JPH038409B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention is a friction material used as a so-called clutch or brake material as a means for arbitrarily controlling the rotation or movement of various machines such as machine tools, construction machines, automobiles, motorcycles, railways, and aircraft. It is related to materials. (Prior Art) Conventionally used clutch or brake materials include organic friction materials in which fiber components and filler components are combined with a binder such as resin or rubber; There is also a metallic friction material that is bonded with a binder such as metal, alloy, or metal compound. The mainstream of metallic friction materials is those using Cu-Sn, Cu-Zn, or Cu-Sn-Zn sintered alloy as a binder, and compared to organic friction materials, they are
Decrease in the coefficient of friction at high temperatures (thermal fade phenomenon) and decrease in the coefficient of friction due to the presence of moisture (water fade phenomenon)
It has the advantage of having a small tendency to cause wear and tear. (Problems to be Solved by the Invention) The present invention is an improvement of metallic friction materials, and seeks to extend the advantages of conventional metallic materials, extend the advantages of metallic materials, and solve the problems required of metallic friction materials. It is something to do. In other words, the characteristics or improvements required for metallic friction materials are: 1. Further increasing the coefficient of friction. 2. There is little decrease or fluctuation in the coefficient of friction even under high load operating conditions where the material temperature reaches approximately 500℃. 3. Further improving wear resistance. 4. No chipping or excessive welding to the mating material during sliding. 5. There is little tendency to attack the mating material, such as by abrading the mating material. In addition, there are other characteristics such as not making abnormal noise (squeal) or jitters, being resistant to rust, and having a good usability when used on motorcycles etc.
There has been a demand for the development of a metallic friction material that satisfies these requirements. (Means for Solving the Problem) As a result of various experiments, the inventor of the present invention found that the composition of the matrix contains 10 to 70% Ni and 30 to 80% Cu. Contains Ni
It has been discovered that a friction material composition in which the sum of Cu and Cu is 60% or more is compatible with the above purpose. Since Ni is a metal with excellent heat resistance and strength, it can be used as an alloy based on Ni, or as a metal with excellent heat resistance and strength.
It is widely used by adding it to Fe-based alloys, etc., and their use in applications such as sliding materials and friction materials has also been considered. However, the present invention is the first to demonstrate that by combining Ni with Cu and using it as a matrix of a metallic friction material as in the present invention, excellent effects can be exhibited as a clutch or brake material. The matrix of the friction material composition of the present invention is
It is essential that 60% or more is Ni and Cu, but other than that, any metallic material that exists as an additive or impurity in ordinary metallic friction materials may be used as appropriate, and the effects of the present invention are improved. is demonstrated. However, particularly preferred embodiments include, in addition to Ni and Cu, 0.1 to 35% Fe, Zn, Sn.Ti,
Al, Cr, Mo and Si are each 0.1-20%,
Mn, Mg, V, Pb, Bi, Sb, In, Be, Cd, W
and Co 0.05-15%, B, S, C,
The friction material composition contains one or more of N, Ce, and P in the range of 0.01 to 4.5%, respectively. By adding these, matrix dispersion strengthening, precipitation hardening, grain refinement, improvement and adjustment of oxidation resistance, promotion of sintering,
It is effective in generating carbides, oxides, and nitrides, increasing the melting point, adjusting hardness, and other effects, and these effects are combined to improve the heat resistance, strength, toughness, lubricity, and compatibility with the mating plate of the matrix. The defects of conventional Cu alloys have been eliminated, and it has a stable high coefficient of friction from low to high temperature conditions, reducing wear, chipping, transfer to the mating plate, squealing, etc.
A metallic friction material that is excellent in terms of WET performance, rust, and usability can be obtained. The metallic material forming the matrix of the friction material composition of the present invention is partially or entirely made of a Cu alloy,
Fe alloy powder such as Ni alloy and stainless steel,
One or two selected from fibers and whiskers
It can be added as more than one seed. This is especially true when using metallic materials such as Al, which form strong, high-melting-point oxides on the surface and inhibit sintering. When using stainless steel instead of Fe, when alloying makes it less likely to rust, when fibers have excellent strength and elasticity, or when a certain type of heterogeneous system is intentionally used to improve friction properties. This is effective when you want to create Although this type of addition exists in the production of conventional friction material compositions, in the case of the present invention, an even greater effect is achieved by combining the effects of the ingredients. The ratio of the matrix to the filler in the friction material composition of the present invention is not particularly limited, but the matrix accounts for 45 to 90% of the total composition, and the filler accounts for 10 to 55% of the total composition.
% is preferable. The filler of the friction material composition of the present invention is barium sulfate, talc, diatomaceous earth, serpentine, coke, or a metal oxide (MgO,
Friction modifiers such as Fe ₂ O ₃ , TiO ₂ etc.), hard particles such as silica, mullite, alumina, silicon nitride, silicon carbide or zircon sand, graphite, MoS ₂ ,
Lubricant components such as WS ₂ , BaF ₂ , CaF ₂ , graphite fluoride, boron nitride or mica, pulp fibers, rayon fibers, carbon fibers, silica alumina fibers, wollastonite, potassium titanate fibers, silicon carbide fibers, carbonized silicon whiskers, boron fibers,
It consists of one or more types selected from organic, inorganic, and metal fibers such as rock wool and mineral wool. Although these are all known as friction materials or friction modifying and reinforcing materials, the matrix of the friction material composition of the present invention acts as an excellent binder for any of these known fillers. This allows the frictional properties of the filler to be fully utilized. (Example) Below are 10 representative examples of the present invention.
I will give an example. Examples 1 to 9 are dry examples,
Example 10 is a wet example used in lubricating oil. This example is a part of the examples carried out to confirm the effect of the present invention and confirm the scope of application, and the scope of the claims is not limited to the example. Table 1 shows the compositions of the matrices of Examples 1 to 9 in weight % based on the entire friction material composition, and Comparative Example 1 is shown as an example of a conventional Cu-based matrix. The total composition of both matrices is 80%.

[Table] In order to compare the matrices, fillers are 1% diatomaceous earth, 3% zircon sand, 8% graphite,
CaF ₂ 1%, TiO ₂ 3%, wollastonite 4% total
Fixed at 20%. By using the same filler, the effects of the present invention are clearly manifested as described later, but even greater effects can be achieved by selecting different optimal fillers depending on the matrix of each embodiment. Pb, Sb, etc. are considered to be fillers as lubricant components, but since they are also effective as sintering aids, they were used as constituent components of the matrix in this example. The components of Comparative Examples and Examples were weighed, mixed, molded, and sintered to produce products. Using the normal powder metallurgy manufacturing method, the compacting pressure is 2.0ton/cm ² and the sintering temperature is
The test was carried out at 900°C, for 120 minutes, and at a pressure of 20 kg/cm ² . Fe, Al, Cr, Ti and Si and others, brass alloy, bronze alloy, aluminum brass alloy, manganese brass alloy, high strength brass alloy, phosphor bronze alloy, aluminum bronze alloy, silicon bronze alloy , manganese bronze alloy, tin-containing brass alloy,
Cu-Al alloy, Cu-Fe-Mn alloy, Ni-Si alloy,
Ni-Mn alloy, Ni-Cu alloy, Monel metal alloy, German silver alloy, Ni-Ti alloy, Ni-Cr alloy, Ni-Al alloy, Ni-Cr-Cu-Fe alloy,
Ni-Cr-Mo-Cu-Fe alloy, Hastelloy alloy, Inconel alloy, Cr stainless steel, Cr-
Ni-based stainless steel, Cr, Al, Si, Ni, Mo,
When added in the form of alloy powder, fibers, or whiskers, such as Fe-based alloys containing components selected from Mn and B, sintering is accelerated, strength is increased, and mechanical strength is increased compared to when added alone. Physical characteristics improved in most cases. However, the frictional properties were not necessarily improved, and evaluations were therefore made using samples using different optimal manufacturing methods for each example. The samples were evaluated using stainless steel for the mating plate, a disk effective diameter of 222φ, and a disk brake type with a lining outer diameter of 110R, width of 28mm, and area of 20cm ² . Also, the inertial body is 1.16
Kg・m・sec ² , pressure 7Kg/cm ² , and initial velocity of each
Braking was performed from 5.3m/sec, 10.5m/sec, and 15.8m/sec a total of 120 times. Among the measurement results, the friction coefficient is shown in Table 2 as μ ₁ , μ ₂ , and μ ₃ for each of the above-mentioned initial speeds, and the wear (unit: mm) for a total of 120 times is also shown in Table 2. The surface condition was "chips and welds" in Comparative Example 1, and "no chips and welds" in Examples 1 to 9. There was no squeak in both the comparative examples and the examples. The absorbed energy per unit area for each condition is 26.1Kg・m/cm ² , 104.5Kg・m/cm ² , and 237.0Kg・for each initial velocity condition.
m/cm ² and the cycle time was about 40 seconds.

[Table] As shown in Table 2, the friction coefficient of the example was considerably higher than that of the comparative example, and the wear was about 60% lower than the same level. Moreover, the surface condition showed no occurrence of chipping or welding. Furthermore, in order to investigate high-temperature characteristics, braking was performed at a part temperature of 400°C. At this time, the temperature inside the pad material at a distance of approximately 0.5 mm from the sliding surface of the friction material rose to approximately 550°C. In Comparative Example 1, the initial friction coefficient of 0.42 decreased to 0.31 after 10 cycles, whereas in Example 5, the initial friction coefficient of 0.57 remained 0.58 even after 10 cycles. In other Examples, the friction coefficient was 0.45 to 0.63 under these conditions. In the water fade test (WET efficacy test),
Example 5 shows low surface pressure (3Kg/cm ² ) to high surface pressure (30
Kg/cm ² ), the friction coefficient is as high as 0.4 or more, and in this surface pressure range, the ratio of the WET friction coefficient to the DRY friction coefficient is
It has an excellent value of 0.85 to 1.10, and is better than other examples.
The WET friction coefficients were all 0.35 or higher. If the mating plate (disk) is cast iron, the American Association of
In the VESCV-3 standard test conducted by the designated testing institute of Motor Vehicle Administratos (AAMVA), the normal friction coefficient was 0.759, and the hot friction coefficient was 0.709, which was extremely high. Furthermore, the conventional
For Cu-based materials, both the normal friction coefficient and the hot friction coefficient ranged from 0.30 to slightly over 0.50 at most. Next, an example in the case of wet use will be described as Example 10. The ingredients and composition are as a matrix,
Cu25%, Ni15%, Sn1%, Al1%, Mn0.5%,
P0.01%, Pb0.5%, stainless steel fiber (SUS316 i.e. Cr10.88%, Ni8.24%, Mo1.30%, Si0.55
%, Mn 0.06%, C 0.08% or less, residual Fe) 7%, fillers of graphite 25%, wollastonite 20%, silica 5%, and after forming and sintering, oil groove processing is performed. It was used as a sample. The porosity of the sample is 30%,
The transverse rupture strength was 360 Kg/cm ² . To give an example of the evaluation of this sample, the friction plate size is 194φ x 164φ, 2 surfaces per plate, absorbed energy 7Kg・m/cm ² , moment of inertia 0.147Kg・m/
sec ² , surface pressure 10Kg/cm ² , clutch frequency 15sec/cycle, lubricating oil is SAE standard engine oil #30,
When tested at an oil volume of 8 c.c./cm ² min and a supply temperature of 80°C, the average dynamic friction coefficient was 0.125, and the static friction coefficient was
The coefficient of dynamic friction was 0.165, which was 1.2 to 2 times higher than that of conventional metallic wet friction materials. Note that the level of wear was almost the same as that of the conventional product. (Effects of the Invention) Since the present invention provides an excellent friction material composition, the present invention has great industrial value.

Claims (1)

[Claims] 1. One or two of metals, alloys, and metal compounds
In a friction material composition consisting of a binder, i.e., a matrix, containing at least one metal material (hereinafter collectively referred to as a metal-based material), and fillers such as a friction modifier, a lubricant, hard particles, and a reinforcing material, among the components constituting the matrix, , 10 to 70% Ni and Cu in the matrix (all weight%)
A friction material composition characterized by containing 30 to 80% of Ni and Cu, with the total amount of Ni and Cu being 60% or more. 2 The matrix is Fe due to the composition within the matrix.
is 0.1~35%, Zn, Sn, Ti, Al, Cr, Mo and
Si is 0.1 to 20%, Mn, Mg, V, Pb,
Bi, Sb, In, Be, Cd, W and Co are respectively
0.05 to 15%, B, S, C, N, Ce and P each in the range of 0.01 to 4.5% or two.
Contains more than seeds, Ni10~70%, Cu30~80% and
The friction material composition according to claim 1, wherein the total content of Ni and Cu is 60% or more. 3. A patent claim in which a part or all of the metallic material forming the matrix is added as one or more selected from powder, fiber, and whisker of Cu alloy, Ni alloy, and Fe alloy such as stainless steel. The friction material composition according to the first range. 4. The friction material composition according to claim 1, wherein the matrix accounts for 45 to 90% and the filler accounts for 10 to 55% of the total friction material composition.