45 results about "Sintered alloy" patented technology

The invention provides a method suitable for additive manufacturing of a high-crack-sensitivity alloy, and belongs to the technical field of 3D printing. The metal powder is pre-sintered by using the characteristics of large spot diameter, high laser power and uniform energy distribution of the homogenized laser, so that the effect of preheating the substrate can be realized, and the preheating of the formed material can be realized in the middle and later periods of additive manufacturing; then Gaussian laser is used for treatment, the temperature difference between a molten pool and a substrate (or a formed material) is reduced, the temperature gradient is reduced, thermal stress in the cooling process is reduced, stress concentration is reduced, and therefore formation and expansion of cracks are reduced; by means of the characteristics that Gaussian laser is small in spot diameter and concentrated in energy, the pre-sintered alloy is subjected to secondary scanning sintering, the material can be finer, the possible problems of uneven material distribution, surface defects and the like are solved, the risk of cracks is further reduced, and the method is suitable for additive manufacturing of the high-crack-sensitivity alloy.

The invention discloses a manganese-copper alloy composite material and a preparation method thereof. The preparation process comprises the following steps: step 1, adopting copper powder, manganese powder and silicon powder with the purity of 99.9% or above as main elements of a matrix alloy; 2, copper powder, manganese powder, silicon powder and the composite particles are evenly mixed according to the mass percent; step 3, loading the uniformly mixed powder into a mold; 4, sintering the material after hot press molding; 5, the sintered alloy material is subjected to aging treatment; sixthly, hot rolling or hot extrusion treatment is conducted; and 7, the prepared alloy composite material is subjected to polishing or coating surface treatment, and preparation is completed. The manganese-copper alloy composite material is prepared by adopting the steps. The composite particles are added into the manganese-copper alloy to serve as a reinforcing phase, the strengthening phase is formed, the abrasion resistance of the material is greatly improved, the internal component and structure gradient of the material is effectively achieved, and comprehensive improvement of the performance of the manganese-copper alloy is successfully achieved.

A method for manufacturing a Cu—Ni—Al-based sintered alloy according to the present invention includes: adding pure Al powder to alloy powder containing Cu, Ni, and Al and mixing them to produce raw material powder with a composition ratio of Ni: 1% to 15% by mass, Al: 1.9% to 12% by mass, and a Cu balance containing inevitable impurities; compacting the raw material powder to form a green compact; and sintering the green compact in a mixture gas atmosphere of hydrogen gas and nitrogen gas that contains 3% by volume or more of hydrogen gas.

To provide a contact material for a vacuum valve with good current interruption properties at low cost.SOLUTION: A contact material for a vacuum valve includes a sintered alloy containing a copper matrix, a filler containing molybdenum, and at least one sintering aid of chromium or vanadium.SELECTED DRAWING: Figure 1

The application provides a method suitable for additive manufacturing of high crack sensitivity alloy, and belongs to the technical field of 3D printing. The application utilizes the characteristics of a uniform laser spot diameter, high laser power and uniform energy distribution to pre-sinter metal powder, so that the preheating of a substrate can be realized, and the preheating of the formed material can be realized in the middle and later stages of additive manufacturing. Then, a Gaussian laser is used for processing, so that the temperature difference between the molten pool and the substrate (or the formed material) is reduced, the temperature gradient is reduced, the thermal stress in the cooling process is reduced, the stress concentration is reduced, and thus the formation and expansion of cracks are reduced. The characteristics of a small Gaussian laser spot diameter and energy concentration are used for secondary scanning sintering of the pre-sintered alloy, so that the material is more fine, the problems of uneven material distribution, surface defects and the like that may exist are eliminated, the risk of cracks is further reduced, and the additive manufacturing of high crack sensitivity alloy is suitable.

Provided are a valve seat that is made of an iron-based sintered alloy and has superior wear resistance, and a combination of a valve seat and a valve.　This valve seat that is made of an iron-based sintered alloy has a structure in which the base phase is a fine carbide precipitation phase in which an area ratio of 15-40% pearlite and fine carbides of 10 μm or less are precipitated, hard particles with a Vickers hardness of 650-1300 HV are dispersed in the base phase in an area ratio of 20-40%, the structure further has a high alloy phase in an area ratio of 0-5%, and solid lubricant particles are dispersed in an area ratio of 0-5%. Consequently, there is little valve wear even when a Tribaloy-based alloy-metallized valve with a face surface hardness of 550 HV is used, and a combination of a valve and a valve seat that has superior wear resistance can be achieved.

Provided is an iron-based sintered alloy valve seat having excellent wear resistance and radial compressive strength. The sintered body is made of an iron-based sintered alloy having a double-layer structure in which a functional member-side layer and a support member-side layer are integrally sintered. A functional member-side layer of the sintered body made of an iron-based sintered alloy has a structure in which 5.0-30.0% by area of a high alloy phase, 10.0-40.0% by area of Si-Cr-Mo-Ni-based Fe-based intermetallic compound particles having a hardness of 700-1300 HV, and 0-4.0% by area of solid lubricant particles are dispersed in a matrix phase comprising a fine carbide precipitated phase. And a matrix part having a composition containing, in mass%, 0.50 to 2.80% of C, 1.80% or less of Si, 2.50% or less of Mn, 2.00 to 7.00% of Cr, 3.00 to 25.00% of Mo, 2.00 to 8.00% of Ni, 0 to 10.00% of Co, 0.50 to 4.00% of V, 4.00 to 10.00% of W, and 0 to 2.00% of S, with the balance being Fe. As a result, a valve seat having excellent radial compressive strength and excellent wear resistance can be produced.

Hard particles for incorporation into a sintered alloy, consisting of: more than 25 to 60% Mo by mass; 3 to 15 mass% Mn; and the remainder consisting of Fe and unavoidable impurities.

To provide a valve seat made of an iron-based sintered alloy excellent in wear resistance and falling-off resistance.SOLUTION: The valve seat 1 has a two layer structure in which a functional member side layer 11 and a support member side layer 12 are integrated by sintering. The functional member side layer has a structure in which hard particles or further solid lubricant particles are dispersed in a base matrix phase mainly including 5.87% or less of a fine carbide precipitation phase and a tempered martensite phase, and further including 8.11 to 21.39% of a high alloy phase around the hard particles, the iron-based sintered alloy material has a matrix portion composition containing, by mass%, C:0.5 to 2.0%, Si: 0.1 to 1.0%, Mn: 0.1 to 2.5%, Ni: 1.0 to 7.0%, Cr: 1.0 to 12.0%, Mo: 2.0 to 12.0%, Co: 2.0 to 20.0%, W: 0.1 to 2.0%, and V: 0.01 to 1.0%, and further containing S: 0 to 1.5%, and includes pores filled with Cu by infiltration.SELECTED DRAWING: Figure 1

This sintered alloy bearing is obtained by compressing a raw-material powder to form a green compact and sintering the green compact. A sintered alloy contains 1.0-5.0 wt. % of Cu, 0.4-2. 0 wt. % of Sn, and 0 wt. % or 0.3-3.0 wt. % of C as free carbon, with the balance consisting of Fe and unavoidable impurities. An iron structure is formed of an iron powder and is configured so that a ferrite structure has an area ratio of 90% or more.

The objective is to provide an iron-based sintered alloy with excellent surface pressure fatigue strength. [Solution] An iron-based sintered alloy having an overall composition of Cr: 1-5% and C: 0.6-1.5% by mass, with the remainder being Fe and unavoidable impurities, comprising a matrix and metal carbides dispersed in the matrix, with the number of metal carbides having a particle size of 0.2-2.0 μm being 10,000-25,000 in the range of 100 μm × 100 μm.

The invention provides a valve seat made of an iron-based sintered alloy. The sintered body is made of an iron-based sintered alloy and has a double-layer structure in which a functional member-side layer and a support member-side layer are integrally sintered. The functional member-side layer has, dispersed in a matrix phase comprising a fine carbide precipitated phase, 5.0-30.0% by area ratio of a high alloy phase, 10.0-40.0% by area ratio of Si-Cr-Mo or Si-Cr-Mo-Ni Co-based intermetallic compound particles having a Vickers hardness of 600-1200 HV, and 0-4.0% by area ratio of solid lubricant particles. The sintered body made of the iron-based sintered alloy has a composition in which the matrix part contains, in mass%, 0.50 to 2.80% of C, 1.80% or less of Si, 2.50% or less of Mn, 3.00 to 11.00% of Cr, 3.00 to 17.00% of Mo, 1.00 to 8.50% of Ni, 5.00 to 30.00% of Co, 0.50 to 4.00% of V, 4.00 to 10.00% of W, and 0 to 2.00% of S. As a result, it is possible to produce a valve seat having excellent radial compressive strength and excellent wear resistance compared to the prior art.

A solid solution phase composed of at least one metal element among Ti, Ta, Nb, and V and at least one of C and N is formed, 80 vol% or more of which is composed of a compound phase having an NaCl structure and a Cr3C2 phase, and the sintered alloy is characterized by containing 38-95 vol% of the compound phase.

The invention relates to the field of powder metallurgy, in particular to a powder metallurgy alloy / composite material for improving strength and plasticity based on an interface micro-casting technology and a preparation method of the powder metallurgy alloy / composite material. The material is prepared by taking micron-sized metal or alloy powder as matrix powder, adding low-melting-point metal powder relative to a matrix and carrying out spark plasma sintering. Wherein according to the mass percent, the matrix accounts for 60%-95%, and the low-melting-point metal phase accounts for 5%-40%. According to the method, a low-melting-point metal phase is added, a spark plasma sintering process is combined, a substrate and a second phase form a solid solution firstly, a liquid phase is continuously formed and solidified through a mechanism that the melting point of the solid solution and the sintering real-time temperature compete, and through the process similar to casting, the element diffusion rate is increased, original inter-particle defects are removed; the mechanical property of the composite material is improved, the material has good plasticity on the premise that the strength is guaranteed, and the method can be used for comprehensively improving the mechanical property of the powder metallurgy sintered alloy or the metal-based composite material.

The present invention relates to a method for manufacturing a part in austenitic stainless steel comprising successively the following steps: 1) Provision of a powder and sintering of said powder to form a sintered alloy with an austenitic structure; said alloy having a nitrogen content greater than or equal to 0.1% by weight, 2) Treatment of the sintered alloy to transform the austenitic structure into a ferritic or two-phase ferrite + austenite structure on a layer (2) on the surface of the alloy, 3) Treatment of the sintered alloy to transform the ferritic or two-phase ferrite + austenite structure obtained in step 2) into an austenitic structure and to form after cooling the part (1) having on the layer (2) subjected to the transformations of steps 2) and 3) a density greater than that of the core (3) of the part (1).

The invention discloses an alloy ball sintering method, which belongs to the technical field of tungsten alloy ball production, and comprises the following steps: metal sand is adhered to the peripheral surface of an under-sintered alloy ball, the melting temperature of the metal sand is higher than the re-sintering temperature of the alloy ball, and the alloy ball adhered with the metal sand is re-sintered. And the metal sand with the melting temperature higher than the re-sintering temperature is used as an anti-sticking isolation measure, so that the problems of mutual adhesion, block formation or caking caused by surface diffusion, liquid phase generation or micro-area melting and the like in the high-temperature sintering process of the spheres can be avoided.

The invention belongs to the technical field of metallurgy, and particularly relates to a preparation method and application of Ni-Co-Mn-Ti shape memory alloy. The preparation method comprises the following steps that 1, raw materials are weighed according to the element molar ratio of Ni: Co: Mn: Ti = 37: 13: 34.5: 15.5, an ingot is formed through electric arc melting, and then homogenizing annealing treatment is conducted; step 2, mechanically crushing the annealed alloy ingot into small blocks, grinding the small blocks into alloy powder, and then performing stress relief annealing; 3, the alloy powder obtained after stress relief annealing is placed in a graphite mold, and then the graphite mold is placed in a spark plasma sintering device to be sintered; and 4, carrying out annealing heat treatment on the sintered body alloy sample. According to the preparation method of Ni-Co-Mn-Ti, a complex and time-consuming preparation process is not needed, that is, the powder alloy is directly used as the parent alloy for sintering, the alloy preparation cost is remarkably reduced, and the compression strength of the alloy is improved.

The invention discloses a high-specific-gravity high-toughness tungsten-nickel-copper alloy material and a preparation method thereof, and the alloy material comprises the following components in percentage by mass: 91-96% of tungsten, 3-8% of nickel and copper in total, wherein the ratio of Ni to Cu is (1: 1)-(7: 3), and 1% of cobalt. The preparation method comprises the steps that the tungsten powder, the nickel powder, the copper powder and the cobalt powder are firstly put into an acoustic resonance mixer to be premixed and then put into an all-dimensional planetary machine to be subjected to ball milling; pressing the uniformly mixed powder into a biscuit in a cold isostatic pressing manner; the pressed biscuit is introduced into a tubular furnace to be pre-sintered; carrying out hot isostatic pressing sintering on the sintered alloy material in an inert atmosphere; and the alloy in the hot isostatic pressing state is subjected to vacuum oil quenching heat treatment. According to the invention, through the process of combining two-step mixing, two-step sintering and heat treatment, the strength and elongation of the alloy are synergistically improved while the density of the tungsten-nickel-copper alloy is improved, and the problems of coarse grains, low density and poor elongation of the traditional tungsten-nickel-copper alloy are solved.

The invention discloses a preparation method of tungsten heavy alloy strengthened by oxide dispersion in tungsten crystal grains, and belongs to the field of dispersion strengthened tungsten heavy alloy materials. The method comprises the following steps: firstly, obtaining a mixture of a tungsten heavy alloy oxide and a dispersion strengthened second-phase oxide through liquid combustion synthesis, and carrying out hydrogen reduction to obtain in-situ synthesized oxide-doped second-phase dispersion distribution tungsten heavy alloy nano powder; and finally, non-pressure two-step liquid phase sintering is conducted in hydrogen, and the tungsten heavy alloy strengthened by dispersion of the oxide in the tungsten crystal grains is obtained. The process for preparing the alloy powder is simple and rapid, one-step synthesis of in-situ synthesis of the nano tungsten heavy alloy powder doped with the second-phase particles can be achieved, the average particle size of the alloy composite powder is small, and the preparation time of the alloy powder is greatly shortened. Non-pressure two-step liquid phase sintering is adopted, the density of a sintered body can be effectively improved, the liquid phase sintering time is shortened, excessive growth of tungsten crystal grains is prevented, second-phase oxide particles can be dispersed and distributed in the tungsten crystal grains, and meanwhile the sintering period is shortened. The compressive strength of the sintered alloy is not lower than 1500 MPa.

Provided is an iron-based sintered alloy valve seat that has excellent wear resistance and peeling resistance. A valve seat is produced that has a double-layer structure in which a functional component side layer and a support component side layer are integrated by sintering. The functional component side layer is a layer in which a hard particle or a solid lubricant particle is dispersed in a matrix phase mainly composed of an annealed martensite phase, and further, a high alloy phase is present around the hard particle, and further, a matrix portion composition containing C: 0.3 to 2.0% by mass, and further, one or two or more selected from Si, Mn, Ni, Cr, Mo, Co, or further, S, and a layer in which pores are filled with Cu by melting and impregnation. Thus, the wear resistance and peeling resistance are improved, and even when used in a cast iron cylinder head of an internal combustion engine, sufficient durability can be maintained.

Provided is a separation and recovery device for continuously separating and recovering a hydrolysis component a of a hydrolyzable polymer A and a non-hydrolyzable polymer B from a resin mixture containing a resin containing the hydrolyzable polymer and a resin containing the non-hydrolyzable polymer, the separation and recovery device comprising: a crushing unit for crushing the resin mixture; a melting and ejecting unit for melting the crushed product obtained by the crushing unit to form a fluid and ejecting the fluid at high pressure; and a hydrothermal reaction treatment unit for continuously performing a hydrothermal reaction treatment on the fluid ejected from the melting and ejecting unit, in which the hydrolyzable polymer A is hydrolyzed to dissolve and transfer the hydrolysis component a thereof to water impregnated through a sintered alloy diaphragm, thereby separating the non-hydrolyzable polymer B.

This invention provides an iron-based sintered alloy valve seat with excellent radial compressive strength. The functional component side layer and the support component side layer are integrally sintered to form a double-layer sintered body. The mixed powders for the functional component side layer and the support component side layer are sequentially filled into a mold and stamped to form a pressed powder body. This pressed powder body is then sintered to form the double-layer iron-based sintered alloy valve seat. In the mixed powders for the functional component side layer, an iron-based powder with a hardness of 170–220 HV is used as the iron-based powder for matrix phase formation, forming a matrix phase in the form of fine carbide precipitates. Within this matrix phase, 20–40% of Si-Cr-Mo based Co-based intermetallic compound particles or Si-Cr-Mo-Ni based Co-based intermetallic compound particles are dispersed by area, and 0–5% of solid lubricant particles are also dispersed by area.

This invention provides a cathode electrode for water electrolysis that achieves catalytic performance equivalent to, or even exceeding, that of platinum (Pt), without using any platinum (Pt). [Solution] In a cathode electrode used for hydrogen production by water electrolysis, the spaces between tungsten carbide (WC) nanoparticles are composed of a sintered alloy with nickel (Ni) and chromium (Cr) as binder phases. The sintered alloy constituting the cathode electrode contains 5-25% by weight of Ni and 0.5-3.0% by weight of Cr. By using this sintered alloy as the cathode electrode for water electrolysis, the hydrogen overpotential (ηH(V)) during hydrogen production is reduced, enabling highly efficient and stable hydrogen production.

The invention discloses a MoNb alloy target material and a preparation method thereof, and belongs to the technical field of target material preparation. Comprising the following steps that Mo powder and Nb powder are mixed in an inert atmosphere, and MoNb mixed powder is obtained; placing under a vacuum condition, and pre-sintering to obtain MoNb pre-sintered alloy powder; sheathing the MoNb pre-sintered alloy powder according to sheathing assembly, degassing, putting into a hot isostatic pressing sintering furnace, carrying out gradient heating to 1250-1400 DEG C, increasing the pressure to 110-160 MPa at a constant speed while heating, carrying out heat preservation calcination for 3-5 hours, cooling along with the furnace, and recovering the pressure to obtain a MoNb alloy target blank; and the MoNb alloy target blank is machined through a grinding machine, and then the MoNb alloy target with the qualified size is obtained. The prepared MoNb alloy target material is high in density, not prone to cracking, high in purity, uniform and fine in grain structure, good in conductivity and excellent in sputtering performance.

To provide a valve seat made of an iron sintered alloy excellent in wear resistance and falling resistance.SOLUTION: There is provided a two layer structure valve seat 1 which is obtained by integrating by sintering, a function member layer 11, and a support member layer 12, the function member layer includes in a matrix phase including mainly, 20.0% of a fine carbide precipitation phase, and an annealing martensite phase: dispersed hard particles or solid lubricant particles; and a high allow phase around the hard particles. The iron sintered alloy material includes in mass%, one or two or more kinds selected from: 0.5-2.0% of C; 0.1-1.0% of Si; 0.1-2.5% of Mn; 1.0-7.0% of Ni; 1.0-12.0% of Cr; 2.0-12.0% of Mo; 2.0-20.0% of Co; 0.1-2.0% of W; 0.01-1.0% of V, and further has a matrix part composition including 0-1.5% of S, and includes holes in which Cu is filled by infiltration.SELECTED DRAWING: Figure 1

This invention provides a sputtering apparatus and a sputtering method. The sputtering apparatus includes: a vacuum chamber in which a target and a substrate are arranged opposite each other; a DC power supply electrically connected to the target; a gas supply source for introducing a film-forming gas containing nitrogen into the vacuum chamber; and a pulsed unit for pulsed current flowing from the DC power supply to the target. Using a sintered gold target material with a binary or higher composition as the target, plasma is generated in the vacuum chamber to form a nitride thin film with a ternary or higher composition containing nitrogen on the substrate.

To provide a sintered alloy bearing that is resistant to wear against a mating member (mating shaft) and can minimize adverse environmental effects during manufacturing.SOLUTION: A sintered alloy bearing is obtained by compressing raw material powder to form a green compact, and sintering the green compact. The sintered alloy contains Cu: 1.0-5.0 wt.%, SN: 0.4-2.0 wt.%, and C: 0.3-3.0 wt.% as free carbon, with the remainder: Fe and unavoidable impurities. An iron structure formed from iron powder has an area ratio of a ferrite structure of 90% or more.SELECTED DRAWING: Figure 1

A sintered alloy, characterized in that it includes a compound phase and a Cr3C2 phase, wherein the compound phase forms a solid solution phase and more than 80% by volume has a NaCl type structure, and the solid solution phase includes: one or more metal elements among Nb, Ta and Ti; one or more of W and Mo; and one or more of C and N. The sintered alloy contains 13 to 37% by volume of the compound phase, and 0.1 to 45 atomic % of one or more of W and Mo are solid-dissolved in the compound phase relative to the total amount of metal elements in the compound phase.

The invention discloses preparation of high-entropy binding phase tungsten heavy alloy nano-powder through one-step hydrogen reduction and a sintering process, and belongs to the field of preparation of high-entropy binding phase tungsten heavy alloy materials. According to the preparation method, an oxide composite precursor substance with uniformly mixed metal elements is obtained through a solution combustion synthesis wet chemical method, reduction is carried out in a hydrogen atmosphere, and atomic-scale uniformly-mixed high-entropy binding phase tungsten heavy alloy nano powder is directly obtained; and finally, the high-entropy binding phase tungsten heavy alloy is prepared through pressureless sintering in a hydrogen environment and one-step hydrogen reduction. The process is simple and rapid, the high-entropy binding phase tungsten heavy alloy nano-powder can be prepared through one-step hydrogen reduction, the average particle size of the alloy composite powder is small, and the preparation time of the alloy powder is greatly shortened. By adopting a pressureless sintering technology, the density of a sintered body can be effectively improved, the liquid-phase sintering time is shortened, meanwhile, the sintering period is shortened, and excessive growth of tungsten crystal grains can be effectively prevented. The relative density of the sintered alloy is not lower than 97%, the tensile strength is not lower than 800 MPa, and the compressive strength is not lower than 1000 MPa.

A sintered alloy characterized in that it forms a solid solution phase consisting of at least one metal element selected from the group consisting of Ti, Ta, Nb, and V, and at least one of C and N, and that it contains 38 to 95 volume % of said compound phase, which is composed of 80 volume % or more of a compound phase having a NaCl type structure and a Cr3C2 phase.