CN116638100A - Internal microscopic defect repairing method suitable for laser cladding forming metal material - Google Patents

Internal microscopic defect repairing method suitable for laser cladding forming metal material Download PDF

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Publication number
CN116638100A
CN116638100A CN202310614237.8A CN202310614237A CN116638100A CN 116638100 A CN116638100 A CN 116638100A CN 202310614237 A CN202310614237 A CN 202310614237A CN 116638100 A CN116638100 A CN 116638100A
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metal material
positive
pulses
magnetic
negative
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黄坤兰
李强
王杰
曾波
孙宏飞
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Sichuan University
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Sichuan University
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/60—Treatment of workpieces or articles after build-up
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/20—Direct sintering or melting
    • B22F10/25—Direct deposition of metal particles, e.g. direct metal deposition [DMD] or laser engineered net shaping [LENS]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/20—Direct sintering or melting
    • B22F10/28—Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y40/00—Auxiliary operations or equipment, e.g. for material handling
    • B33Y40/20—Post-treatment, e.g. curing, coating or polishing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2999/00—Aspects linked to processes or compositions used in powder metallurgy
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/25—Process efficiency

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Laser Beam Processing (AREA)

Abstract

The invention discloses a method for repairing internal microscopic defects of a metal material formed by laser cladding, which comprises the steps of firstly determining the type of the microscopic defects of the metal material to be treated; then placing the metal material to be treated in an electric field and magnetic field application environment for electromagnetic coupling treatment; and determining electromagnetic coupling processing parameters according to the microscopic defect types, and performing electromagnetic coupling processing on the metal material to be processed according to the determined electromagnetic coupling processing parameters. The invention uses pulse electromagnetic field to carry out electromagnetic coupling treatment on the laser cladding forming metal material, regulates and controls dislocation, vacancy, solid solution atoms and the like in the metal on microscopic scale, is used for repairing the defects of the forming material fundamentally, and can inhibit the defects in the subsequent service process of the material.

Description

Internal microscopic defect repairing method suitable for laser cladding forming metal material
Technical Field
The invention belongs to the technical field of metal material processing, relates to metal treatment for laser additive manufacturing, and particularly relates to an internal microscopic defect repairing method suitable for laser cladding forming of metal materials.
Background
Unlike conventional subtractive or equi-dimensional manufacturing, additive manufacturing is a technique that gradually builds up material to shape the entire part on a point-by-point, line-by-line, layer-by-layer basis on a discrete-stacked principle. Laser cladding forming is an additive manufacturing technology developed based on laser cladding surface modification technology. The high-energy laser beam is used to form molten pool on metal matrix, and the molten pool is used to melt the powder preset on the matrix or the powder synchronously fed to the metal matrix by nozzle, so that after the molten pool and the powder are solidified fast, the molten pool and the powder form metallurgical bond with the matrix, and the molten pool and the powder are stacked layer by layer, thus realizing the formation of three-dimensional parts. The laser cladding forming has the advantages of forming parts with complex structures, processing refractory metals, forming without a mold, forming parts with excellent mechanical properties, high flexibility degree and the like, and has wide application in the fields of aerospace, biomedical, automobile electronics, part repair and the like. In the forming process, because the parts undergo quenching and rapid heating, larger temperature gradient can be generated, thermal stress is easy to form and remain in the parts, and in the subsequent heat treatment process, the residual stress is released, so that warping and even cracks can be generated, the parts are invalid, and the performance and the service life of the parts are seriously influenced. In addition, metastable byproducts are also easily generated in the forming process, and the byproducts are also an important reason for generating cracks in subsequent part treatment.
At present, aiming at the defects of laser cladding formed parts, domestic and foreign scholars mostly adopt modes of synchronously preheating base materials, optimizing laser cladding process parameters, adjusting alloy components and the like to improve the performance of the formed parts, such as reducing energy input in the additive manufacturing process, controlling scanning speed, changing scanning paths and the like.
However, on one hand, due to different components of different materials and different physical and chemical properties, the evolution rule of the microstructure in the laser cladding forming process has a certain difference, so that the optimized laser cladding process parameters are always effective only for specific materials, the universality is poor, and the control effect on defects of other material cladding forming parts is very small or even not effective; on the other hand, because the formation information of the defects cannot be known, a large number of experiments are often needed for optimizing the process parameters, the optimal process parameters are repeatedly and iteratively selected through a trial-and-error method, for example, the optimal laser power, the scanning speed and the like are selected through a large number of experiments, so that the period of the optimization process is longer, the optimization process is complex, and the time and money are wasted; in addition, the reasons for forming defects are often not single, the process optimization cannot fundamentally solve the problems, and the improvement effect is limited.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide an internal microscopic defect repairing method suitable for laser cladding forming metal materials, so as to reduce the cracking tendency of the materials and improve the comprehensive performance of parts; solves the problems of poor universality, long optimization period, poor effect and the like in the existing method for regulating and controlling the defects of the laser cladding forming part.
In order to achieve the above object, the present invention can be achieved by the following means.
The invention provides a method for repairing internal microscopic defects of a laser cladding formed metal material, which comprises the following steps:
s1, determining the type of microscopic defects of a metal material to be processed; the microscopic defect types comprise dendrite microsegregation, microcracks and tiny holes;
s2, placing the metal material to be treated in an electric field and magnetic field application environment for electromagnetic coupling treatment;
s3, determining electromagnetic coupling processing parameters according to the microscopic defect types, and performing electromagnetic coupling processing on the metal material to be processed according to the determined electromagnetic coupling processing parameters:
(1) When the microscopic defect type is dendrite microscopic segregation, firstly, 10-20 groups of positive magnetic pulses are applied to the metal material, and the magnetic treatment time is 50-100 s; then the interval is 5-10 s, 400-500 groups of positive electric pulses are applied to the metal material, and the electric treatment time is 80-100 s;
(2) When the microscopic defect type is a tiny hole, firstly, 10-20 groups of negative magnetic pulses are applied to the metal material, and the magnetic treatment time is 50-100 s; then the interval is 5-10 s, 400-500 groups of negative electric pulses are applied to the metal material, and the electric treatment time is 80-100 s;
(3) When the microscopic defect type is microcrack, firstly, applying 20-40 groups of positive and negative magnetic pulses to the metal material, wherein the magnetic treatment time is 100-200 s; then the interval is 5-10 s, 800-1000 groups of positive and negative electric pulses are applied to the metal material, and the electric treatment time is 160-250 s;
in the step S1, the metal material to be processed is a metal material formed by laser cladding. The present invention is not limited to the laser cladding forming method of the metal material, and the metal material to which the present invention is directed may be processed by the laser cladding forming method disclosed in the art, which is not included in the scope of the present invention. The metal material to be treated is mainly nickel-based superalloy and the like. Microscopic defect types are determined by research, for example: (1) dendrite microsegregation; (2) The size of the micro holes is generally 0.1-2 mu m; (3) The microcrack defects are caused by excessive microscopic residual stress, and the microcrack length is generally 10-20 μm, the width is generally 0.1-1 μm, and the depth is generally 5-20 μm. Of course, the type of microscopic defects present in the metallic material to be treated can also be determined by various tests (e.g. XED, SEM).
In the above step S2, an electromagnetic coupling processing apparatus (for example, an electromagnetic coupling material processing apparatus disclosed in the art, for example, in application number CN 201910271697.9) may be used to provide an electric field environment and a magnetic field environment required for the electromagnetic coupling processing, and the metal material to be processed is placed in the center of the pulsed magnetic field and held by a jig and is connected to both ends of the electrode generating the pulsed current.
In the step S3, the time interval between two adjacent groups of positive magnetic pulses in the step (1) is 1-10S, the magnetic field intensity of the positive magnetic pulses is 1.0-2.5T, and the action time of a single magnetic pulse is 0.1-1S; the positive pulse group contains 5-20 positive pulses, and the current density of the positive pulse is 5 multiplied by 10 7 ～1×10 8 A/m 2 The frequency is 50-100 Hz, the duty ratio is 10% -50%, and the time interval between two adjacent groups of positive electric pulses is 1-10 ms; (2) The time interval between two adjacent groups of negative magnetic pulses is 1-10 s, the magnetic field intensity of the negative magnetic pulses is 1.0-2.5T, and the action time of a single magnetic pulse is 0.1-1 s; a group of negative electric pulses comprising5-20 negative pulses with current density of 5×10 7 ～1×10 8 A/m 2 The frequency is 50-100 Hz, the duty ratio is 10% -50%, and the time interval between two adjacent groups of negative electric pulses is 1-10 ms; (3) Wherein the positive magnetic pulse and the negative magnetic pulse form a group of positive and negative magnetic pulses, the interval between two adjacent groups of positive and negative magnetic pulses is 1-10 s, the magnetic field intensity of the positive magnetic pulse and the negative magnetic pulse is 1.0-2.5T, and the action time of a single magnetic pulse is 0.1-1 s; the positive and negative electric pulse units form a group of electric pulses, and the current density of positive and negative electric pulses in the positive and negative electric pulse units is 5 multiplied by 10 7 ～1×10 8 A/m 2 The frequencies of the positive pulse and the negative pulse in the positive pulse unit and the negative pulse unit are 50-100 Hz, and the interval between two adjacent groups of electric pulses is 1-10 ms.
The internal defects of the metal are microscopically represented by periodic arrangement of atoms at the defect sites different from other sites such as dislocation, vacancy, stacking fault and the like; at the same time, the existence of the defect site also causes the migration of atoms to be blocked, and the accumulation of dislocation and grain boundary causes stress concentration at the defect site. Due to the specificity of defective sites, there is a certain difference in the physicochemical properties of these sites and other sites. According to the characteristic difference of the defect part, a pulse magnetic field is firstly applied, the magnetic plasticity of the magnetic field to the metal material is utilized, atoms of the defect part with higher energy are induced and excited, meanwhile, excited electrons are subjected to the action of Lorentz force, the binding force of the electrons of the defect part is weakened, and a driving force is provided for the migration of the atoms of the defect part; then a pulse electric field is applied, and the large current generated by the electric field causes intense electron migration, electrons frequently strike defects such as dislocation and the like, so that microscopic defects are unpinned and move to a low-energy part, rearranged and uniformly distributed in the crystal; meanwhile, the defect part has higher resistivity, so that the temperature of the defect part is higher than that of other parts due to the Joule heating effect, atoms, vacancies and the like of the defect part are in a more active state, and migration and diffusion are easier to occur under the actions of electron wind force, skin effect, electro-plasticity and the like, so that the defects of microcracks, micropore holes and the like in the metal are healed. Further, under the action of electromagnetic force generated by the pulse electromagnetic field, the internal tissue structure of the metal is more uniform, and macroscopic appearance is that the mechanical property of the metal material is improved.
At present, the improvement is mainly carried out on the technological parameters of the laser cladding process, and the method is a method for solving the problems at the source; the laser cladding forming process involves various factors such as laser power, scanning path planning, scanning speed, temperature control, protective atmosphere selection and the like; in addition, the difference of different metal materials is considered, so that repeated experiments are often required to obtain optimal process parameters, time and economic cost are high, and beneficial results cannot be obtained. The invention relates to a method for reprocessing parts after laser cladding forming, which belongs to a metal post-treatment process method, has short treatment process time, is a method for regulating and controlling metal microscopic defects from a metal material microscopic scale, does not generate macroscopic deformation in the treatment process, does not generate obvious thermal effect, and has low time and economic cost and high efficiency. Compared with the prior art, the method for repairing the internal microscopic defects of the metal material suitable for laser cladding has the following beneficial effects:
(1) The invention utilizes the pulse electromagnetic field to carry out electromagnetic coupling treatment on the laser cladding forming metal material, regulates and controls dislocation, vacancy, solid solution atoms and the like in the metal on a microscopic scale, fundamentally repairs the defects of the forming material, and can inhibit the defects in the subsequent service process of the material;
(2) The invention has short treatment time, low applied external field intensity, no obvious heat effect in the treatment process, and no deformation or other defects;
(3) The laser cladding forming material repaired by the method has the advantages that the internal residual stress is obviously reduced, the cracking tendency is obviously reduced, the microstructure morphology is obviously improved, and the mechanical properties such as fatigue strength, tensile strength and the like are obviously improved;
(4) The invention adopts the pulse electromagnetic field to process the laser cladding forming metal material, waste gas and waste water are not generated in the processing process, and the equipment adopts electric energy as energy input, thus being a green and environment-friendly processing method.
Drawings
FIG. 1 is a graph showing the residual stress test results in a laser clad nickel-base superalloy of example 3; wherein (a) corresponds to along the laser cladding scan direction (i.e., the printhead strike) and (b) corresponds to perpendicular to the laser cladding scan direction.
Detailed Description
The technical solutions of the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden on the person of ordinary skill in the art based on the embodiments of the present invention, are within the scope of the present invention.
Example 1: electromagnetic coupling treatment for repairing dendritic micro segregation defect of laser cladding formed nickel-base superalloy
The nickel-based superalloy sample aimed at by the embodiment is that a layer of nickel-based superalloy A is further laser-clad on a nickel-based superalloy A (W11%, co 9%, cr 8%, al5.1%, mo 2.4%, ti 2% and the balance Ni) substrate (the size is 5mm multiplied by 2 mm) by a single-channel multilayer scanning mode by using laser cladding equipment; the total dimensions of the resulting samples were 10mm by 5mm by 2mm. In the laser cladding forming process, the nickel-based superalloy is easy to generate microscopic segregation in a heat affected zone to form a low-melting-point Laves phase, and the Laves phase is an important cause of liquefaction cracks generated in the laser cladding forming of the nickel-based superalloy.
The micro defect repairing method provided by the embodiment comprises the following steps:
s1, determining the microscopic defect type of the metal material to be processed.
The type of defect in the nickel-base superalloy sample has been previously indicated as dendrite microsegregation.
S2, placing the metal material to be treated in an electric field and magnetic field application environment for electromagnetic coupling treatment.
The sample is clamped by a clamp and is connected to two ends of an electrode generating pulse current, and the sample is positioned at the center of a pulse magnetic field.
S3, determining electromagnetic coupling processing parameters according to the microscopic defect types, and performing electromagnetic coupling processing on the metal material to be processed according to the determined electromagnetic coupling processing parameters.
In the embodiment, the microscopic defect type is dendrite microscopic segregation, firstly, 15 groups of positive magnetic pulses are applied to a metal material, the magnetic field strength of the positive magnetic pulses is 1.5T, the action time of a single magnetic pulse is 1s, the processing interval of each group of magnetic pulses is 5s, and the processing time of the magnetic pulses is 90s; then 500 groups of positive electric pulses are applied to the metal material at intervals of 5 seconds, wherein one group of positive electric pulses comprises 10 positive electric pulses, and the electric field current density of the positive electric pulses is 5 multiplied by 10 7 A/m 2 The frequency was 50Hz, the duty cycle was 25%, and the electrical treatment time was 100.5s for each 1ms interval of one set of electrical pulse treatments.
After the treatment is finished, the repair of the dendritic micro segregation defect of the nickel-based superalloy formed by laser cladding can be completed. The result shows that the tensile strength of the repaired nickel-base superalloy is improved by 16.25%, the fatigue limit is improved by 12.93%, and the cracking tendency of the subsequent heat treatment is obviously reduced. The electromagnetic coupling treatment has selective action and energy focusing effect on the defect part, and electromagnetic force acts on Laves phases among dendrites, so that the size and the number of the Laves phases can be reduced, the element distribution is more uniform, the mechanical property of the metal material is improved, and the cracking tendency is reduced.
Example 2: electromagnetic coupling treatment for repairing micropore defect at joint of laser cladding forming nickel-based superalloy
The nickel-base superalloy sample aimed at in this example is a layer of nickel-base superalloy a (W11%, co 9%, cr 8%, al5.1%, mo 2.4%, ti 2%, and the balance Ni) further laser-clad on nickel-base superalloy B (Co 12.5%, cr 7%, al 6.5%, ta 6.5%, W4.8%, re 2.5%, the balance Ni, and the dimensions 5mm×5mm×2 mm) by a single-pass multilayer scanning method using a laser cladding apparatus; the total dimensions of the resulting samples were 10mm by 5mm by 2mm. Because the nickel-based superalloy A, B has higher Al and Ti contents, belongs to a difficult-to-weld material, tiny holes are easy to appear in the laser cladding forming process, and thus the service performance is not ideal.
The micro defect repairing method provided by the embodiment comprises the following steps:
s1, determining the microscopic defect type of the metal material to be processed.
The type of defect in the nickel-base superalloy sample has been previously indicated as tiny holes, approximately 0.5 μm in size.
S2, placing the metal material to be treated in an electric field and magnetic field application environment for electromagnetic coupling treatment.
The sample is clamped by a clamp and is connected to two ends of an electrode generating pulse current, and the sample is positioned at the center of a pulse magnetic field.
S3, determining electromagnetic coupling processing parameters according to the microscopic defect types, and performing electromagnetic coupling processing on the metal material to be processed according to the determined electromagnetic coupling processing parameters.
In the embodiment, the microscopic defect type is a micro hole, firstly, 15 groups of negative magnetic pulses are applied to a metal material, the magnetic field strength of the negative magnetic pulses is 2T, the action time of a single magnetic pulse is 1s, the interval of processing of one group of magnetic pulses is 5s, and the processing time of the magnetic pulses is 90s; then at intervals of 5s, 200 groups of negative electric pulses are applied to the metal material, wherein one group of positive electric pulses comprises 20 negative electric pulses, and the current density of the negative electric pulses is 1 multiplied by 10 8 A/m 2 The frequency was 50Hz, the duty cycle was 25%, and the electrical treatment time was 80.2s for each 1ms interval of one set of electrical pulse treatments.
Carrying out appearance inspection and internal flaw detection on the treated metal sample, wherein the sample has no hole defect and the part has no obvious deformation; crack expansion does not occur in the subsequent service process, and the service life is prolonged by 12.53 percent compared with untreated service life.
Example 3: electromagnetic coupling treatment for repairing microcrack defect caused by overlarge microscopic residual stress of laser cladding forming nickel-base superalloy
The nickel-based superalloy sample aimed at by the embodiment is to further laser cladding a layer of nickel-based superalloy B on a nickel-based superalloy B (12.5% Co, 7% Cr, 6.5% Al, 6.5% Ta, 4.8% W, 2.5% Re and the balance Ni) substrate (5 mm×5mm×2mm in size) by using a laser cladding device through a single-pass multilayer scanning mode; the total dimensions of the resulting samples were 10mm by 5mm by 2mm. In the process of forming the nickel-based superalloy by laser cladding, the plasticity and strength of the grain boundary in a heat affected zone are drastically reduced due to the large temperature gradient, the thermal strain is concentrated on the grain boundary, and the stress is released in the subsequent heat treatment process, so that microcracks are generated. The alloy heat affected zone was examined to be formed with microcracks 10 μm long by 0.5 μm wide by 5 μm deep.
The micro defect repairing method provided by the embodiment comprises the following steps:
s1, determining the microscopic defect type of the metal material to be processed.
The type of defect in the nickel-base superalloy sample has been previously indicated as microcrack.
S2, placing the metal material to be treated in an electric field and magnetic field application environment for electromagnetic coupling treatment.
The sample is clamped by a clamp and is connected to two ends of an electrode generating pulse current, and the sample is positioned at the center of a pulse magnetic field.
S3, determining electromagnetic coupling processing parameters according to the microscopic defect types, and performing electromagnetic coupling processing on the metal material to be processed according to the determined electromagnetic coupling processing parameters.
In the embodiment, the microscopic defect type is microcrack, 20 groups of positive and negative magnetic pulses are firstly applied to a metal material, the magnetic field strength of the positive magnetic pulses and the negative magnetic pulses is 2.5T, the action time of a single magnetic pulse is 0.5s, the treatment interval of each group of magnetic pulses is 9s, and the treatment time is 200s; then, 1000 groups of positive and negative electric pulses are applied to the metal material at intervals of 5 seconds, a group of electric pulses is formed by 5 positive and negative electric pulse units, and the current densities of positive and negative electric pulses in the positive and negative electric pulse units are 1 multiplied by 10 8 A/m 2 The frequency of positive pulse and negative pulse in the positive and negative pulse unit is 50Hz, and the electrical treatment time is 201s when a group of electrical pulse treatment is performed for 1 ms.
As shown in fig. 1, the residual stress of the treated metal sample is reduced by 73.84% at the highest along the scanning direction, and the average residual stress is reduced by 57.38%; the residual stress is reduced by 76.85% at maximum and 42.38% at average perpendicular to the scan direction. Carrying out heat treatment on the treated metal sample, and then carrying out appearance inspection and internal flaw detection, wherein the sample has no cracking defect and the part has no obvious deformation; crack growth does not occur in the subsequent service process.
Those of ordinary skill in the art will recognize that the embodiments described herein are for the purpose of aiding the reader in understanding the principles of the present invention and should be understood that the scope of the invention is not limited to such specific statements and embodiments. Those of ordinary skill in the art can make various other specific modifications and combinations from the teachings of the present disclosure without departing from the spirit thereof, and such modifications and combinations remain within the scope of the present disclosure.

Claims (5)

1. The internal microscopic defect repairing method suitable for the laser cladding forming metal material is characterized by comprising the following steps of:
s1, determining the type of microscopic defects of a metal material to be processed; the microscopic defect types comprise dendrite microsegregation, microcracks and tiny holes;
s2, placing the metal material to be treated in an electric field and magnetic field application environment for electromagnetic coupling treatment;
s3, determining electromagnetic coupling processing parameters according to the microscopic defect types, and performing electromagnetic coupling processing on the metal material to be processed according to the determined electromagnetic coupling processing parameters:
(1) When the microscopic defect type is dendrite microscopic segregation, firstly, 10-20 groups of positive magnetic pulses are applied to the metal material, and the magnetic treatment time is 50-100 s; then the interval is 5-10 s, 400-500 groups of positive electric pulses are applied to the metal material, and the electric treatment time is 80-100 s;
(2) When the microscopic defect type is a tiny hole, firstly, 10-20 groups of negative magnetic pulses are applied to the metal material, and the magnetic treatment time is 50-100 s; then the interval is 5-10 s, 400-500 groups of negative electric pulses are applied to the metal material, and the electric treatment time is 80-100 s;
(3) When the microscopic defect type is microcrack, firstly, applying 20-40 groups of positive and negative magnetic pulses to the metal material, wherein the magnetic treatment time is 100-200 s; then the interval is 5-10 s, 800-1000 groups of positive and negative electric pulses are applied to the metal material, and the electric treatment time is 160-250 s;
2. the method for repairing internal microscopic defects of a metal material according to claim 1, wherein in step S1, the metal material to be treated is mainly nickel-based superalloy.
3. The method for repairing internal microscopic defects of a metal material according to claim 1, wherein the microcracks have a length of 10 to 20 μm, a width of 0.1 to 1 μm, and a depth of 5 to 20 μm.
4. The method for repairing internal microscopic defects of a metal material according to claim 1, wherein the size of the micro holes is 0.1-2 μm.
5. The method for repairing internal microscopic defects of a metal material suitable for laser cladding forming according to claim 1, wherein in the step S3, (1), the time interval between two adjacent groups of positive magnetic pulses is 1-10S, the magnetic field strength of the positive magnetic pulses is 1.0-2.5T, and the action time of a single magnetic pulse is 0.1-1S; the positive pulse group contains 5-20 positive pulses, and the current density of the positive pulse is 5 multiplied by 10 7 ～1×10 8 A/m 2 The frequency is 50-100 Hz, the duty ratio is 10-50%, and the time interval between two adjacent groups of positive electric pulses is 1-10 ms; (2) The time interval between two adjacent groups of negative magnetic pulses is 1-10 s, the magnetic field intensity of the negative magnetic pulses is 1.0-2.5T, and the action time of a single magnetic pulse is 0.1-1 s; the negative electric pulse group contains 5-20 negative electric pulses with current density of 5 x 10 7 ～1×10 8 A/m 2 The frequency is 50-100 Hz, the duty ratio is 10-50%, and the time interval between two adjacent groups of negative electric pulses is 1-10 ms; (3) Wherein the positive magnetic pulse and the negative magnetic pulse form a group of positive and negative magnetic pulses, the interval between two adjacent groups of positive and negative magnetic pulses is 1-10 s, the magnetic field intensity of the positive magnetic pulse and the negative magnetic pulse is 1.0-2.5T, and the action time of a single magnetic pulse is 0.1-1 s; the electric pulse group is composed of 5-10 positive and negative electric pulse units, the positive and negative electric pulse units are positiveThe current density of the electric pulse and the negative electric pulse is 5×10 7 ～1×10 8 A/m 2 The frequencies of positive pulses and negative pulses in the positive and negative pulse units are 50-100 Hz, and the interval between two adjacent positive and negative electric pulses is 1-10 ms.
CN202310614237.8A 2023-05-29 2023-05-29 Internal microscopic defect repairing method suitable for laser cladding forming metal material Pending CN116638100A (en)

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