956 results about "Laser additive manufacturing" patented technology

The invention relates to duplex stainless steel powder for laser additive manufacturing and a preparation method and application thereof, and belongs to the technical field of nitrogen-containing stainless steel powder preparation, the duplex stainless steel powder comprises, by mass, 0.09-0.20% of C, 5.00-15.00% of Mn, 1.00-5.00% of Mo, 5.00-15.00% of Ni, 10.00-30.00% of Cr, 0.10-0.40% of N, less than or equal to 0.02% of S, less than or equal to 0.02% of P, and the balance Fe. According to the method, vacuum induction melting and high-pressure inert gas atomization methods are utilized, the conditions such as the adding time of the mixture of the metal manganese particles and the nitrogen-containing alloy particles are controlled, and therefore the purpose of controlling the nitrogen content in the alloy powder is achieved.

The invention belongs to the technical field of laser processing, and particularly relates to a method for manufacturing a titanium alloy through wire powder coordinated multi-mode laser coupling additive manufacturing, and the method comprises the steps of base material pretreatment, multi-mode coupling laser construction, additive manufacturing, surface strengthening and the like. According to the titanium alloy part manufacturing device and method, material conveying is conducted in the mode that wire feeding and powder feeding are combined, structures with large areas in parts are rapidly manufactured through wire feeding, fine structures are manufactured through powder, and the titanium alloy parts can be efficiently manufactured in a high-precision mode. In the additive manufacturing step, multi-mode coupling annular laser is adopted, annular flat-topped pulse laser can accelerate flowing of a liquid phase before solidification, so that dendritic crystal arms formed through solidification in advance are broken to form new crystal nucleuses, then an equiaxed crystal structure is formed, and the strength and plasticity of the titanium alloy are improved. The annular flat-topped pulse laser can accelerate stirring of the molten pool, the heat mass conveying rate in the molten pool is increased, the element segregation phenomenon is relieved, and finally a uniform and stable titanium alloy structure is obtained.

The invention relates to a high-toughness corrosion-resistant aluminum alloy and a preparation method thereof. The high-toughness and corrosion-resistant aluminum alloy is prepared from the following components in percentage by mass: 3.5 to 4.6 weight percent of Mg, 1.3 to 1.5 weight percent of Zn, 0.1 to 0.4 weight percent of Sc, 0.4 to 0.5 weight percent of Zr, 0.4 to 0.5 weight percent of Cu and the balance of Al. The optimized preparation method comprises the steps that aluminum alloy mixed powder serves as a raw material, laser additive manufacturing is adopted, and a printed product is obtained through printing; during printing, the laser power is controlled to range from 250 W to 350 W, the laser scanning speed ranges from 800 mm / s to 1200 mm / s, the laser spot diameter ranges from 60 micrometers to 80 micrometers, the scanning interval ranges from 0.02 mm to 0.05 mm, and the powder laying thickness ranges from 0.03 mm to 0.05 mm. Based on a cross alloy design strategy, the in-situ alloying powder manufacturing technology and the laser powder bed melting technology are combined, collaborative optimization of the mechanical property and the corrosion resistance is achieved, meanwhile, the material development and preparation cost is effectively reduced, and the application requirements of multiple fields are met.

The invention discloses a closed-loop self-adjusting method for online defect identification and real-time feedback in the additive manufacturing process of a titanium alloy component based on intelligent sensing, belongs to the field of laser additive manufacturing, and solves the key problems of insufficient defect identification capability, quality control lag and the like in the current additive manufacturing process. The method is based on a multi-mode sensor architecture, integrates an infrared thermal imager, a molten pool camera and a spectrum sensor, and synchronously monitors a molten pool thermal field, radiation characteristics and surface topography. Traditional image processing and signal analysis are adopted to extract defect features such as air holes and cracks, and calibration is implemented in combination with off-line detection such as industrial CT. The recognition result is analyzed in real time through the central control platform, causes are automatically diagnosed based on defect types and distribution characteristics, parameters such as laser power and scanning paths are dynamically adjusted by matching a preset control strategy, and defect suppression and online repair are achieved. And a closed-loop self-adaptive dynamic adjustment mechanism improves the forming quality and reliability. The method is suitable for aerospace and other scenes with extremely high requirements for the quality of large complex titanium alloy components.

The invention belongs to the field of electrical electronics and advanced non-ferrous metal additive manufacturing, and particularly relates to a preparation method of a laser additive manufacturing copper alloy-tungsten copper composite electrical contact, which comprises the following steps of: preparing a nickel or nickel alloy coating on a copper alloy base material by adopting coaxial powder feeding laser cladding to serve as a middle layer, and then preparing a tungsten copper coating by laser cladding to obtain the copper alloy-tungsten copper composite electrical contact. The composite electrical contact is composed of a pure copper or copper alloy base material layer, a pure nickel or nickel alloy coating and a tungsten copper coating in sequence. The electrical contact obtained by the invention has relatively high electrical conductivity and thermal conductivity, and also has good arc ablation resistance; the copper alloy-tungsten copper electrical contact is prepared by adopting the laser cladding technology, so that the production cost can be effectively reduced, the production efficiency is improved, meanwhile, later maintenance and repair are facilitated, and the method is green and environment-friendly.

The invention provides a high-precision laser additive manufacturing method and device based on metal powder melting, and relates to the technical field of metal additive manufacturing, and the high-precision laser additive manufacturing device comprises a multi-element powder supply and electrification unit which is used for carrying out independent metering supply and airflow dispersion mixing on various metal powder in an inert atmosphere environment and enabling powder particles to obtain controllable charges; the electromagnetic field cooperative control unit is used for actively regulating and controlling the falling speed and the transverse track of the powder particles through the cooperative effect of a longitudinal magnetic field and a transverse electric field when the powder particles are in a charged state; the invention provides a metal powder forming technology path based on particle size active conveying and spatial positioning, and active conveying and accurate positioning of the metal powder particles in the flying process are realized by performing electrified regulation and control on single or small-scale metal powder particles and utilizing the action of an electromagnetic field. Therefore, layer-by-layer stacking forming is completed under the condition of not depending on the whole powder laying layer.

A laser additive manufacturing system and method for a magnesium-based composite material. The system comprises a laser adjuster (1), a laser (2), a forming cover (3), an oxygen content adjuster (4), an inert gas cylinder (5), a powder feeder (6), a substrate (7) and a wire feeder (8), wherein the laser adjuster is used for controlling laser processing parameters of the laser; the laser is connected to a laser processing head (10) by means of an optical fiber (9); the oxygen content adjuster is in communication with the forming cover, so as to control the oxygen content of a processing environment in the forming cover; the inert gas cylinder and the powder feeder both pass through the forming cover to be connected to the laser processing head; the substrate is located inside the forming cover; the wire feeder is connected to a wire feeding head (12) by means of a wire feeding tube (11); the wire feeding head passes through the forming cover to perform laser additive manufacturing for a magnesium-based composite material, together with the laser processing head; and a real-time cooling sleeve (13) is also mounted on the wire feeding tube. Also provided are a method for preparing a magnesium-based composite material using the laser additive manufacturing system for the magnesium-based composite material, and a prepared magnesium-based composite material. By means of the manufacturing system and method, the additive processing of wires and powder is realized, and a magnesium-based composite material with a good mechanical property is prepared.

The invention discloses a composite regulation and control method for improving the performance of a laser additive manufacturing high-strength aluminum alloy, and relates to the technical field of laser additive manufacturing high-strength aluminum alloy materials, micron-sized ceramic particles and micron-sized AlMgScZr alloy powder are mixed, and ceramic particle reinforced aluminum-based composite powder is prepared. According to the composite material powder, the solidification structure is regulated and controlled through the characteristics of ceramic particles, stress concentration is reduced, and meanwhile the reinforcing phase particle aggregation phenomenon is avoided. The obtained composite material is excellent in quality and few in metallurgical defects in laser forming, and the density reaches up to 99.8% or above. By combining the optimized selective laser melting and heat treatment process, the room-temperature mechanical property of the prepared composite material part is remarkably improved, the tensile strength exceeds 540 MPa, the yield strength exceeds 490 MPa, and the elongation at break exceeds 10%.

The invention discloses an additive manufacturing deposition layer morphology measuring device and method based on intelligent image reconstruction. The method comprises the steps that a molten pool area image and vibration data are collected; the collected molten pool area image and vibration data are input into a depth self-encoder to be processed, and a reconstructed image is generated through the depth self-encoder; the quality and the stability of the reconstructed image are evaluated by using the PSNR and the SSIM; if the image quality does not reach the preset standard, the system calculates an optimal illumination angle and a camera position required for improving the image quality; the angles and the positions of the LED light and the camera are adjusted through the hollow shaft motor, it is ensured that a light path evenly covers the surface of the molten pool, and all possible illumination dark areas are captured; and if the image quality reaches a preset standard, outputting a reconstructed image. By combining the improved monitoring equipment and the deep learning technology, the challenge faced by the deposition layer morphology test in the laser additive manufacturing process is effectively solved, and the test quality and reliability are improved.

The invention discloses a laser additive manufacturing method for an aluminum / titanium alloy gradient structure, and belongs to the technical field of laser additive manufacturing. The laser additive manufacturing method comprises the steps that TiNbVZr or TiNbV high-entropy alloy powder is used for preparing the high-entropy alloy transition layer on the surface of titanium alloy through the laser additive manufacturing process, and then the aluminum alloy layer is prepared on the surface of the high-entropy alloy transition layer through the laser additive manufacturing process. According to the preparation method, the aluminum / titanium alloy gradient structure with high performance is prepared by combining optimization of the intermediate transition layer of the high-entropy alloy with two preferable components with a laser additive manufacturing technology, and the problems of interface cracking and low bonding strength of the current aluminum / titanium alloy can be effectively solved.

The invention belongs to the technical field of metal additive manufacturing, and relates to a preparation method of a large-size thin-wall structure based on magnetic field regulation and control of laser directional energy deposition. According to the method, the part forming area is filled with the protective gas, the oxygen content of the forming area is 100 ppm or below, and oxidation and inclusion pollution of alloy in the forming process are avoided. By starting the electromagnetic field generator, a stable uniform magnetic field is formed in a part forming area, the metallurgical behavior of a molten pool is regulated and controlled through the thermal damping effect and the thermal electromagnetic convection effect generated by the magnetic field in the molten pool, and optimization of the grain structure is achieved. A laser cladding head is started, powder metal materials are conveyed to the position of a molten pool through powder carrying gas, and the powder metal materials are molten through laser to form a stable molten pool; and a laser cladding head is controlled to scan in a uniform magnetic field area according to a set track to carry out circulating deposition, and light stopping is carried out every time deposition of one layer is completed, so that heat of a deposition layer is released, and heat accumulation is reduced until part forming is completed.

The invention provides a post-treatment method for laser additive manufacturing of titanium alloy. The post-treatment method comprises the steps that a titanium alloy workpiece is sequentially subjected to first annealing treatment, beta heat treatment, hot isostatic pressing treatment and second annealing treatment. Through the specific process combining beta heat treatment and hot isostatic pressing treatment, comprehensive regulation and control over the stress, defects and tissue of the titanium alloy workpiece are achieved, the internal stress of the laser additive manufacturing titanium alloy workpiece is eliminated, and meanwhile the microstructure of the laser additive manufacturing titanium alloy workpiece can be regulated and controlled while most metallurgical defects are eliminated; the strength, toughness and damage tolerance performance of the titanium alloy are synergistically improved, and the service scene of the titanium alloy can meet the static strength and fatigue damage tolerance requirements at the same time.

The invention discloses a manganese-copper alloy with high damping performance and a preparation method and application thereof. The preparation method comprises the steps that manganese-copper alloy powder is subjected to laser layer-by-layer scanning printing through a laser powder bed melting technology, and then the printed manganese-copper alloy is subjected to direct aging treatment. Obtaining a result parallel to the construction direction by regulating and controlling printing processes such as a laser scanning strategy, a layer thickness, a scanning interval and a substrate temperature; 001gt, 001gt; and the manganese-copper alloy is manufactured through strong texture additive manufacturing. Owing to lt; 001gt, 001gt; the oriented grains have more twin-crystal martensite variants, and twin-crystal martensite is easier to move under the action of external stress, so that the manganese-copper alloy has higher damping performance. The vibration reduction component is prepared by utilizing the special advantages of forming hollow, hollow-out, thin-wall and other complex structures of laser additive manufacturing, combination of manganese-copper damping alloy material vibration reduction and structure vibration reduction can be effectively achieved, and the manganese-copper damping alloy material can be widely applied to the field of vibration reduction and noise reduction of satellites, ships, rail transit, high-precision machine tools and other high-end equipment.

The invention belongs to the technical field of additive manufacturing, and particularly relates to a multi-mode laser coupling additive manufacturing method for a high-strength and high-toughness wear-resistant layered part, which comprises the steps of part manufacturing planning, base material pretreatment, multi-mode coupling laser construction, additive manufacturing and the like. Through the laser shaping system and the light path system, the laser light source is shaped into the continuous flat-topped annular laser, the continuous flat-topped annular laser is assisted by the flat-topped pulse laser and the flat-topped oscillation laser for additive manufacturing, the organization structure of a component is homogenized, the nucleation rate in the solidification process is effectively increased, and finally refined crystal grains are obtained; meanwhile, the shape and stress state of the molten pool can be changed, and then the performance of the component is improved. Gradient changes of component components are achieved through cooperative feeding of multiple wires, a workpiece obtains excellent strength, plasticity and toughness, meanwhile, the surface layer of the component is strengthened through a ceramic material, the part obtains extremely high wear resistance, and finally the part with high strength, toughness and wear resistance is obtained.

The present invention relates to a medical magnesium rare earth alloy powder and a preparation method and application thereof, belonging to the technical field of metal additive manufacturing. It is used to solve the problem that the existing magnesium alloy powder is used for additive manufacturing of formed bone implants, which will lead to excessive degradation rate of magnesium alloy bone implants, decreased biocompatibility, poor corrosion resistance and antibacterial properties, and fail to meet the performance requirements of bone implants. A medical magnesium rare earth alloy powder, the composition by weight percentage is: Sc: 0.5-2.75%, Zr: 0-0.5%, Y: 4-7%, and the rest is Mg and non-removable impurity elements. The magnesium alloy powder of the present invention has high purity, few impurities, slight surface oxidation, is suitable for laser additive manufacturing, has no obvious component deviation, and is controllable in composition; the magnesium alloy bone implant obtained by additive manufacturing has good corrosion resistance, can continuously provide mechanical support, and the number of mechanical support days is ≥85 days, which is better than the performance requirements of bone implants in my country's medical industry.

The invention belongs to the technical field of laser processing, and provides a powder laying layer thickness and beam shaping coordinated regulation and control system and method for laser additive manufacturing, and the system comprises a light source device which is used for emitting laser beams required by additive manufacturing; then, when the manufacturing and forming device determines the thickness of the powder laying layer needed by laying, the light source device uses a point light source and / or an annular light source to emit laser beams, and the spot diameter of the laser beams or the size of a molten pool formed by the laser beams is dynamically adjusted according to the thickness of the powder laying layer. The method has the beneficial effects that intelligent segmentation and process planning are conducted on all parts of the L-PBF forming component, the large-layer-thickness powder laying-large-size light source forming process and the small-layer-thickness powder laying-small-size light source forming process are adopted, and meanwhile the forming precision and efficiency of the component are considered.

The invention discloses a ceramic / high-entropy alloy composite particle reinforced aluminum-based composite material and a laser additive manufacturing method thereof. Firstly, ceramic / high-entropy alloy composite powder and aluminum alloy powder are mixed through ball milling to obtain ceramic / high-entropy alloy composite particle reinforced aluminum alloy composite powder, then the composite powder of the three components is laid on a powder bed, laser power, scanning speed, scanning spacing and the like are adjusted, and laser scanning melting solidification is conducted to prepare the ceramic / high-entropy alloy composite particle reinforced aluminum alloy composite powder. And the ceramic / high-entropy alloy composite particle reinforced aluminum-based composite material is formed. The composite material disclosed by the invention is highly compact, so that the ceramic / high-entropy alloy composite particles can effectively improve the mechanical property of the aluminum-based composite material, and can be used for manufacturing high-performance complex parts for aerospace, automobile rail transit and the like.

The invention provides a laser additive manufacturing device and method cooperating with light spot shape control and energy regulation and control, and belongs to the field of additive manufacturing. A wire feeding mechanism conveys a wire and limits the wire to be perpendicular to the surface of a substrate; a plurality of laser beams are arranged around the wire material, the laser beams comprise first light beams and second light beams, the irradiation directions of the first light beams intersect at the same point on the substrate at the same time and form a first light spot, and the first light beams fuse the wire material and form a molten pool at the position of the first light spot on the substrate; and the second light beams irradiate the substrate to form second light spots, the second light spots are arranged around the first light spot, the second light spots move around the first light spot or are coupled with the first light spot, and the shapes and energy distribution of the light spots are cooperatively regulated and controlled. Coaxial laser cooperative scanning is adopted, dynamic adjustment and cooperative coupling of the light spot shape and energy distribution in the additive manufacturing process are achieved, the shape, size, depth and other characteristics of a molten pool are accurately controlled, and the high-efficiency and high-precision additive manufacturing requirements of complex components are met.

The invention relates to the technical field of additive manufacturing, and discloses a method and equipment for restraining the crack defect of a high-temperature alloy difficult to weld in laser additive manufacturing. When the gradient of a first molten pool is larger than a preset temperature gradient threshold value, a metal powder scanning area corresponding to each layered slice of a target part can be fused through a composite laser spot; the central light spot is used for providing enough energy to melt metal powder and form a stable molten pool, and the annular light spot preheats the periphery of the molten pool to adjust temperature distribution of the molten pool. The second laser power needed by the annular light spot is determined according to the molten pool center temperature and the molten pool radius generated by the center light spot in the scanning area at the preset scanning speed, so that accurate control over the gradient and the cooling rate of the molten pool is met, the molten pool can be cooled more uniformly in the solidification process, and the solidification quality of the molten pool is improved. The defects of cracks, air holes and the like caused by high temperature gradient and high cooling rate are effectively reduced, and the problem that high-performance high-temperature alloy laser additive manufacturing cracks are difficult to weld is solved.

Additive manufacturing systems and associated methods are disclosed herein. In some embodiments, the additive manufacturing system includes a build chamber that has an active build region, an energy beam system positioned to direct energy beams toward the active build area, and a controller operably coupled to the energy beam system. During an additive manufacturing process, the controller can control the energy beam system to execute a hybrid sintering process. For example, for a first region of a planned build object, the controller can operate the energy beam system in a continuous wave mode to generate a first energy beam to sinter powder in the first region. Then, for a second region, the controller can operate the energy beam system in a pulsed mode to generate a second energy beam with to sinter the second region.

The invention discloses a copper-chromium alloy contact part and a preparation method thereof, and belongs to the technical field of contact material processing. The preparation method comprises the steps that a substrate is installed, a cursor is printed on the substrate, and the cursor is consistent with the bottom face of a copper-chromium alloy contact target part in specification; bonding the connecting surface of the base body on the substrate to obtain a connected material; the connecting surface is matched with the cursor on the substrate; the connected material is fixed in a printing bin, infrared laser printing is conducted on the printing face of the base body according to preset laser additive manufacturing parameters, and a copper-chromium alloy contact part printing piece is obtained; and the copper-chromium alloy contact part printing piece is taken out to be subjected to solid solution heat treatment and separation, then groove position and inner hole machining is carried out, and a copper-chromium alloy contact target part is obtained. By means of the method, the high-strength and high-compactness copper-chromium alloy contact can be obtained.

The present application relates to the technical fields of laser additive manufacturing, and discloses a kind of metal matrix composite composite additive manufacturing methods, comprising: the mixing of pre-prepared composite powder, substrate pretreatment, laser bottom layer cladding preparation bottom layer structure;Electron beam selective melting additive preparation main functional layer, obtain rough parts;Rough parts post-processing.The present application improves the wettability between metal matrix and TiC reinforcing phase through the transition effect of laser cladding bottom layer and hot isostatic pressing post-processing, improves the interface bonding strength, avoids the interface peeling problem under load;Through laser cladding, realize rapid bottom layer forming, electron beam selective melting ensures high-precision functional layer manufacturing, and is suitable for the integrated manufacturing of complex structure (such as hollow, thin-walled) metal matrix composite parts.

The invention discloses a method and application for ultrasonic-assisted laser additive manufacturing of a multi-scale structure coupling high-toughness aluminum alloy, and the method comprises the steps that high-Ni-content alloy steel powder is refined through high-energy ball milling, and then the refined alloy steel powder is dispersed and distributed in Al-Mg-Sc-Er-Zr alloy powder; an ultrasonic energy field is introduced to assist selective laser melting to form mixed powder, the ultrasonic energy field assists in generating nonlinear effects such as cavitation, acoustic streaming and heat effect, defects such as air holes and cracks are overcome to eliminate residual stress, and the Marlangoni effect is accelerated to increase the solidification speed; and finally, the high-strength and high-toughness aluminum alloy which has high density and is composed of micron-scale, submicron-scale and nano-scale multi-scale phase structures is prepared. The production cost is low, and the room-temperature tensile properties of the prepared high-strength and high-toughness aluminum alloy are as follows: the strength is greater than 850 MPa, and the fracture strain is greater than 6%.

The invention discloses a method for manufacturing a CoCrNi medium-entropy alloy by TiC ceramic powder-enhanced laser additive manufacturing. The method comprises the following steps: S1, selecting CoCrNi alloy powder and TiC ceramic powder with a particle size of (10-60) μm; S2, mixing the CoCrNi and TiC powders by mechanical ball milling, wherein the atomic ratio of the two powders is CoCrNi:TiC=(0.8-1):(0.1-0.2); S3, vacuum drying the mixed powder, and preparing a TiC ceramic powder-enhanced CoCrNi medium-entropy alloy material with fewer defects and excellent performance by using a laser selective melting (SLM) technique; the invention reduces the generation of cracks and pores in the process of additive manufacturing, and reduces the generation of defects inside the printed material; improves the density and Vickers hardness of the CoCrNi medium-entropy alloy, refines the average grain size, etc., and prepares a CoCrNi / TiC medium-entropy alloy with better performance; the invention adds a specific proportion of TiC ceramic powder, which can effectively achieve the effect of refining grains and reducing internal defects.

The invention discloses a multi-beam coaxial composite oscillation laser additive manufacturing device and method. The multi-beam coaxial composite oscillation laser additive manufacturing device comprises a cladding working chamber, a laser cladding mechanism, a multi-dimensional moving mechanism, a thickness measuring mechanism and a control mechanism. The workbench, the multi-dimensional moving mechanism and the thickness measuring mechanism are all installed in the cladding working cavity, a laser cladding head of the laser cladding mechanism is installed on the multi-dimensional moving mechanism, and the multi-dimensional moving mechanism is used for driving the laser cladding head to conduct synchronous laser cladding on a base material located on the workbench according to a preset track; the powder feeding mechanism is used for outputting composite metal powder with different proportions to the laser cladding head; the thickness measuring mechanism is used for measuring the thickness of the laser cladding layer on the base material; the multi-dimensional moving mechanism, the laser cladding mechanism, the powder feeding mechanism and the thickness measuring mechanism are electrically connected with the control mechanism. The quality of the composite gradient laser cladding layer is effectively improved, and the defects of cracks, inner holes and the like are avoided.

The invention discloses a nano TiB2 particle reinforced CoCrNi medium-entropy alloy and a preparation method of the nano TiB2 particle reinforced CoCrNi medium-entropy alloy. The preparation method comprises the following steps: firstly, respectively drying CoCrNi medium entropy alloy powder and nano TiB2 particles, then mechanically mixing, and finally carrying out ball milling treatment to obtain composite material powder. And under the condition of no substrate preheating, the composite material powder is subjected to additive manufacturing forming according to key parameters optimized in a specific range. The preparation method optimizes a pretreatment process and improves the quality of raw materials; and laser additive manufacturing process parameters are optimized, the strengthening effect of the nano TiB2 particles is fully exerted, and a high-performance material can be prepared without preheating the substrate. The average grain size of the obtained alloy is smaller than 3 microns, the density reaches 99.6%, the room-temperature ultimate tensile strength is larger than 1200 MPa, the yield strength is larger than 1000 MPa, the mechanical property is excellent, material guarantee is provided for key equipment application, and application of the CoCrNi medium-entropy alloy in the field of high-strength requirements is expanded.

The invention discloses a preparation method of ODS alloy composite powder for laser additive manufacturing. The invention belongs to the technical field of metal additive manufacturing materials, and particularly relates to a preparation method of oxide dispersion strengthening (ODS) alloy composite powder for laser additive manufacturing. The metal matrix powder is divided into two particle size intervals by taking 30 [mu] m as a particle size critical point, the metal matrix powder in the two particle size intervals is mixed with the nano oxide powder through differential acoustic resonance to form two kinds of composite powder, and the ODS alloy composite powder is obtained by mixing the two kinds of composite powder. According to the method, different high-energy acoustic resonance mixing time is adopted for coating characteristic differences caused by different masses of metal powder (smaller than or equal to 30 microns and gt; 30 microns) in different particle size intervals. And finally, the thicknesses of nano oxide coating layers of all the powder are accurately controlled to be 500 nm or below, and the risks of nano oxide agglomeration and large-size slag formation in the SLM process are remarkably reduced.

The invention discloses a heterogeneous material powder bed laser additive manufacturing device and method.The heterogeneous material powder bed laser additive manufacturing device comprises a fixed-point powder suction ultrasonic powder feeding system, an electrostatic powder laying system and a powder bed additive manufacturing forming system, and the fixed-point powder suction ultrasonic powder feeding system and the electrostatic powder laying system are both arranged in the powder bed additive manufacturing forming system. The automatic powder spreading device has a heterogeneous material powder spreading mode of ultrasonic powder feeding and electrostatic powder spreading, the utilization rate of materials is effectively improved, the manufacturing efficiency is improved, the scraper, the electrostatic powder spreading device and the powder spreading trolley are combined into a whole, the flexibility and applicability of equipment are enhanced, the conversion and waiting time between the equipment can be shortened, the production efficiency is improved, and the production cost is reduced. The powder feeding device has the advantages that automatic replacement of the powder feeding needle tubes is achieved, manual intervention is not needed, the working efficiency is greatly improved, the powder feeding needle tubes with different calibers are adopted, the powder laying quality of the connecting positions of the heterogeneous materials is further improved while the powder laying efficiency is not lost, and the final interface connecting effect of the heterogeneous materials is indirectly enhanced.

The invention discloses a laser additive manufacturing double-layer structure gradient hard alloy cutter and a manufacturing method, the alloy cutter comprises a base body, a transition layer and a surface layer, and the transition layer is arranged between the base body and the surface layer; the base body and the transition layer are both made of WC-Co particles, and the surface layer is made of WC-TiC-TaC-Co particles; the grains of the substrate and the surface layer are smaller than those of the transition layer. The manufacturing method comprises the following steps that spherical hard alloy particles are obtained through an atomization pre-sintering granulation method; technological parameters and environmental parameters of selective laser melting are optimized; the substrate, the transition layer and the surface layer are sequentially formed through selective laser melting printing; and the double-layer structure gradient hard alloy cutter is obtained. By optimizing the atomization pre-sintering granulation method and the laser additive manufacturing process, the high-density, high-precision and high-performance gradient hard alloy cutter with the double-layer structure can be prepared.

The invention discloses a high-temperature wear-resistant crack-free high-entropy alloy and a preparation method and application thereof, the molecular formula of the alloy is as follows: Fe < 11.9 > Co < 23.8 > Cr < 23.8 > Ni < 35.7 > Nb < 4.8 >, and a Laves phase exists in the microstructure of the alloy. The preparation method comprises the following steps: putting weighed powder into a ball milling tank for ball milling, uniformly mixing the powder, and then drying, sieving and drying for storage; 304L stainless steel is selected as a base material, a sand mill is used for polishing the surface of the base material so as to remove surface oxide skin until a bright surface is exposed, and oil stains on the surface are cleaned; and the dried powder is placed in a powder feeding tank in a laser system, high-purity Ar gas is used for feeding the powder to a round spot laser head for melting and stacking, and the high-temperature wear-resistant crack-free high-entropy alloy without cracks is formed through layer-by-layer continuous deposition. By adding the Nb element, a Laves phase capable of improving the high-temperature performance is formed in a matrix, a high-entropy alloy sample is prepared through the laser directional energy deposition technology, subsequent heat treatment does not need to be conducted on the high-entropy alloy sample, and the deposited alloy has the excellent wear resistance at the high temperature.