Abstract: There is provided a sintered friction material for railway vehicles that has excellent frictional properties and wear resistance even in a high speed range of 280 km/hour or more. The sintered friction material for railway vehicles is a green compact sintered material containing, in mass %, Cu: 50.0 to 75.0%, graphite: 5.0 to 15.0%, one or more selected from the group consisting of magnesia, zircon sand, silica, zirconia, mullite, and silicon nitride: 1.5 to 15.0%, one or more selected from the group consisting of W and Mo: 3.0 to 30.0%, and one or more selected from the group consisting of ferrochromium, ferrotungsten, ferromolybdenum, and stainless steel: 2.0 to 20.0%, with the balance being impurities.

Abstract: Metallic alloys and methods for the preparation of free-standing metallic materials in a layerwise manner. The resulting layerwise construction provides a metallic skeleton of selected porosity which may be infiltrated with a second metal to provide a free-standing material that has a volume loss of less than or equal to 130 mm3 as measured according to ASTM G65-04 (2010).

Abstract: There is provided a brake lining for a railway vehicle that can reduce brake squeal in braking. A brake lining for a railway vehicle is used for a disc brake system of a railway vehicle. This brake lining includes a base plate, a sintered friction material, and a friction material supporting mechanism. The friction material supporting mechanism is disposed between the base plate and the sintered friction material and supports the sintered friction material in such a manner that the sintered friction material can move with respect to the base plate. The sintered friction material has a Young's modulus of 35.0 GPa or more.

Abstract: This free-cutting copper alloy contains Cu: 58.5 to 63.5%, Si: more than 0.4% and 1.0% or less, Pb: 0.003 to 0.25%, and P: 0.005 to 0.19%, with the remainder being Zn and inevitable impurities, a total amount of Fe, Mn, Co and Cr is less than 0.40%, a total amount of Sn and Al is less than 0.40%, a relationship of 56.3?f1=[Cu]?4.7×[Si]+0.5×[Pb]?0.5×[P]?59.3 is satisfied, constituent phases of a metal structure have relationships of 20?(?)?75, 25?(?)?80, 0?(?)<2, 20?(?)1/2×3+(?)×(?0.5×([Si])2+1.5×[Si])?78, and 33?(?)1/2×3+(?)×(?0.5×([Si])2+1.5×[Si])+([Pb])1/2×33+([P])1/2×14, and a compound including P is present in ? phase.

Abstract: The invention relates to a highly heat conductive valve seat ring (1) comprising a carrier layer (2) and a functional layer (3), wherein the carrier layer (2) consists of a solidified copper matrix containing 0.10 to 20% w/w of a solidifying component and the functional layer (3) consists of a solidified copper matrix which further contains, based on the copper matrix, 5 to 35% w/w of one or more hard phases.

Abstract: A sliding member includes a base substrate and a coating layer formed on the base substrate. The coating layer includes a steel portion derived from austenitic stainless steel particles and a copper portion derived from copper particles or copper alloy particles. The steel portion and the copper portion are bonded to each other via an interface between the steel portion and the copper portion.

Abstract: A fine particle in which a surface of a copper oxide fine particle (a) is coated with a coating layer (b) containing a monovalent copper compound, in which the fine particle has a specific surface area of 100 m2/g or greater, an average primary particle diameter in a range of 5 to 20 nm, and an average secondary particle diameter in a range of 5 to 50 nm, is provided.

Abstract: Novel metallic systems and methods for their fabrication provide high temperature machine parts formed of a consolidated nano-crystalline metallic material. The material comprises a matrix formed of a solvent metal having a melting point greater than 1,250° C. with crystalline grains having diameters of no more than about 500 nm, and a plurality of dispersed metallic particles formed on the basis of a solute metal in the solvent metal matrix and having diameters of no more than about 200 nm. The particle density along the grain boundary of the matrix is as high as about 2 nm2 of grain boundary area per particle so as to substantially block grain boundary motion and rotation and limit creep at temperatures above 35% of the melting point of the consolidated nano-crystalline metallic material. The machine parts formed may include turbine blades, gears, hypersonics, radiation shielding, and other high temperature parts.

Abstract: Novel metallic systems and methods for their fabrication provide an extreme creep-resistant nano-crystalline metallic material. The material comprises a matrix formed of a solvent metal with crystalline grains having diameters of no more than about 500 nm, and a plurality of dispersed metallic particles formed on the basis of a solute metal in the solvent metal matrix and having diameters of no more than about 200 nm. The particle density along the grain boundary of the matrix is as high as about 2 nm2 of grain boundary area per particle so as to substantially block grain boundary motion and rotation and limit creep at temperatures above 35% of the melting point of the material.

Abstract: A clay-like composition for forming a sintered copper body of the present invention includes a powder constituent containing a copper-containing metal powder which contains copper and a copper-containing oxide powder which contains copper; a binder; and water, wherein the amount of oxygen contained in the powder constituent is in a range of from 4 mass % to 8 mass %.

Abstract: Seizure resistance and wear resistance of Cu—Bi—In copper-alloy sliding material are enhanced by forming a soft phase of as pure as possible Bi. Mixed powder of Cu—In cuprous alloy powder and Cu—Bi containing Cu-based alloy powder is used. A sintering condition is set such that Bi moves outside particles of said Cu—Bi containing Cu-based powder and forms a Bi grain-boundary phase free of In, and In diffuses from said Cu—In containing Cu-based powder to said Cu—Bi containing Cu-based powder.

Abstract: Electrodes for metal-air batteries and the metal-air batteries employing such electrodes are provided. The electrodes include metal nanoparticles synthesized via a novel route. The nanoparticle synthesis is facile and reproducible, and provides metal nanoparticles of very small dimension and high purity for a wide range of metals. The electrodes utilizing these nanoparticles thus may have superior capability. Electrochemical cells employing said electrodes are also provided.

Abstract: A sintered metal bearing is obtained by compression-molding of a raw-material powder containing at least a Cu powder, an SUS powder, and a pure Fe powder and thereafter sintering a compression-molded body at a predetermined temperature.

Abstract: [Problems to be Solved] To provide a sputtering target that is capable of forming a Cu—Ga film to which Na is favorably added by a sputtering method, and a method for producing the same. [Means to Solve the Problems] The sputtering target is provided wherein 20 to 40 at % of Ga, 0.05 to 2 at % of Na, and 0.025 to 1.0 at % of S are contained and a remaining portion has a component composition consisting of Cu and unavoidable impurities. Also, a method for producing the sputtering target includes the step of hot pressing a mixed powder of Na2S powder and Cu—Ga alloy powder or a mixed powder of Na2S powder, Cu—Ga alloy powder, and pure Cu powder in a vacuum atmosphere or an inert gas atmosphere or sintering a mixed powder of Na2S powder and Cu—Ga alloy powder or a mixed powder of Na2S powder, Cu—Ga alloy powder, and pure Cu powder by hot isostatic pressing.

Abstract: A sintered body of silver fine particles for a bonding member to bond components of a semiconductor device, wherein an activation energy for creep of the sintered body of the silver fine particles is from 0.4 to 0.75 times that of an activation energy for a lattice diffusion of bulk silver.

Abstract: [Problems to be Solved] To provide a sputtering target that is capable of forming a Cu—Ga film to which Na is favorably added by a sputtering method, and a method for producing the same. [Means to Solve the Problems] The sputtering target is provided wherein 20 to 40 at % of Ga, 0.05 to 2 at % of Na, and 0.025 to 1.0 at % of S are contained and a remaining portion has a component composition consisting of Cu and unavoidable impurities. Also, a method for producing the sputtering target includes the step of hot pressing a mixed powder of Na2S powder and Cu—Ga alloy powder or a mixed powder of Na2S powder, Cu—Ga alloy powder, and pure Cu powder in a vacuum atmosphere or an inert gas atmosphere or sintering a mixed powder of Na2S powder and Cu—Ga alloy powder or a mixed powder of Na2S powder, Cu—Ga alloy powder, and pure Cu powder by hot isostatic pressing.

Abstract: Provided is a copper-based sliding material including a steel back-metal layer and a Cu alloy layer. The Cu alloy layer contains, by mass %, 10 to 30% of Bi, 0.5 to 5% of an inorganic compound, and the balance being Cu and inevitable impurities. The Cu alloy layer may further contain 0.5 to 5% of Sn and/or at least one element selected from the group consisting of Ni, Fe, P and Ag in a total amount of 0.1 to 10%. The inorganic compound has an average particle size of 1 to 5 ?m and a specific gravity of 70 to 130% relative to the specific gravity of Bi. Bi phase is formed in the Cu alloy layer in an average particle size of 2 to 15 ?m, and the Bi phase is dispersed in the Cu alloy layer and isotropic.

Abstract: The present invention relates to sliding material provided by sintering a lead-free copper or copper alloy and contains at least one mineral selected from the group consisting of talc, mica, kaolinite mineral and montmorillonite mineral. Pb has conventionally been included in sliding materials for the purpose of obtaining conformability and seizure resistance. Despite the absence of Pb, the Pb-free copper-based sliding material and sliding parts according to the present invention have improved sliding properties.

Abstract: [Problems] To provide a sputtering target that is capable of forming a Cu—Ga film to which Na is favorably added by a sputtering method, and a method for producing the same. [Means for Solving the Problems] The sputtering target is provided wherein 20 to 40 at % of Ga and 0.05 to 1 at % of Na are contained as metal components except fluorine (F) of the sputtering target, a remaining portion has a component composition consisting of Cu and unavoidable impurities, and Na is contained in the state of a NaF compound. Also, a method for producing the sputtering target includes the steps of forming a molded article consisting of a mixed powder of NaF powder and Cu—Ga powder or a mixed powder of NaF powder, Cu—Ga powder, and Cu powder; and sintering the molded article in a vacuum atmosphere, an inert gas atmosphere, or a reducing atmosphere.

Abstract: A composite sintered powder metal article including a first region including a cemented hard particle material such as, for example, cemented carbide. The article includes a second region including: a metallic material selected from a steel, nickel, a nickel alloy, titanium, a titanium alloy, molybdenum, a molybdenum alloy, cobalt, a cobalt alloy, tungsten, a tungsten alloy; and from 0 up to 30 percent by volume of hard particles. The first region is metallurgically bonded to the second region, and each of the first region and the second region has a thickness of greater than 100 microns. The second region comprises at least one mechanical attachment feature so that the composite sintered powder metal article can be attached to another article. The article comprises one of an earth boring article, a metalcutting tool, a metalforming tool, a woodworking tool, and a wear article.

Abstract: Provided are a method of producing mixed powder comprising noble metal powder and oxide powder, wherein powder of ammonium chloride salt of noble metal and oxide powder are mixed, the mixed powder is subsequently roasted, and ammonium chloride is desorbed by the roasting process in order to obtain mixed powder comprising noble metal powder and oxide powder, and mixed powder comprising noble metal powder and oxide powder, wherein chlorine is less than 1000 ppm, nitrogen is less than 1000 ppm, 90% or more of the grain size of the noble metal powder is 20 ?m or less, and 90% or more of the grain size of the oxide powder is 12 ?m or less. Redundant processes in the production of noble metal powder are eliminated, and processes are omitted so that the inclusion of chlorine contained in the royal water and nitrogen responsible for hydrazine reduction reaction is eliminated as much as possible.

Abstract: The invention relates to a slide bearing composite material having at least one carrier layer and a sintered bearing metal layer. The sintered bearing metal layer is designed in at least one layer region as a gradient layer.

Abstract: An Au—Sn alloy bump that does not include large voids and a method of producing the same are provided. The Au—Sn alloy bump that does not include large voids comprises a composition containing Sn: 20.5 to 23.5 mass % and the balance Au and unavoidable impurities, and a structure where 0.5 to 30 area % of Sn-rich primary crystal phase is crystallized in the matrix.

Abstract: A bearing material and a method for the manufacture of a bearing having a lining of the bearing material is described, the bearing material comprising: in wt %: 4-12 tin; 0.1-2 nickel; 1-6 bismuth; 0.01-less than 0.10 alumina; balance copper apart from incidental impurities.

Abstract: [OBJECT] A composition of a metal nanoparticle is provided in which reproducibility in a method of producing a metal film with excellent low-temperature sinterable properties is improved. An article using the metal nanoparticle composition is also provided. [SOLVING MEANS] A composition of a metal nanoparticle that has a secondary aggregation diameter (median diameter) of 2.0 ?m or less as determined by disk centrifugal-type particle size measurement is used.

Abstract: High-density thermodynamically stable nanostructured copper-based metallic systems, and methods of making, are presented herein. A ternary high-density thermodynamically stable nanostructured copper-based metallic system includes: a solvent of copper (Cu) metal; that comprises 50 to 95 atomic percent (at. %) of the metallic system; a first solute metal dispersed in the solvent that comprises 0.01 to 50 at. % of the metallic system; and a second solute metal dispersed in the solvent that comprises 0.01 to 50 at. % of the metallic system. The internal grain size of the solvent is suppressed to no more than 250 nm at 98% of the melting point temperature of the solvent and the solute metals remain uniformly dispersed in the solvent at that temperature. Processes for forming these metallic systems include: subjecting powder metals to a high-energy milling process, and consolidating the resultant powder metal subjected to the milling to form a bulk material.

Abstract: The present invention relates to Cu33Al17 alloys and Cu33Al17-based bulk alloys and coatings that exhibit significantly increased hardness characteristics compared to traditional copper-aluminum alloys

Abstract: A composite article (1; 10; 40) comprises a plurality of inclusions (5) of a magnetocalorically active material embedded in a matrix (4) of a magnetocalorically passive material. The inclusions (5) and the matrix (4) have a microstructure characteristic of a compacted powder.

Abstract: A process for producing a Cu—Cr material by powder metallurgy for a switching contact, in particular for vacuum switches, includes the steps of pressing a Cu—Cr powder mixture formed from Cu powder and Cr powder and sintering the pressed Cu—Cr powder mixture to form the material of the Cu—Cr switching contact. The sintering or a subsequent thermal treatment process is carried out with an alternating temperature profile, in which the Cu—Cr powder mixture or the Cu—Cr material is heated above an upper temperature limit value and cooled again below a lower temperature limit value at least twice in alternation. All of the steps are carried out at temperatures at which no molten phase forms.

Abstract: Copper powder is provided, which, while having fine granularity and resistance to oxidation, does not lose either resistance to oxidation or balance in conductivity, and furthermore, copper powder for conductive paste in which variations in shape and granularity are small and having a low concentration in oxygen content. The copper powder for conductive paste contains 0.05 to 10 atomic % Bi inside each particle.

Abstract: Copper powder is provided, which, while having fine granularity, does not loose either resistance to oxidation or balance in conductivity, and furthermore, copper powder for conductive paste in which variations in shape and granularity are small and having a low concentration in oxygen content. The copper powder for conductive paste contains 0.07 to 10 atomic % Al inside each copper particle in the powder.

Abstract: A macroscopic composite sintered powder metal article including a first region including cemented hard particles, for example, cemented carbide. The article includes a second region including one of a metal and a metallic alloy selected from the group consisting of a steel, nickel, a nickel alloy, titanium, a titanium alloy, molybdenum, a molybdenum alloy, cobalt, a cobalt alloy, tungsten, and a tungsten alloy. The first region is metallurgically bonded to the second region, and the second region has a thickness of greater than 100 microns. A method of making a macroscopic composite sintered powder metal article is also disclosed, herein. The method includes co-press and sintering a first metal powder including hard particles and a powder binder and a second metal powder including the metal or metal alloy.

Abstract: The present invention relates to a copper-based sintered slide member comprising 0.5 to 20% by weight of tin, 0.1 to 35% by weight of manganese, 2 to 25% by weight of a solid lubricant and the balance essentially consisting of copper; and a multilayer copper-based sintered slide member comprising a copper-based alloy sintered layer and a metal backing plate which are formed into an integral multilayer structure, wherein the copper-based alloy sintered layer comprises 0.5 to 20% by weight of tin, 0.1 to 35% by weight of manganese, 2 to 25% by weight of a solid lubricant and the balance essentially consisting of copper. The above slide members are in the form of a lead-free copper-based sintered slide member.

Abstract: A sintered metal bearing is obtained by compression-molding of a raw-material powder containing at least a Cu powder, an SUS powder, and a pure Fe powder and thereafter sintering a compression-molded body at a predetermined temperature.

Abstract: [Object] A composition of a metal nanoparticle is provided in which reproducibility in a method of producing a metal film with excellent low-temperature sinterable properties is improved. An article using the metal nanoparticle composition is also provided. [Solving Means] A composition of a metal nanoparticle that has a secondary aggregation diameter (median diameter) of 2.0 ?m or less as determined by disk centrifugal-type particle size measurement is used.

Abstract: A bonding material comprising metal particles coated with an organic substance having carbon atoms of 2 to 8, wherein the metal particles comprises first portion of 100 nm or less, and a second portion larger than 100 nm but not larger than 100 ?m, each of the portions having at least peak of a particle distribution, based on a volumetric base. The disclosure is further concerned with a bonding method using the bonding material.

Abstract: The present invention relates to a copper-based sintered slide member comprising 0.5 to 20% by weight of tin, 0.1 to 35% by weight of manganese, 2 to 25% by weight of a solid lubricant and the balance essentially consisting of copper; and a multilayer copper-based sintered slide member comprising a copper-based alloy sintered layer and a metal backing plate which are formed into an integral multilayer structure, wherein the copper-based alloy sintered layer comprises 0.5 to 20% by weight of tin, 0.1 to 35% by weight of manganese, 2 to 25% by weight of a solid lubricant and the balance essentially consisting of copper. The above slide members are in the form of a lead-free copper-based sintered slide member.

Abstract: A discontinuously reinforced metal matrix composite wherein the reinforcing material is a particulate binary intermetallic compound is described along with methods for preparing the same. The binary intermetallic compound includes the same type of metal as is the principal matrix metal in combination with one other metal. The particle size of the particulate binary intermetallic compound may be less than about 20 ?m and may be between about 1 ?m and about 10 ?m. The intermetallic particles may be present in the discontinuously reinforced metal matrix composites in an amount ranging from about 10% to about 70% by volume. The discontinuous reinforced metal matrix composites of the invention may be used in structures requiring greater strength and stiffness than can be provided by matrix metal alone. The materials of the invention may be used for vehicle parts, structural materials, and the like.

Abstract: A method of manufacturing a metal-graphite brush material for a motor, which allows high-density formation of copper particles on the surfaces of graphite particles. The method: attaches copper complex to graphite particles; heat-treats the graphite particles attached with the copper particles, thereby to pyrolyze the copper complex to form copper particles on the surfaces of the graphite particles; forms the graphite particles having the copper particles formed thereon, together with a resin, into a formed product; and reduction-sinters the formed product under a reducing atmosphere to pyrolyze the resin, thereby to form a sintered body and also to reduce copper oxide formed in surface layers of the copper particles during the heat-treating.

Abstract: The present invention includes consolidated hard materials, methods for producing them, and industrial drilling and cutting applications for them. A consolidated hard material may be produced using hard particles such as B4C or carbides or borides of W, Ti, Mo, Nb, V, Hf, Ta, Zr, and Cr in combination with an iron-based, nickel-based, nickel and iron-based, iron and cobalt-based, aluminum-based, copper-based, magnesium-based, or titanium-based alloy for the binder material. Commercially pure elements such as aluminum, copper, magnesium, titanium, iron, or nickel may also be used for the binder material. The mixture of the hard particles and the binder material may be consolidated at a temperature below the liquidus temperature of the binder material using a technique such as rapid omnidirectional compaction (ROC), the CERACON® process, or hot isostatic pressing (HIP). After sintering, the consolidated hard material may be treated to alter its material properties.

Abstract: Hard phase particles including Co alloy particles, carbide alloy particles, and silicide particles are dispersed substantially uniformly throughout a matrix composed of Cu self-fluxing alloy of a cladded portion. The cladded portion contains 6 to 15% by weight of Co, 3 to 8% by weight of one of Cr and Mo, 0.3 to 1% by weight of W, 0.5 to 1.8% by weight of Fe, 8 to 15% by weight of Ni, 0.08 to 0.2% by weight of C, 1.5 to 4% by weight of Si, 0.5 to 0.8% by weight of Al, and 0.1 to 0.3% by weight of P, and inevitable impurities and Cu as a balance. The hard phase particles have an average particle diameter of 8 to 20 ?m and a particle size distribution width of 0.1 to 100 ?m, and to occupy 10 to 20% in an arbitrary cross section of the cladded portion.

Abstract: An electrical contact used herein comprises chromium; one of copper and silver; and a carbide, in which the electrical contact comprises a matrix and chromium, the matrix phase mainly comprising one of copper and silver, and the chromium being surrounded by the carbide and dispersed in the matrix. The electrical contact contains 1 to 30 percent by weight of a carbide, with the balance being copper. Another electrical contact contains chromium, copper, and a carbide and has a weight ratio of chromium to the carbide within the range of 1:1.5 to 1:50.

Abstract: Medium- and high-density articles are formed from alloys containing tungsten, iron, nickel and optionally manganese and/or steel. In some embodiments, the articles have densities in the range of 8-10.5 g/cm3, and in other embodiments, the articles have densities in the range of 10.5-15 g/cm3. In some embodiments, the articles are ferromagnetic, and in others the articles are not ferromagnetic. In some embodiments, tungsten forms the largest weight percent of the alloy, and in other embodiments the alloy contains no more than 50 wt % tungsten. In some embodiments, the articles are shell shot.

Abstract: Discontinuous diamond particulate containing metal matrix composites of high thermal conductivity and methods for producing these composites are provided. The manufacturing method includes producing a thin reaction formed and diffusion bonded functionally graded interactive SiC surface layer on diamond particles. The interactive surface converted SiC coated diamond particles are then disposed into a mold and between the particles and permitted to rapidly solidify under pressure. The surface conversion interactive SiC coating on the diamond particles achieves minimal interface thermal resistance with the metal matrix which translates into good mechanical strength and stiffness of the composites and facilitates near theoretical thermal conductivity levels to be attained in the composite. Secondary working of the diamond metal composite can be performed for producing thin sheet product.

Abstract: The present invention relates to particle reinforced noble metal matrix composites and a method of making the same. The composites include a noble metal such as silver, gold, and alloys thereof, as a base or matrix, and a particle reinforced filler material, such as a carbide. A pressureless infrared heating, or superheating, process is used to produce the particle reinforced noble metal matrix composites thereby providing a composite with at least sufficient hardness, i.e. wear resistance, and/or low resistivity. The composites may be used in the jewelry industry, such as for making watches, rings, and other jewelry, and/or in the power, automobile, and aircraft industries, such as for making electrical contact materials.

Abstract: A liquid coating composition including a coating vehicle and composite powder particles disposed within the coating vehicle. Each composite powder particle may include a magnesium component, a zinc component, and an indium component.

Abstract: A turbomachinery component includes a substrate having a surface, the surface consisting essentially of at least one composite of at least one metal and at least one compound having the chemical formula Mn+1AXn, wherein M is at least one early transition metal selected from groups IIIB, IVB, VB, and VIB, A is at least one element selected from groups IIIA, IVA, VA, VIA, and VIIA, X is one or both of carbon and nitrogen, and n is an integer between 1 and 3. The component is made by compressing a powdered material to form a substrate that consists essentially of the composite and sintering the substrate, or by coating a substrate with the composite.

Abstract: The present invention includes consolidated hard materials, methods for producing them, and industrial drilling and cutting applications for them. A consolidated hard material may be produced using hard particles such as B4C or carbides or borides of W, Ti, Mo, Nb, V, Hf, Ta, Zr, and Cr in combination with an iron-based, nickel-based, nickel and iron-based, iron and cobalt-based, aluminum-based, copper-based, magnesium-based, or titanium-based alloy for the binder material. Commercially pure elements such as aluminum, copper, magnesium, titanium, iron, or nickel may also be used for the binder material. The mixture of the hard particles and the binder material may be consolidated at a temperature below the liquidus temperature of the binder material using a technique such as rapid omnidirectional compaction (ROC), the CERACON™ process, or hot ecstatic pressing (HIP). After sintering, the consolidated hard material may be treated to alter its material properties.

Abstract: The problem is to provide an Au—Sn alloy powder for use in producing an Au—Sn alloy solder paste having reduced generation of voids. The problem is solved by an Au—Sn alloy powder for a solder paste, which has a composition consisting of Sn of 20.5-23.5% by mass and a remainder containing Au and inevitable impurities, and which has a microstructure in which 0.5 to 30 area % of fine Sn-rich primary crystal phase regions having a diameter of 3 ?m or less are crystallized in a matrix.

Abstract: An inner rotor having excellent corrosion resistance, which has an outer gear serving as a component of an internal gear pump, and an outer rotor having excellent corrosion resistance, which has an inner gear engaging with the outer gear. The inner rotor and outer rotor of are made of Cu—Ni-based sintered copper alloy that contains 12 to 50% by mass of Ni, 5 to 20% by mass of Sn, 0.5 to 5% by mass of C, and if necessary, further contains 5 to 20% by mass of Zn, 0.1 to 0.9% by mass of P, and a balance being Cu and inevitable impurities.