41 results about "Electron-beam additive manufacturing" patented technology

The invention belongs to the related technical field of additive manufacturing, and discloses an electron beam melting wire liquid nitrogen copious cooling additive manufacturing method and system.The method comprises the steps that in the electron beam melting printing forming process, liquid nitrogen is sprayed to a molten printing wire under electron beam irradiation, and the liquid nitrogen is sprayed to the molten printing wire; the molten printing wires are subjected to nitridation reaction under the action of electron beams while being subjected to liquid nitrogen cryogenic cooling, so that the crystal structure of a formed part is regulated and controlled, and the mechanical performance is enhanced; and / or liquid nitrogen is sprayed to the printing wire material which begins to be solidified, so that the printing wire material is subjected to liquid nitrogen deep cooling, and the crystal structure of the formed part is regulated and controlled to achieve mechanical property enhancement. Liquid nitrogen is introduced into the electron beam additive manufacturing device for deep cooling, the extruded printing wire is solidified at an extremely high cooling speed after being melted, a large number of homogeneous nucleation sites are formed in a melting area due to the high supercooling degree, the solidification speed is high, a microstructure is customized into uniform and fine equiaxed crystals, the strength and toughness of the material are improved, and the production cost is reduced. The mechanical property is improved.

The invention provides a method for improving the structure uniformity of an electron beam additive manufacturing TiAl alloy, and relates to the technical field of additive manufacturing TiAl alloys. The method for improving the structure uniformity of the TiAl alloy manufactured through the electron beam additive specifically comprises the following steps that a base plate is preheated, specifically, the temperature of the base plate is preheated to 1100-1300 DEG C, and the forming environment temperature is not lower than 1000 DEG C; tiAl alloy powder is preheated, wherein non-focusing electron beams are adopted in the preheating mode, and gradient increasing is adopted in the heat input mode; and filling scanning: designing a defocusing value according to the energy density, and regulating and controlling the molten pool morphology and the molten pool thermal gradient. According to the method, the TiAl alloy component is prepared through substrate preheating, TiAl alloy powder preheating and filling scanning, through linkage optimization of electron beam non-focusing scanning key parameters, the forming process window of intermetallic compounds is effectively widened, the applicability of the TiAl alloy in the field of additive manufacturing is greatly improved, and the method is suitable for large-scale popularization and application. And a reliable method is provided for preparation of high-performance components.

The invention belongs to the technical field of titanium alloy additive manufacturing, and particularly relates to an electron beam additive manufacturing method for oxygen-enriched titanium alloy. According to the method, circulating titanium alloy coarse powder with the oxygen content being 0.25 wt.%-0.30 wt.% is adopted, the circulating titanium alloy coarse powder is dried and then subjected to printing forming, and a powder layer is obtained; according to the method, electron beam powder bed cladding is conducted on a powder layer under the environment that the vacuum degree is 10 <-3 > Pa to 10 <-5 > Pa, a BCC phase is reserved by means of a steady-state thermal field formed by electron beam powder bed cladding at a preheated substrate at the temperature of 700 DEG C to 800 DEG C, in the deformation process, transformation from BCC to HCP and transformation from HCP to FCC are induced by stress, and the high-toughness oxygen-enriched titanium alloy is obtained; the excellent performance matching of the tensile strength of 1220 MPa and the elongation percentage of 14.5% is realized, and meanwhile, the uniform elongation percentage of 8.1% is kept.

The invention discloses an electron beam additive manufacturing method for an integrated copper-chromium contact-conducting rod assembly, and belongs to the technical field of copper-chromium contact manufacturing. The electron beam additive manufacturing method comprises the steps that S1, a special powder system is designed and prepared, specifically, contact area powder and conducting rod area powder are prepared and subjected to drying treatment; s2, digital modeling and support design: establishing an integrated copper-chromium contact-conducting rod assembly model by using three-dimensional software and slicing; S3, fusing and integrally forming by using an electron beam powder bed: printing an integrated copper-chromium contact-conducting rod assembly in a vacuum chamber of the electron beam powder bed, and S4, a printing post-treatment process is carried out, specifically, returning treatment, hot isostatic pressing treatment and machining treatment are carried out on the integrated copper-chromium contact-conducting rod assembly printed piece. According to the printing post-treatment process, the residual stress of the integrated copper-chromium contact-conducting rod assembly can be effectively eliminated through the printing post-treatment process; and the problems of macroscopic cracks and part warping caused by high residual thermal stress can be effectively avoided.

The invention belongs to the technical field of additive manufacturing, and discloses electron beam additive manufacturing equipment which comprises a forming chamber, a forming cylinder module, a powder laying platform, a scraper, a vacuumizing module and a cooling circulation module, the forming chamber is provided with a vacuumizing opening, a cooling medium inlet and a cooling medium outlet, and the forming cylinder module is arranged in the forming chamber; the forming cylinder module is provided with a printing cavity, the powder spreading platform is located at the top of the forming cylinder module, the scraper can slide relative to the powder spreading platform, and in the actual working process, the powder spreading platform is used for spreading metal powder, and the scraper is matched to achieve the powder spreading action. The vacuumizing module is connected with the vacuumizing opening, an output opening of the cooling circulation module penetrates through the cooling medium inlet through a circulation pipeline to communicate with the printing cavity, and a backflow opening of the cooling circulation module communicates with the cooling medium outlet. The electron beam additive manufacturing equipment is simple in structure, high in cooling efficiency and low in process gas consumption.

A method for preparing a wide-temperature-range constant-elasticity low-modulus titanium alloy based on additive manufacturing technology, relates to the field of electron beam additive manufacturing technology, and the method comprises the following steps: step 1, preparing an electron beam powder with a particle size of 30-150 microns; step 2, establishing a three-dimensional model of a printed metal part; step 3, adjusting the printing process parameters and scanning strategy, using an electron beam device for additive manufacturing, and directly obtaining a high-precision wide-temperature-range constant-elasticity titanium alloy. The wide-temperature-range constant-elasticity characteristics of the alloy prepared by the method can be directly generated by controlling the additive manufacturing process parameters, without subsequent processing, and the room-temperature elastic modulus is 35-55 GPa, and the elastic modulus remains unchanged in the temperature range of-50 DEG C to 200 DEG C. The method has the advantages of simple process steps, low production cost and short processing cycle, and has good application prospect in the fields of national defense, aerospace, precision machinery and the like.

The invention discloses a method for additive manufacturing of a diamond-M2 high-speed steel composite material. The method comprises the following steps: 1, plating a layer of metal film on the surface of a diamond particle; secondly, the coating diamond particles and M2 high-speed steel powder are mixed; thirdly, the mixed raw materials are put into a stock bin of electron beam additive manufacturing equipment, and layer cutting data and layer cutting scanning data are imported; and fourthly, a base plate is preheated, then powder laying and presintering are conducted, then melting scanning is conducted, layer-by-layer preparation is repeatedly conducted, finally solidification is conducted, and the diamond-M2 high-speed steel composite material is obtained. Diamond particles are added into M2 high-speed steel powder, and the composite material is prepared through electron beam additive manufacturing, so that diamond and carbide have a synergistic effect in the friction process, a wide and continuous wear-resistant layer is formed, the islanding effect of the diamond is effectively solved, the comprehensive performance of the obtained composite material is comprehensively improved, and the service life of the composite material is prolonged. The manufacturing period is short and the cost is low.

The invention discloses a method for improving the low-temperature performance of an electron beam additive manufacturing Ti80 titanium alloy, and belongs to the technical field of additive manufacturing. According to the invention, the problem of low-temperature toughness and brittleness of the Ti80 titanium alloy manufactured by current electron beam fuse additive manufacturing is solved. According to the method, the titanium alloy manufactured through electron beam fuse additive manufacturing is heated to the temperature below the phase transformation point temperature for heat treatment, and the alpha-phase morphology, size and relative content of the Ti80 titanium alloy are regulated and controlled by adjusting the target temperature, the heat preservation time and the cooling speed. The Ti80 titanium alloy is prepared by adopting an electron beam fuse additive manufacturing technology, elements unfavorable for the low-temperature toughness of the titanium alloy are kept at an extremely low level, a foundation is laid for regulating and controlling the microstructure of the Ti80 titanium alloy through subsequent heat treatment, then thick primary alpha p is realized through heat treatment, a sufficient growth space is provided for low-temperature deformation twin crystals, and the high-temperature deformation twin crystals are obtained. The low-temperature toughness of the titanium alloy is improved. The method is simple in process, convenient to operate and high in generalization performance.

This invention discloses an electron beam additive manufacturing method for molybdenum-rhenium alloy based on positive defocus-induced in-situ recovery. Using electron beam additive manufacturing equipment and molybdenum-rhenium alloy powder as raw material, the method proceeds according to the following steps: 1. Establishing a vacuum environment and preheating the substrate; 2. Setting electron beam melting parameters, then scanning and melting the powder layer with the electron beam along a preset path, repeatedly laying powder layers and scanning to obtain a shaped part; after each powder layer is completely melted and before laying the next powder layer, the electron beam focusing state is adjusted to positive defocus, and the electron beam is used to scan the interlayer thermal compensation area of ​​the solidified region. This method, by introducing interlayer in-situ thermal compensation under positive defocus mode, constructs a thermal field distribution that facilitates the in-situ dynamic recovery of molybdenum-rhenium alloy during the electron beam powder bed melting process, achieving optimization of the microstructure and effective release of residual stress, avoiding brittle fracture of the additively manufactured component, and is applicable to fields such as nuclear energy engineering and aerospace.

This invention relates to the field of metal material processing technology, specifically to a method for optimizing the composition of high-strength and high-toughness aluminum-lithium alloys for additive manufacturing using rare earth synergistic refinement. The method includes the following steps: obtaining aluminum-lithium alloy matrix powder, and separately obtaining CeH2 powder as a cerium source and ZrH2 powder as a zirconium source as reaction precursors; uniformly mixing the CeH2 powder, ZrH2 powder, and aluminum-lithium alloy matrix powder to form a composite powder raw material; during electron beam additive manufacturing, based on the ultra-high temperature and ultra-high cooling rate environment provided by the molten pool formed on the composite powder raw material by high-energy beam scanning, CeH2 and ZrH2 decompose into highly active Ce atoms and Zr atoms, and promote the in-situ synthesis reaction between the two and molten aluminum to generate a (Ce,Zr)Al3 nanocomposite phase. This invention achieves spatiotemporal synchronization of refined phase generation and solidification nucleation by using CeH2 and ZrH2 as precursors to generate the (Ce,Zr)Al3 nanocomposite phase.

The application discloses a titanium-niobium alloy double-gradient material and a preparation method thereof, and belongs to the field of gradient material preparation. The application utilizes an electron beam additive manufacturing technology, controls the temperature of a powder bed, controls the precipitation quantity and distribution of an alpha" phase from a beta phase, forms double-gradient changes of the volume fraction and the elastic modulus of the precipitated phase along a preset direction, and finally successfully prepares the titanium-niobium alloy double-gradient material. The method is highly controllable, the combined action of the precipitation phase gradient and the elastic modulus gradient in the prepared double-gradient material significantly improves the impact resistance of the additive manufactured titanium alloy material, and the production is simple, the production cost is low, the efficiency is high, and the method has high further research and application values.

The invention relates to titanium alloy based on electron gun scanning oscillation and an additive manufacturing method thereof, and belongs to the technical field of metal additive manufacturing. According to the titanium alloy additive manufacturing method, after titanium alloy powder is subjected to vacuum degassing, electron beam additive manufacturing is conducted, the scanning track is a circular track or a sine curve track, the oscillation frequency and amplitude are controlled, and the titanium alloy is prepared. The titanium alloy prepared through the method has low porosity and high tensile strength and ductility, and anisotropy is remarkably reduced. The porosity of the titanium alloy is 0.5% or below, the tensile strength is 1000 MPa or above, the ductility is 12% or above, and the anisotropy is smaller than 5%.

The invention relates to a device and a method for manufacturing a heterogeneous alloy structure through ultrasonic regulation and control electron beam additive manufacturing, in particular to an electron beam additive manufacturing device for feeding wires through a main shaft and a shaft side and regulating and controlling element diffusion and phase generation in combination with an ultrasonic field effect and a forming method of the electron beam additive manufacturing device. According to the electron beam + double-wire + ultrasonic synergetic additive manufacturing method and system, in the wire bundle coaxial cold cathode electron beam fuse additive manufacturing process, an ultrasonic auxiliary system is introduced to act on a forming base plate, dynamic regulation and control over the heterogeneous alloy element mixing behavior and the structure evolution process in a molten pool are achieved, and therefore the mechanical performance of the molten pool is improved. The problems of coarse grains, uneven structures and performance fluctuation in the heterogeneous alloy deposition process are solved, structure refinement and component homogenization are achieved, and the overall service performance of a deposition component is improved.

The invention discloses an electron beam current control device, a control method and electron beam additive manufacturing equipment. A data processing module performs interpolation or nonlinear discrete processing on original coordinate data and original process parameters and then generates a digital control signal; the controller converts a digital control signal into an analog control signal to drive the high-voltage power supply to enable the electron gun to generate an electron beam and drive the magnetic field excitation module to generate a magnetic field, and the feedback module collects a first feedback signal from the magnetic field excitation module and generates a second feedback signal based on a temperature diagram of a machining area. The data processing module calibrates the digital control signal based on the feedback signal, so that the whole process of data processing, control and feedback adjustment is free of human intervention, the feedback calibration control signal can be quickly responded, and the control signal can be automatically calibrated according to the feedback of the magnetic field excitation module and the feedback of a temperature diagram of an electron beam processing area. The control precision of the electron beam is improved, and the additive manufacturing quality is further improved.

The present application relates to a kind of multi-material electron beam additive manufacturing device.Multi-material electron beam additive manufacturing device includes sealed shell, first powder storage unit, second powder storage unit, forming unit, falling powder laying unit, single-arm powder laying unit, electron beam gun, first powder recycling unit and powder suction device.Sealed shell has working chamber and mounting chamber inside.Falling powder laying device is used to lay A powder material in first powder storage unit to forming cavity.Single-arm powder laying device is used to lay B powder material in second powder storage unit to forming cavity, and also used to push the excess B powder material outside forming cavity to second opening after B powder material laying is completed.Powder suction device is used to extract the powder dispersed in working chamber out of sealed shell after 3D printing of each material is completed.Multi-material electron beam additive manufacturing device realizes the overall forming of multi-material component, and solves the problems of multi-material cross contamination and material mixing that cannot be reused.

The present application relates to the technical field of metal material processing, in particular to a rare earth synergistic refining high-strength and high-toughness aluminum-lithium alloy composition optimization method for additive manufacturing, comprising the following steps: obtaining aluminum-lithium alloy base powder, and respectively obtaining CeH2 powder as a cerium source and ZrH2 powder as a zirconium source as reaction precursors; uniformly mixing the CeH2 powder, the ZrH2 powder and the aluminum-lithium alloy base powder to form a composite powder raw material; in an electron beam additive manufacturing process, based on the super-high temperature and super-high cooling rate environment provided by the molten pool formed on the composite powder raw material by high-energy beam scanning, the CeH2 and the ZrH2 are decomposed into high-activity Ce atoms and Zr atoms, and in-situ synthesis reactions of the two with molten aluminum are promoted to generate (Ce, Zr)Al3 nanocomposite phases. By using CeH2 and ZrH2 as precursors, (Ce, Zr)Al3 nanocomposite phases are generated, and the spatial and temporal synchronization of refined phase generation and solidification nucleation is realized.

The invention discloses a method for forming a nickel-based superalloy through electron beam additive manufacturing, belongs to the technical field of electron beam additive manufacturing, and aims to solve the problem that cracks are easy to occur during existing electron beam additive manufacturing of the nickel-based superalloy. The method comprises the following steps: designing a three-dimensional model of a part by utilizing software; the part three-dimensional model is imported into a software platform to repair the model, the repaired model is placed on a printing platform, after model repairing and placing are completed, the model is exported as an STL format file, and the STL format file is imported into printing equipment; preheating the substrate; forming a core area and a contour area of the part by electron beams respectively, printing to obtain an initial part, and then performing hot isostatic pressing treatment to obtain a final part; in the step 4, the scanning beam of the outline area of the electron beam forming part is smaller than that of the core area of the electron beam forming part, and the scanning rate of the outline area of the electron beam forming part is larger than that of the core area of the electron beam forming part. The formed nickel-based superalloy is free of cracks.

This application discloses a vacuum chamber-based wire feeding device for electron beam fused wire additive manufacturing, belonging to the field of electron beam additive manufacturing. This application addresses the problems of existing wire feeding mechanisms located outside the vacuum chamber, which can easily lead to a drop in vacuum level and interruption of printing during the printing process; and the inability of easily bent and deformable thin and soft metal wires to continuously pass through the vacuum seal, limiting the selection of metal wires and the flexibility of electron beam fused wire additive manufacturing. This application places the wire feeding mechanism entirely inside the vacuum chamber, avoiding air leakage in the vacuum chamber caused by the rotation of the wire feeding gun and wire feeding, thus preventing printing interruptions. The wire feeding gun and the wire feeding device can adjust the wire feeding angle according to the direction of wire movement, avoiding wire puncture during printing. The built-in wire feeding mechanism can be added or removed according to actual usage needs, enabling multi-angle, multi-wire printing and ensuring the stability and continuity of the printing operation. This application is mainly used as a wire feeding device for electron beam fused wire additive manufacturing.

The invention discloses an online monitoring and process optimization system and method for electron beam additive manufacturing, and aims to solve the problems that in the prior art, the source of monitoring information is single, monitoring and control are disjointed, and the process cannot be adaptively adjusted according to real-time working conditions. Comprising a thermal infrared imager, a machine vision camera, a thermocouple array, a high-temperature strain gauge, a preset process parameter database and a data processing and display control unit. Through cooperative arrangement of multiple sensors and a special mounting structure, synchronous acquisition of surface temperature, molten pool state and stress strain is realized, a three-dimensional thermal sensing model is constructed and operated in real time, data of the multi-source sensors are fused, a temperature field and a strain state in the additive manufacturing process are reconstructed, and the temperature field and the strain state of the additive manufacturing process are obtained. And real-time data is monitored by combining a unified human-computer interaction interface, and the monitored data is directly applied to process control through a real-time sensing-intelligent decision method, so that the process optimization of the manufacturing process is realized, and the stability of the process is remarkably improved.

This invention discloses a heat treatment method for additively manufactured Ti2AlNb alloys: First, an electron beam additively manufactured Ti2AlNb alloy lattice heat sink ingot is heated to the B2 single-phase region for solution treatment. Then, it undergoes furnace cooling followed by pre-intermediate-temperature aging treatment, and then a short-time high-temperature aging treatment. Finally, it is air-cooled to room temperature to obtain an additively manufactured Ti2AlNb alloy lattice heat sink product. The internal structure of this product is a basket-like structure composed of alternating nano-scale O precipitates and residual B2 phases. This product can be used as the main material for heat dissipation components in aerospace and new energy fields. This invention, through solution treatment in the B2 single-phase region, pre-intermediate-temperature aging treatment, and short-time high-temperature aging treatment, promotes the uniform distribution of nano-scale O precipitates, resulting in a basket-like structure of alternating nano-scale O precipitates and residual B2 phases. This gives the product both good structural stability and strength, making it suitable for aerospace, new energy, and other fields.

The invention relates to the technical field of NiTiNb additive manufacturing, and discloses an electron beam additive manufacturing method for NiTiNb shape memory alloy, which comprises the following steps of: performing three-dimensional modeling on a target component, and performing layer-by-layer slicing treatment; niTiNb alloyed welding wires are used as raw materials, a TC4 plate is used as a substrate, electron beam additive manufacturing process parameters are set, and additive manufacturing is implemented according to path planning. The NiTiNb alloy component which is uniform in microstructure, high in density, high in compressive strength and excellent in ductility can be prepared.

The invention discloses a post-treatment method for improving the surface quality of electron beam additive manufacturing, and belongs to the technical field of additive manufacturing of alloy structural parts. The technical problem that the product surface quality is poor due to residual of a loose layer on the surface of existing electron beam selective melting forming titanium alloy is solved. The surface quality improvement method comprises the following steps: step 1, a model processing stage: constructing a blank model; step 2, part printing; performing program subdivision according to the blank model, then setting electron beam selective melting process parameters, and then performing electron beam printing; 3, after printing of the parts is completed, the parts are taken out and subjected to powder cleaning treatment; 4, after powder cleaning, the parts are supported and removed; 5, chemical milling liquid is adopted for conducting chemical milling on the part with the support removed; and 6, the surface of the part is subjected to hydrogen removal. According to the method, uniform removal and surface improvement of the titanium alloy product can be realized, and the potential hydrogen embrittlement risk is eliminated.

The invention discloses an additive manufacturing method of a high-plasticity molybdenum-rhenium alloy, which comprises the following steps of: 1, carrying out electron beam powder bed melting additive manufacturing by using electron beam additive manufacturing equipment and taking molybdenum-rhenium alloy spherical powder as a raw material, and reducing powder splashing and molten drop splashing by adopting a method that an electron beam focusing point deviates from a molten pool plane, a molybdenum-rhenium alloy printing piece is obtained; and secondly, the molybdenum-rhenium alloy printing piece is subjected to hot isostatic pressing treatment, and the high-plasticity molybdenum-rhenium alloy is obtained. Powder splashing and molten drop splashing are inhibited through electron beam focus deviation during electron beam additive manufacturing, keyholes and cracks formed by fluctuation of a molten pool are reduced, the structure uniformity is improved, pores caused by focus deviation are eliminated in combination with a subsequent hot isostatic pressing process, grain growth is avoided, and the product quality is improved. Various defects in the molybdenum-rhenium alloy electron beam additive manufacturing process are greatly inhibited, the high-plasticity molybdenum-rhenium alloy with the ductility exceeding 30% is obtained, and the high-plasticity molybdenum-rhenium alloy can be used for directly printing various high-temperature structural materials.

Methodologies and manufacturing processes to manufacture components by electron beam melting additive manufacturing, particularly components of molybdenum or a molybdenum-based alloy and particularly of complex nuclear component geometries. Input parameters are provided for controlling electron beam melting additive manufacturing equipment, such as electron beam melting machines. The input parameters relate to various process steps, including build set-up, initial thermal treatment, initial layering of powder, pre-consolidation thermal treatment, consolidation, post-consolidation thermal treatment, indexing of layers, and post-build thermal treatment. The methodologies and manufacturing processes allow manufacture of components of molybdenum having a purity of ≥99.0% and a density of ≥99.75%. Metallographic cross-sections of the manufactured molybdenum components were porosity-free and crack-free.

The application belongs to the field of material performance adjustment, and particularly relates to a method for adjusting modulus temperature coefficient of titanium alloy material. Step 1: preparing high-purity titanium alloy powder; step 2: formulating a printing strategy and establishing a process model; step 3: first layer adjustment method: designing process parameters, and confirming energy input value P according to the relationship between energy input value P and modulus temperature coefficient X; step 4: second layer adjustment method: determining printing angle alpha according to the relationship between printing angle alpha and modulus temperature coefficient X; step 5: printing and preparing titanium alloy; step 6: third layer adjustment method: performing vacuum aging treatment on the titanium alloy obtained in step 5, and adjusting aging temperature T and aging time Y according to the relationship among aging temperature T, aging time Y and modulus temperature coefficient X; and step 7: ending heat preservation and vacuum cooling to room temperature. The modulus temperature coefficient of the titanium alloy is successfully adjusted by combining electron beam additive manufacturing technology with aging treatment.

The invention relates to a point melting additive manufacturing simulation method and system based on multi-scale coupling, and aims to solve the problems that electron beam high-speed point melting is high in energy deposition transient state, rapid in temperature gradient change and the like, a multi-scale collaborative simulation strategy is provided, and efficient and accurate temperature field and molten pool form prediction in the point melting process is achieved. According to the method, by analyzing coupling of a temperature field prediction model and local CFD fine molten pool simulation, the mesoscopic molten pool evolution behavior in the electron beam point melting process can be efficiently obtained in a minimum computational domain, and the correlation between the mesoscopic molten pool evolution behavior and the macroscopic forming quality is established. Compared with a full-field CFD direct modeling mode, the method has the advantages that the calculation scale can be remarkably reduced, the calculation efficiency can be greatly improved, rapid simulation of the whole process of additive manufacturing high-speed point melting is achieved, and important technical support is provided for predicting the surface appearance, internal defect and thermal stress distribution of a formed part and improving the stability and forming quality of the electron beam additive manufacturing process.

The application discloses a kind of methods for the stable forming of additive manufacturing, the grid framework model is constructed, and the printing part model is established, and based on the grid framework model and printing part model, additive manufacturing is carried out to realize stable forming.The method uses a grid framework model covering preheating forming area, and the powder bed is solidified by electron beam outer contour point scanning mode, solves the problems of powder bed cracking, powder bed peeling and other problems in the processing process of traditional process, enhances the stability of powder bed, and helps to realize the stable forming of high-temperature alloy electron beam additive manufacturing.

The invention provides a defect suppression and process method for refractory alloy powder bed electron beam additive manufacturing, and relates to the technical field of refractory alloy additive manufacturing. The method comprises four links of powder pretreatment, substrate segmented and partitioned preheating, electron beam cladding forming and post-treatment stress release, specifically, a forming foundation is laid through accurate oxygen-controlled and density-controlled powder pretreatment, a substrate thermal field is balanced by adopting a segmented progressive and partitioned synchronous heating mode, electron beam parameters are regulated and controlled based on a self-created correction energy density formula, and the electron beam cladding forming process is completed. And a full-region segmented staggered scanning strategy is matched, real-time early warning and closed-loop regulation and control of defects are realized in combination with a hot crack sensitivity pre-judgment algorithm, and finally residual stress is released through segmented heat preservation annealing. Through full-process coupling regulation and control, the method is suitable for preparing complex components with the wall thickness being 2-50 mm and the size being smaller than or equal to 1000 mm, has forming stability and industrial application value, and can be widely applied to the field of high-end equipment such as aerospace and the nuclear industry.

The invention discloses a polycrystalline raw material bar electron beam additive manufacturing method for molybdenum-rhenium alloy single crystal preparation. The method comprises the following steps that firstly, molybdenum-rhenium alloy mixed powder is prepared; 2, cold isostatic pressing; 3, sintering; 4, rotary swaging and wiredrawing; 5, alkali washing and ethanol cleaning; 6, electron beam fuse wire additive manufacturing; and seventhly, the molybdenum-rhenium alloy polycrystalline raw material bar is used for preparing the molybdenum-rhenium alloy single crystal material through electron beam floating zone smelting. According to the method, the molybdenum-rhenium alloy polycrystalline raw material bar is printed through direct rotary swaging and wire drawing after cold isostatic pressing and sintering and subsequent electron beam additive manufacturing, the process links of repeated smelting, subsequent extrusion and the like in the prior art are avoided, the raw material utilization rate is greatly increased, and the manufacturing cost is reduced; the problems that an existing polycrystalline raw material bar manufacturing process for molybdenum-rhenium alloy single crystal preparation is extremely long in period, extremely low in raw material utilization rate and extremely high in manufacturing cost are solved, and an existing raw material bar manufacturing technology is replaced in the molybdenum-rhenium alloy single crystal preparation process.