48results about How to "Improve mechanical shock resistance" patented technology

The invention discloses a gas-blowing and slag- gathering spray gun for assisting slag-off of molten iron and a using method of the spray gun. The gas-blowing and slag-gathering spray gun comprises a gun barrel, wherein the gun barrel is provided with an opening end and a closed end; spray ports are symmetrically formed on the barrel wall, close to the closed end, of the gun barrel based on the middle axis of the gun barrel; the middle axes of the spray ports are vertical to the middle axis of the gun barrel; and the ratio of the inner diameters of the spray ports to the inner diameter of the gun barrel is (0.35-0.70):1. The gas-blowing and slag-accreting spray gun has the characteristics of being simple in structure, long in service life, stable in gas-blowing and slag-accreting operation and the like. The gas-blowing and slag-gathering spray gun disclosed by the invention is combined with the using method of the spray gun, so that the molten iron slag gathering degree can be improved, the bare area of the molten iron is increased, the erosive wear to the molten iron tank wall is small, the slag-off iron loss is low and the slag-off time is short.

The invention relates to a graphene reinforced copper-rare earth based electrical contact material and a preparing method thereof. The electrical contact material comprises, by weight, 0.1-3.0% of graphene and 97.0-99.9% of copper-rare earth alloy, and rare earth accounts for 0.05-3.0% of the total weight of copper-rare earth alloy. The preparing method comprises the steps of powder atomization, ball milling and powder mixing, cold press molding, sintering, secondary forming and sintering. By adding a graphene reinforcing body to copper alloy to serve as the framework, the material has high hardness, high wear resistance, high mechanical impact resistance and high welding resistance. By adding rare earth, the oxidation resistance and electric arc erosion resistance of the copper alloy electrical contact material are improved.

Provided is a current detection circuit module wherein it is possible to correct the current detection sensitivity before assembling a finished product and to achieve high mechanical shock resistance. A current detection circuit module (11) provided with a control circuit board (9) on which a control IC (7) for controlling power modules (5) is mounted, magnetic cores (21) which each have a gap (27) on a portion thereof and which surround busbars (15) extending from the power modules (5), magnetic detection elements (40) which are disposed within the gaps (27), and a detection circuit (44) which outputs to the control IC (7) the detection signal of the current value flowing through the busbars (15) in response to the output of the magnetic detection elements (40), wherein the detection circuit (44) is mounted on the control circuit board (9), the control circuit board (9) is provided with passing parts (29) which are formed by notches and which are used to arrange the busbars (15) perpendicular to the board surface, the magnetic cores (21) are mounted on the control circuit board (9) so as to surround the respective busbars (15) passing the respective passing parts (29), and the magnetic detection elements (40) are mounted on the control circuit board (9) such that the magnetic detection elements (40) are located within the gaps (27) of the respective magnetic cores (21).

The invention discloses a varifocal double-liquid lens based on inverse piezoelectric effect. An accommodating chamber wall is made of a piezoelectric material; an accommodating chamber is internally divided into an upper chamber and a lower chamber by a transparent elastic membrane; different liquids are filled in the two chambers; electrodes are respectively arranged in places where a container wall is connected with an upper end cover and a lower end cover of the accommodating chamber and the membrane, wherein a voltage is connected between two electrodes arranged above the membrane, and the other voltage is connected between two electrodes arranged below the membrane; the piezoelectric material generates the inverse piezoelectric effect to deform through regulating the polarity and the size of the two voltages, so as to change the liquid lens curvature to achieve the zooming effect of the lens. The invention solves the drive technique limitation of the traditional liquid lens, and enlarges the selection range of two liquids to increase the zooming range.

The invention discloses an anti-aging ceramic insulator and a preparation method thereof, and relates to the technical field of an insulator. The anti-aging ceramic insulator is prepared from the following raw materials in parts by weight: 20 to 32 parts of potassium feldspar, 15 to 24 parts of zeolite, 25 to 30 parts of mica, 8 to 16 parts of kaolin, 15 to 22 parts of epoxy resin, 10 to 18 partsof organic silicon, 10 to 20 parts of ceramic fiber, 6 to 10 parts of zirconium dioxide, 7 to 15 parts of calcium silicate, 4 to 10 parts of nanometer silicon dioxide, 4 to 10 parts of nanometer titanium dioxide, 3 to 8 parts of nanometer silicon nitride, 3 to 6 parts of silane coupling agents, 3 to 6 parts of antioxidants, 2 to 5 parts of anti-freezing agents and 3 to 6 parts of surface active agents. The anti-aging ceramic insulator has the advantages that the property is stable; the corrosion resistant performance and the anti-aging performance are good; the low temperature and high temperature resistant performance is good; strong mechanical stress is realized; the preparation method is simple and easy; the manufacturing cost is low; good market application prospects are realized.

The invention relates to an electrical contact material, in particular to a graphene reinforced copper-based electrical contact composite material and a preparation method of the material. The electrical contact material is prepared from, by weight, graphene 0.1-1.0% and copper alloy 99.0-99.9%. The preparation method comprises the steps of copper alloy atomization, ball milling and powder mixing, primary molding, sintering, secondary molding and sintering. The graphene is added in the copper alloy to serve as a framework of the electrical contact material, so that reduction of electrical conductivity and thermal conductivity is avoided while the material has high hardness, mechanical shock resistance performance and arc ablation resistance performance. A cold-pressing molding sintering preparation technology is adopted in the preparation method, the production cost is reduced, and the electrical contact material is suitable for large-scale industrial production.

The invention discloses a corrosion-resistant cable material and a preparation method thereof and relates to the field of cable materials. The corrosion-resistant cable material is prepared from 60 to70 parts by weight of polypropylene, 20 to 30 parts by weight of an ethylene-propylene-diene monomer, 15 to 22 parts by weight of glass fibers, 8 to 15 parts by weight of ultrafine diatomite, 10 to 16 parts by weight of modified basic magnesium sulfate whisker, 3 to 7 parts by weight of white carbon black, 3 to 7 parts by weight of zirconium dioxide, 1 to 3 parts by weight of polytetrafluoroethylene, 1.5 to 3.2 parts by weight of neodymium oxide, 2 to 4 parts by weight of tetrabutyl titanate, 1.5 to 2.5 parts by weight of melamine, 0.8 to 1.8 parts by weight of a beta-nucleating agent, 2.5 to4 parts by weight of a plasticizer, 0.4 to 0.8 parts by weight of a cross-linking agent, 1.5 to 2.5 parts by weight of an antioxidant and 1.5 to 2.5 parts by weight of a lubricant. Through cooperation of the cable material components, the corrosion-resistant cable material has good strength and mechanical toughness, corrosion resistance, aging resistance, high temperature resistance, high flame retardancy, no harmful smoke in burning and environmental friendliness.

This invention provides a moving iron unit for loudspeakers, which includes coil, iron core, diaphragm, and magnet, among which, the iron core is disposed in the coil, and the magnet is connected to the diaphragm on a transmission basis. It is characterized in that it also includes vibrating ring, to which the magnet is secured, and which is secured to the inner wall of a shielded cavity through its elastic body disposed radially, and which is connected to the diaphragm on a transmission basis through the transmission rod. Further, the unit comprises two diaphragms, which are disposed symmetrically at two sides of the vibrating ring and connected respectively to the vibrating ring on a transmission basis through a transmission rod. The coil is shaped directly by coiling on the iron core.

Relating to the field of thermal insulation materials, the invention discloses an energy-saving and environment-friendly thermal insulation material and a preparation method thereof. The energy-savingand environment-friendly thermal insulation material comprises the following raw materials by weight: 8-15 parts of calcium carbonate powder, 12-25 parts of industrial coal slag, 5-12 parts of aluminum oxide, 2-5 parts of aluminum stearate, 8-15 parts of waste asbestos, 5-9 parts of polypropylene fiber, 11-18 parts of bamboo charcoal powder, 12-18 parts of coconut shell powder, 7-16 parts of attapulgite, 8-13 parts of quartz powder, 11-23 parts of potassium feldspar, 12-17 parts of montmorillonite, 15-21 parts of waste polyethylene foam plastic, 20-28 parts of Portland cement, 0.8-2 parts ofsodium pyrophosphate, 0.6-1.2 parts of a penetrating agent, 0.6-1.2 parts of a water reducing agent, 0.4-0.8 part of a foaming agent, and 10-15 parts of water. Through coordination of the raw materials, the thermal insulation material provided by the invention has low thermal conductivity coefficient, excellent thermal insulation performance, and also has the advantages of high mechanical impact resistance, good flame retardance and high crack resistance.

The invention discloses an anti-mechanical shock armature device with an innovated structure used for a moving-iron receiver / speaker. The anti-mechanical shock armature device comprises a vibration energy changing part, an anti-mechanical shock device and magnetic conduction connection parts, and is characterized in that the vibration energy changing part which is of a planar structure is arranged in the middle, the protruding and concave-shaped anti-mechanical shock device which is directly crossed with the planar structure is distributed on the vibration energy changing part, and the vibration energy changing part is further connected with the magnetic conduction connection parts arranged on the two sides and tail portion to form the armature device. Compared with a traditional armature device, the anti-mechanical shock armature device has at least the advantages that the anti-mechanical shock device is additionally arranged to the vibration energy changing part in an innovated mode, the mechanical shock resistance property of the moving-iron receiver / speaker using the armature device is greatly improved, manufacturability is strong, cost is low, and packaging technology is simple and convenient in the subsequent manufacturing process of the receiver / speaker. In addition, the anti-mechanical shock device can also be applied to various armature devices conveniently, and a marketing value is large.

The invention relates to a heavy type high-efficient composite broken line edge blade for cutting and turn milling, belongs to the technical field of tools for turn milling machining, and solves the problems that a single blade welded type lathe tool is easy to fracture and becomes invalid when bearing a heavy mechanical shock in the rough machining process of an ultra-large barrel forged piece blank, and a blade is cut by a workpiece due to the loss of the hardness required by cutting at the high temperature in the cutting process. Flank surfaces of the cutting tool are formed by alternately connecting long inclined planes with short inclined planes in sequence; long cutting edges and short cutting edges are combined to form the broken line-shaped cutting edges; long edges and short edges are formed at the periphery of the external surface of a raised platform; the long cutting edges are provided with long inclined planes which incline to the bottom of the raised platform; inverted trapezoid chip breaker grooves are formed in the areas between the long inclined planes and sides of the long edges; the short cutting edges are provided with short inclined planes which incline to the bottom of the raised platform; V-shaped chip breaker grooves are formed in the areas between the short inclined planes and the sides of the short edges of the raised platform; and a bottom surface of the blade is provided with bottom heat radiating grooves. The heavy type high-efficient composite broken line edge blade for cutting and turn milling is used for cutting, turning and milling the large hydrogenation barrel blank.

A piezoelectric diaphragm has principal-surface electrodes formed on upper and lower principal surfaces of a multilayer ceramic body. An internal electrode is disposed in an interface between adjacent piezoelectric ceramic layers. The upper and lower principal surfaces of the multilayer ceramic body are substantially entirely covered with a resin layer. A first cutout is formed in a side-edge portion, along the first side surface electrode, of the upper resin layer such that the upper principal-surface electrode is partially exposed in the first cutout. A second cutout is formed in a side-edge portion, along the first side surface electrode, of the lower resin layer such that the lower principal-surface electrode is partially exposed in the second cutout. The locations of the first and second cutouts formed in the upper and lower resin layers, respectively, are selected such that they do not oppose each other.

The invention discloses a high-temperature ceramic plate type array capacitor and a preparation method thereof. The capacitor main body includes: a ceramic medium, an inner electrode and a terminal electrode, the capacitor main body is of a multilayer plate-shaped structure with a plurality of signal holes, the inner electrode comprises a plurality of common grounding electrodes and a plurality ofsignal electrodes, the plurality of common grounding electrodes and the plurality of signal electrodes are alternately arranged in the lamination direction of the ceramic medium, and the projectionsof the common grounding electrodes and the signal electrodes on a lamination plane are partially overlapped; each common grounding electrode extends inwards from the outer edge of the ceramic medium and is spaced from the signal hole; and each signal electrode extends outwards from the signal hole and is spaced from the outer edge of the capacitor and the signal electrode of the adjacent signal hole. The problems that in the prior art, a discrete ceramic tube type capacitor filter is poor in mechanical shock resistance and prone to damage, and the reliability of the whole filter is prone to being reduced are solved.

An electrochemical device includes a housing, an electrode assembly, a first bonding piece, a second bonding piece, and a third bonding piece. The electrode assembly comprises pole pieces and an isolating membrane. The pole pieces comprise a first pole piece and a second pole piece, and the isolating membrane is arranged between the first pole piece and the second pole piece. The electrode assembly is of a winding structure and is arranged in the shell. In the winding direction, the electrode assembly comprises a first section, a first bent section, a second section and a second bent section, wherein the outermost ring of the first section is the isolating membrane. The electrode assembly includes a first end portion and a second end portion opposite to each other in a winding center axis direction. The first bonding piece is bonded with the outer surface of the first bent section and the tail part of the isolating membrane; the second bonding piece is bonded on the outer surface of the second bent section and is bonded on the tail part of the first pole piece; and the third bonding piece is arranged at the first end part and is bonded with the outer surface of the isolating membrane at the outermost ring of the first section and / or the outer surface of the pole piece at the outermost ring of the first section. The security is improved. The invention further provides an electronic device.

The invention discloses anti-corrosion paint for a guardrail surface layer and a preparation method thereof, and relates to the field of paint. The paint is prepared from the following raw materials in parts by weight: 30 to 40 parts of epoxy resin, 25 to 30 parts of organic silicon resin, 10 to 20 parts of polyvinyl acetate, 5 to 10 parts of mica powder, 6 to 12 parts of attapulgite, 4 to 10 parts of silicon dioxide, 3 to 8 parts of ceramic fiber, 3 to 6 parts of nanometer titanium dioxide, 3 to 6 parts of nanometer magnesium hydroxide, 3 to 6 parts of nanometer antimonous oxide, 2 to 5 partsof nanometer iron powder, 3 to 6 parts of tea meal powder, 4 to 7 parts of bamboo charcoal powder, 2 to 5 parts of zirconium oxide, 1.8 to 3.6 parts of pigments, 2.5 to 4.5 parts of silane coupling agents, 2.2 to 3.8 parts of anti-aging agents, 1.4 to 3.1 parts of leveling agents and 2.5 to 4.8 parts of tackifiers. The anti-corrosion paint has the advantages of high bonding performance, stable physicochemical property, high anti-corrosion performance, difficult pulverization falling, high anti-mechanical-impact performance, bacteriostatic effect and air purification effect.

The invention discloses an integrated structure of a servo driver and a backup power supply for a pitch control system. The integrated structure of the servo driver and the backup power supply for the pitch control system comprises a three-phase uncontrolled rectification circuit, a three-phase bridge inverter circuit, a DC / DC two-way switching circuit, the backup power supply, a first voltage and current detection circuit, a second voltage and current detection circuit, a first drive protection circuit, a second drive protection circuit, a DSP, a DC / DC auxiliary power supply, an AC / DC auxiliary power supply and a sing-pole double-throw switch. Through the integrated design carried out on the servo driver and the backup power supply on a hardware structure, the compactness of the system is improved, the volume of the system is reduced, the internal space of a hub is saved, cost is lowered, and connection fault points are reduced.

The invention provides a high-temperature-resistant and easy-to-unroll composite expansion adhesive tape. The composite expansion adhesive tape comprises a base layer and an adhesive layer which are compounded with each other, and the adhesive layer comprises a temperature-resistant layer; and the base layer is an oriented polystyrene film, and the oriented polystyrene film is prepared from, by weight, 85-90% of general polystyrene, 5-8% of high-impact polystyrene and 0.9-2.3% of nano silicon dioxide. The composite expansion adhesive tape provided by the invention has high expansion rate, can be kept not shrunk at high temperature, and is easy to uncoil in industrial production.

The invention discloses a flapping device used for a minitype loudspeaker device, wherein the flapping device is provided with an improved structure. The flapping device comprises a vibrating disk part, a mechanical structure reinforcing rib part and through hole structures, and is characterized in that the vibrating disk part is of a planar structure, the mechanical structure reinforcing rib part is arranged on a vibrating disk according to the design demands, at the same time, and a plurality of through hole structures are distributed in the vibrating disk and the mechanical structure reinforcing rib part to form the flapping device together. The flapping device has at least the advantages that compared with a traditional flapping device, the flapping device makes an improvement on the design of a mechanical structure reinforcing rib, and a mechanical shock resistance property and vibration stability of the flapping device are greatly improved. Compared with a traditional design, the design of the flapping device is strong in manufacturability and low in cost. In addition, the flapping device can meet different frequency response requirements of various minitype loudspeaker devices by adjusting of the shapes of the vibrating disk, the shapes and the number of mechanical structure ribs and the through holes, and an application range is very wide.

The invention discloses a strong pillar porcelain insulator for high-voltage lines, which comprises an insulator body, an upper steel cap and a lower steel cap. The insulator body has a bone cylinder, an upper core head and an The lower core head and the bone cylinder are provided with large and small umbrella skirts at intervals, the upper core head is provided with annular grooves and insertion grooves, the inner surface of the upper steel cap is provided with annular bosses at intervals, and the upper steel cap and Connectors are arranged between the upper core heads, annular grooves are arranged at intervals along the axial direction of the lower core head, annular grooves are arranged at intervals on the inner surface of the lower steel cap, and the lower steel cap and the lower core head There are clamping parts between them. The present invention has high mechanical strength, excellent electrical performance, stable and reliable quality, high mechanical impact resistance, strong pollution resistance, small maintenance workload, and low cost, which can fully meet the requirements of 110‑330KV Technical requirements for pillar porcelain insulators for high voltage transmission lines.

The invention relates to a preparation method for a graphene reinforced copper-matrix electrical contact material. The preparation method comprises the steps that 1.0%-5.0% by weight of graphene and 95.0%-99.0% by weight of copper powder are subjected to ball milling for powder mixing and cold press molding, copper is smelted in an intermediate frequency furnace, copper-graphene intermediate alloy is added into molten copper, a composite is prepared through a casting process, and the composite is subjected to stress relief annealing and processing molding. According to the preparation method, graphene reinforcements are added into copper alloy to be used as a framework, so that the material has high hardness, high abrasion resistance, mechanical shock resistance and fusion-welding resistance. By adding rare earth, the oxidation resistance and electric arc burning resistance of the copper-alloy electrical contact material are improved.

The invention provides a knife stone, which is prepared from the following components in parts by weight: 14 to 23 parts of a first particle material, 55 to 69 parts of a second particle material, 9 to 14 parts of a third particle material, 7 to 10 parts of a powder material and 0.4 to 1 part of a liquid binding agent, the particle size of the first particle material ranges from 0.425 mm to 0.85 mm, the particle size of the second particle material ranges from 0.25 mm to 0.425 mm, and the particle size of the third particle material ranges from 0.15 mm to 0.25 mm. The knife stone is high in density and uniform in structure, has good mechanical shock resistance, wear resistance and self-sharpening performance, is beneficial for cutting a knife, has high-content chromic oxide, and can greatly improve the recovery value of sediment when being used for grinding chromic oxide bricks.

A piezoelectric diaphragm has principal-surface electrodes formed on upper and lower principal surfaces of a multilayer ceramic body. An internal electrode is disposed in an interface between adjacent piezoelectric ceramic layers. The upper and lower principal surfaces of the multilayer ceramic body are substantially entirely covered with a resin layer. A first cutout is formed in a side-edge portion, along the first side surface electrode, of the upper resin layer such that the upper principal-surface electrode is partially exposed in the first cutout. A second cutout is formed in a side-edge portion, along the first side surface electrode, of the lower resin layer such that the lower principal-surface electrode is partially exposed in the second cutout. The locations of the first and second cutouts formed in the upper and lower resin layers, respectively, are selected such that they do not oppose each other.

The invention discloses an enameled wire for an oil-cooled motor of a new energy automobile and a production and processing technology thereof, and belongs to the technical field of enameled wire production and processing. The enameled wire comprises a copper conductor, a primer layer, a middle paint layer and a finish paint layer, the primer layer adopts high-adherence polyamide-imide paint, the middle paint layer adopts corona-resistant polyimide paint, the finish paint layer adopts oil-resistant and hydrolysis-resistant polyamide-imide paint, the paint film thickness of the primer layer accounts for 3%-20% of the total paint film thickness, the middle layer accounts for 40%-90% of the total paint film thickness, and the finish paint layer accounts for 3%-20% of the total paint film thickness. According to the invention, three different types of insulating paint are combined for coating, and the primer layer, the intermediate paint layer and the finish paint layer are respectively coated with different types of paint, so that the primer layer, the intermediate paint layer and the finish paint layer play respective advantages and make up for deficiencies, and finally, the enameled wire for the oil-cooled driving motor of the automobile, which has the advantages of corona resistance, high winding property, mechanical shock resistance and strong oil-water resistance, is prepared.

The invention discloses an arch load-bearing platform of a fluidized roasting furnace and a pouring method thereof, comprising a main body of the load-bearing platform and a support platform, the main body of the load-bearing platform and the support platform are fastened together through an L-shaped fastening surface, and the main body of the load-bearing platform is composed of multiple layers. Different castable materials are poured in layers, and the layers are separated by hydrophobic fiberboards. The vent holes on the main body of the load-bearing platform are connected by wear-resistant and high-temperature resistant high-alumina ceramic tubes at the junction of different material layers; The water fiber board, the improvement of the matching structure between the main body of the load-bearing platform and the support platform, and the addition of different contents of steel fibers to the castables enable the arched load-bearing platform to reliably withstand the weight of the material itself in the roasting chamber and the high-frequency vibration load during fluidized roasting. It can also effectively prevent materials from falling into the lower combustion chamber from the roasting chamber.

The invention discloses a tough column-type porcelain insulator for a high-voltage line. The insulator comprises an insulator body, an upper steel cap and a lower steel cap. The insulator body is provided with a bone column body, and an upper core head and a lower core head which are integrally connected with the two ends of the bone column body. Large umbrella skirts and small umbrella skirts arearranged on the bone column body at intervals. An annular groove and a plug-in slot are formed in the upper core head. Annular bosses are arranged on the surface of the inner side of the upper steelcap at intervals. A plug connector is arranged between the upper steel cap and the upper core head. Annular clamping slots are formed in the lower core head at intervals in the axial direction of thelower core head. Annular trenches are formed in the surface of the inner side of the lower steel cap at intervals. A clamping piece is arranged between the lower steel cap and the lower core head. Thetough column-type porcelain insulator has the advantages of high mechanical strength, excellent electrical performance, good quality stability and reliability, high mechanical impact resistance, highpollution resistance, small maintenance workload and low cost, and can completely meet the technical requirements on a column-type porcelain insulator for a 110-330KV high-voltage power transmissionline.

A hearing assisting (10) device including a receiver (1) for generation of acoustic signals and a fixture (3, 8, 9) for positioning the receiver. A suspension (2, 21, 22) supports the receiver to the fixture. The combination of the receiver and the suspension has a mechanical resonance frequency in the range from 6 kHz to 10 kHz.

The filtration cartridge (10) comprises a filtration element (20) and a heat-resistant extension band (40) having a first (42) and a second longitudinal edge (44). The first edge (42) of the extension band (40) is attached along an edge (22) of the filtration element (20). In a first embodiment, a metallic cast end member (30) is formed by immersing the second edge (44) of the extension band (40) into molten metal. The molten metal is then allowed to solidify with the second edge (44) of the extension band (40) embedded therein. In a second embodiment, the extension band (40) is squeezed on a porous inner core (50) and an end plate (72) is welded on the end of the inner core (50). Providing filtration cartridges (10) with a metallic end member (30) allows increasing their resistance to mechanical shocks and increasing their maximum operating temperatures.

A high-power square-piece silicon controlled rectifier packaging structure comprises an upper molybdenum plate (7), a third welding flux layer (6), a chip (5), a second welding flux layer (4), a lower molybdenum plate (3) and a first welding flux layer (2) which are sequentially arranged from top to bottom, wherein the upper molybdenum plate (7), the third welding flux layer (6), the chip (5), the second welding flux layer (4), the lower molybdenum plate (3) and the first welding flux layer (2) are arranged in a silica gel frame (8), two ends of the chip (5) are inserted into the silica gel frame (8), a conductive casing (1) is installed outside the silica gel frame (8), the top of the conductive casing (1) is open, the other three sides are of semi-surrounded structures, and the bottom of the conductive casing (1) is welded at the position where a high-power square-piece silicon controlled rectifier is required to be installed. When the high-power square-piece silicon controlled rectifier packaging structure is used, the assembling operation is simple and easy. Compared with traditional packaging modes, the reject ratio is reduced by one magnitude order.

The invention relates to a copper-plated graphene reinforced copper-based electrical contact material and a preparation method thereof. The electrical contact material comprises 0.1-5.0 wt% of copper-plated graphene and 95.0-99.9 wt% of copper-rare earth alloy, and the weight ratio of rare earth in the copper-rare earth alloy accounts for 0.03-2.0%. The preparation method comprises the following steps of graphene copper plating, atomization for powder making, ball milling and power mixing, cold-press forming, sintering, secondary forming and sintering. A copper-plated graphene reinforced body is added into the copper alloy and taken as a framework, so that the material has the advantages of high hardness, high wear resistance, mechanical impact resistant performance and welding resistance; and with the addition of the rare earth, the oxidation resistance and the arc burning resistant capability of the copper alloy electrical contact material are improved.

This invention provides a moving iron unit for loudspeakers, which includes coil, iron core, diaphragm, and magnet, among which, the iron core is disposed in the coil, and the magnet is connected to the diaphragm on a transmission basis. It is characterized in that it also includes vibrating ring, to which the magnet is secured, and which is secured to the inner wall of a shielded cavity through its elastic body disposed radially, and which is connected to the diaphragm on a transmission basis through the transmission rod. Further, the unit comprises two diaphragms, which are disposed symmetrically at two sides of the vibrating ring and connected respectively to the vibrating ring on a transmission basis through a transmission rod. The coil is shaped directly by coiling on the iron core.