Various commercially available starting materials [as layered material, mica with h / t ≧ 15, h / t ≧ 20: ash content 1 w
t% or less: Flake graphite having a crystallite size of 10 nm or more (abbreviated as C2 in the table), granular graphite (abbreviated as C1 in the table), Cu: Mn = 6: 4 Cu-Mn alloy, Fe: M
Fe-Mn alloy with n = 3: 7, and others shown in Table 1 KD: Cashew dust, Cu-F: Cu fiber, AR
-F: aramid fiber, PH-R: starting material of phenol resin] were weighed according to the compounding compositions in Table 1 and mixed to obtain a mixture, which was then molded at a pressure of ² ton / cm ² , and then a molded product. Placed on a Cu-plated steel plate, 10 kg
/ Cm ² was applied and the product was fired at 850 ° C. for 60 minutes in an H ₂ atmosphere to obtain Inventive Products 1 to 8 and Comparative Products 1 to 3.
Comparative product 4 was prepared by weighing and mixing the compounding compositions shown in Table 1 and mixing the resulting mixture on a steel plate coated with an adhesive to give 18
It was produced by hot forming at 0 ° C. and a pressure of 200 kg / cm ² , and then heat-treated at 200 ° C. for 180 minutes to cure the phenol resin.

The matrix content, the Mn element content, the content of the layered material of h / t ≧ 10, and the high purity in the layered material with respect to the entire friction material in the inventive products 1 to 8 and the comparative products 1 to 4 thus obtained. The layered substance content of graphite and the total content of Cu, Ni and Fe in the matrix were determined and shown in Table 2.

Next, products 1 to 8 of the present invention and comparative products 1 to 4
Inertia moment: 6.75kg ・ m
・ Sec ² , pad area: 52 cm ² , mating plate: FC25
In with the speed: sliding fit at 65km / h, the friction test at 40 km / h, surface pressure: sliding fit at 25 kg / cm ^2, friction at testing 5~40kg / cm ^2, brake temperature before: sliding fit upon 120 ° C., The friction test was performed under the conditions of 50 to 300 ° C. during the friction test, 200 times during braking: 100 times during the rubbing, and 100 times during the friction test, and the squeal of the brake at that time was measured with a noise meter,
It was determined that the brake squeal was generated when the sound pressure reached a certain level or more, the brake generation rate at that time was calculated, the wear amount and the friction coefficient were calculated, and the results are shown in Table 3.
Further, by using the present invention products 1 to 8 and the comparative products 1 to 4, the passenger car brake test JASO specified by the Japanese automobile standard.
A friction test according to C406-82 was conducted, and the results are also shown in Table 3.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

[0024]

INDUSTRIAL APPLICABILITY The friction material of the present invention is more effective than conventional organic friction materials in suppressing the generation of squeal without lowering the friction coefficient and wear resistance from low load to high load. Remarkably excellent, less likely to cause cohesive wear damage to the mating material at the time of rubbing, stable strength against temperature, and excellent in oxidation resistance and heat resistance. , Also, compared to conventional sintered friction materials,
The variation of the friction coefficient is small, the various friction material characteristics are well balanced, and the vibration damping ratio is remarkably high.
Less likely to cause cohesive wear damage to the mating material during friction,
There is an effect that the occurrence rate of squeal during braking is low. Therefore, the friction material of the present invention has a high possibility of being put to practical use in various applications and is an industrially useful material.

Claims (9)

[Claims] 1. In a friction material comprising a matrix made of a metal and / or an alloy and the rest being a filler mainly made of an inorganic substance excluding the matrix, the filler has a thickness (t) and a length in a layer direction. A layered substance having a ratio to the length (h) in the depth direction of 10 or more (h / t ≧ 10) is contained in the friction material in an amount of 10 to 60% by volume, and Mn, a Mn alloy, and Mn. At least one Mn element-containing substance in the compound is 30% by volume in terms of Mn with respect to the friction material.
A Mn-containing sintered friction material containing the following: 2. The Mn according to claim 1, wherein the matrix contains 50% by volume or more of at least one of Cu, Ni, Fe and mutual alloys thereof with respect to the matrix. Containing sintered friction material. 3. The filler is, in addition to the layered substance, metal oxides, carbides, nitrides, fluorides, sulfides, suicides and mutual solid solutions thereof, metal carbonates, mineral substances, intermetallic compounds, The Mn-containing sintered friction material according to claim 1 or 2, wherein at least one inorganic substance selected from graphite, carbon, short fibers and long fibers is contained. 4. The layered material contains at least one of graphite, metal sulfide, boron nitride, mica, vermiculite, talc and kaolin. 3. The Mn-containing sintered friction material described in 3. 5. The layered material contains graphite and, in addition thereto, one or more of metal sulfide, boron nitride, mica, vermiculite, talc and kaolin. The sintered friction material containing Mn according to 1, 2, or 3. 6. The Mn-containing sintered friction material according to claim 4, wherein the layered material contains 50% by volume or more of graphite with respect to the entire layered material. 7. The Mn-containing sintered friction material according to claim 5, wherein the graphite has an ash content of 1% by weight or less and a crystallite size in the C-axis direction of 10 nm or more. . 8. The Mn element-containing substance is contained in an amount of 2 to 20% by volume in terms of Mn with respect to the entire friction material, 1, 2, 3, 4, 5, 6 or 7. A sintered friction material containing Mn according to 7. 9. The Mn element-containing substance is metal Mn, C.
It is made of one or more of u-Mn alloy, Fe-Mn alloy and manganese oxide.
The sintered friction material containing Mn according to 4, 5, 6, 7 or 8.