14376results about "Increasing energy efficiency" patented technology

The invention relates to the technical field of additive manufacturing, in particular to an air field system with uniform airflow distribution for an additive manufacturing large-breadth forming platform, which comprises an air inlet three-way pipe unit and a negative pressure air draft unit, the air inlet three-way pipe unit comprises a main air supply pipe, an upper air outlet pipe and a lower air outlet pipe; the upper air outlet pipe and the lower air outlet pipe are each internally provided with a flow dividing grating assembly, air outlets of the upper air outlet pipe and the lower air outlet pipe are divided into a plurality of sub air outlets with the same opening size through the flow dividing grating assemblies, and flow guide pipes are arranged at the air outlets of the upper air outlet pipe and the lower air outlet pipe. An airflow dispersion unit is arranged on the side, close to the sub air outlets, in the flow guide pipe, a linear air outlet hole is formed in the other side of the flow guide pipe, and a conical flow channel with a conical section is arranged between the airflow dispersion unit and the linear air outlet hole. By means of the multi-stage flow dividing and guiding design, the effect that airflow in all areas of the large-breadth forming platform is evenly distributed under the condition of low air volume is achieved.

The invention provides a preparation method of laser cladding heterostructure stainless steel. According to the method, dried stainless steel pre-alloyed powder is subjected to laser melting deposition to form heterostructure stainless steel alloy with cross deposition of coarse grains and fine grains; the grain size of the fine crystal is 3-6 [mu] m, and the structure of the fine crystal layer is an equiaxed structure; the grain size of the coarse crystal is 20-50 [mu] m, and the structure of the coarse crystal layer is a columnar crystal formed along the Z axis. According to the method, the specific coarse grain / fine grain cross deposition heterostructure is presented in the stainless steel by changing the deposition layer process parameters and the scanning path, the material strength is improved while the material ductility is guaranteed, and the alloy has the excellent mechanical property.

The invention relates to the technical field of steel rail repair, and provides a steel rail laser additive defect detection method and system.The method comprises the steps that before laser additive repair is conducted on a steel rail damage area, a local area of a steel rail base body is instantly heated, so that an instant hot spot is formed in the corresponding local area; collecting thermal radiation attenuation information of the instantaneous hot spot; according to the thermal radiation attenuation information, the actual heat dissipation rate of the local area corresponding to the instantaneous hot spot is calculated so as to achieve detection of the steel rail damage area; according to the actual heat dissipation rate, repairing process parameters used for laser additive repairing are selected from a pre-stored process parameter combination; and carrying out laser additive repair on the damaged region of the steel rail by adopting the repair process parameters. The method has the effect of improving the quality and reliability of steel rail laser additive repair.

A sonotrode includes a stem extending along a longitudinal axis and a cap configured to carry out an ablative process on tissue using mechanical oscillation. The cap has at least one portion that protrudes further in a radial direction than the stem, and the at least one portion has at least one sharp rim. A surface of the cap, which is arranged between a distal end of the stem and the sharp rim of the portion, is a concave surface and / or runs at an opening angle with respect to the stem that is equal or smaller than 90 degrees. A center of mass of the cap is on the longitudinal axis.

The invention discloses a dynamic monitoring and analyzing method for a thermal management component molten pool based on image recognition, and relates to the technical field of laser powder bed melting additive manufacturing. The method comprises the following steps: continuously capturing an original thermal management component molten pool image and temperature field distribution data during laser powder bed melting additive manufacturing; and optimizing the original thermal management component molten pool image to generate an optimized thermal management component molten pool image. Molten pool images and temperature field data are captured in real time through a high-frame-rate synchronous camera and an infrared sensor, defect types are recognized online in combination with a lightweight classification model, classification results are fed back to a control system to dynamically adjust laser power or scanning speed, interlayer defect accumulation can be inhibited in time, and the defect quality is improved. The defect diffusion problem caused by response lag of a traditional off-line analysis method is avoided, and the forming precision and the process stability of the heat management component are remarkably improved.

The invention relates to the technical field of additive manufacturing, and particularly provides a heat treatment method of a nickel-based superalloy for additive manufacturing. The heat treatment method comprises the following steps: S1, preparing a nickel-based high-temperature alloy forming part by adopting a selective laser melting process; s2, the formed part is subjected to homogenizing annealing treatment at the temperature ranging from 1000 DEG C to 1200 DEG C; s3, the formed part subjected to homogenizing annealing treatment is subjected to water quenching treatment and cooled to the room temperature; and S4, the formed part subjected to water quenching treatment is subjected to primary aging treatment at the temperature of 700-800 DEG C, then cooled to 600-700 DEG C, subjected to secondary aging treatment and then air-cooled to the room temperature. According to the method, the effect of simultaneously regulating and controlling the grain structure and the precipitated phase of the SLM-GH4169 alloy is achieved by increasing the homogenizing annealing heat treatment time, combining a water quenching cooling mode and cooperating with two-stage aging, and the strength and plasticity of the alloy are successfully and synergistically improved. According to the prepared SLM-GH4169 alloy, not only can the tensile strength reach 1400 MPa, but also the elongation at break can reach 22% or above.

The invention discloses an electric arc additive manufacturing temperature field and stress field real-time reconstruction method, which comprises the following steps of: 1, constructing a sequential coupling finite element model in which heat conduction analysis and thermoelastic-plastic mechanical analysis are combined on the basis of process parameters of an electric arc additive manufacturing process and three-dimensional geometry of parts, generating a multi-physical field coupling data set among heat flux density, temperature and stress; step 2, constructing and training a neural network model based on a multi-physics field coupling data set, and realizing mapping from heat flux density to temperature and stress; 3, dynamically optimizing heat source model parameters in combination with real-time monitoring data and process parameters in the electric arc additive manufacturing process; and 4, based on the optimized heat source model parameters and the trained neural network model, real-time reconstruction of a temperature field and a stress field in the electric arc additive manufacturing process is achieved. According to the invention, the requirements of rapid sensing and intelligent regulation and control of temperature and stress states on an additive manufacturing site are met.

The invention relates to an additive manufacturing method and application of an aluminum-based silicon carbide composite material complex component, and the additive manufacturing method of the aluminum-based silicon carbide composite material complex component comprises the following steps: step 1, uniformly mixing silicon carbide powder and aluminum alloy powder, and drying; 2, establishing a structural model for the target part, and importing the structural model into selective laser melting forming equipment; thirdly, selective laser melting forming is conducted; fourthly, linear cutting and surface treatment are conducted; and fifthly, hot isostatic pressing treatment is conducted. The invention further provides application of the aluminum-based silicon carbide composite material complex component to precise structural components such as aviation structural components, guided missile and satellite components and optical instruments. According to the method, the problem of subsequent large-allowance removal of the aluminum-based silicon carbide composite material component is solved, the wettability between the aluminum alloy and the silicon carbide particles is improved, the mechanical property meets the application requirement, and the aluminum-based silicon carbide structural component with stable performance is obtained.

The invention relates to the technical field of quality detection, in particular to a gas atomization powder sphericity degree multi-dimensional online analysis system and a method thereof.The gas atomization powder sphericity degree multi-dimensional online analysis system comprises a dynamic dual-mode imaging module, a transverse wind field auxiliary detection unit and a multi-dimensional feature fusion analysis module; the transverse wind field auxiliary detection unit is used for applying controllable transverse wind power through an airflow nozzle orthogonal to the powder falling direction and measuring the deflection track of gas atomization powder ball particles in combination with a laser displacement sensor. The online calibration module is used for spraying standardized spherical particles to the powder flow according to a preset period; the traditional density detection depends on destructive sampling and off-line measurement, the efficiency is low, and the whole production line particles cannot be covered; through an orthogonal wind field trajectory inversion technology, a density value and an internal defect mark are synchronously output through non-contact dynamic measurement, 100% lossless online full inspection of a production line is realized, and sampling limitation and aging bottleneck of a traditional means are broken through.

The invention discloses a fuse wire additive manufacturing method for regulating and controlling the strength of titanium alloy by adding rare earth oxide, which comprises the following steps of: 1, ultrasonically stirring and mixing rare earth oxide nano powder and ethanol solution to obtain turbid liquid; 2, polishing the surface of the titanium or titanium alloy substrate until the roughness is not greater than Ra1.6; thirdly, the surface of a substrate is evenly coated with the turbid liquid, after drying, fuse wire additive manufacturing of titanium or titanium alloy wires is carried out under inert atmosphere protection, and the titanium alloy with the improved strength is obtained; the fuse wire additive manufacturing process comprises the steps that layer-by-layer deposition is conducted, and after each layer is deposited and completely solidified and cooled, the surface of the deposited layer is coated with turbid liquid and dried. According to the method, coating of the turbid liquid containing the rare earth oxide and the fuse wire additive manufacturing process are combined, the titanium or titanium alloy containing the rare earth oxide and uniform in component is prepared, metallurgical bonding of the rare earth oxide and the titanium or titanium alloy wire is achieved, and the method is suitable for the technical field of metal additive manufacturing.

The invention provides a method and a device for evaluating and measuring microscopic mechanical properties of TC4 alloy, relates to the technical field of microscopic mechanical properties, and realizes accurate evaluation of material properties through combination of multi-scale characterization and numerical simulation. Firstly, a standard sample is prepared through selective laser melting, and residual stress field distribution is obtained through X-ray diffraction; dividing a stress field into sub-regions, and establishing a quantitative relationship between microscopic structure parameters and residual stress by combining SEM and EBSD analysis; the method comprises the following steps: acquiring local mechanical properties through a nanoindentation test, and constructing a stress-performance correlation model; and finally, establishing a finite element model, transmitting stress and tissue parameters by adopting trilinear interpolation and an inverse distance weighting method, verifying data reliability through a stress difference criterion, and calculating mechanical properties of each unit. According to the method, multi-scale correlation from microstructure characteristics to macroscopic mechanical properties is innovatively realized, so that the mechanical property distribution of the material is accurately evaluated.

The invention discloses a laser energy threshold millisecond-level dynamic matching method for multi-metal fuse manufacturing, and the method comprises the steps: pre-storing a multi-metal thermophysical parameter model, calibrating a thermal signal in real time through Kalman filtering, and carrying out the online correction of a melting threshold key parameter during the switching of a material; millisecond-level thermal feedback closed-loop control is achieved through the high-frame-rate thermal imaging technology, and the laser power accurately follows the corrected melting threshold value; meanwhile, a three-dimensional imaging and deep learning segmentation algorithm is adopted, geometric information of a welding wire and a molten pool is obtained, the position and the diameter of a light spot are adjusted in real time through an adjustable optical system after the offset is calculated, and millimeter-level space registration closed-loop control is achieved; the two closed-loop systems cooperatively operate according to respective control periods, and precise dynamic matching of laser heat input in a time domain and a space domain is achieved. The problem that the adaptability of a traditional process is insufficient during multi-metal switching and complex geometric change is solved, and the forming quality, the process stability and the efficiency of manufacturing are remarkably improved.

The invention discloses a preparation method of a nickel-based tungsten carbide laser cladding wear-resistant gradient coating, which comprises the following steps: step 1, preparing mixed powder of a transition layer, a functional layer and a repair layer; step 2, pretreating a matrix: removing oxide skin on the surface of the matrix, polishing to be smooth, and preheating the matrix to 350-500 DEG C; step 3, sequentially preparing a first functional layer, a transition layer, a second functional layer and a repair layer by adopting a laser cladding process; and 4, coating post-treatment is conducted, specifically, the surface of the repairing layer is polished to the specified thickness, and the defect-free wear-resistant gradient coating is formed. Through gradient component layered design, the functional layer adopts high tungsten carbide content to maximize wear resistance, and the transition layer relieves thermal expansion difference between the coating and a matrix, reduces interface stress and reduces crack initiation; according to the repairing layer, micro-cracks and air holes generated in the cladding process are filled through low-hardness nickel-based components, and the compactness and surface integrity of the coating are remarkably improved.

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.

The application discloses a kind of based on 3D printing's three-dimensional model slice path processing method and device. Including: control 3D printer to starting point as starting point;Based on the region surrounded between starting point and reference point, determine the printing point to be printed that 3D printer needs to execute printing action during executing 3D printing job;Starting point and the printing point to be printed are sequentially connected by smooth straight line, generate printing path;Based on printing path control 3D printer executes 3D printing job and obtains target object, to effectively reduce the number of line segments of slice contour line of three-dimensional model forming target object, avoid 3D printer in printing job, in the pause frequency of line segment head, tail, simultaneously avoid the problem that 3D printing model surface protrusion is caused by long time scanning due to pause.In reducing pause frequency, printing is more smooth, improve printing efficiency, simultaneously also reduce algorithm complexity, help the simplification of algorithm.And effectively simplify the algorithm of 3D printer.

The invention relates to the technical field of intelligent sintering, and discloses a rare earth magnet intelligent sintering production line and a control system, and the system comprises a temperature data collection module, a temperature gradient evaluation module, a temperature change rate fitting module, a heating power adjustment module, a directional heat energy compensation module and an optimized heating instruction generation module. Temperature distribution information in the sintering furnace is obtained; evaluating real-time temperature gradients of different positions in the sintering furnace, and comparing the real-time temperature gradients with a preset gradient threshold value to identify a temperature abnormal region in the sintering furnace; fitting the temperature change rate of the temperature abnormal area; the material phase change critical parameters of the rare earth magnet in the current sintering stage are combined to adjust the heating power of the temperature abnormal area; performing directional heat energy compensation on the temperature abnormal region to obtain a power compensation amount; superposing the power compensation amount and the reference power of the sintering furnace to generate an optimized heating instruction; the intelligent sintering control efficiency of the rare earth magnet can be improved.

The invention belongs to the technical field of metal material forming, and relates to a high-strength plastic titanium-based composite material annular part and a preparation method and application thereof. The preparation method comprises the following steps: firstly, uniformly mixing titanium alloy powder and reinforced phase powder, then preparing an annular blank according to the technological process of smelting, plasma rotating electrode atomization, degassing seal welding, hot isostatic pressing and ring rolling, and finally, annealing the annular blank to prepare the target annular part. According to the method, the titanium-based composite material powder is prepared by replacing a traditional laboratory small-batch ball milling method with a large-batch mixing method, a vacuum induction melting rod manufacturing method and a plasma rotating electrode atomization method, a reinforced phase can be introduced into a titanium matrix crystal and uniformly distributed, and the method is suitable for industrial large-batch production requirements; the titanium-based composite material annular part is prepared through the technology of powder metallurgy blank making and thermal deformation, and the effects of shortening the machining period and improving the material utilization rate and the forming rate are achieved through the precise size of powder metallurgy forming and the high efficiency of special-shaped ring rolling.

The invention provides a liquid cooling plate surface quality optimization method based on red light printing, and belongs to the field of additive manufacturing. According to the liquid cooling plate surface quality optimization method based on red light printing, when a model of a heat dissipation structure with a curved surface on a liquid cooling plate is sliced, all slice layers are divided into a plurality of intervals according to the included angles between the lower surfaces where the slice layers are located and the horizontal plane, so that the whole workpiece model is segmented into a plurality of parts; and then the multiple parts obtained through division are subjected to powder laying printing, and process parameters are given to the different parts for printing. The roughness of the surface of the liquid cooling plate can be reduced by adjusting the red light printing process parameters, and the equipment cost is saved. Besides, the surface quality of the liquid cooling plate can be stabilized at about Ra5, the use requirements of most liquid cooling plates can be met, extra post-treatment procedures are reduced or even not needed, the production cost is greatly reduced, and the production efficiency is improved.

The invention discloses a method for reducing the inclusion degree of metal particles in additive manufacturing of a spaceflight propulsion chamber. The method comprises the following steps that 1, a printing layer data set is constructed; 2, constructing an initial multi-scale graph structure; 3, outputting an inclusion risk probability graph of the current printing layer based on a multi-scale graph growth generation network; 4, inputting the inclusion risk probability graph into a mimicry hummingbird optimization algorithm to generate a path optimization target space; 5, performing path search by adopting a mimicry hummingbird optimization algorithm, and outputting a final scanning path; 6, controlling a laser to perform printing and scanning operation according to the final scanning path; 7, inputting process feedback data into the multi-scale graph growth generation network, and outputting an updated inclusion risk probability graph of a next printing layer; and 8, the step 4 to the step 7 are executed repeatedly till all the printing layers are printed. According to the method, the multi-scale graph growth generation network and the mimicry hummingbird optimization algorithm are fused, and the metal particle inclusion degree is effectively reduced.

The invention relates to the field of additive manufacturing, and discloses a dynamic phase change control additive ultrahigh-strength steel strengthening and toughening process which comprises the following steps: S1, constructing a phase change structure design target which comprises retained austenite distribution, a structure space structure and mechanical property requirements; s2, based on the phase change structure design target, establishing a free energy model taking a phase field variable as a core for representing a phase change driving behavior between austenite and martensite; s3, on the basis of the free energy model, constructing a multi-field partial differential control model coupling phase field evolution, element diffusion and heat conduction; and S4, in combination with the multi-field partial differential control model, determining an interface adsorption parameter, a diffusion coefficient and a thermophysical parameter based on experimental characterization data. According to the method, path parameters are optimized through a multi-field partial differential control model and tissue deviation feedback, and accurate control of the phase change tissue and dynamic closed-loop adjustment of the machining process are achieved.

The invention discloses a high-strength high-temperature alloy and a preparation method thereof. The high-strength high-temperature alloy comprises a high-temperature alloy matrix and rare earth oxides dispersed and distributed in the high-temperature alloy matrix. The high-temperature alloy matrix is GH4169, and the high-temperature alloy matrix is made of The rare earth oxide is one or two of La2O3 and Ce2O3, the particle size of the rare earth oxide is 50-500nm, and the total adding amount of the rare earth oxide is 0.02-0.03% of the mass of the alloy; the preparation method of the high-strength high-temperature alloy comprises the following steps: (1) preparing rare earth oxide particles; (2) charging and smelting rare earth oxide particles and alloy raw materials in a vacuum induction furnace, and casting into ingots after the components are qualified; (3) electroslag remelting: adding analytically pure rare earth oxide into a slag system; and (4) the electroslag ingot is subjected to homogenization, forging and solid solution aging treatment, and then the alloy is obtained. According to the method, the strength and plasticity of the high-temperature alloy are improved.

The invention provides a high-strength aluminum alloy selective laser melting forming thermal stress prediction method based on deep learning. The method comprises the steps of 1, finite element model establishment and simulation, wherein a heat transfer model and a thermal coupling model are established; an SLM process is used as a simulation object, a Gaussian model is adopted to define a laser heat source, and thermal stress distribution under different process parameters and different sample sizes is simulated; wherein the process parameters comprise laser power, scanning speed and hatch spacing; step 2, data processing and deep learning model training; comprising the steps of data preprocessing, neural network model architecture determination, adversarial network part generation and model configuration and training. 3, evaluating and optimizing the model; and 4, thermal stress prediction and process optimization. By learning a complex mode in finite element simulation data through a deep learning model, efficient and accurate thermal stress prediction is achieved, and the problems that traditional finite element analysis is complex in calculation and large in resource consumption are solved.

The invention relates to the technical field of additive manufacturing, and discloses an additive manufacturing hot-crack-free precipitation strengthening high-temperature alloy and a preparation method thereof.The method comprises the steps that a laying layer is divided into a plurality of parallel scanning strips according to the preset translation direction and the scanning strip interval, strip type scanning is conducted in a laser autorotation and translation motion coupling mode, and the high-temperature alloy is obtained; molten pool disturbance is remarkably enhanced, periodic shear fracture of the tip of dendritic crystal is achieved, epitaxial growth of columnar crystal is broken, grain equiaxalization is achieved, and anisotropy is weakened; in addition, laser scanning is a high-speed scanning strategy with the translation speed larger than or equal to 1500 mm / s, a shallow molten pool is formed through regulation and control of the high scanning speed, surface tension in the shallow molten pool is utilized, convection in the molten pool is enhanced, dendritic crystals are refined, columnar crystals in the high-temperature alloy are further reduced, and anisotropy of mechanical properties is remarkably eliminated; and the transverse strength and creep resistance at high temperature are improved. The isometric crystals can effectively prevent cracks from expanding in the orientation direction of the columnar crystals, and the fatigue life and the damage tolerance are remarkably prolonged.

The invention discloses post-processing equipment for a rolled strip, relates to the technical field of strip rolling post-processing, and aims to solve the problems of waved edge warping and overall warping caused by non-uniform residual stress distribution of edge and central areas after a metal strip is rolled in the prior art. Comprising a gradient annealing device and an edge stress grading regulation and control device, the gradient annealing device at least comprises a plurality of heating roller groups; the plurality of heating roller groups are arranged at equal intervals along the moving direction of the strip, each heating roller group comprises two heating rollers, the two heating rollers respectively heat the upper surface and the lower surface of the rolled strip, each heating roller at least comprises a magnetic induction coil, and the coil density of the magnetic induction coil is gradually reduced from the edge part to the middle part; the edge stress grading regulation and control device at least comprises a plurality of edge pressing roller sets arranged in the strip moving direction. The included angle between each edge pressing roller set and the width direction of the strip is gradually reduced in the moving direction of the strip. The method is used for realizing precise regulation and control of the residual stress.

An additive manufacturing method based on micro-selective laser melting technology. By using a spot size of 30 μm or less, a metal powder layer thickness of 10 μm or less and ultrafine metal powders having a D90 particle size of 30 μm or less, and in combination with the control of a scanning laser power, a scanning rate, a linear energy density and a volumetric energy density within specific ranges, the method can print complex-structured metal parts having extremely high resolutions and surface smoothness, and can obtain a high-density internal structure of a component even under a relatively low energy density or power condition, thereby effectively protecting an optical system. Moreover, a printed component exhibits a defect-free microstructure, and has excellent electrical properties, thermal properties and mechanical properties. Particularly, ultrafine grains and a high dislocation density provide superior mechanical properties compared to conventional manufacturing materials. An infrared laser device can be used, thereby achieving low costs.

The invention discloses a flue gas purification device for a sintering machine, and relates to the technical field of sintering machines, the flue gas purification device comprises a purification cylinder, the outer side of the purification cylinder is fixedly connected with a gas inlet pipe, one end of the gas inlet pipe penetrates through the inner side of the purification cylinder, and a treatment unit for purifying flue gas of the sintering machine is arranged on the upper side of the gas inlet pipe; an exhaust pipe is fixedly connected to the outer side of the purification barrel and located above the air inlet pipe, a first water pump is fixedly connected to the right side of the purification barrel, a fixing disc is arranged on the inner side of the purification barrel, and a plurality of branch plates are fixedly connected between the fixing disc and the purification barrel. According to the flue gas purification device for the sintering machine, the purification cylinder, the gas inlet pipe, the fixed pipe, the spray head and the first water pump are arranged, the spray head can spray out an alkaline solution conveniently to treat flue gas of the sintering machine, introduced gas can be dispersed conveniently through a rotating rod, a stirring plate, the fixed cylinder, a branch cylinder, a dispersion plate, a first dispersion piece and a second dispersion piece, high-concentration flue gas is evenly distributed, and the service life of the flue gas is prolonged. The flue gas purification effect is improved.

Described herein are systems and methods for detecting flaws during an additive manufacturing (AM) process. A method can include accessing, by a computer, simulation results of a computer-modelled part representing a physical part to be formed using the AM process. The simulation includes a thermal history model for the computer-modelled part. During run-time formation of the physical part, the method includes receiving, from sensor devices, real-time sensor data of temperature values for nodes within regions of the physical part as each region is formed. The method also includes determining, for each region as the region is formed in the physical part, a deviation between the real-time sensor data of temperature values for nodes within the region and temperature values of the thermal history model for the computer-modelled part, and identifying flaws in the physical part based on determining that the deviation satisfies criteria indicating a flaw.

The invention relates to the technical field of metal powder processing, and discloses a high-performance dissimilar metal powder precision forming process which comprises the following steps: filling powder into a mold cavity, applying vibration disturbance, monitoring the change rate of a phase lag angle, judging that the powder is dense when the change rate is lower than an offset threshold value, outputting a pressing mode switching signal, an induction heating device is used for applying transient thermal load to induce cracks of an oxide film on the surfaces of particles, the pressure load is applied, the side wall is adjusted to generate shear displacement to peel off the oxide film, and metallurgical bonding is achieved through fresh metal surface contact. An interface is activated through thermal expansion mismatch and mechanical friction synergistically, a high-density uniform green body is obtained at low temperature, generation of brittle intermetallic compounds is inhibited, and the fatigue resistance of a formed part is enhanced.

The invention provides a high-hardness cobalt-based alloy welding wire and a preparation method thereof, and the high-hardness cobalt-based alloy welding wire comprises the following components in percentage by mass: less than or equal to 0.5% of C, 3-4% of Si, 15-20% of Cr, 1-4% of Ni, 25-30% of Mo, 45-55% of Co, less than or equal to 1% of Fe, less than or equal to 0.02% of La, less than or equal to 0.02% of B, less than or equal to 0.01% of S and less than or equal to 0.01% of P. According to the cobalt-based welding wire, through regulation and control of alloy elements, the hardness of the cobalt-based welding wire is remarkably improved, the uniformity of components of the welding wire is improved, the welding strength is improved, the size of the welding wire is extremely thin, and the welding manufacturability of the welding wire is improved.

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.