322 results about "Sintered alloy" patented technology

An electrically powered steering device comprises a ball screw mechanism for transmitting a steering force from a steering wheel to steerable vehicle wheels. The ball screw mechanism includes a rotary nut 11 having a nut body 11a in which a circulating passage 15 is formed so as to extend axially thereof, and end caps 14a and 14b secured respectively to opposite ends of the nut body 11a. Each of the end caps 14a and 14b has defined therein respective guideways 17a and 17b for balls 13 that communicate opposite ends of the circulating tunnel 14 with a ball rolling passage 12. The end caps 14a and 14b and the nut body 11a are made of a sintered alloy. The nut body 11a has an outer periphery of one end thereof that is axially progressively reduced in diameter to define a tapered surface.

A valve seat made of an iron base sintered alloy for internal combustion engines comprises of hard particles of hardness 700-1300 Hv dispersed by 3-20% by volume in a matrix phase comprising comprising of a 5-40% psarlite phase, a 20-60% fine carbide dispersed phase, and a 5-20% high alloy diffusd phase. The hard paricles are preferably selected from a group of Mo-Ni-Cr-Si-Co intermetallic compound particles, Cr-Mo-Co intermetallic compound particles, and Fe-Mo alloy particles. The iron base sinteed alloy is conpised of, by weight, C: 0.2-2.0%, Cr: 1.0-9.0%, Mo: 1.0-9.0%, Si: 0.1-1.0%, W: 1.0-50%, V: 0.2-3.0%, one or more Cu, Co and Ni of 0.5-10.0% in total, and the remainder substantial Fe.

The invention discloses a high-strength lamellar Al-based metal ceramic composite material and a preparation method thereof, aiming at solving the problems of high preparation cost, complex operation, single type of reinforcement ceramic and low strength. The high-strength lamellar Al-based metal ceramic composite material, i.e., high-strength lamellar structure Al-Si-Mg/(Al2O3, SiC, TiC) composite material comprises ceramic powder and Al-Si-Mg alloy. The volume fraction of ceramic powder is 20%-40vol%; the volume fraction of Al-Si-Mg alloy is 80%-60vol%; the mass ratio of aluminum in the Al-Si-Mg alloy is 75-84wt%; the mass ratio of silicon is 10-15wt%; the mass ratio of magnesium is 6-10wt%. The preparation method of the high-strength lamellar Al-based metal ceramic composite material comprises the following steps: preparation of water-based ceramic slurry; directional solidification; freezing and drying; sintering of blanks; smelting of alloy; and non-pressure infiltration.

A rare earth alloy sintered compact includes a main phase represented by (LR_1-xHR_x)₂T₁₄A, where T is Fe with or without non-Fe transition metal element(s); A is boron with or without carbon; LR is a light rare earth element; HR is a heavy rare earth element; and 0<x<1. The sintered compact is produced by preparing multiple types of rare earth alloy materials including respective main phases having different HR mole fractions, mixing the alloy materials so that the sintered compact will include a main phase having an average composition represented by (LR_1-xHR_x)₂T₁₄A, thereby obtaining a mixed powder, and sintering the mixed powder. The alloy materials include first and second rare earth alloy materials represented by (LR_1-uHR_u)₂T₁₄A (where 0≦u<x) and (LR_1-vHR_v)₂T₁₄A (where x<v≦1) and including a rare earth element R(=LR+HR) at R1 and R2 (at %), respectively. ΔR=|R1−R2| is about 20% or less of (R1+R2)/2.

In a Cu—Bi based sintered alloy, to which hard particles, such as Fe₃P, are added, the main constituent components of the microstructure are a Cu matrix, Bi phase and the hard particles. In the sintering method of the present invention, the flow of the Bi phase is suppressed to as low level as possible. The novel structure is that the contact between the Bi phase and hard particles is kept to a low ratio. A lead-free bearing used for a fuel injection pump according to the present invention contains from 1 to 30 mass % of Bi and from 0.1 to 10 mass % of hard particles having from 10 to 50 μm of the average particle diameter, the balance being Cu and unavoidable impurities. The properties of the main component phases are utilized at a high level such that the sliding properties are equivalent to those of a Pb containing Cu-based sintered alloy.

The present invention relates to the preparation of cermet material, and the sintered alloy has submicron crystal grain structure, and high hardness, toughness and strength. The cermet is prepared through mixing IVB, VB, VIB, Ti, one or more metal carbide, nitride or complex solid solution carbide-nitride ceramic powder and iron family element Ni, Co, etc.; high-energy ball milling, drying, pressing to form, vacuum sintering, hot isostatic pressing and other steps. The cermet has hard crystal phase reaches submicron granularity of 0.6-1.0 micron. Under scanning electronic microscope, four kinds of metal structure may be observed including black core phase, white core phase, gray ring phase and white adhesion phase. Compared with available cermet, the present invention has obviously improved hardness and toughness, and may be used in cutter and other wear resistant parts.

Alloy powder for forming a hard phase for a valve seat material having excellent high temperature wear resistance. The overall composition is consisted of Mo: 48 to 60 mass %, Cr: 3 to 12 mass % and Si: 1 to 5 mass %, and the balance of Co and inevitable impurities.

An iron-base mixed powder for powder metallurgy which comprises an iron-base powder and at least one member selected from between talc and steatite and preferably further contains a metal soap.This mixed powder does not produce adverse effect on furnace atmosphere in sintering a compact of the powder and exhibits excellent compactibility even in a low-temperature region of below 100 DEG C and the sintered compact made from the powder is favorably excellent in machinability.

An iron-based sintered alloy material for a valve seat having improved wear resistance and reduced opposite aggressibility to a mating valve. The iron-based sintered alloy material contains 10% to 20% by area of first hard particles and 15% to 35% by area of second hard particles dispersed in a base matrix phase, the first and the second hard particles accounting for 25% to 55% by area in total. The first hard particles are composed of a cobalt-based intermetallic compound and have a size of 10 to 150 μm and a hardness of at least 500HV0.1 and less than 800HV0.1. The second hard particles are composed of a cobalt-based intermetallic compound and have a size of 10 to 150 μm and a hardness of at least 800HV0.1 and less than 1100HV0.1. Solid lubricant particles may also be dispersed in the base matrix phase.

The invention discloses a preparation method of a carbon fiber reinforced copper-based composite material. The preparation method comprises the following steps: I, weighing ingredients and carrying out ball-milling mixing for 3 hours, thereby obtaining a mixed material, and wrapping the surface of carbon fiber by a nickel layer, wherein the particle size of graphite powder is 50mu m, the graphite powder is subjected to chemical plating technical treatment, and a copper layer is plated on the surface of the graphite powder; II, pressing the mixed material prepared in the step I under the pressure of 700MPa, thereby obtaining a blank; III, performing secondary sintering on the blank prepared in the step II, thereby obtaining a sintered alloy block; and IV, performing thermal treatment on the alloy block treated in the step III, thereby obtaining the carbon fiber reinforced copper-based composite material. The carbon fiber reinforced copper-based composite material disclosed by the invention not only has excellent self-lubrication property, but also is particularly excellent in wearing resistance and mechanical property.

A sliding bearing which is suitable for and durable in the use under high load of sliding in rocking motion, and the structure of bearing is not complicated so as to facilitate the manufacturing. The alloy used for making the bearing is composed of iron-based sintered alloy having quenched structure, and the bearing surface is provided with inclined grooves of an inclination angle of 10 to 40° relative to the direction perpendicular to the sliding direction and a width of 2 to 8 mm and the area of inclined grooves is 50% or less of the total inner bearing surface and an imaginary line perpendicular to the sliding direction crosses both the inclined groove and the bearing surface at any position of the inner surface of bearing. When the bearing is used, at least the inclined grooves are impregnated with a lubricant.

The invention discloses a preparation method of a high-strength nano-porous nickel film, and belongs to the technical field of a nano-porous metal film material, in particular discloses a method for preparing a high-strength nano-porous metal film material combining a micron-sized reinforcing framework and nano-sized pores through mixing alloy and metal powder, implementing powder metallurgy to obtain an alloy sheet, and further dealloying the sintered alloy sheet. The preparation method, through preparing a film precursor by powder metallurgy and selective corrosion in junction with dealloying, can increase the number of pores, and simultaneously keep high strength; aperture of the nano-porous metal film is adjustable from 0.5nm to 100nm when controlling various reaction conditions and parameters. The entire process, which is implemented in a stable environment, is safe, reliable, pollution-free, simple, low in cost and up to industrial demand, so that the prepared nano-porous metal film material is applicable to such aspects as biological medicine, organic synthesis, organic solvent micro and nano-filtration, catalysis and the like.

A bearing for a motorized fuel pump is made of a Cu—Ni based sintered alloy, composed of: 21 to 35% by mass of Ni, 5 to 12% by mass of Sn, 3 to 7% by mass of C, 0.1 to 0.8% by mass of P, and the balance of Cu and inevitable impurities. A matrix of the bearing is formed with pores with a porosity of 8 to 18%, and the P component is predominantly included at the grain boundary, and free graphite is distributed along the insides of open pores that are open to the surface and extending into the bearing. In this bearing, a Sn rich alloy layer containing equal to or more than 50% by mass of Sn is formed on the insides of the open pores and near openings of the open pores.

The invention discloses a coating for high bonding phase cemented carbide sintering. The coating comprises the following components in percentage by mass: 55-69.5 percent of metal oxide powder, 2.85-6.1 percent of carbon black, 0.15-3.5 percent of water soluble adhesive (powder) and 27.5-38 percent of distilled water. When the coating prepared by utilizing the components is painted on a graphite sintering boat, the coating can effectively separate the direct contact between a high bonding phase cemented carbide sintering product and the graphite boat, prevent the occurrence of diffusion and migration of liquid phase and carbon between the sintered alloy and the graphite boat under the liquid phase sintering temperature and achieve the purposes of anti-bonding and anti-carburizing. The coating has the advantages of low cost, simple preparation and no pollution on a sintering furnace, no toxicity for an operator, no dust harm and easy cleaning and is an ideal coating for high bonding phase cemented carbide sintering.

Disclosed is a manufacturing process of a sintered iron-copper base porous alloy and of an oil-impregnated sintered bearings, having the steps of: preparing a mixed powder comprising an iron powder, and at least one of a copper powder and a copper alloy powder; forming the mixed powder into a green compact; and sintering the green compact to obtain a sintered iron-copper base porous alloy. The iron powder contains a porous iron powder which has a particle size of 177 microns or less and a specific surface area of 110 to 500 m²/kg according to a gas adsorption method. The sintered compact has high intercommunicating porosity and low permeability, and it is sized to prepare the sintered bearing into which a lubricating oil is impregnated.

To provide a sintered alloy capable of showing wear resistance and a process for producing the same as well as a valve seat of good wear resistance. A sintered alloy comprising 4-30% by weight Mo, 0.2-3% by weight C, 1-30% by weight Ni, 0.5-10% by weight Mn, 2-40% by weight Co, and the balance of inevitable impurities and Fe when the entirety is taken as 100% by weight. Aprocess for producing a sintered alloy in which a green compact of a raw mixture powder including hard particles is sintered, thereby producing said sintered alloy. A valve seat comprising said sintered alloy.

Disclosed is a sintered gear composed of a sintered alloy having a metal matrix and pores. The tooth surface (2, 3, 4) of the tooth and the bottom land (5) have a densified layer (11) in which the porosity is reduced to 10% or less from the sintered alloy. The densified layer at the tooth surface is formed with a thickness of 300 to 1,000 microns, and the densified layer at the bottom land is formed with a thickness of 10 to 300 microns. The boundary surface of the densified layer is continuous from the tooth surface side to the bottom land side so as not to have a substantial level difference.

A disk cutter including an annular disk-shaped base adapted to be driven about an axis of rotation, a plurality of tip supports formed along the outer circumference of the base integrally therewith so that a gullet is defined between adjacent ones of the tip supports, a plurality of tip inserts respectively fixed to the tip supports, and a TiAlN coating formed on the surface of each tip insert. Each tip insert is formed of a sintered alloy composed of 98 to 90 w % of WC powder having a particle size of 0.1 to 0.8 μm and 2 to 10 w % of Co powder. The TiAlN coating has a thickness of 1 to 5 μm.

The invention discloses a hard alloy mold material for a fastener formed through cold upsetting and a preparation method of the hard alloy mold material. The hard alloy mold material comprises 72.4%-77% of WC, 22%-25% of Co, 0.5%-0.8% of Ni, 0.3%-0.8% of Cr3C2 and 0.2%-1% of WC-TiC-NbC solid solution. The technique of the hard alloy mold material comprises the steps that WC, Co, Ni, Cr3C2 and the WC-TiC-NbC solid solution are placed in a ball mill, wet milling media, forming agents and additives are added under the matching of wet milling balls and mixtures, and ball milling is conducted; slurry obtained after wet milling is dried by means of a spray tower for granulation; dried alloy powder is subjected to press-forming and placed in a low-pressure sintering furnace for heat preservation, and a sintered alloy product is obtained after the sintering furnace is cooled to the indoor temperature; and the sintered alloy liquid nitrogen is subjected to subzero treatment, and finally, low-temperature tempering treatment is conducted. The hard alloy mold material has the advantages of being resistant to abrasion, oxidation and corrosion, high in strength, long in service life and the like.

Disclosed is a Fe—Ga—P—C—B—Si based metallic glass alloy particle prepared by a gas atomizing process, which has an approximately complete spherical shape, a relatively large particle size and a high crystallization temperature (Tx). The plurality of particles may be subjected to a spark plasma sintering process at the crystallization temperature or less under a compression pressure of 200 MPa or more, to provide a bulk Fe-based sintered metal soft magnetic material of metallic glass, which has a high density, a single phase structure of metallic glass in an as-sintered state, excellent soft magnetic characteristics applicable to a core of a magnetic head, a transformer or a motor, and a high specific resistance.

A controlled combustion synthesis apparatus comprises an ignition system, a pressure sensor for detecting internal pressure, a nitrogen supply, a gas pressure control valve for feeding nitrogen and exhausting reaction gas, means for detecting the internal temperature of the reaction container, a water cooled jacket, and a cooling plate. A temperature control system controls the temperature of the reaction container by controlling the flow of cooling water supplied to the jacket and the cooling plate in response to the detected temperature. By combustion synthesizing, while controlling the internal pressure and temperature, the apparatus can synthesize a silicon alloy including 30-70 wt. % silicon, 10-45 wt. % nitrogen, 1-40 wt. % aluminum, and 1-40 wt % oxygen.