774 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 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 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 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 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 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 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.

The invention discloses a novel laser thermal spraying gun, and belongs to the technical field of laser additive manufacturing, the novel laser thermal spraying gun comprises a connecting seat, an air knife assembly, an inner nozzle, an outer nozzle, a cooling sleeve cover plate and a cooling sleeve, the outer nozzle comprises a powder feeding body and a Laval pipe, and a diffusion hole is formed in the Laval pipe; the Rafael nozzle accelerates air flow through a gradually-shrinking-gradually-expanding structure, a high-speed and high-temperature jet flow environment is formed, powder is fully preheated and evenly dispersed before reaching a base body, the Rafael pipe and laser spraying are combined, the advantages of the laser cladding technology and the thermal spraying technology are combined, the acceleration effect of Rafael air flow is overlaid, and the thermal spraying effect of the laser cladding technology and the thermal spraying technology is improved. Under the action of high-temperature and high-pressure air flow, the powder is in full contact with a laser heat source in a flying distance long enough through a Laval nozzle, so that the powder and a matrix form metallurgical bonding in a molten state, the bonding strength can be 2-3 times that of traditional thermal spraying, and the powder is suitable for the limited space environment of water erosion protection and repair of the steam turbine blade.

The invention provides an additive defocusing amount regulation and control device and method based on image recognition and machine learning, and relates to the technical field of laser additive manufacturing. The device comprises an industrial camera image acquisition device for acquiring molten pool and splash plume images in a laser additive manufacturing process in real time, and an image processing device for preprocessing the received images and performing feature extraction through a three-dimensional convolutional self-encoding neural network, the image recognition and data analysis module is used for carrying a to-be-processed workpiece and further determining a defocusing amount deviation value and a deviation direction; the three-dimensional real-time regulation and control workbench is used for receiving a control instruction and carrying out real-time position compensation on a to-be-processed workpiece in the X direction, the Y direction and the Z direction according to the received control instruction; and the laser energy deposition device is used for executing a laser directional energy deposition process. The method is suitable for molten pool state monitoring and laser focus regulation and control processes in a metal laser additive manufacturing process, and is particularly suitable for additive manufacturing tasks with complex curved surface structures or high compactness requirements.

The invention discloses a preparation method for improving the toughness of 17-4PH stainless steel manufactured by an additive in the technical field of heat treatment of metal materials. The preparation method comprises the following steps: forming a 17-4PH stainless steel component through an additive manufacturing process; the 17-4PH stainless steel component obtained through additive manufacturing is subjected to heat treatment, and the heat treatment process sequentially comprises direct aging treatment, subzero treatment and tempering treatment. According to the method, the 17-4PH stainless steel component is formed through the laser additive manufacturing process, then specific heat treatment is conducted on the 17-4PH stainless steel component, the strength and toughness of the component are optimized and improved, the method is simple in process, the problem of strength and toughness mismatch and the deformation and cracking risk caused by traditional high-temperature solid solution and aging heat treatment can be remarkably solved, and the method is suitable for industrial production. The strength and toughness of the laser additive manufactured 17-4PH stainless steel are greatly improved, and the service stability and safety of the laser additive manufactured 17-4PH stainless steel component are guaranteed.

The invention discloses a reverse design method and device for additive manufacturing nickel-based superalloy components, a medium and a product, and relates to the technical field of laser additive manufacturing alloy optimizing.The method comprises the steps that a performance prediction model is constructed; setting performance constraint conditions; constructing an alloy component generation model; obtaining a random vector; inputting the random vectors and the performance constraint conditions into an alloy component generation model to obtain a plurality of groups of candidate alloy components, and inputting the random vectors and the performance constraint conditions into a performance prediction model to obtain phase contents of the candidate alloy components; screening out candidate alloy components of which the phase contents do not meet performance constraint conditions to obtain primary samples; taking a multi-dimensional crack sensitivity index value as an optimization target, and constructing a Pareto frontier solution set based on the primarily selected sample; candidate alloy components corresponding to the primary samples meeting set conditions in the Pareto frontier solution set are used as optimal alloy components; and obtaining the optimized target alloy based on the optimal alloy components by adopting an additive manufacturing technology. According to the method, the alloy component design efficiency and precision can be improved.

The invention provides laser additive manufacturing of a FeCoNi-based soft magnetic high-entropy alloy multilayer alternate composite structure, and relates to the technical field of advanced manufacturing of soft magnetic high-entropy alloys. The laser additive manufacturing of the FeCoNi-based soft magnetic high-entropy alloy multi-layer alternate composite structure comprises the steps of respective preparation of three kinds of pre-alloyed powder, respective ball-milling preparation of two kinds of mixed powder, pretreatment of a base plate, argon protection in a forming bin and laser additive manufacturing. The FeCoNi-based soft magnetic high-entropy alloy multi-layer alternate composite structure is obtained through respective preparation of three kinds of pre-alloy powder, respective ball milling preparation of two kinds of mixed powder, pretreatment of a base plate, argon protection in a forming bin and laser additive manufacturing. The preparation method is simple and easy to operate, green and environment-friendly, low in cost, short in process, high in efficiency and beneficial to industrial large-scale production and popularization.

The invention discloses a laser additive manufacturing system and method for in-situ self-adaptive regulation and control of the component shape through a temperature field and an airflow field. The laser additive manufacturing system comprises a sealed protection cavity, a master control unit, a temperature field monitoring-control unit and an airflow field monitoring-control unit. The temperature field monitoring-control unit comprises an infrared thermometer, a thermocouple temperature measuring element and an induction heating coil; and the airflow field monitoring-control unit comprises a protective gas pipeline, an electromagnetic flow regulating valve, an oxygen content monitor and a vacuum air filter. The master control unit comprises a temperature field control module and an airflow field control module. The master control unit conducts in-situ self-adaptive regulation and control on the temperature field of laser additive manufacturing through the temperature field control module, distribution of the temperature field in the whole process of additive manufacturing is improved, the temperature gradient of a molten pool in the laser additive manufacturing process is reduced, the forming defect is improved, and the material performance is improved.

The utility model relates to the technical field of laser additive manufacturing, and specifically to a coaxial powder feeding head with variable powder spot, comprising: a nozzle, wherein the interior of the nozzle is provided with a first powder feeding channel, a second powder feeding channel and a channel for laser to pass through, wherein the first powder feeding channel and the second powder feeding channel are not connected to each other; a powder feeding component, comprising a powder feeding pipe and an air intake pipe, wherein the powder feeding pipe and the air intake pipe are respectively connected to the first powder feeding channel or the second powder feeding channel. The present application assembles three nozzles in a mutually nested manner to form a nozzle, and forms two independent powder feeding channels, wherein the powder feeding pipe and the air intake pipe in the powder feeding component are respectively connected to one of the two powder feeding channels, i.e., one for powder feeding and the other for air feeding, and by changing the position of the powder feeding component, the media transported by the two powder feeding channels can be switched to each other, thereby realizing the switching between large powder spot and small powder spot, without disassembling the powder feeding pipeline and the nozzle, and thus ensuring the continuity of processing.

An electromagnetic field assisted laser additive manufacturing device and method comprises a laser cladding mechanism, an electromagnetic field regulation and control mechanism and an electromagnetic impact mechanism, the laser cladding mechanism plans and controls a deposition path of a laser cladding head through a laser cladding mechanical arm, and the electromagnetic impact mechanism plans and controls a moving path of an electromagnetic impact coil through an electromagnetic impact mechanical arm. The variable curvature characteristic of a deposition path in the additive manufacturing process is adapted; an electromagnetic field is introduced in the metal laser additive manufacturing process, a substrate is preheated through electromagnetic induction heating, a molten pool is regulated and controlled through electromagnetic force, and metallurgical defects are reduced from the source; and meanwhile, by means of high-speed pulse electromagnetic force, synchronous impact is conducted on the surfaces and the side faces of the multiple layers of welding beads with the deposition path curvature continuously changing, then metallurgical defects such as air holes, incomplete fusion and cracks in the metal laser additive manufacturing process are restrained, grains are refined, residual stress is reduced or even eliminated, and high-performance and high-precision additive manufacturing of metal forming parts is achieved.

The invention relates to the technical field of laser additive manufacturing, and provides a steel rail laser additive path control method and system.The method comprises the steps that a real-time morphology image of a molten pool is monitored and obtained; processing the real-time morphology image to obtain asymmetric characteristics of the molten pool; according to the asymmetrical characteristics, the asymmetrical distortion degree of the molten pool is calculated; according to the asymmetric distortion degree, the laser beam is controlled to perform asymmetric microscopic motion; the asymmetric microcosmic motion comprises the step of adjusting the scanning speed or residence time of a laser beam in different areas of a molten pool so as to reconstruct energy distribution in the molten pool; and according to the real-time morphology image corresponding to the molten pool after the energy distribution inside the molten pool is reconstructed, parameters of asymmetric micro-motion of the laser beam are adjusted, so that steel rail laser additive path control is achieved. The method has the effect of improving the quality, geometric accuracy and mechanical property of the steel rail laser additive repairing layer.

A method of operating a laser additive manufacturing machine includes manufacturing at least one first fluid-flow coupon, that includes a plate defining a plurality of holes, at a corresponding beam offset value of the laser additive manufacturing machine. The method further includes disposing the at least one first fluid-flow coupon in a testing rig, directing a fluid flow towards the at least one first fluid-flow coupon, measuring a fluid flow rate through the at least one first fluid-flow coupon, determining a calibration curve by correlating a beam offset of the laser additive manufacturing machine with a flow parameter based on the fluid flow rate through the at least one first fluid-flow coupon and the corresponding beam offset value, determining a target beam offset value corresponding to a target flow value of the flow parameter, and calibrating and operating the laser additive manufacturing machine using the target beam offset value.