Technical field
[0001]
The present invention relates to a sintered friction material and a manufacturing method thereof, and more particularly, for railway vehicles sintered friction material used in railway, and a method for producing the same.
BACKGROUND
[0002]
The brake lining and disc brake pads for railway vehicles, sintered friction material formed by sintering a metal powder or granular material or the like is used. These railcar sintered friction material, together with the excellent frictional properties, are required to have excellent wear resistance.
[0003]
　JP-5-86359 (Patent Document 1), JP-A-10-226842 (Patent Document 2) and JP 2012-207289 (Patent Document 3) increases the wear resistance of the sintered friction material It has been proposed for the technology.
[0004]
　Dry friction material disclosed in Patent Document 1, Cu, or Sn with Cu, Zn, Ni, a material obtained by adding one or two or more selected from Fe and Co and a matrix component, metal oxides, metal composite oxides, metal nitrides, metal carbides, metal carbonitrides, metal borides, intermetallic compounds and one selected from Mohs' hardness 3.5 or more various minerals, or two or more of the hard particle component, graphite , coke, BN, metal sulfides, CaF 2 , BaF 2 , PbO, Pb and B 2 O 3 and one or more lubricating components selected from selected W, Mo, Nb, Ta, and the Zr 0.5 ~ 30 vol% of these ingredients one or by adding two or more members, hard particle component 2 ~ 30 vol%, the remainder of the lubricating component is 10 ~ 70 vol% of 10 ~ 70 vol% Matrigel A box component.
[0005]
　Metallic friction material disclosed in Patent Document 2, the metal material as a matrix, at least friction modifier, sintered friction material obtained by solid-phase sintering by addition of solid lubricant. In this sintered friction material, a metal material forming the matrix may include Cu and Ni as main components, friction modifier and solid lubricant is a granular material of a particle size of 10 ~ 300 [mu] m, the sintered friction 15 to 50% by total weight relative to the total timber (wt%, hereinafter the same) are contained.
[0006]
　Fast railway sintered friction material disclosed in Patent Document 3, in mass%, 7.5% or more Fe, 50% or more of Cu, 5 ~ 15% of graphite 0.3 to 7% disulfide containing molybdenum and 0.5 to 10 percent of silica, Fe / Cu is from 0.15 to 0.40.
CITATION
Patent Document
[0007]
Patent Document 1: JP-A-5-86359 Patent Publication
Patent Document 2: JP-A 10-226842 JP-
Patent Document 3: JP 2012-207289 JP
Summary of the Invention
Problems that the Invention is to Solve
[0008]
　Japan's Shinkansen, the German ICE (Intercity-Express), the traveling speed of the high-speed rail vehicle, such as the French TGV (Train a Grande Vitesse) is, 0 ~ 70km / low-speed range of the time, 70 ultra ~ 170km / medium speed of time not only the frequency, exceeding the 170km / hour, further, reaching up to the high-speed range of more than 280km / hr. Therefore, the sintered friction material for railroad vehicles, not only the low speed range to medium speed range, even in the high speed range, is required excellent friction characteristics and wear resistance.
[0009]
　Patent Documents 1 and 2, brake in the brake test initial velocity is at 220 km / hour or less, braking initial speed is not the consideration at 280 km / hour or more. Therefore, the sintered friction material disclosed in these documents, there is a possibility that a low friction characteristics and wear resistance in high speed range.
[0010]
　The fast railway sintered friction material disclosed in Patent Document 3, friction properties and wear resistance in a high speed region has been studied. However, more excellent frictional properties and abrasion resistance are required.
[0011]
　Purposes of this disclosure, the low-speed range, not only the medium speed region, even in the 280 km / h or more high speed range, has excellent wear resistance, sintered friction material for railroad vehicles obtained also sufficient frictional properties it is to provide a.
Means for Solving the Problems
[0012]
　The railway vehicle sintered friction material according to the present disclosure, a mass% Cu: 50.0 ~ 75.0% graphite: 5.0 to 15.0%, magnesia, zircon sand, silica, zirconia, mullite and nitride least one selected from the group consisting of silicon: 1.5 to 15.0%, one or more selected from the group consisting of W and Mo: 3.0 ~ 30.0% and, ferrochromium, ferrotungsten , ferromolybdenum, and one or more selected from the group consisting of stainless steel: 2.0 to 20.0%, containing the balance being sintered material of the green compact consisting of impurities.
[0013]
　Production method of the present disclosure by railway vehicle sintered friction material, a molding step of manufacturing a green compact powder mixture described above with cold forming, at a sintering temperature of 800 ~ 1000 ° C. relative to the powder compact by carrying out pressure sintering, and a pressure sintering process for manufacturing a railcar sintered friction material.
Effect of the invention
[0014]
　The present disclosure by railway vehicle sintered friction material, the low-speed range, not only the medium speed region, even in the 280 km / h or more high speed range, has excellent wear resistance, sufficient frictional characteristics can be obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015]
[1] Figure 1 is a schematic diagram of a bench test machine used in the brake test.
FIG. 2 is a diagram showing a relationship between brake in Examples initial velocity and (km / h) and the average friction coefficient of sintered friction material (mu).
FIG. 3 is a diagram showing a relationship between the braking in the embodiment the initial speed (km / h) and the average wear amount (g / one side).
DESCRIPTION OF THE INVENTION
[0016]
　The present inventors have low-speed range, not only the medium speed range, were investigated and studied the frictional characteristic and wear resistance at 280 km / h or more high-speed range. As a result, (1) a matrix component as Cu, Ni, Sn, does not contain Zn, (2) ferrochrome, ferro tungsten, ferro molybdenum, and, one or more selected from the group consisting of stainless steel, ( 3) W and green compact containing at least one element selected from the group consisting of Mo, sintered friction material sintered at a known production conditions using well-known manufacturing method (pressure sintering) in low-speed range, not only the medium speed range, found that excellent friction characteristics and wear resistance even in high speed range above 280 km / h is obtained.
[0017]
　Above the railway vehicle sintered friction material according to the present embodiment has been completed based on the finding, in mass% Cu: 50.0 ~ 75.0% graphite: 5.0 to 15.0%, magnesia, zircon sand, silica, zirconia, one or more selected from the group consisting of mullite and silicon nitride: 1.5 to 15.0%, one or more selected from the group consisting of W and Mo: 3.0 ~ 30. 0%, and, ferrochromium, ferro tungsten, ferro molybdenum, and, one or more selected from the group consisting of stainless steel: 2.0 to 20.0%, containing, balance of the green compact consisting of impurities a sintered material.
[0018]
　Rail vehicle sintered friction material of the present embodiment, for example, a sintered material formed by the green compact was pressure sintering at 800 ~ 1000 ° C..
[0019]
　Rail vehicle sintered friction material of the present embodiment, for example, a 20mm diameter is 400 mm, thickness, it has a chemical composition corresponding to SCM440 specified in JIS G 4053 (2016), a tensile strength of about 1000MPa prepare a brake disk having, a caliper for braking the brake disc, each of the left and right inner surfaces of the caliper, the width 38mm, length 55 mm, four sintered friction material of height 15 mm, the center of the brake disc 10 on a virtual circle of radius 170mm from and arranged in a row shifted by 25 ° around the center axis of the brake disc, relative to the rotating brake disc, the sintered friction material which is attached to the left and right inner surfaces of the caliper, constant when carrying out the brake test pressing on both sides of the brake disc at a pressure 2.24kN of braking initial speed is 365Km / h The average friction coefficient of sintered friction material in is not less 0.280 or more and an average amount of friction sintered friction material on each surface of the brake disc, brake initial velocity at 6.30 g / one side or less at 300 km / h Yes, the braking initial speed is at 6.50g / single-sided or less at 325km / h, the braking initial speed is 9.00g / single-sided or less at 365km / hr. Here, a tensile strength of the brake disk "about 1000MPa" refers to a range of 1000 ± 20MPa.
[0020]
　Incidentally, as described above, sintered for railway vehicles sintered friction material according to the present embodiment is a sintered material. Sintered material component analysis and itself, the neck thickness, the bonding state of the powder particles together (fusion-shaped body), such as the dispersion state of sintered material inside the pores, chemical structure of the sintered material (chemical composition) and against physical structure, it is very difficult to define the numerical limitation or the like by measurement techniques and analysis technology presently. Therefore, the railway vehicle sintered friction material of the present embodiment, as described above, the configuration of the green compact, sintering temperature during sintering under pressure, the mechanical properties of the sintered friction material (average friction coefficient, the average amount of friction ) are defined by the like. Incidentally, as described later, a manufacturing method for a railway vehicle sintered friction material in this embodiment is a well-known method. That is, for railway vehicles sintered friction material of the present embodiment is characterized in the composition of the green compact.
[0021]
　The railway vehicle sintered friction material of the present embodiment, the green compact, instead of a part of the Cu, hexagonal boron nitride: 3.0% or less, molybdenum disulfide: 3.0% or less, mica: 3.0% or less, iron sulfide, at least one species selected from copper sulfide and copper matte: 10.0% or less, vanadium carbide: 5.0% or less, and, Fe: 20.0% or less, consisting of the group it may contain one or more members selected from the.
[0022]
　Manufacturing method for a railway vehicle sintered friction material according to the present embodiment, a molding step of manufacturing a green compact powder mixture described above with cold forming, sintering temperature of 800 ~ 1000 ° C. relative to the powder compact in and out the pressure sintering, and a pressure sintering process for manufacturing a sintered railcar sintered friction material.
[0023]
　It described in detail below railcar sintered friction material according to the present invention.
[0024]
　[Chemical composition]
　The present invention according to the railway vehicle sintered friction material, as described above, is used in brake linings and disc brake pads for railway vehicles. Before sintering of the green compact of the sintered friction material contains the following composition (matrix for particulate material, dispersing agent). Here, the green compact is mixed powder which has been formed by cold forming by press. The particle diameter of each particle of the mixed powder as a raw material of the green compact is not particularly limited, but is 1 ~ 1000 .mu.m as an example. The following describes the composition of the mixed powder constituting the green compact. Incidentally, "%" relating to the composition of the mixed powder constituting the green compact means mass%.
[0025]
　[Matrix (base material) for particulate
　material] Cu: 50.0 ~ 75.0%
　copper (Cu) serves as a matrix (base material) of the sintered for railway vehicles sintered friction material. Cu has a high thermal conductivity. Therefore, when the brake can suppress an increase in the interface temperature between the braked member at (Friction at) (brake disk) and sintered friction material inhibits excessive Seizure. Therefore, the wear resistance of the sintered friction material increases. Cu is a matrix further holds a dispersing agent described later are contained in the matrix (lubricant, hard particles). If less than 50.0% Cu content of mixed powder group, not the effect. On the other hand, Cu content if it exceeds 75.0% the friction coefficient is excessively large. In this case, friction due to adhesion with respect to the sliding surface of the brake target (e.g. brake disk) is excessively generated, the wear resistance of the sintered friction material is lowered. Therefore, Cu content is 50.0 to 75.0%. The preferable lower limit of Cu content is 52.0%, still more preferably 53.0%. The preferable upper limit of Cu content is 70.0%, more preferably 67.0%.
[0026]
　Incidentally, the railway vehicle sintered friction material according to the present invention do not contain a rule Ni, Zn and Sn as the matrix. Here, "Principles free" is meant Ni, Zr, not to actively added Sn, Ni, Zn and Sn are meant to be impurities.
[0027]
　Ni is in solid solution in Cu, the matrix of the sintered friction material tends to adhesion to the sliding surface of the braked (brake disks, etc.), abrasion resistance is lowered. Zn and Sn are decreased heat resistance of the matrix is ​​easy to generate a fade. Therefore, the matrix of the sintered friction material Ni, does not contain principles of Zn and Sn.
[0028]
　[Dispersant]
　The above green compact further contains a dispersing agent of the following (1) to (4).
[0029]
　(1) Graphite: from 5.0 to 15.0%
　graphite referred to herein include natural graphite and / or artificial graphite. In sintered friction material after pressure sintering, graphite is contained in the matrix as particles. Graphite serves as a lubricant, the friction coefficient of the sintered friction material stabilized to reduce the amount of wear of the sintered friction material. If the graphite content is less than 5.0%, not the effect. On the other hand, if it exceeds 15.0% graphite content, mixed powder during pressure sintering is not sufficiently sintered, so that the wear resistance of the sintered friction material is lowered. Accordingly, the graphite content is 5.0 to 15.0%. The preferable lower limit of the graphite content is 8.0%, more preferably from 9.0%. The preferable upper limit of the graphite content is 13.0%, more preferably 12.0%.
[0030]
　(2) magnesia, zircon sand, silica, zirconia, one or more selected from the group consisting of mullite and silicon nitride: 1.5 to 15.0%
　magnesia (MgO), zircon sand (ZrSiO 4 ), silica (SiO 2 ), zirconia (ZrO 2 ), mullite (3Al 2 0 3 · 2SiO 2 ~ 2Al 2 0 3 · SiO 2 ), and silicon nitride (Si 3 N 4 ) any functions as hard particles. In sintered friction material after pressure sintering, these ceramics are contained in the matrix as particles. All of these ceramics also, by scratching the sliding surface of the braked (brake disks, etc.), to remove an oxide film generated on the sliding surface, stable to generate adhesion. This can suppress the reduction of the friction coefficient for braking target sintered friction material (brake disks, etc.), obtained excellent friction characteristics. If the total content of one or more selected from the group consisting of ceramics is less than 1.5%, it can not be obtained excellent friction characteristics. On the other hand, the total content of one or more selected from the group consisting of ceramic if it exceeds 15.0%, sinterability of the sintered friction material is lowered. In this case, the wear resistance of the sintered friction material is lowered. Therefore, the total content of one or more selected from the group consisting of ceramics is 1.5 to 15.0%. A preferred lower limit of 1 or more of the total content is selected from those of the ceramic group was 2.0%, more preferably from 4.0%. The preferable upper limit of one or more of the total content is selected from those of the ceramic group was 12.0 percent, still more preferably 10.0%.
[0031]
　(3) W and one or more selected from the group consisting of Mo: 3.0 ~ 30.0%
　tungsten (W) and molybdenum (Mo) either serves as the hard particles. W and Mo, without a solid solution in a matrix of Cu, contained in the matrix as particles. W and Mo are both, by being contained together with the Fe-based alloy particles described below, increase the wear resistance of the sintered friction material. If it is less than 1 or more of the total content is 3.0% which is selected from the group consisting of W and Mo, the effect can not be obtained. On the other hand, the total content of one or more selected from the group consisting of W and Mo is if it exceeds 30.0%, sinterability of the sintered friction material is lowered. In this case, the wear resistance of the sintered friction material is lowered. Thus, one or more of the total content is selected from the group consisting of W and Mo are 3.0 to 30.0%. A preferred lower limit of 1 or more of the total content is selected from the group consisting of W and Mo is 3.5%, more preferably 4.0%. The preferable upper limit of one or more of the total content is selected from the group consisting of W and Mo was 25.0%, more preferably 20.0%.
[0032]
　(4) ferrochrome, ferro tungsten, ferro molybdenum, and, one or more selected from the group consisting of stainless steel: 2.0 to 20.0%
　ferrochromium (FeCr), ferrotungsten (FeW), ferromolybdenum (FeMo) and either stainless steel, without solid solution in the matrix, is contained in the matrix as particles. In this specification, ferrochrome, ferro tungsten, ferro molybdenum, and, collectively referred to as Fe-based alloy particles stainless steel. Both of these Fe-based alloy particles, enhance the abrasion resistance of the sintered friction material. Although the reason is not clear, but is likely due to one of the following reasons.
[0033]
　Hardness of Fe alloy particles is higher than the matrix (Cu). Fe-based alloy particles further above ceramics (magnesia, zircon sand, silica, zirconia, mullite and silicon nitride) as compared to the affinity for the matrix is ​​high, not easily peeled off from the matrix. Therefore, Fe-based alloy particles increase the abrasion resistance of the sintered friction material. This effect, that with one or more selected from the group consisting of W and Mo are contained in the matrix, even higher. Fe-based alloy particles particularly enhance the abrasion resistance of the low-speed range to medium speed range, W and Mo are considered particularly enhance the abrasion resistance at high speed range.
[0034]
　If the total content of the Fe-based alloy particles is less than 2.0%, the wear resistance of the sintered friction material is lowered. On the other hand, the total content of the Fe-based alloy particles if it exceeds 20.0%, sinterability of the sintered friction material is lowered. In this case, the wear resistance of the sintered friction material is lowered. Accordingly, the total content of the Fe-based alloy particles is 2.0 to 20.0%. A preferred lower limit of the Fe-based alloy particles is 3.0%, more preferably from 4.0%. The preferable upper limit of the Fe-based alloy particles is 18.0%, still more preferably 16.0%.
[0035]
　In this specification, ferrochrome, high-carbon ferrochromium defined in JIS G 2303 (1998) (FCrH0, FCrH1, FCrH2, FCrH3, FCrH4, and, FcRH5), medium carbon ferrochrome (FCrM3, FCrM4), and low carbon ferrochromium (FCrL1, FCrL2, FCrL3, and, FCrL4) contains at least one element selected from the group consisting of.
[0036]
　In this specification, ferro tungsten, means ferro tungsten (FW) having a chemical composition as defined in JIS G 2306 (1998).
[0037]
　In this specification, ferromolybdenum comprises one or more selected from the group consisting of high carbon ferro molybdenum specified in JIS G 2307 (1998) (FMoH) and low carbon ferro molybdenum (fmol).
[0038]
　As used herein, stainless steel refers to steel alloys containing more than 50 wt% of Fe and 10.5% or more chromium. More preferably, stainless steel in the present specification, JIS G 4303 (2012), JIS G 4304 (2012), JIS G 4304 (2015), JIS G 4305 (2012), JIS G 4305 (2015), JIS G 4308 means a defined stainless steel (2013) and JIS G 4309 (2013). Stainless steel herein, for example, may be a martensitic stainless steel as defined in the JIS G 4304 (2012), may be a ferritic stainless steel, there austenitic stainless steel may be, it may be a two-phase system (austenitic ferritic) stainless steel may be precipitation hardened stainless steel.
[0039]
　Martensitic stainless steel, for example, SUS 403 defined in the JIS standard, SUS410, SUS410S, SUS420 (SUS420J1, SUS420J2), it is SUS440A like.
[0040]
　Ferritic stainless steel for example, is defined in the JIS standard SUS405, SUS410L, SUS429, SUS430, SUS430LX, SUS430J1L, SUS434, SUS436L, SUS436J1L, SUS443J1, SUS444, SUS445J1, SUS445J2, SUS447J1, SUSXM27 like.
[0041]
　Austenitic stainless steels, for example, the above defined JIS standard SUS301, SUS301L, SUS301J1, SUS302B, SUS303, SUS304, SUS304Cu, SUS304L, SUS304N1, SUS304N2, SUS304LN, SUS304J1, SUS304J2, SUS305, SUS309S, SUS310S, SUS312L, SUS315J1, SUS315J2, SUS316, SUS316L, SUS316N, SUS316LN, SUS316Ti, SUS316J1, SUS316J1L, SUS317, SUS317L, SUS317LN, SUS317J1, SUS317J2, SUS836L, SUS890L, SUS321, SUS347, SUSXM7, SUSX 15J1 is like.
[0042]
　Two-phase system (austenitic ferritic) stainless steel for example, the JIS standard to defined SUS821L1, SUS323L, SUS329J1, SUS329J3L, SUS329J4L, SUS327L1 like.
[0043]
　Precipitation hardening stainless steel for example, is defined in the JIS standard SUS630, SU631, etc..
[0044]
　The remainder of the green compact for sintering friction material is an impurity. Here, the impurity, when the industrial production of powder compact, there is to be mixed, such as from raw materials or manufacturing environment, is allowed to the extent that the sintered friction material of the present embodiment does not adversely affect means shall.
[0045]
　[For any additional material]
　the green compact is further instead of a part of the Cu, may contain one or more dispersing agents selected from the group consisting of the following (5) to (7).
[0046]
　(5) below (a) ~ (d) 1 or more selected from the group consisting of
　(a) hexagonal boron nitride: 3.0% or
　less, (b) molybdenum disulfide: 3.0% or
　less, (c ) mica: 3.0% or less,
　and, (d) iron sulfide, at least one species selected from copper sulfide and copper matte: 10.0% or less
　hexagonal boron nitride (h-BN), molybdenum disulfide (MoS 2 ), mica and iron sulfide, both one or more selected from copper sulfide and copper matte function as lubricant. These lubricant, like graphite, the friction coefficient of the sintered friction material stabilized, resulting excellent friction characteristics. However, the content of each of these lubricant if it exceeds 3.0%, decreased sintering of the sintered friction material, the wear resistance is lowered. Accordingly, the content of hexagonal boron nitride is 3.0% or less, the content of molybdenum disulfide is 3.0% or less, the content of the mica is not more than 3.0%, iron sulfide, sulfide the total content of one or more selected from copper and copper matte is 10.0%.
[0047]
　Copper matte are those listed in copper products term number 5400 of JIS H 0500 (1998), mainly consisting of iron sulfide and copper sulfide. Iron sulfide, which acts as a lubricant, respectively copper sulfide alone. It is also possible to use a mixture of copper sulfide and iron sulfide. Copper matte described above can be used in a mixture with copper sulfide and iron sulfide, and is advantageous in economical point of view because it is inexpensive.
[0048]
　(6) Vanadium carbide: 5.0% or less
　of vanadium carbide (VC) is a hard particles are contained as particles in the matrix. Vanadium carbides, the synergy is W, further enhancing the wear resistance of the sintered friction material. However, if the content of vanadium carbide is too high, sinterability of the sintered friction material is reduced, the wear resistance is lowered. Therefore, the content of vanadium carbide is 5.0% or less. A preferable lower limit of the content of vanadium carbide is 0.2%, more preferably 0.5%. Preferred upper limit of the content of vanadium carbide is 4.0%, more preferably from 3.0%.
[0049]
　(7) Fe: 20.0% or less
　of iron (Fe) is contained in the sintered friction material as particles or agglomerates in a matrix of sintered friction material. Fe increases the strength of the matrix, increasing the wear resistance of the sintered friction material. Fe further increase the friction coefficient of the sintered friction material by seizure. However, if the Fe content is too high, adhesion is likely to occur, wear resistance of the sintered friction material is lowered. Therefore, Fe content is less 20.0%. The preferable lower limit of the Fe content is 0.5%, more preferably from 4.0%. The preferable upper limit of the Fe content is 15.0%, more preferably 12.0%.
[0050]
　[Sintered for sintered friction material]
　sintered friction material according to the present embodiment is formed by pressure sintering at a known pressure sintering condition green compact described above by a known pressure sintering method. More specifically, the sintered friction material according to the present embodiment is formed by pressure sintering a green compact described above in 800 ~ 1000 ° C.. Sintered friction material according to this embodiment, the matrix of Cu, in particular containing the (1) to (4), containing optionally (5) at least one or more - (7) Accordingly, while having a sufficient frictional properties, excellent has wear resistance, in particular, excellent wear resistance at high speed range of more than 280 km / h.
[0051]
　More specifically, the sintered friction material according to the present embodiment is a 20mm diameter is 400 mm, thickness, has a chemical composition corresponding to SCM440 specified in JIS G 4053 (2016), of about 1000MPa a brake disc having a tensile strength, and prepares a caliper for braking the brake disc, each of the left and right inner surfaces of the caliper, the width 38mm, length 55 mm, four sintered friction material of height 15 mm, the brake disc 10 on a virtual circle of radius 170mm from the center of, and arranged in a row are shifted by 25 ° around the center axis of the brake disc 10, the sintered friction material which is attached to the left and right inner surfaces of the caliper relative to the brake disk that rotates when carrying out the brake test pressing on both sides of the brake disk at a constant pressure 2.24KN, braking initial speed is 365km / Average friction coefficient of the sintered friction material when is not less 0.280 or more and an average amount of friction sintered friction material on each surface of the brake disc, 6.30 g / one side braking initial speed is at 300 km / h or less, and the braking initial speed is at 6.50g / single-sided or less at 325km / h, the braking initial speed is 9.00g / single-sided or less at 365km / hr.
[0052]
　Preferably, the sintered friction material of the present embodiment, when carrying out the brake test, the preferred average friction coefficient of the brake initial velocity when 365Km / is at 0.285 or more, more preferably be 0.290 or more , still more preferably 0.300 or more.
[0053]
　Preferably, the sintered friction material of the present embodiment, when carrying out the brake test, the preferred average amount of friction braking initial speed is at 300 km / h is at 5.50 g / one side or less, more preferably 5.00 g / one side less. Braking initial speed is less than or equal to an average amount of friction is 5.70 g / one side of 325Km / h, more preferably not more than 5.20 g / one side. Braking initial speed is less than or equal to an average amount of friction is 8.50 g / one side of 365Km / h, more preferably not more than 8.00 g / one side.
[0054]
　[Manufacturing Method]
　An example of a method of manufacturing sintered friction material of the present invention will be described. An example of a method of manufacturing sintered friction material of the present invention comprises a mixed powder preparation step, a molding step, a pressure sintering process. Hereinafter, the respective steps will be described.
[0055]
　Mixed powder production process]
　granule of the above (1) to (4), further, preparing a granular material as needed (5) to (7). The prepared granular material was mixed using a known mixer or mixing, to produce a mixed powder. Known mixer, for example, a ball mill or a V-type mixer.
[0056]
　Molding Step]
　by cold-forming the produced mixed powder into a predetermined shape to produce a green compact. In the molding of the mixed powder may be applied to a known molding method. For example, by press molding, to produce the green compact. Specifically, to prepare a mold for molding a predetermined shape (die). Filling the mixed powder into a mold. Mold filling the granular material is pressurized in a known pressure with a press machine, is cold-formed into a green compact. Since a cold-forming, the green compact is usually formed at room temperature. The pressure in the press machine, for example, 180 N / mm 2 or more, preferably, 196 N / mm 2 at least. The upper limit of the pressure of a press, for example, 1000 N / mm 2 is. Molding is sufficient be carried out in the atmosphere.
[0057]
　[Pressure Sintering Step]
　by implementing well-known pressure sintering respect manufactured green compact to produce a sintered friction material. For example, placing the green compact on a graphite plate of the pressure in the sintering device. Thereafter, the inner peripheral surface to the high-frequency heating coil is arranged a box-shaped frame, and stores the graphite plate which compact is disposed in stacking. Then, while pressing the green compact by applying pressure to the top of the graphite plate and sintered at a predetermined sintering temperature in the sintering atmosphere.
[0058]
　Pressure sintering, sufficient to carried out in known conditions. Incidentally, the sintering temperature during sintering under pressure, for example, a 800 ~ 1000 ° C.. A preferred lower limit of the sintering temperature is 820 ° C., more preferably from 830 ° C., more preferably from 840 ° C.. The preferable upper limit of the sintering temperature is 980 ° C., more preferably from 970 ° C., more preferably from 960 ° C..
[0059]
　Pressure applied to the green compact during sintering under pressure, for example, 0.2 ~ 5.0 N / mm 2 is. A preferred lower limit of the pressure applied to the green compact during pressure sintering 0.3 N / mm 2 is, more preferably 0.4 N / mm 2 is, more preferably 0.5 N / mm 2 is. A preferred upper limit of the pressure applied to the green compact during pressure sintering 4.0 N / mm 2 is, more preferably 3.0 N / mm 2 is, more preferably 1.5 N / mm 2 is.
[0060]
　Holding time at the sintering temperature during sintering under pressure is 10 to 120 minutes. The lower limit of the preferred retention time is 20 minutes, more preferably from 60 minutes. The upper limit of the preferred retention time is 110 minutes, more preferably from 100 minutes.
[0061]
　Atmosphere during pressure sintering, for example, an inert gas and impurities, or an inert gas H and 2 contain gas, the balance being impurities. H 2 when containing gas, preferably H 2 content of the gas is 5 to 20%. Inert gas, for example, N 2 or a gas, is Ar gas. Preferred atmosphere during pressure sintering is 5 to 20% of H 2 containing gas, the balance being N 2 consists of and impurities. Or, preferably the atmosphere during pressure sintering, consists of Ar gas and impurities.
[0062]
　By the pressure sintering, the neck is formed in the contact portion of the green compact of the granular material, sintered friction material described above is manufactured.
[0063]
　[Other Steps]
　The above production process may further comprise the well-known coining processes and / or well known cutting process.
[0064]
　[Coining Step]
　The coining step may be carried out after the pressure sintering process. The coining step, the sintered friction material after the pressure sintering step pressurized with cold, adjust the shape of the sintered friction material.
[0065]
　[Cutting Step]
　The cutting step may be performed after pressure sintering process or after the coining process. The cutting step, by cutting the sintered friction material to a desired shape.
[0066]
　Sintered friction material for a railway vehicle according to the present invention is manufactured by the above manufacturing process. When sintered friction material for railroad vehicle is brake line training, one or more sintered friction material to the mounting plate member is fixed, it is attached to the railway vehicle.
Example
[0067]
　The mixed powder containing Table 1 shows granular material was produced.
[0068]
[Table 1]

[0069]
　Specifically, raw material, was charged into a V type mixer, mixes 20-100 minutes at a rotation speed 20 ~ 40 rpm, to produce a mixed powder of each test number.
[0070]
　By using a mixed powder of each test number, to produce a green compact by cold molding. In molding, after filling the mixed powder into a mold made of hard metal, 196 ~ 588 N / mm 2 and pressurized with, were molded green compact at ambient temperature (25 ° C.).
[0071]
　The green compact was pressure-sintered by pressure sintering to form a sintered friction material. Specifically, placing the green compact on the graphite plate. Thereafter, the inner peripheral surface to the high-frequency heating coil is arranged a box-shaped frame, and stores the staked a graphite plate which compact is placed. 850 was heated 60 minutes at ~ 950 ° C., the green compact 0.5 ~ 1.0 N / mm 2 sintered pressurized powder compact at, to produce a sintered friction material. Atmosphere in the frame in the pressure sintering is 5-10% of H 2 gas, N 2 and a mixed gas composed of the gas. With the above-described manufacturing process, to produce a sintered friction material.
[0072]
　[Brake Test]
　using a sintered friction material produced was carried out brake tests. Specifically, we were prepared bench tester 1 shown in FIG. Bench testing machine 1, equipped with a brake disc 10 is braked member, a flywheel 11, a motor 12, and a caliper 13. Brake disc 10, via a shaft 14, coupled with the flywheel 11 and the motor 12. Brake disc 10 is half the size of the brake disk used in the Shinkansen, diameter 400 mm, thickness was 20 mm. The chemical composition of the brake disc is braked member corresponded to SCM440 specified in JIS G 4053 (2016). Brake discs may implement the quenching and tempering, it was adjusted tensile strength of the brake disc to 1000 MPa.
[0073]
　Four sintered friction material 15 (lining material) was attached to the mounting plate 16. Four sintered friction material 15 the mounting plate 16 (lining material) is attached to two sets prepared, fitted with the mounting plate 16 each to the left and right inner surfaces of the caliper 13. Each sintered friction material 15 is a rectangular parallelepiped, a width 38mm, length 55 mm, a height of 15 mm. Each four of the sintered friction material, on a virtual circle of radius 170mm from the center of the brake disc 10, arranged in a row shifted by 25 ° around the center axis of the brake disc 10.
[0074]
　Friction coefficient of the brake test measurement]
　After attaching the mounting plate 16 the sintered friction material 15 (lining material) is attached to the caliper 13, it was carried out brake tests. Specifically, with respect to the brake disk is braked member that rotates, the sintered friction material 15 attached to the left and right inner surfaces of the caliper 13, against the two sides of the brake disc at a constant pressure 2.24KN (brake over), was measured torque was determined coefficient of friction (mu).
[0075]
　Speed ​​(braking initial speed) of the disc brake when the start braking, 160,240,300,325,365Km / sometimes in each braking initial speed calculated coefficient of friction. Calculated friction coefficient by multiplying the three brake in each braking initial speed, the average of three friction coefficient was defined as the average friction coefficient in the braking initial speed.
[0076]
　[Amount of wear of the brake Test
　before and after the brake test at each braking initial speed described above, obtains a mass difference of the sintered friction material, from the resulting mass difference, one side of the brake disc of a single brake test average abrasion loss of the sintered friction material per a (g / one side) was determined. Specifically, the whole mass was measured before the test in a state of sintered friction material 15 is attached to the mounting plate 16, to measure the total mass in the same state after three brakes, the mass difference 1 It was determined by set. Then, after total mass difference between the right and left two sets, divided by 3 brakes times, further a value obtained by dividing the second set number, defined average wear amount at the braking speed as (g / one side).
[0077]
　[Test Results]
　The test results of Test No. 1-8 are shown in Table 2. Also, Figure 2 shows the relationship between the braking initial speed (km / h) and the coefficient of friction of the test numbers 1 ~ 3 (μ). Furthermore, Figure 3 shows the relationship between the brake with the test numbers 1 to 3 initial speed (km / h) and the average wear amount (g / one side).
[0078]
[Table 2]

[0079]
　Referring to Table 2 and FIG. 2, in any of the braking initial speed, high average friction coefficient of more than 0.280 were obtained.
[0080]
　Further, referring to Table 2 and FIG. 3, the Fe-based alloy particles and W together Test Nos. 2 to containing 8, as compared with Test No. 1 containing no together W and Fe alloy particles, any braking also in initial speed, the average wear amount (g / one side) is low. Furthermore, by comparing the test numbers 2 ~ 8, the W content is high Test No. 3, as compared to other test number is low W content than test No. 3, the friction coefficient is relatively high, and, average wear amount was relatively low.
[0081]
　It has been described an embodiment of the present invention. However, the above-described embodiment is merely an example for implementing the present invention. Accordingly, the present invention is not limited to the embodiments described above, it can be implemented by changing the above-described embodiments without departing from the scope and spirit thereof as appropriate.

The scope of the claims
[Requested item 1]
　Mass%
　Cu: 50.0 ~ 75.0%
　graphite: 5.0 to 15.0%,
　magnesia, zircon sand, silica, zirconia, one or more selected from the group consisting of mullite and silicon nitride: 1.5 to 15.0%,
　one or more selected from the group consisting of W and Mo: 3.0 ~ 30.0% and,
　ferrochromium, ferro tungsten, ferro molybdenum, and, from the group consisting of stainless steel one or more selected: from 2.0 to 20.0 percent,
　containing the balance being sintered material of the green compact consisting of impurities, sintered for railway vehicles sintered friction material.
[Requested item 2]
　A railcar sintered friction material according to claim 1,
　wherein a green compact a sintered material formed by pressure sintering at 800 ~ 1000 ° C., sintered for railway vehicles sintered friction material.
[Requested item 3]
　A claim 1 or claim 2 for railway vehicles sintered friction material according to,
　organic 400mm diameter, a is 20mm thick, the chemical composition corresponding to SCM440 specified in JIS G 4053 (2016) and a brake disk having a tensile strength of about 1000 MPa, to prepare a caliper for braking the brake disc, each of the left and right inner surfaces of the caliper, the width 38mm, length 55 mm, 4 one of said baked height 15mm the binding friction material, on a virtual circle of radius 170mm from the center of the brake disc, are arranged in a row are shifted by 25 ° around the central axis of the brake disc, with respect to the brake disk rotating, the right and left of the caliper the sintered friction material attached to the inner surface, the brake test pressing on both sides of the brake disk at a constant pressure 2.24kN If implemented, braking initial speed is the average friction coefficient of the sintered friction material when 365Km / is 0.280 or more and an average amount of friction of the sintered friction material on each surface of the brake disc, brake initial velocity is at 6.30g / single-sided or less at 300km / h, the braking initial speed is at 6.50g / single-sided or less at 325km / h, it is 9.00g / single-sided or less in the braking initial speed is 365km / hour, for a railway vehicle sintered friction material.
[Requested item 4]
　Claims 1 to 3 further comprising a railcar sintered friction material according to any one,
　the green compact, instead of a part of the Cu,
　hexagonal boron nitride: 3.0% hereinafter,
　molybdenum disulfide: 3.0% or less,
　mica: 3.0% or less, and,
　iron sulfide, at least one species selected from copper sulfide and copper matte: 10.0% or less,
　vanadium carbide: 5.0 % or less, and,
　Fe: 20.0% or less,
　containing one or more members selected from the group consisting of, sintered for railway vehicles sintered friction material.
[Requested item 5]
　The manufacturing method of claims 1 to railcar sintered friction material according to any one of 4, a molding step for manufacturing the green compact mixed powder was cold forming,
　the pressure by carrying out pressure sintering at a sintering temperature of 800 ~ 1000 ° C. the powder, the and a pressure sintering process for manufacturing a railcar sintered friction material, sintered for railway vehicles sintered friction material the method of production.