30results about How to "Avoid cold welding" patented technology

The invention relates to a lithium ion battery composite cathode material and a preparation method thereof, which belongs to the technical field of lithium ion battery. The invention aims at improving the cycle performance of silicon cathode material at the same time when keeping the high ratio volume of lithium ion battery silicon cathode material. The proposal of the invention is that silica-based material coated by disordered carbon is treated with surface modification processing by utilizing lithium salt, namely, the lithium salt is coated on the surface of Si/G/DC (silicon/graphite/disordered carbon) to be prepared into the composite cathode material, therefore, the lithium-embedding and removing depth of the silicon can be effectively controlled, and the material is the lithium ion battery composite cathode material which has high specific capacity and good cyclical stability; furthermore, the material is safe and pollution-free, and presents higher thermal stability in various lithium salt electrolytes and solvents.

The invention provides a preparation method of a high-toughness metal-based nanometer composite material and belongs to the technical field of composite materials. The preparation method provided by the invention comprises the following steps of: firstly, using an atmosphere heat treatment process, generating a layer of a nanometer ceramic thin film on the sheet-shaped metal powder through reaction in-situ; and then carrying out densifying treatment by using a powder metallurgical process, so as to obtain the large compact metal-based composite material. The metal-based composite material prepared by the invention has a metal/ceramic alternative laminated structure, wherein a ceramic layer can be used for effectively restraining the reply of a metal layer and the crystal grain growth, improving the high-position wrong storage capability, keeping a nanometer crystal matrix structure, and causing the rotation and inactivation of fissures, so as to realize mechanical properties matched with the high toughness. The preparation method provided by the invention is simple, convenient and practicable, can be used for realizing the macro-quantized preparation of the large-size composite material, and is good for prompting engineering applications of the metal-based nanometer composite material.

The invention discloses a method for preparing nano particle reinforced aluminum matrix composites. The method comprises the steps that firstly, mixed powder of nano ceramic powder and micron-sized aluminum or aluminum alloy powder is used for preparing millimeter-sized composite particles through a dry high-energy ball mill under the protection of vacuum or argon, wherein the volume fraction of nano ceramic particles in the millimeter-sized composite particles is 10-50%; and secondly, the millimeter-sized composite particles are melted directly or added into aluminum or aluminum melt, and supersonic vibration is applied, so that the nano ceramic particles are promoted to be uniformly dispersed in the metal melt, and the nano particle reinforced aluminum matrix composites are prepared. According to the method for preparing the nano particle reinforced aluminum matrix composites, the millimeter-sized composite particles prepared through a dry milling method can be added into the metal melt easily and completely, the problems that the wettability between the nano ceramic particles and matrix metal is poor, and adding of the particles is difficult are solved, and the advantage of low cost of a casting method for preparing metal matrix composites is given to play; the nano particles in the prepared composites are distributed uniformly, and the material performance is high.

The invention discloses a preparation method of a titanium, aluminum, niobium, zirconium and molybdenum alloy, and belongs to the technical field of preparation of titanium alloys. The method comprises the following steps: weighing Ti, Al, Nb, Zr and Mo metal powder according to certain proportions, mixing the metal powder, performing intermittent dry type ball grinding through a ball grinder to obtain mixed powder, putting the obtained mixed powder into a graphite mold, prepressing the mixed powder, placing the graphite mold into a discharge plasma sintering furnace, applying axial pressure of 10 to 50 MPa for sintering under the condition that the vacuum degree is 2 to 8 Pa, heating the mixed powder in a multi-stage heating mode to 1,000 to 1,150 DEG C, preserving the heat for 3 to 8 min, cooling the mixture to room temperature, and demolding the mixture, thus obtaining the titanium, aluminum, niobium, zirconium and molybdenum alloy material. The titanium, aluminum, niobium, zirconium and molybdenum alloy prepared by the method disclosed by the invention has the advantages of uniform component, high compactness, high intensity, high plasticity and the like; and in addition, the method is easy to operate, short in time, energy-saving and environmentally friendly and has a good popularization value.

The invention discloses a solder paste injection valve, and belongs to the technical field of fluid control of automatic equipment. The solder paste injection valve comprises a valve body, a striker, a spring regulating base, a drive spring and an injection part, wherein the valve body comprises a piston cavity, a spring base cavity and a valve body shaft hole; a gas inlet is formed in the side wall, which corresponds to the lower portion of the piston cavity, of the valve body; a piston is formed in the middle of the height direction by the striker; the piston is accommodated in the piston cavity; an air runner which communicates with the gas inlet is formed by a gap, which corresponds to the lower portion of the piston, of the piston cavity; a spring cavity is formed at one end, towards the valve body, of the spring regulating base; the drive spring is arranged in the spring cavity and sleeves the striker; an injection part shaft hole for allowing the striker to insert is formed in the middle of the axial direction of the injection part; a solder paste runner is formed by a gap between the inner side wall of the injection part shaft hole and the striker; a feeding hole which communicates with the solder paste runner is formed in the side wall of the injection part; and a spray nozzle is arranged at the bottom end of the injection part. The solder paste injection valve can prevent a solder ball from cold welding due to contact extrusion, expands types of tin solder paste capable of being injected, is convenient to maintain, is long in service life, and is low in cost.

The invention discloses an automatically expandable autodyne support for the outer space. The automatically expandable autodyne support for the outer space comprises a fixing device, an electromagnetic locking device and an automatic expanding device, wherein the fixing device comprises a fixing seat, a first fixing rod, a second fixing rod and a third fixing rod; the first fixing rod, the secondfixing rod and the third fixing rod are successively perpendicularly arranged on the fixing seat; the automatic expanding device comprises a first joint, a first movable rod, a second joint, a secondmovable rod and a camera mounting seat; and torsional springs are separately arranged in the first joint and the second joint. The automatically expandable autodyne support for the outer space uses principles of electromagnetic locking and torsional spring driving, under the condition that the electromagnetic locking device is energized and unlocked, the autodyne support is automatically expandedunder the driving effect of the torsional spring, the problem that an existing expanding device driven by a motor is high in cost, large in size and poor in reliability is solved, and meanwhile, the technical problems that an existing locking mechanism using initiator explosive bolts for the outer space is high in cost, and the safety and reliability of an aircraft are affected are also solved.

The invention relates to silver micro powder and a preparation method and application thereof, and relates to the technical field of functional materials. The preparation method comprises the following steps: preparing a silver nitrate solution at a temperature of 10-20 DEG C, a dispersant solution at a temperature of 30-60 DEG C, a morphology regulator solution at a temperature of 25-35 DEG C, a pH regulator solution at a temperature of 30-60 DEG C and a reducing agent solution at a temperature of 55-65 DEG C; adding the pH regulator solution into the silver nitrate solution, performing stirring, adding the morphology regulator solution, the reducing agent solution and the dispersing agent solution, performing mixing, adjusting the temperature to 30-60 DEG C, and performing reaction for 30-90 minutes; performing cleaning until the electric conductivity of the reacted product is less than 50 [mu]s/cm, and performing settling and separating; and adding a surface treating agent, performing drying, powdering and sieving to obtain a product. The mass of a morphology regulator is 0.1-0.5% of the mass of the silver micro powder, and the morphology regulator comprises at least one of silver chloride, silver bromide and silver iodide. The preparation method is simple and easy to implement and high in production efficiency.

The invention discloses a 3D printing system suitable for a micro-gravity space environment. The 3D printing system comprises a housing (1) and a control unit (2) as well as a workbench (12) arrangedinside the housing (1), a base plate (11) arranged on the workbench (12), a feeding unit, and a processing head part, wherein the feeding unit comprises a storage device (4), a feeding mechanism (6) arranged at one end of the storage device (4) and an ejecting-out mechanism (3) arranged at the other end of the storage device (4); and the processing head part comprises a small laser unit (7). The invention further discloses a 3D printing method suitable for the micro-gravity space environment. The system avoids the crystallization risk that an amorphous alloy is connected and formed in a thermoplastic mode under a long-time high-temperature condition, can achieve coaxial feeding, is high in forming efficiency, guarantees uniform and continuous discharge, can form a part of any shape, can obtain a large-dimension amorphous alloy part with high forming quality, can keep good equipment work stability, and is especially suitable for on-track manufacturing in the space environment.

The invention relates to the technical field of powder metallurgy preparation of refractory metal materials, and specifically discloses a preparation method of a powder metallurgy refractory multi-principal-element high-entropy alloy. The preparation method of the powder metallurgy refractory multi-principal-element high-entropy alloy specifically comprises the following steps: step S1, refractory metal element powder is sieved through a 300-mesh sieve and mixed in a multi-element powder mixing mode, so that a mixture is obtained; the mixture comprises at least four elements of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W; the atomic percent of each element in the mixture is 5%-35%; and the total percentage is 100%; step S2, pressing forming is carried out, and a pressed blank is obtained; and S3, vacuum high-temperature solid-phase sintering is carried out to obtain a sintered block. The preparation method of the powder metallurgy refractory multi-principal-element high-entropy alloy has the advantages that the components are easy to regulate and control, the production efficiency is high, and near-net forming is achieved; the prepared powder metallurgy refractory multi-principal-element high-entropy alloy is stable in structure and performance and low in cost; and the powder metallurgy refractory multi-principal-element high-entropy alloy has remarkable advantages in research and development of high-performance powder metallurgy refractory multi-principal-element high-entropy alloy and flexible batch production of products of various shapes and varieties.

The invention discloses a satellite-borne dual-band four-channel rotary joint which comprises a first single-waveguide rotor, a first dual-waveguide stator, a dual-waveguide rotor, a second dual-waveguide stator and a second single-waveguide rotor. The first single-waveguide rotor, the double-waveguide rotor and the second single-waveguide rotor are rotors, and the first double-waveguide stator and the second double-waveguide stator are stators; the first double-waveguide stator is arranged between the first single-waveguide rotor and the double-waveguide rotor and is supported and connected through a bearing, the second double-waveguide stator is arranged between the second single-waveguide rotor and the double-waveguide rotor and is supported and connected through a bearing, and the rotors and the stators can rotate relatively. The dual-band four-channel rotary joint is a Ka-high-band four-channel rotary joint and a K-high-band four-channel rotary joint and has the advantages of being high in working frequency and large in number of channels, the channels are independent of one another due to the concentric stacking structure, and the requirement for high isolation between the channels is met.

The invention discloses a lateral load application device for an ERW pipe. The lateral load application device for the ERW pipe comprises electrode blocks, electrode panels, a pressure spring, an electrode connection rod, a workbench, a telescoping mechanism, a support plate, a lifting device, a base and a conductive plate, wherein under the pressure effect of the pressure spring, the electrode blocks in the electrode panels cling to the side surface of a pipe blank. The invention further provides a lateral load application method for the ERW pipe. A hydraulic rod on an electrode hydraulic cylinder is fixed to a connection rod sleeve, and the two electrode plates at corresponding positions on the electrode panels at the two sides can be driven simultaneously, so that the problem that the two electrode blocks are asymmetric with respect to a welding joint is solved; a high-frequency current is loaded onto the side surface of the pipe blank, uniform temperature distribution of the welding joint of the pipe blank in a wall thickness direction is realized by properly adjusting the relative positions of the electrode blocks on the side surface of the pipe blank, and then the defects ofcold welding, overburning and the like which are brought by non-uniform temperature distribution is avoided, and the quality of the welding joint of the pipe blank is improved.

The invention discloses a nanometer aluminum oxide reinforced 316L stainless steel composite material and a preparation method thereof. The preparation method comprises the following steps that mixed powder A is subjected to powder laying and laser forming, and a formed body is obtained; stress regulation and control are carried out on the formed body, and the nanometer aluminum oxide reinforced 316L stainless steel composite material is obtained; the mixed powder A is a mixed powder obtained by ball-milling 316L steel powder and pretreated Al2O3 powder together; and the pretreatment process of the Al2O3 powder comprises the steps that spherical Al2O3 is placed in NH4OH to be subjected to erosion treatment, washing and drying are carried out after erosion, and the pretreated Al2O3 powder is obtained. The nanometer aluminum oxide reinforced 316L stainless steel composite material contains 0.1%-0.2% of nanoscale Al2O3 particles and the balance a 316L matrix. According to the method, the nanometer aluminum oxide reinforced 316L stainless steel composite material is prepared through the laser melting technology, the method has the characteristics of being high in machining speed, high in efficiency and short in working procedure, meanwhile, the ceramic material Al2O3 can be evenly distributed in a 316L stainless steel matrix, the strength of 316L is remarkably improved, and the method has important significance for expanding the applicability of 316L.

The invention belongs to the technical field of plastic products. The invention discloses a PE drain pipe and a production process thereof. The PE drain pipe is prepared from, by weight, 80-100 partsof PE, 3-5 parts of nano MgO, 0-5 parts of nano MnS, 5-15 parts of ground calcium carbonate, 2-5 parts of a coupling agent, 0-3 parts of EVA, 3-5 parts of a flame retardant, 3-10 parts of a tougheningagent, 1-5 parts of a heat stabilizer and 0-2 parts of a processing aid. Beneficial effects of the PE drain pipe and the process are that the nano MgO can enhance the heat-conducting property of a PEproduct and avoid the cold welding phenomenon in a PE pipe welding process; the nano MnS can keep the stability of a polyethylene molecular chain in the welding process, and thermal oxidation of polyethylene when the welding temperature is too high is avoided; the ground calcium carbonate, the nano MgO and the nano MnS have a synergistic effect, so that the stability of a welding part can be improved, and the firmness of the welding part is improved; by adding the nano MgO, the nano MnS and the ground calcium carbonate, the temperature range of the PE pipe during welding can be widened, and the welding stability of the PE pipe is improved.

The invention provides a space camera focusing mechanism. The focusing mechanism comprises an optical lens barrel, a motor assembly and a focusing cam roller assembly. The motor assembly comprises a motor and a small gear arranged on an output shaft of the motor in a sleeving mode. The focusing cam roller assembly comprises a cam gear, a CMOS bracket, and at least one set of cam roller clamps which is assembled on the CMOS bracket and is used for clamping the cam gear, wherein the cam gear and the CMOS bracket sleeve the optical lens barrel; and the cam gear is engaged with the small gear, andwhen the cam gear rotates, rotation motion of the cam gear is converted into reciprocating linear motion of the CMOS assembly fixed on the CMOS bracket so as to change a distance between a CMOS focalplane of the CMOS assembly and an optical lens group in the optical lens barrel. An outer wall of the optical lens barrel serves as a rotating shaft of the cam gear, axial support is provided for thecam gear, self-lubrication is achieved through a molybdenum disulfide material of a cam roller and a PEEK material of the cam gear, and lubricating grease does not need to be used. Therefore, self-lubricating continuous reciprocating focusing in a vacuum environment can be simply realized.

The invention discloses a crusher rack convenient to disassemble and assemble. The crusher rack comprises a rack shell, the rack shell comprises an upper rack body and a lower rack body, and an auxiliary disassembling and assembling assembly is arranged at the joint of the upper rack body and the lower rack body. The auxiliary disassembling and assembling assembly comprises a driving part, a punching rod is arranged on the driving part, separating inclined blocks located on the joint face of the upper rack body and the lower rack body are arranged on the two sides of the punching rod, and the separating inclined blocks can move in the radial direction of the rack shell. By arranging the auxiliary disassembling and assembling assembly between the upper rack body and the lower rack body, it is guaranteed that during disassembling, the joint face of the rack bodies can be laterally cut through the separating inclined blocks, the cold welding phenomenon caused by metal atom diffusion is avoided, and disassembling of the crusher rack bodies is facilitated.

The invention discloses a method for manufacturing an engine connecting rod through aluminum-base powder metallurgy and forging. The method comprises the following steps that a plasticizer is dissolved in a plasticizer solvent, and thus a plasticizer solution is formed; powder materials obtained after batch calculation and weighing are added into the plasticizer solution, wherein the powder materials comprise, by weight, 93.5% of aluminum powder, 5% of copper powder, 1% of silicon powder and 0.5% of magnesium powder; a demoulding lubricant is added, and all materials are placed in a mixer to be mixed to be uniformly distributed; the power materials are pressed into a preformed blank on a pressing machine; the preformed blank is sintered at the temperature of 610-620 DEG C in a vacuum sintering chamber with the vacuum degree being 720-740 mmH2O till the preformed blank is completely alloyed; then a sintered body is moved into a heat preservation furnace with an oxidation-free atmosphereto be subjected to heat preservation for 30 min; and the sintered body is heated again and forged after being cooled to the indoor temperature.

The invention discloses a method for stabilizing the friction coefficient of the nut supporting surface and a nut, and relates to the technical field of fastener connection, the method comprises the following steps that S1, a microstructure with surface undulation is formed on the nut supporting surface; and S2, a concave area of the surface undulation of the nut supporting surface is filled witha solid lubricant. According to the method for stabilizing the friction coefficient of the nut supporting surface and the nut, the friction coefficient of the nut supporting surface can be stabilized,the abrasion of the supporting surface in the nut tightening process is reduced, and the cold welding phenomenon is avoided.

The present invention provides an IC testing seat and testing interface thereof. The IC testing seat comprises of a testing seat body, a top surface, a bottom surface and a hatch through the top and bottom surface. The testing interface is set in the testing seat body which comprises of first and second non-electric conductivity flexible sheet space and many conductive spheres. The first, second non-electric conductivity flexible sheet space has one top surface and bottom surface respectively and many first, second via holes corresponding to meeting points on bottom of IC encapsulation parts. The first, second via holes have identical number and vertical contraposition through combination of first, second non-electric conductivity flexible sheet space and conductive spheres can accepted and fixed in it, and one end of each conductive sphere extends outside the top surface of testing seat body to contact electrically with corresponding meeting points on bottom of IC encapsulation parts, the other end extends outside of the bottom of testing seat body to contact electrically with corresponding meeting points on testing board.