JP2000355685A - Friction material - Google Patents

Abstract

(57) [Problem] To provide a metal-based friction material and a resin-based friction material having a high friction coefficient and improved wear resistance, which can be suitably used as a brake material and a clutch material. SOLUTION: A matrix composed of at least one or more of Cu, Ni, Fe and alloys thereof,
In a friction material containing a lubricant and a friction modifier, the friction modifier contains Al ₂ O ₃ and ZrO ₂ , and the weight of (Al ₂ O ₃ ) / (Al ₂ O ₃ + ZrO ₂ ) in the friction modifier. The ratio is between 0.3 and 0.7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction material having a high coefficient of friction and excellent wear resistance.

[0002]

2. Description of the Related Art In automobiles, motorcycles, railway vehicles, aircraft, various industrial machines, etc., friction materials are used as clutch materials such as clutch facing materials and brake materials such as brake lining materials and brake pad materials. Conventionally, as a friction material, there are an organic friction material using a resin or the like as a binder, and a metal friction material using a metal or an alloy as a matrix.

Generally, an organic friction material has a lower friction coefficient and a lower abrasion resistance than a metal friction material, but is inexpensive. A metal friction material has a high friction coefficient and excellent abrasion resistance. It is expensive, and is used properly depending on the application by taking advantage of each feature. Generally, friction coefficient and abrasion resistance are opposite properties.The higher the coefficient of friction, the more abrasion, and the lower the friction, the lower the coefficient of friction. hand,
There is a demand for a friction material having a high friction coefficient and excellent wear resistance.

[0004]

SUMMARY OF THE INVENTION In order to obtain a friction material which satisfies the above-mentioned requirements, the present invention relates to the components contained in an organic friction material and a metal friction material, especially the composition of a friction modifier and the friction and wear characteristics. The purpose of the present invention is to provide a friction material having a high friction coefficient and improved wear resistance.

[0005]

According to a first aspect of the present invention, there is provided a friction material comprising Cu, Ni,
In a friction material including a lubricant and a friction modifier in a matrix containing a metal material composed of one or more of Fe and an alloy thereof, Al ₂ O ₃ and Z
rO ₂ , and (Al ₂ O ₃ ) /
The weight ratio of (Al ₂ O ₃ + ZrO ₂ ) is 0.3 to 0.7.

In the friction material according to the second aspect, the Al ₂ O ₃ and the ZrO ₂ in the friction modifier are A
l ₂ O ₃ alone, not only ZrO ₂ itself, characterized in that it comprises also Al ₂ O ₃ and ZrO ₂ to form a SiO ₂ composite oxide.

The friction material according to claim 3 is characterized in that, in claim 2, one or more of kaolinite, sillimanite, mullite and zircon sand are contained as a composite oxide in the friction modifier. Features.

The friction material according to claim 4 is characterized in that the matrix is a sintered material of a metal and / or an alloy composed of one or more of Cu, Ni, Fe and their alloys.

A friction material according to a fifth aspect of the present invention is characterized in that an organic friction material using a thermosetting resin as a binder contains the friction modifier according to any one of the first to third aspects. And

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The friction material is at least Cu, Ni, Fe and these
Matrix a metal material consisting of one or more alloys
At least a lubricant and friction
A metal-based friction material containing a friction modifier;
Is Al_TwoO_ThreeAnd ZrO_TwoContaining in the friction modifier
(Al _TwoO_Three) / (Al_TwoO_Three+ ZrO_Two) Weight ratio
0.3 to 0.7.

The matrix components are Cu, Ni, Fe,
And Cu alloys containing Zn, Sn, etc., Ni alloys such as Ni-Cu-based alloys containing Cu as a main alloy component,
It is composed of one or more Fe-based alloys such as stainless steel. Further, in addition to these metal components, Z
n, Sn, and Pb may exist alone. Especially,
It is preferable that powders of these metals and alloys are mixed with powders of a lubricant, a friction modifier and the like, and a friction material is produced by a powder metallurgy method of molding and sintering.

As the friction modifier, metal oxides, barium sulfate, diatomaceous earth and the like are applied. In the present invention, the friction modifier contains Al ₂ O ₃ and ZrO ₂ , and (Al) ₂ O ₃₎ / weight ratio of _{(Al 2 O 3 + ZrO 2} ) is characterized in that 0.3 to 0.7. Al ₂ O ₃ and ZrO ₂ in the friction modifier are not limited to those contained as Al ₂ O ₃ alone or ZrO ₂ alone,
Al ₂ O ₃ and Zr forming a composite oxide with O ₂
O _{2 is} also included.

As the composite oxide of Al ₂ O ₃ and SiO ₂ , kaolinite, sillimanite and mullite are preferable, and as the composite oxide of ZrO ₂ and SiO ₂ , zircon sand is preferable. In a preferred embodiment,
One or more of kaolinite, sillimanite, and mullite and zircon sand are contained in the friction modifier.

We have found that the inclusion of Al ₂ O ₃ in the friction modifier functions to increase the coefficient of friction but increases wear, whereas the inclusion of ZrO ₂ tends to reduce wear but increase the coefficient of friction. It has been found that a friction material having a high friction coefficient and a small amount of wear can be obtained by changing the content ratio thereof. (Al ₂ O ₃ ) /
If the weight ratio of (Al ₂ O ₃ + ZrO ₂ ) is less than 0.3, Z
The effect of rO ₂ increases and wear decreases, but the coefficient of friction decreases, and (Al ₂ O ₃ ) / (Al ₂ O ₃ + ZrO ₂ )
If the weight ratio exceeds 0.7, the effect of Al ₂ O ₃ is large and the friction coefficient is high, but the wear increases.

Al ₂ O ₃ , ZrO ₂ and Si and Al
90% by weight or more of the composite oxide of O ₂ is 5 to 500 μm.
When the particle size is less than 5 μm, wear tends to increase and the strength tends to decrease.
If the thickness exceeds 0 μm, inconveniences such as abnormal damage to a friction partner material are likely to occur.

As the lubricant contained in the friction material,
Graphite, MoS_Two, CaF_Two, BaF _Two, Graphite fluoride, nitrogen
Boron oxide, mica and the like are used. Friction materials also include
If necessary, silica, silicon nitride, silicon carbide, etc.
Which hard particles, silicon carbide fiber, carbon fiber, carbonized
Whisker, boron fiber, silica-alumina fiber,
Glass fiber, aramid fiber, brass fiber, steel fiber,
Including other inorganic, organic and metallic fibrous reinforcements
You can also.

According to a fifth aspect of the present invention, there is provided a friction material comprising an organic friction material containing a thermosetting resin as a binder and the friction modifier described above. As the thermosetting resin serving as a binder, a phenol resin, a silicon-modified phenol resin, an acrylic-modified phenol resin,
Modified phenolic resin such as epoxy knitted phenolic resin, and furan resin, epoxy resin, melamine resin,
Alkyd resin and the like. These resins may be used as a mixture, and if necessary, a curing agent such as trichloroacetic acid and vala-toluenesulfonic acid may be added.
Further, barium sulfate or the like can be blended as a friction modifier.

[0018]

EXAMPLES Examples of the present invention will be described below in comparison with comparative examples, and the effects thereof will be demonstrated based on them. It should be noted that these examples are for describing a preferred embodiment of the present invention, and the present invention is not limited thereto.

Example 1 Powders of the components shown in Table 1 were mixed by a mixer, and
After molding into a predetermined shape at a pressure of 0 MPa, the pressure is reduced to 0.49 MPa in a reducing atmosphere at a temperature of 900 ° C. for 30 minutes.
After sintering for a minute, a friction material (test material) was obtained.

The obtained test material has a running area of 17c.
m ² , using a SUS disk rotor with an outer diameter of 270 mm and a caliper with a cylinder diameter of 14 cm ² ,
A brake test was performed by a 1.9 kgm ² dynamo test.

In the brake test, after sufficient rubbing, the vehicle was braked 300 times at a pad temperature cycle of 80 ° C. and a deceleration of 3 m / s ² before braking from a speed equivalent to a vehicle speed of 100 km / hr to obtain an average friction coefficient and lining wear. The amount was measured.

Table 2 shows the measurement results. As can be seen from Table 2, the friction material according to the present invention exhibited an excellent value of less than 1 mm while maintaining a high friction coefficient of 0.50 or more on average.

[0023]

[Table 1]

[0024]

[Table 2]

Comparative Example 1 Powders having the components shown in Table 3 were mixed in a mixer, and the mixed powder was treated in the same manner as in Example 1 to produce a sintered friction material (test material). , The same brake test as in Example 1 was performed, and the average friction coefficient and the lining wear amount were measured.

Table 4 shows the measurement results. As shown in Table 4
And (Al_TwoO_Three) / (Al_TwoO_Three+ ZrO_Two) Weight
The test material no. 7 has a large amount of wear,
(Al _TwoO_Three) / (Al_TwoO_Three+ ZrO_Two) Weight ratio
Test material no. 8 has a coefficient of friction of less than 0.50
Met.

[0027]

[Table 3]

[0028]

[Table 4]

Example 2 and Comparative Example 2 Powders having the components shown in Table 5 were mixed in a mixer, and the mixed powder was heated and pressed under the conditions of a pressure of 390 MPa and a temperature of 140 ° C. for 12 minutes. For 5 hours to prepare a friction material (test material) using a resin material as a binder.

The obtained test material (lining area: 17c
For m ² ), the same brake test as in Example 1 was performed, and the average friction coefficient and the lining wear amount were measured. Table 6 shows the measurement results.

As shown in Table 6, the test material N according to the present invention
o. Test material No. 9 had a high coefficient of friction and an abrasion amount of less than 1 mm, but the weight ratio of (Al ₂ O ₃ ) / (Al ₂ O ₃ + ZrO ₂ ) exceeded 0.7. 10 has a wear amount of 1 mm
Is over.

[0032]

[Table 5] << Table Notes >> Phenol resin: Sumitomo Durez Co., Ltd., trade name PR-50578, Silicon carbide fiber: Nippon Carbon Co., Ltd., trade name Nicalon

[0033]

[Table 6]

[0034]

According to the present invention, a metal-based friction material and a resin-based friction material having a high coefficient of friction and improved wear resistance are provided. The friction material is suitably used as a brake material, particularly as a brake pad.

Claims (5)

[Claims] 1. A friction material containing at least one of Cu, Ni, Fe and one or more of these alloys as a matrix and containing a lubricant and a friction modifier, wherein the friction modifier is Al ₂ O _3. And ZrO ₂ , and (Al ₂ O ₃ ) / (Al ₂ O ₃ +
A friction material having a weight ratio of ZrO ₂ ) of 0.3 to 0.7. 2. Al ₂ O ₃ and Z in said friction modifier
2. The friction material according to claim 1, wherein rO ₂ includes those forming a composite oxide with SiO ₂ . 3. The friction material according to claim 2, wherein the friction modifier contains one or more of kaolinite, sillimanite, and mullite as a composite oxide, and zircon sand. 4. The matrix according to claim 1, wherein the matrix is a sintered material of a metal and / or an alloy of one or more of Cu, Ni, Fe and alloys thereof.
4. The friction material according to any one of items 1 to 3. 5. A friction material comprising a thermosetting resin as a binder and the friction modifier according to claim 1 incorporated therein.