Sintered material for high-current sliding electric contact. RU patent 2506334.
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Method of making part semis for electric terminals and electric terminal component / 2497632 Invention relates to powder metallurgy, particularly, to making of semi-finished part for electric terminals in the form of a strip. Unit is made from silver-based composite including one or more metal oxides or carbon. Coating of basic metal powder is applied on said composite unit. Coated unit is compacted and annealed in reducing or inert atmosphere or in vacuum. This prevents formation of eutectic melt of composite silver and basic metal that coat the composite silver-based unit. Annealed unit is subjected to extrusion to obtain strip with top side of composite and bottom side of silver or silver-based alloy. |
 Method for production of ag/sno2 powder mixture for interrupting contacts / 2442835The invention relates to powder metallurgy, in particular, to metal powder products. It can be used in production of ceramic metal materials for interrupting contacts based on silver and used in low-voltage equipment. The intermediate thermally unstable composition components Ag2O and Na2SnO3 are produced during the single-stage deposition from the solution containing AgNO3, Na2SnO3 and NaOH. The deposit containing SnO2 is extracted from the resulting mixute, and the mixture is dried and thermally processed. |
 Method of producing superfine charge of silver-zink oxide for electric contacts / 2434717Invention relates to grinding and may be used for production of arcing electric contacts. Proposed method comprises chemical deposition solution of silver and zinc nitrates, filtration, rinsing and annealing of precipitate. Note here that water-soluble surface-active poly(vinylpirrolidone) in amount of 1 to 3% of total volume of solution is added to solution of nitrates. |
 Radio-frequency microelectromechanical switch (rf mems-switch) with flexible and free membrane of switch / 2433499Radio-frequency microelectromechanical switch (RF MEMS-switch) comprises a micromechanical switching device arranged on a substrate and made with the possibility of actuation between two positions: the first position (switched-off condition) and the second position (switched-on condition), and an activating device designed to put the switching device into the appropriate position. At the same time the micromechanical switching device comprises a flexible membrane (6) freely supported with a support device (3) and made with the possibility to bend under the action of the activating device (7) and freely slide relative to the support device (3) during its bending motion. |
 Contact piece, method and tool for its manufacture / 2420823Contact piece is made from composite material in the form of body of rotation, which is restricted with side surface with generatrix consisting of straight-line and (or) curved sections and two parallel surfaces of bases, made from fine dense graphite with specific resistance of not more than 16.0 mcOhm*m, compression strength of not less than 60 MPa, ash content of not more than 0.3% and volume porosity of not more than 20%. Manufacturing method of contact piece consists in the fact that flat workpiece is made from fine dense graphite, which has thickness equal to height of contact piece; workpiece is installed into the device, part of contact piece is cut out on one side, and workpiece is reinstalled and the rest part of contact piece is cut out on the other side. Contact piece manufacturing tool includes shank and working part consisting at least of one cutting element offset relative to rotation axis of tool the cutting edges of which form side furnace of contact piece. |
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Sintered electro-contact material on base of copper / 2415958 Sintered electro-contact material on base of copper contains, wt %: soot of zinc oxide - 2.2 - 2.5; aluminium - 0.001 - 0.005; tungsten - 3 - 10; copper - the rest. |
 Domestic device and methods of its control / 2406177According to the present invention, one version of domestic device implementation includes control panel and controller. The control panel may contain electric switch, which can be utilised by the user to supply commands for device energising and de-energising, and input unit for supplying commands for device actuation by the user. |
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Method of producing powder ceramet cu-cd/cdo for electric contacts / 2401314 Mix material is prepared containing powders of copper and cadmium with the solution of thermally unstable cadmium salt. Said mix is dried and thermally treated at 300-500°C. Produced burden is subjected to cold briquetting and sintering. Then second compaction and annealing are performed to produce Cu-Cd/CdO. |
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Composite electric contact and method of its fabrication / 2400852 Proposed contact is made from graphite-based material containing metal additives. Note here that graphite base is made from fine-grained busy graphite with specific resistance of not over 16 mcmOhm*m, compression strength making at least 60 MPa, ash content not exceeding 0.3% and bulk porosity of 15-25%. Metal additive is distributed in graphite pores in amount making at least 10% of pore volume, while metal additive particles form discontinuous 10 mcm-thick surface coat on graphite base surface. Proposed method involves mechanical dimensional processing of contact made from structural graphite, impregnating said contact with ethanol and holding it in water solution of silver nitrate of density varying from 1.4 to 1.17 g/cm3 at temperature 10-40°C higher than boiling temperature of impregnation liquid during 10-15 min. Then contact is subjected to thermal treatment at below 0.95 of silver melting temperature for 0.5-1.0 h, said contact being placed in container and backfilled by char coal. |
 Method of producing composite material for copper-based electric contacts / 2398656Invention relates to powder metallurgy, particularly to method of producing copper-based composite materials. It can be used for production of electric contacts. Powders of graphite, copper, aluminium, phosphor copper and copper oxide are mixed at the following ratio, wt % graphite 0.10-0.20; aluminium 0.20-0.30; phosphor copper 0.05-0.15; copper oxide 1.15-1.4; copper making the rest. Prepared mix is subjected to high-power treatment in ball mill to produce granules of material representing copper-based matrix with reinforcing particles uniformly distributed therein in amount of 0.35 to 0.55 wt % of total weight with average size of 0.1 to 0.5 mm. Material matrix represents α-Cu(Al) substitutional solution while reinforcing particles - γ-Al2O3 with average size of 20-40 nm. Mix is compacted by extruding in heated state. |
 Method of steel production with strengthening nanoparticles / 2493282Invention may be used for production of parts elements for storage of spent fuel, nuclear reactor fuel assembly cases, cases of shells of neutron sources control and safety system, fuel-element claddings. By centrifugal spraying flake matrix powder of steel is obtained and is subject to crushing in high-energy vibrational attritor. Powder composition is formed of crushed powder, nanosized powder of strengthening compounds and fine powder of titanium hydride, then mechanical alloying is performed. Mechanically alloyed powder is filled in a capsule, heated to 1000-1100°C in high vacuum, exposed at this temperature till hydride decomposition and reduction of surface oxides, capsule is sealed and treated by hot deformation. |
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Low-alloy steel powder / 2490353 Pre-alloyed steel powder sprayed with water contains the following, wt %: 0.2-1.5 Cr; 0.05-0.4 V; 0.09-0.6 Mn; less than 0.1 Mo; less than 0.1 Ni; less than 0.2 Cu; less than 0.1 C; less than 0.25 O; less than 0.5 of inevitable impurities and iron is the rest. Powder composition for obtaining sintered parts contains steel powder mixed with 0.35-1.0 wt % of graphite, 0.05-2.0 wt % of lubricating substances, optionally with copper additive in the quantity of up to 4 wt %, and optionally with solid-phase materials and agents improving processibility. The composition is pressed at the pressure of 400-2000 MPa, sintered at 1000-1400°C, and when required, subject to hot forging at the temperature of more than 500°C or heat treatment. |
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Iron-based powder and its composition / 2490352 Iron-based powder sprayed with water, which is alloyed with 0.75-1.1 wt % of nickel, 0.75-1.1 wt % of molybdenum and up to 0.45 wt % of manganese contains 0.5-3.0 wt %, preferably 0.5-2.5 wt % and most preferably 0.5-2.0 wt % of copper and inevitable impurities. Alloyed powder composition based on iron contains iron-based powder sprayed with water, 0.4-0.9 wt %, preferably 0.5-0.9 wt % of graphite, lubricant and if required solid-phase materials improving machinability and flow characteristic. The obtained composition is pressed and sintered in a reducing or neutral atmosphere at atmospheric pressure or lower than that and temperature of more than 1000°C. |
 Method of making powder on basis of iron chips / 2486031Invention relates to powder metallurgy, particularly, to production of iron-based powder with minor amount of carbon. It may be used for making steel powder from machining wastes, that is, iron chips. Powder made by grinding and baking of iron chips is mixed with iron scale powder to be heated 900-1100°C and cured for 4-8 hours. |
 Method of producing magnetic powder materials / 2484926Invention relates to powder metallurgy, particularly, to treatment of metal powders for making composite articles and coatings operated in HF and SHF ranges. Proposed method of making magnetic powder materials based on carbonyl iron includes preparing mix of powders of carbonyl iron and cobalt and grinding said mix in two steps. At first step, said mix is ground to complete implantation of cobalt atoms in crystalline lattice of α-iron in inert gas medium. At second step, powder is ground in inert fluid to production of magnetic powder material with specific surface of 0.2 - 4.0 m2/g. Used cobalt powder is electrolytic cobalt powder. Fraction of cobalt in said mix of powders ground in inert medium may approximate to 0.1-24 wt %. |
 Method of producing high-nitrogenous austenite steel powder of nanocrystalline structure / 2484170Mix of chromium, nickel, manganese and iron is prepared and placed into metallic flow reactor of high-duty vibrating mill equipped with gas flow system. Grinding balls are added to fill 30-50% of reactor volume. Said reactor is sealed to blow said mix by nitrogen-bearing gas at the rate of 2-16 l/h for 10-20 minutes. Then, gas flow rate is reduced to 0.2-0.3 l/h to subject said mix to mechanical alloying with power dose of 15o-720 kJ/g. Reactor is completely sealed and subjected to fast cooling. Polymethyl methacrylate in amount of 1-3% of powder weight is added thereto, reactor is closed to perform extra mechanical alloying for 10-15 minutes. Now, powder is withdrawn and placed into stainless steel tube to catty out hot rolling with reduction to 80-90% and annealing with fast cooling. |
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Low-alloyed steel powder / 2482208 Water-sprayed previously alloyed steel powder contains the following components, in wt %: 0.4-2.0 Cr, 0.1-0.8 Mn, less than 0.1 V, less than 0.1 Mo, less than 0.1 Ni, less than 0.2 Cu, less than 0.1 C, less than 0.25 O, less than 0.5 unavoidable admixtures, balance - iron. The powder composition on the basis of the iron comprises a steel powder mixed with 0.35-1 wt % of graphite, 0.05-2 wt % of lubricant materials, and optionally, copper in the amount of up to 3%, and solid phase materials, and agents that improve treatability. A sintered item having perlite/ferrite microstructure is produced by means of pressing of a powder composition under the pressure of 400-2000 MPa, sintering in the reducing atmosphere at the temperature making 1000-1400°C and if required, forging of the heated item at the temperature making more than 500°C or thermal processing, or tempering of the produced item. |
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Ceramic-metal friction alloy / 2482207 Powder friction alloy based on iron, contains, wt %: tin 9-11, molybdenum disulfide 1.5-2.5, diamond powder 4.5-5.5, graphite 8.5-9.5, lead 1.5-2.5, iron - balance. |
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Sintered anti-friction material on basis of iron / 2475555 Sintered anti-friction material on basis of iron contains the following, wt %: copper 1.5-2.0; nickel 20.0-23.0; chrome 13.0-15.0; molybdenum disulphide 4.0-4.5; carbon 0.1-0.15, tellurium 0.002-0.003; stannum 0.02-0.03; boron 0.1-0.15, antimony 0.03-0.05; iron is the rest. |
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Sintered anti-friction material on basis of iron / 2475554 Sintered anti-friction material on basis of iron contains the following, wt %: copper 1.5-2.0; nickel 20.0-23.0; chrome 13.0-15.0; molybdenum disulphide 4.0-4.5; zirconium 0.1-0.15; antimony 0.03-0.05; silver 0.01-0.015; iron is the rest. |
 Modification and refining compound for iron-carbon and non-ferrous alloys (versions) / 2502808Compound includes material containing calcium, barium and strontium carbonates; with that, it contains the following components, wt %: CaO 16.0 - 40.0, BaO 10.0 - 24.0, SrO 2.5 - 11.5, CO2 18.0 - 30.0, SiO2 2.0 - 15.0. In addition, compound can contain carbon-bearing material or metallic aluminium in quantity of 2-35 wt %, or titanium-bearing material in quantity of 0.01-35 wt %, or rare-earth metals in quantity of 2-49.5 wt %. |
FIELD: metallurgy.
SUBSTANCE: invention relates to powder metallurgy, and namely to powder antifriction materials for high-current sliding contacts. It can be used for fabrication of current-collecting brushes, for example unipolar generators or current-collecting shoes contacting a rail of a tunnel railway. Material of the high-current sliding electric contact working in the pair with a steel counter relay with contact current density of more than 100 A/cm2 includes the following, wt %: copper 24-57; graphite 2-3; iron is the rest.
EFFECT: providing high electric conductivity of the contact and low wear intensity at sliding.
1 tbl, 1 ex
The invention relates to and materials science, in particular to the antifriction materials used in manufacture of the collector of brushes, for example, unipolar generators or the collector of boots in contact with the rail tunnel railway.
Known sintered material for the collector of sliding contacts based on iron [RU2126457, 22 33/02, B60L 5/08, 01 1/02, publ. 20.02.1999] [1], containing graphite and copper in the following quantities, mass%:
Graphite 8-18 Copper 8-20 Ironthe rest of it.
The disadvantages of this composite is low hardness and mechanical strength, due to the high content of graphite. High content of graphite or other solid lubricant (lead, tin and others) in the material due to the need of protection of a surface of friction copper counterface from fast destruction and increased wear. A common shortcoming of the famous collector of materials, moving over copper flat rigid solid is developed without grease is impossible to provide specific surface electrical conductivity contact exceeding 150 Cm/cm 2 and a satisfactory wear resistance, the resistance of the current density of more than 50 A/cm2 .
The closest to the purpose and the result achieved is the material for high-current moving [RU2368971, 01 1/021, 22 33/02, publ. 27.09.2009] [2] the following composition,% Mas.:
Copper 18 to 46 Graphite 2-3Recycled steel SX 15
the rest of it.
This well-known composite (prototype) is satisfactory hardness HB (see table). In addition, it forms the contact with higher specific surface electrical conductivity r s -1 (r - resistivity contact) and low intensity of wear I h in conditions of friction on steel without lubrication at a current density of more than 100 A/cm2 . At a certain critical current density j c conductivity r s -1 reaches the maximum values of r sc -1 corresponding to the beginning of the catastrophic wear.
Object of the invention is development of materials for high-current moving to work in tandem with steel , having high conductivity contact and low wear rate in sliding contact current density of more than 100 A/cm2 .
For achievement of the specified technical effect is proposed sintered material, moving on the steel flat rigid solid is developed at contact current density more than 100 A/cm2 containing copper , graphite, iron, in the following component ratio, (wt.%):
Copper 24-57 Graphite 2-3 Ironthe rest of it.
Comparison of the proposed invention of the prototype suggests that the proposed sintered material differs from the known use of iron as a structural component. Decrease of hardness HB proposed the sintered material (see the table) is due to the fact that the hardness of iron particles lower compared to the hardness particles are SHKH15. Resistivity ρ material in the proposed technical solution decreases due to lower resistivity of iron in comparison with heating resistor steel. The fundamental difference porosity Paragraph of the proposed material and porosity of the prototype is not observed (see table).
The introduction of copper more than 57% reduces hardness, conductivity and wear resistance of the contact, and also increases the coefficient of friction. The copper content of less than 24% leads to brittle, reduction of the heat conductivity and electrical conductivity . Introduction graphite more than 3% leads to decrease of strength and conductivity of tribosystem in General. The introduction of less than 2% carbon will increase the coefficient of friction.
Conductivity contact the proposed sintered material when paired with a steel increases with the increase of the contact current density and at a certain critical contact current density j c reaches a peak that corresponds to the beginning of catastrophic wear of the material. Conductivity r sc -1 and intensity of wear I hc corresponding to the start of catastrophic wear, are presented in the table. It is seen that the regime catastrophic wear of the known material [2] is more low r sc -1 , than r sc -1 contact the proposed material (see table). It should be noted that the conduction rs -1 proposed pair of friction at the contact current density of about 50 A/cm is at the level of 200 Cm/cm 2 , ie, the higher r s -1 contact known materials, moving the copper. Wear I hc known material [2] at the beginning of catastrophic wear higher than I hc proposed material (see table). It is also clear that the regime catastrophic wear implemented in friction pairs known and sintered materials - steel almost the same current density j c .approximately 300 A/cm 2 (see table). The surface layer in the materials of friction pairs deformed by the mechanism of a viscous liquid that does not lead to accumulation of structural defects and implemented some plasticity. Lack of alloying elements in iron particles is the cause of their higher plasticity and lower resistivity, which leads to the formation of a more conductive and thus more heat-conducting contact layer in the proposed friction pair. More high thermal conductivity (at the expense of lower ρ) and the easy transition to plastic flow (due to the lower NV) offered materials are factors, which provide higher r s -1 and I h .
loading carried out under the scheme «shaft-pad, speed of 5 m/s at a pressure of 0.13 MPa on a flat rigid solid is developed of steel 45 (50 HRC) wear I h is specified in terms of I h =h/L, where h is the change in the height of the sample on the road friction L (36 km).
Table p/p Si Fe SHKH15 Withr sc -1 , Cm/cm 2
I hc , MM/KM
P, %j c , A/cm 2
ρ, ice m*m
HB, MPa wt.% 1 24 73 - 3 362 9 10 290 0,16 1220 2 57 40 - 3 333 8 8 300 0,09 820 3 35 62.5 - 2.5 342 8 10 280 0,13 940 4 45 53 - 2 321 11 11 305 0,11 890 5 24 - 73 3 190 60 12 280 0,24 1722The table shows the top conductivity contact r sc -1 and the corresponding wear I HS , porosity P, resistivity ρ, hardness HB sintered composites containing iron (p/1-4) and recycled steel SHKH15 (p.5).
Example. Powders components in proportions given in the table (p/1-4), mix in vibrating mill for 2 hours. Dried powder mixture is placed in a steel mould with upper and lower and pressed at a pressure of 550 MPa. Pressed briquettes is sintered at temperatures 1080-1100 degC in vacuum for 2 hours.
Sintered material for high-current moving , working in pair with a steel at contact current density more than 100 A/cm2 containing copper and graphite, characterized in that it additionally contains iron in the following ratio of components, mass%:
copper 24-57 graphite 2-3 ironthe rest of it.