CN113182534A

CN113182534A - Powder feeding device and laser cladding additive manufacturing system and method with powder feeding device

Info

Publication number: CN113182534A
Application number: CN202110604647.5A
Authority: CN
Inventors: 蒋士春; 唱丽丽; 吴从皓; 周文超; 张巍; 邢飞
Original assignee: Nanjing Zhongke Raycham Laser Technology Co Ltd
Current assignee: Nanjing Zhongke Raycham Laser Technology Co Ltd
Priority date: 2021-05-31
Filing date: 2021-05-31
Publication date: 2021-07-30
Anticipated expiration: 2041-05-31
Also published as: CN113182534B

Abstract

The invention provides a powder feeding device and a laser cladding additive manufacturing system and method with the same, wherein the powder feeding device comprises: at least one powder feeder having a powder feeding barrel; the powder distributor combination is connected with the powder feeder; the first lateral powder feeding assembly and the second lateral powder feeding assembly are arranged in axial symmetry about the central axis of the laser cladding machining head; a plurality of independent powder pipes are respectively arranged in the first lateral powder feeding assembly and the second lateral powder feeding assembly; the inlet end of the powder pipe is communicated to the powder distributor combination, and the outlet end of the powder pipe faces to the laser spot position; powder stored in the powder feeding barrel is conveyed to one or more powder pipes of the first lateral powder feeding assembly and conveyed to one or more powder pipes of the second lateral powder feeding assembly, so that the synchronous powder feeding of multiple adjustable broadband pipes is realized, efficient broadband 3D printing, synchronous subarea paraxial powder feeding 3D printing under the same light spot and synchronous subarea paraxial powder feeding 3D printing of three materials difficult to mix are facilitated, and the cladding efficiency and quality are improved.

Description

Powder feeding device and laser cladding additive manufacturing system and method with powder feeding device

Technical Field

The invention relates to the technical field of laser additive manufacturing, in particular to a powder feeding device, a laser cladding additive manufacturing system with the powder feeding device and a laser cladding additive manufacturing method with the powder feeding device.

Background

The laser cladding additive manufacturing is characterized in that a cladding material is added on the surface of a base material and is fused with a thin layer on the surface of the base material by utilizing a laser beam with high energy density, and a cladding layer which is metallurgically bonded with the base layer is formed on the surface of the base layer. By applying the laser cladding additive manufacturing technology, a high-performance surface coating, such as a high-strength and wear-resistant coating, can be manufactured on a base material, the wear-resistant, corrosion-resistant, heat-resistant and oxidation-resistant properties of the surface of the base material are obviously improved, and the purpose of surface modification or repair is achieved.

In the industrial application process, the outstanding problems restricting the large-scale popularization of laser cladding additive manufacturing are cladding efficiency and cladding layer quality. The lower production efficiency cannot meet the planned capacity of the production line products.

In order to improve the cladding efficiency, the broadband laser cladding technology is provided in the prior art, so that the broadband laser cladding technology has obvious advantages. However, in industrial application, the appearance of the cladding layer is difficult to control effectively, the aspect ratio of the formed appearance of the section of the coating is large, the problems that the middle is high and the two sides are low and the height difference between the middle and the two ends is large easily occur, and the subsequent problems caused by the formed appearance are large machining allowance and serious waste of powder materials.

In the prior art, the machining allowance is reduced by improving the lapping amount, but the cladding efficiency per unit time is reduced, and meanwhile, due to the increase of the lapping amount, the reduced tissue performance of the coating in the lapping area causes the generation of surface unevenness, internal tissue cracks and air holes, so that the forming quality and performance of the cladding layer are influenced.

Disclosure of Invention

The invention aims to solve the problems of large adding amount, low efficiency and more defects of a follow-up machine caused by non-ideal profile of the cross section of a broadband laser cladding coating in the prior art, and provides a powder feeding device, a laser cladding additive manufacturing system and a laser cladding additive manufacturing method, which can realize the adjustment of different powder feeding widths, realize the controllable appearance of a coating interface by matching with a variable-spot laser beam, and improve the preparation efficiency and quality of the coating.

The first aspect of the present invention provides a powder feeding device for laser cladding additive manufacturing, including:

at least one powder feeder having a powder feed barrel;

the powder distributor combination is connected with the at least one powder feeder;

the first lateral powder feeding assembly and the second lateral powder feeding assembly are positioned on two sides of the laser cladding processing head and are arranged in an axisymmetric manner about the central axis of the laser cladding processing head; a plurality of independently distributed powder pipes are respectively arranged in the first lateral powder feeding assembly and the second lateral powder feeding assembly; the inlet end of the powder pipe is communicated to the powder distributor assembly, and the outlet end of the powder pipe faces to a laser spot position formed by the laser cladding processing head;

the powder conveying barrel is used for storing powder, and the powder conveying barrel is arranged to convey the powder to the powder distributor combination through the powder distributor combination, one or more powder pipes of the first lateral powder conveying assembly and one or more powder pipes of the second lateral powder conveying assembly.

Preferably, the powder pipes of the first lateral powder feeding assembly and the powder pipes of the second lateral powder feeding assembly are arranged in a one-to-one correspondence manner in terms of quantity and position distribution.

Preferably, the first lateral powder feeding assembly and the second lateral powder feeding assembly adopt the same structural design.

Preferably, the first lateral powder feeding assembly comprises a first flat shell and a plurality of powder tubes which are arranged in the first shell and distributed in an array mode, and the distance between every two adjacent powder tubes is equal.

Preferably, the first lateral powder feeding assembly comprises a second flat shell and a water cooling pipeline arranged in the second shell, and the water cooling pipeline is provided with a cooling medium inlet and a cooling medium outlet; the second housing is mounted on the first housing and the second housing is closer to the laser cladding process head than the first housing.

Preferably, the cross-sectional area of the second housing is larger than the cross-sectional area of the first housing.

Preferably, the powder tube of the first lateral powder feeding assembly is a copper tube in which a quartz glass tube is nested.

Preferably, the powder distributor combination comprises at least one powder distributor which is connected with the first lateral powder feeding assembly in a matching way, and at least one powder distributor which is connected with the second lateral powder feeding assembly in a matching way.

A second aspect of the invention provides a laser cladding additive manufacturing system, comprising:

the laser cladding machining head is arranged for forming laser spots on the surface of a workpiece;

a laser spot controller configured to adjust the laser spot;

the powder feeding device is used for feeding powder to the position of the laser spot; and

a powder feed controller configured to control powder feed.

Preferably, the laser spot controller is configured to control the width and/or length of the laser spot, and the size of the powder spot formed by powder feeding is smaller than the size of the spot.

Preferably, the powder pipes of the first lateral powder feeding assembly and the powder pipes of the second lateral powder feeding assembly are arranged to synchronously feed powder to the laser spot positions in a one-to-one symmetrical mode.

Preferably, the powder tube of the first lateral powder feeding assembly is arranged to synchronously feed the powder to the laser spot position in a relative staggered manner with the powder tube of the second lateral powder feeding assembly.

Preferably, the first lateral powder feeding assembly and the second lateral powder feeding assembly are arranged to feed powder through a plurality of powder feeding barrels of the same powder feeder.

Preferably, the first lateral powder feeding assembly and the second lateral powder feeding assembly are arranged to feed powder through powder feeding barrels of different powder feeders.

Preferably, the powder feeding controller is configured to control a powder feeding speed of the powder feeder to control a powder feeding amount in each powder tube.

The invention also provides a laser cladding additive manufacturing method, which comprises the following steps:

firstly, determining the size of a coating preparation area, the width of a printing track and the preparation width of a single-channel coating according to the size of a cladding layer on the surface of a workpiece to be printed, and planning a printing path; setting a powder feeding path according to the planned printing path, designing the powder feeding width, the number of the powder tubes and the spacing distance of the powder tubes, and determining the size of the powder spot; selecting powder tubes with proper inner diameter according to the set powder feeding path, determining the number of the powder tubes to be fed, connecting the powder tubes through different types of powder dividers, and determining a powder feeding control signal S according to the set powder feeding path_i(i＝1，2……N)；

Secondly, determining the size of a light spot matched with the size of the powder spot, and setting the size of the light spot to be larger than the size of the powder spot;

finally, setting cladding parameters, compiling a printing program, and starting a corresponding powder feeding control signal S according to the planned powder spot size_iI is 1, 2 … … N, and corresponds to the spot control signal K for starting the required spot size_jJ is 1, 2 … … N; and i is not equal to j, obtaining the light spot with the required size, and carrying out cladding printing.

Preferably, the spot size is greater than 1mm of the patch size.

The invention also provides an application of the powder feeding device in the synchronous subarea powder feeding laser cladding of the same spot dissimilar material, which is used for the laser cladding processing of two different materials, wherein the powder pipe of the first lateral powder feeding component is arranged to synchronously feed powder to the laser spot position in a one-to-one symmetrical mode with the powder pipe of the second lateral powder feeding component;

and at least one pair of powder pipes which send powder to the same position respectively send different powders, and the two powders realize melting metallurgical reaction in the powder convergence point area to form a metallurgical bonding area.

The invention also provides an application of the synchronous powder feeding and printing of the three kinds of powder with larger difference in physical properties, which is used for laser cladding processing of the three kinds of powder with larger difference in physical properties, wherein the powder pipe of the first lateral powder feeding assembly is arranged to synchronously feed powder to the laser spot position in a relative staggered manner with the powder pipe of the second lateral powder feeding assembly;

the three powder pipes form a group to carry out powder feeding, three different kinds of powder are respectively conveyed, and the three kinds of powder realize melting metallurgical reaction in a powder gathering point area to form a metallurgical bonding area; the three powder tubes meet the following distribution: the first powder tube and the second powder tube are positioned in the first lateral powder feeding assembly, the third powder tube is positioned in the second lateral powder feeding assembly, and in the opposite position, the third powder tube is positioned between the first powder tube and the second powder tube, namely, the staggered position is not arranged corresponding to the position of one of the first powder tube and the second powder tube.

In some embodiments of the invention, the position and size of the powder spot can be adjusted by flexibly adjusting the combination mode of the powder tube according to the laser cladding layer requirements and the cladding process of different products, and the cladding processing of narrow-band, wide-band and interval powder feeding can be realized by matching with the size of the powder spot.

In some embodiments of the invention, the position and size of the powder spot can be adjusted by adjusting the combination mode of the powder pipe according to the laser cladding layer requirements and the cladding process of different products, the different materials under the same light spot can be synchronously fed and printed in a subarea mode by matching with the light spot size, different powder materials can be formed at different positions on the section of the same printing layer, namely, two or more than two powder materials (metal powder materials) can be simultaneously printed by one laser cladding processing head in different areas with a single-channel width without being respectively printed, so that the printing efficiency can be improved by the implementation, and a better coating forming profile can be obtained.

In some embodiments of the invention, aiming at the problems of conveying and printing of different powders and powder conveying and printing of mixed powders which have large physical property difference and are difficult to mix in advance, the invention provides a method for realizing the adjustment of the position and the size of a powder spot by oppositely adjusting the combination mode of powder tubes, is applied to the mixed powder printing with large physical property difference by matching with the size of the light spot, and is used for independently conveying the powders with different physical properties in the opposite powder tubes according to a proportion and finally mixing the powders in a laser molten pool, thereby avoiding the problem of powder layering in the conveying process in a premixing mode.

It should be understood that all combinations of the foregoing concepts and additional concepts described in greater detail below can be considered as part of the inventive subject matter of this disclosure unless such concepts are mutually inconsistent. In addition, all combinations of claimed subject matter are considered a part of the presently disclosed subject matter.

The foregoing and other aspects, embodiments and features of the present teachings can be more fully understood from the following description taken in conjunction with the accompanying drawings. Additional aspects of the present invention, such as features and/or advantages of exemplary embodiments, will be apparent from the description which follows, or may be learned by practice of specific embodiments in accordance with the teachings of the present invention.

Drawings

The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. Embodiments of various aspects of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

fig. 1 is a schematic view of a laser cladding additive manufacturing system of an exemplary embodiment of the present invention.

Fig. 2A is a schematic side powder feeding device and a schematic side powder feeding diagram according to an exemplary embodiment of the present invention.

Fig. 2B is a schematic view of a first lateral powder feed assembly of a lateral powder feed apparatus according to an exemplary embodiment of the invention.

FIG. 3 is a schematic view of the same powder feeder of an exemplary embodiment of the present invention feeding powder to 2 lateral powder feeding assemblies.

Fig. 4 and 5 are schematic diagrams of powder feeding to 2 lateral powder feeding assemblies by different powder feeders of exemplary embodiments of the present invention, and fig. 4 and 5 show examples of powder distribution and conveyance by combinations of different powder distributors.

Fig. 6A is a schematic illustration of the adjustment of the patch size and spot size in accordance with an exemplary embodiment of the present invention.

Fig. 6B is a schematic diagram of the positional relationship of the respective powder streams on the surface of the workpiece according to the exemplary embodiment of the present invention.

Fig. 7A is a schematic diagram of adjustment of the spot size and the spot size for the different-material subarea synchronous powder feeding printing under the same spot condition, that is, a different-area different-material printing powder control manner, according to an exemplary embodiment of the present invention, wherein an area enclosed by a dashed box E, L represents a metallurgical mixing area of two different materials.

FIG. 7B is an example of the result of the different material divisional simultaneous powder feeding printing for the same spot condition according to FIG. 7A, in which different powders T are printed₁+T₂Schematic of the composite layer is printed.

Fig. 8A is a schematic diagram of adjustment of the patch size and the spot size of the simultaneous powder feeding printing of three powders having large differences in physical properties according to the exemplary embodiment of the present invention, in which the dashed box area surrounded by A, B, H is a three-powder mixing area.

FIG. 8B is a schematic diagram showing the positional relationship of three adjacent powder beams in the molten pool during the synchronous powder feeding printing process for the three powders with larger physical property differences according to the schematic diagram shown in FIG. 8A.

FIGS. 9A and 9B are schematic diagrams comparing the cross section of a conventional broad band powder feeding coating with the cross section of a coating prepared by the present invention, respectively.

FIG. 10 is a schematic comparison of the corrosion resistance of the coating prepared by the present invention and the coating prepared by the conventional broad band cladding.

Detailed Description

In order to better understand the technical content of the present invention, specific embodiments are described below with reference to the accompanying drawings.

In this disclosure, aspects of the present invention are described with reference to the accompanying drawings, in which a number of illustrative embodiments are shown. Embodiments of the present disclosure are not necessarily intended to include all aspects of the invention. It should be appreciated that the various concepts and embodiments described above, as well as those described in greater detail below, may be implemented in any of numerous ways, as the disclosed concepts and embodiments are not limited to any one implementation. In addition, some aspects of the present disclosure may be used alone, or in any suitable combination with other aspects of the present disclosure.

Laser cladding additive manufacturing system

The laser cladding additive manufacturing system of the exemplary embodiment shown in fig. 1-5 includes a powder feeder 100, a powder splitter assembly 200, a laser cladding processing head 300, a paraxial powder feeding assembly, and a powder feeding controller 10 and a laser spot controller 30. The powder distributor assembly 200 is connected to the powder feeder 100.

The laser spot controller 30 is configured to control the laser cladding process head 300 to form a laser spot on a workpiece process surface, and is capable of controlling and adjusting a width and/or a length of the spot.

In some embodiments, the laser cladding process head 300 preferably employs an OTZ variable spot lens, with motorized adjustment of the homogenizer mirror unit to control the width and/or length of the laser spot that is impinged on the workpiece surface.

And a powder feeding controller 10 for controlling the powder feeder 100 to perform the powder feeding operation.

The powder feeder 100 may be a conventional multi-barrel powder feeder having a plurality of powder feeding barrels 101, such as a carrier gas type multi-barrel powder feeder, and particularly, a stirrer may be provided in each powder feeding barrel to achieve continuous and stable feeding of powder having poor flowability. The powder feeding barrels of one powder feeder 100 can be loaded with the same kind and/or type of powder, or different kinds and/or types of powder are loaded in the powder feeding barrels, that is, each powder feeding barrel is loaded with one kind and/or type of powder, and the powder is especially metal powder or alloy powder and other powder materials for additive manufacturing.

The powder distributor assembly 200 is provided with a powder distributor, such as a one-to-two powder distributor, a one-to-three powder distributor, a one-to-four powder distributor, etc., connected to a powder feeding barrel of the powder feeder.

The bypass powder feeding assembly comprises a first lateral powder feeding assembly 401 and a second lateral powder feeding assembly 402. The first and second lateral

powder feeding assemblies

401 and 402 are respectively located at both sides of the laser cladding processing head, are axisymmetric with respect to a central axis of the laser cladding processing head 300, and are installed at an angle to the laser cladding processing head 300.

Referring to fig. 3, 4 and 5, the powder distributor assembly 200 includes at least one powder distributor connected with the first lateral powder feeding assembly 401 in a matching manner, and at least one powder distributor connected with the second lateral powder feeding assembly 402 in a matching manner.

In some embodiments, the angle between the first and second lateral

powder feed assemblies

401, 402 and the laser cladding processing head 300 may be adjustable, for example, the first and second lateral

powder feed assemblies

401, 402 may be mounted to both sides of the laser cladding processing head 300 by a robotic arm that is adjusted to adjust the angle.

In other embodiments, the first and second lateral

powder feed assemblies

401 and 402 and the laser cladding process head 300 may share a common mounting base platform, such as the bed or lift platform of a machine tool, by adjusting the mounting positions and angles of the first and second lateral

powder feed assemblies

401 and 402, whether they are fixedly or movably mounted.

As shown in fig. 1 and fig. 2A and 2B, a plurality of independently distributed powder tubes are respectively disposed in the first lateral powder feeding assembly 401 and the second lateral powder feeding assembly 402, and for convenience of description, a sleeve disposed in the first lateral powder feeding assembly 401 is denoted by 401B, and a sleeve disposed in the second lateral powder feeding assembly 402 is denoted by 402B. The inlet end of the powder pipe is communicated to the powder distributor assembly 200, and the outlet end faces to the position of the light spot formed by the laser cladding processing head 300.

In the exemplary structure of fig. 2A and 2B, the first lateral powder feeding assembly 401 and the second lateral powder feeding assembly 402 each take 7 powder feeding pipes as an example, and a mode of controlling powder feeding is explained with 7 powder feeding pipes in the following embodiments of the present invention. Under the teachings of the present invention, the number of powder feeding powder tubes in the first lateral powder feeding assembly 401 and the second lateral powder feeding assembly 402 is not limited to 7, and more or less powder tubes may be designed, for example, each side includes 3 to 6 powder tubes or more than 7 powder tubes.

In an alternative embodiment, the sleeve 401b disposed in the first lateral powder feeding assembly 401 and the sleeve 402b disposed in the second lateral powder feeding assembly 402 may be of the same design, such as a copper tube structure with a quartz glass tube nested inside. The quartz glass tube can be designed with different inner diameters, for example, the inner diameter is 0.8mm, 1.0mm, 1.5mm, 1.7mm, 2.0mm and other specifications, and the inner diameter size is selected according to different process modes.

As shown in fig. 1, 2A and 2B, the powder stored in the powder feeding barrel of the powder feeder 100 is controllably conveyed to the powder distributor assembly 200 by the carrier gas, and conveyed to the one or more powder tubes 401B of the first lateral powder feeding assembly 401 and the one or more powder tubes 402B of the second lateral powder feeding assembly 402 via the powder distributor assembly 200, and the powder tubes on both sides respectively feed the powder to the light spot position, so that symmetrical broadband-adjustable paraxial powder feeding is realized.

Therefore, the symmetrical broadband adjustable multi-tube powder feeding can be realized, the position and the size of the powder spot can be adjusted by adjusting the combination mode of the powder tube for feeding powder according to the requirement of the printed cladding layer and the cladding process during laser cladding printing and processing, the cladding processing of broadband powder feeding, narrow-band powder feeding and interval powder feeding is realized, the overlapping amount and the overlapping times are reduced, the secondary heating area is reduced, and the processing efficiency and the quality of the cladding layer are improved.

Preferably, the powder tubes 401b of the first lateral powder feeding assembly 401 and the powder tubes 402b of the second lateral powder feeding assembly 402 are arranged in one-to-one correspondence and are arranged to feed powder to the spot position in a symmetrical powder feeding manner.

In the preferred embodiment, the first lateral powder feeding assembly 401 and the second lateral powder feeding assembly 402 are of the same structural design. In the following embodiments, the first lateral powder feeding assembly 401 is used to explain the structure and function thereof.

As shown in fig. 2A and 2B, the first lateral powder feeding assembly 401 includes a first housing 401a having a flat shape and a plurality of powder tubes 401B mounted in the first housing and distributed in an array. Preferably, the distance between the adjacent powder tubes 401b is equal, so that the position and the size of the powder spot can be uniformly controlled when the powder is fed by the symmetrical broadband adjustable multi-tube powder feeding device.

As shown in fig. 2B, the first lateral powder feeding assembly 401 further includes a second housing 401c having a flat shape, and a water cooling pipeline (not shown) provided in the second housing, the water cooling pipeline having a cooling medium inlet 401c-1 and a cooling medium outlet 401c-2, and the cooling medium forms a heat dissipation circulation in the water cooling pipeline.

The second housing 401c is mounted on the first housing 401a, and the second housing 401c is closer to the laser cladding processing head 300 than the first housing, whereby the flat second housing 401c and the water cooling pipe provided in the second housing constitute a water-cooled reflective baffle to protect the outlet end of the powder feeding barrel from the laser. The first case 401a and the second case 401c are preferably both metal cases. The first housing 401a and the second housing 401c may be fixed in an integrated design.

Preferably, in a direction toward the laser cladding processing head, the sectional area of the second housing 401c is larger than that of the first housing 401a, so as to better dissipate heat and isolate laser, thereby achieving effective protection.

Preferably, the mounting plane of the second housing 401c of the first housing 401a is parallel to the surfaces of the first housing 401a and the second housing 401 c.

In an alternative embodiment, the first housing 401a is designed as a rectangular parallelepiped or a cube structure having a flat shape. The second housing 402a has an upper bottom surface 402a-1 and a lower bottom surface 402a-2 parallel to the upper bottom surface, and the cross-sectional area of the upper bottom surface 402a-1 is larger than that of the lower bottom surface 402 a-2. The lower bottom surface 402a-2 constitutes a mounting surface with the first housing 401a, and the cross-sectional area of the lower bottom surface 402a-2 is larger than that of the mounting surface of the first housing 401 a.

Preferably, a sloped connection is formed between the lower bottom surface 402a-2 and the upper bottom surface 402a-1 on the side adjacent to the work piece being machined. And the outlet end of the powder tube 401b has a height lower than the edge of the lower bottom surface 402 a-2.

Broadband adjustable multi-tube synchronous powder feeding control

With reference to fig. 1, 2A and 2B, the powder feeder 100, the powder distributor assembly 200, and the first lateral powder feeding assembly 401 and the second lateral powder feeding assembly 402 distributed on two sides of the laser cladding processing head form a broadband adjustable multi-tube synchronous powder feeding device, so as to achieve symmetrical broadband adjustable paraxial synchronous powder feeding, adjust powder spots according to the cladding layer requirements and the cladding process of different workpiece surfaces, such as the thickness and width of the cladding layer, and adjust laser spots in a manner of adapting to the powder spots, thereby achieving broadband/narrow-band/interval powder feeding and synchronous printing of the same material under the same spot condition.

Preferably, the laser spot controller 30 is configured to control the best match of the spot size to the powder spot size, with the powder spot size being smaller than the spot size.

In fig. 2A, reference numeral 1 denotes a workpiece, in particular a roll-shaped workpiece, which is driven in a revolving motion along its central axis o during laser cladding processing. The laser cladding additive manufacturing system provided by the embodiment of the invention can be used for preparing functional coatings on the surface of the material, such as coatings with the functions of wear resistance, temperature resistance, corrosion resistance, low friction and the like.

Reference numeral 301 denotes a laser beam, and forms a spot a on the surface of the workpiece.

Fig. 3 is a schematic diagram illustrating two-sided powder feeding, wherein a powder feeder is used for feeding powder to two lateral side powder feeding assemblies on two sides. The powder feeder 100 takes three powder feeding barrels as an example, which are respectively 101a, 101b and 101c, and the powder distributor assembly 200 includes a five-in-one powder distributor matched with the first lateral powder feeding assembly 401 and the second lateral powder feeding assembly 402, wherein the first powder feeding barrel 101a of the powder feeder is connected to the five-in-one powder distributor, and outlets of the five-in-one powder distributor are respectively connected to five powder feeding pipes 401b of the first lateral powder feeding assembly 401, so as to realize powder conveying. The second powder feeding barrel 101b of the powder feeder is connected to another one-to-five powder distributor, and the outlets of the other one-to-five powder distributor are respectively connected to five powder feeding pipes 402b of the second lateral powder feeding assembly 402, so that powder conveying is realized.

During specific powder feeding control, the powder feeding amount and speed are controlled by the powder feeding controller 10, so that five-path symmetrical synchronous adjustable side powder feeding is realized.

In the example of fig. 3, a fifth embodiment is taken as an example, and synchronous powder feeding of the first powder feeding barrel 101a and the second powder feeding barrel 101b by one powder feeding control signal is realized, so that the composition of powder spots formed by powder conveyed by five oppositely arranged powder pipes is realized to form a wide-band powder spot, and after laser cladding, a cladding layer with a nearly rectangular cross section can be formed, and the quality of the cladding layer is improved.

In another embodiment, in the embodiment that one powder feeder is used for feeding powder to two lateral side powder feeding assemblies on two sides, the powder feeder can be provided with other forms and a plurality of powder feeding barrels, and the powder feeder can be matched with a cladding layer requirement and a light spot size and width determined by a cladding process to select a powder distributor to realize the processing of wide-band powder spot, narrow-band powder spot or interval powder feeding.

In some embodiments, the first lateral powder feeding assembly 401 and the second lateral powder feeding assembly 402 are configured to feed powder through a plurality of powder feeding barrels of the same powder feeder, and particularly, the powder conveyed by the powder pipe of the first lateral powder feeding assembly 401 and the powder pipe 402 of the second lateral powder feeding assembly are the same powder.

In the example shown in fig. 3, five powder pipes are used for the first lateral powder feeding assembly and the second lateral powder feeding assembly, and more or fewer powder pipes may be used for powder feeding.

In the examples shown in fig. 4 and 5, the first lateral powder feeding assembly 401 and the second lateral powder feeding assembly 402 may be configured to feed powder through powder feeding barrels of different powder feeders. In an alternative embodiment, the first lateral powder feeding assembly 401 is configured with at least one powder feeder, and the second lateral powder feeding assembly 402 is configured with at least one powder feeder, and the powder feeding is performed by the respective powder feeders.

Particularly preferably, the powder conveyed by at least one powder pipe of the first lateral powder feeding assembly 401 and the corresponding powder pipe of the second lateral powder feeding assembly 402 is heterogeneous powder.

It should be understood that the foregoing examples of the powder feeder, powder feeder barrel, and powder distributor combination shown in fig. 3, 4, and 5 and their mating relationship with the first lateral powder feeding assembly 401 and the second lateral powder feeding assembly 402 are intended to exemplarily represent the mating relationship thereof. Under the requirements of a cladding layer on the surface of a workpiece to be printed and the requirements of a cladding process, different powder feeders, powder feeding barrels and powder distributor combinations corresponding to different sizes, widths and thicknesses of the cladding layer can be selected to be matched with the first lateral powder feeding assembly 401 and the second lateral powder feeding assembly 402, powder feeding adjustment is achieved, and powder spots with different widths and lengths are obtained.

Speckle and flare modulation

Powder spot conditioning

The powder feeding device and the laser cladding additive manufacturing system provided by the embodiment of the invention realize broadband laser cladding. The combination mode of the powder feeding pipe can be flexibly adjusted according to different requirements of the process. The powder feeding widths obtained by different combination modes are different, and each combination mode is sequentially subjected to a powder feeding control signal S from small to large according to the obtained powder width_iAnd (i-1, 2 … … N) to realize on and off, and the start and stop of each set of control signals are realized according to specific cladding requirements or printing model path planning so as to realize the adjustment of different powder feeding widths. Moreover, the powder feeding amount of each group of connection modes can be independently set, so that different coating thicknesses in different areas can be realized.

Spot adjustment

Setting and feeding control signal S_iThe corresponding light spot control signal is K_j(j ═ 1, 2 … … N) to control spot size variation, K_nAnd S_nThe dimensional relationship in the long side direction is K_nCorresponding dimension is S_nCorresponding dimension +1 mm.

In combination with the embodiment, the laser cladding processing head adopts a laser OTZ variable spot lens, the width and/or the length of a spot irradiated on the surface of a workpiece are controlled by electrically adjusting the homogenizing mirror unit, the geometric parameters of the spot can be changed in the movement process, and the optimal matching of the spot size and the spot size is realized.

In the process of broadband laser cladding and broadband powder feeding 3D printing, the combination mode of powder feeding pipes and the size of a laser spot can be adjusted according to the cladding width requirements of different areas of a product, the size of the powder spot and the size of the light spot are determined, and a powder feeding control signal S and a light spot control signal K are added in a cladding track program and a 3D printing track program through track planning software, namely, the cladding program is written and printed.

Preferably, after the control signals S and K of each step are changed, the movement mechanism and the working laser light emitting instruction are started after uniformly delaying for 3 seconds, so that stable powder feeding after the movement of the laser cladding processing head motor is completed and the powder feeding width is changed is realized.

Thus, as shown in fig. 1, 2A and 2B, when cladding is performed on the surface of a workpiece, firstly, a printing path and a powder feeding plan are determined according to the requirement of a cladding layer on the surface of the workpiece to be printed; planning light spots according to the powder feeding plan; and then programming the powder feeding plan and the light spot plan through trajectory planning software, setting execution of a powder feeding control signal and a light spot control signal, and carrying out cladding processing operation when the programs are executed.

In an exemplary printing process, the method specifically comprises:

finally, setting cladding parameters, compiling a printing program, and starting a corresponding powder feeding control signal S according to the planned powder spot size_iI is 1, 2 … … N, and the required facula ruler is started correspondingly at the same timeInch light spot control signal K_jJ is 1, 2 … … N; and i is not equal to j, obtaining the light spot with the required size, and carrying out cladding printing.

Wherein, in a preferred embodiment, the light spot size is larger than the powder spot size by 1 mm.

FIG. 6A is a schematic diagram illustrating adjustment of the powder spot size and the light spot size according to an exemplary embodiment of the present invention, and FIG. 6B is a schematic diagram illustrating a positional relationship of each powder beam on the surface of the workpiece according to an exemplary embodiment of the present invention, in which the size of the powder convergence point is 3.0mm, and the overlapping amount of each powder beam at the action point is 1mm

A laser LDF 10000W laser and an OTZ variable light spot processing head are adopted for printing test, the laser is provided with a laser water cooler, a carrier gas type powder feeder is adopted for the powder feeder, a plurality of powder distributors are matched, cladding processing is carried out by the cooperation of the movement of a KUKA60-3 type robot, and the programming of a cladding layer printing path adopts Chinese school light-in-light RAY-CAM layered slicing trajectory programming software.

The method comprises the steps of selecting a phi 200m 45 steel pipe and a steel flat plate with the specification of 300mm multiplied by 200mm multiplied by 20mm as test materials, selecting a titanium alloy powder system as powder, wherein the particle size is 25-150 mu m, and carrying out vacuum drying pretreatment for 2h for later use.

Control signal S, as shown in conjunction with FIGS. 6A and 6B_iAnd K_jThe corresponding logical relationship flag table is as follows:

TABLE 1 control signal S for 1mm overlap of powder beam_iAnd K_iCorresponding relation (unit mm)

TABLE 2 control signal S for 1.5mm overlap of powder beam_iAnd K_jCorresponding relation (unit mm)

Numbering	S_iThe signal combination mode corresponds to the size of the powder spot	K_jSignal corresponding spot size
			1	S₁+S₂+S₃+S₄+S₅+S₆＝12	K₄＝13

Wear-resistant and corrosion-resistant coating prepared by broadband laser cladding

In this embodiment, the wear-resistant and corrosion-resistant coating is prepared by adopting the same powder material broadband laser cladding, and the specific process steps are as follows:

(1) clamping a workpiece: clamping a phi 200m 45 steel pipe on a rotary platform, and pretreating the surface of the pipe by using a laser cleaning machine, such as removing oxide skin and oil stain;

(2) selecting and installing a laser cladding machining head: the laser cladding processing head selects an OTZ variable light spot processing head, a signal control line connection of the processing head is installed, and an air knife is protected at a light outlet;

(3) powder feeding connection of a powder pipe: the powder pipes, the powder distributors and the powder feeding barrels of the powder feeders are connected according to the mode of FIG. 6A, and the powder feeding control signals of the combination modes are marked as S₁、S₂、S₃、S₄、S₅、S₆The on-off of different powder feeding barrels of the powder feeder is realized through the on-off of different powder feeding control signals;

the inner diameters of powder pipes of the first lateral powder feeding assembly and the second lateral powder feeding assembly are selected to be 1.7mm, the distance between the lower end part of each powder pipe and a molten pool is 35mm, the size of a powder convergence point at the position of 35mm is actually measured to be 3.0mm, and the lap joint quantity of each powder beam at an action point is 1 mm; dilution ratio of 0.35/3 x 100%, about 11.7%; the powder adopts corrosion-resistant nickel alloy powder in a powder warehouse which is obtained by changing from China Kochen; other cobalt-based alloys, corrosion-resistant nickel alloys and other powders can also be selected, such as a plurality of grades of VDM Metals;

(4) the control signal determines:

performing a 2-spot size spiral cladding track test on the surface of the steel pipe, wherein the test length of each section is 100mm, the test cladding width of the first section is 7mm, and then starting a powder spot control signal S₃And S₄According to the principle that the size of the powder spot is smaller than about 1mm of the size of the light spot, the long edge of the size of the light spot is 8mm, and the control signal is K₁；

The second section carries out cladding test with 15mm cladding width, namely, a powder spot control signal S is started₁、S₂、S₃、S₄、S₅And S₆The long side of the light spot size is 16mm, and the control signal is K₂；

(5) Setting cladding parameters: the first-stage laser cladding power is 4000W, the first-stage laser cladding power is 6500W, the scanning speed is 660mm/min, the powder outlet amount of each powder tube is set at 16g/min, and the rotation number of a powder disc is set on each powder feeding barrel control interface of a powder feeder according to a combination mode;

(6) writing a printing track program through RAY-CAM software, trial running, and performing cladding processing by emitting light after determining no error to prepare the coating.

The traditional laser cladding printing process uses single beam phi 3mm circular facula laser for remanufacturing, and the processing efficiency is generally 0.1-0.2 m²The preparation efficiency of the coating is adjustable based on the sizes of the powder spots and the light spots and can be between 0.1 and 1.6m²The maximum processing efficiency is improved by more than 8-16 times compared with the traditional circular light spot by adjusting within the range of/h, and the problem of low efficiency of traditional remanufacturing and powder feeding printing is greatly improved.

Coating cross-section morphology testing

The cross section of the coating prepared by the process is shown in FIG. 9B, and the comparison of the cross section of the coating prepared by the traditional broadband powder feeding process in FIG. 9A shows that the cross section of the coating prepared by the coating preparation method provided by the invention has obviously changed profile of the cross section compared with the traditional broadband cladding, the height difference between the middle area of the coating and the left side and the right side is reduced, and the coating has the same effective coating thickness h₀Under the condition, the length w of the overlapping region of the coating prepared by traditional broadband powder feeding₁Greater than the length w of the lap zone of the coating prepared according to the invention₀A rectangular trend is presented. Therefore, in the unit length direction, the lapping amount and the lapping times of the powder feeding and cladding treatment are reduced, the secondary heating area is reduced, and the preparation efficiency and the quality of the corresponding coating are improved.

The existing broadband powder feeding structure has the problems that the powder amount in the middle of the powder is large and the powder amount on two sides is small due to the gravity of the powder, and finally the problem that the thick areas in the middle of the coating are thin at two ends is caused, and as shown in a combined view of fig. 9A, the overlapping amount between single channels is increased, and the processing efficiency and the coating quality of the overlapping area are influenced. Aiming at the problem of uneven powder distribution on the powder feeding section, the invention adopts double-side multi-tube adjustable synchronous paraxial powder feeding to realize independent powder feeding control of a plurality of areas, the powder feeding amount of the middle area and the powder feeding amount of the two side areas are the same by independently controlling the powder tubes, the powder feeding amount control of different areas on the broadband powder feeding section is realized, the powder feeding amount of the two sides is equivalent to the powder feeding amount of the middle area, so that the section shapes of the middle and two sides of the coating are equivalent to each other, the problems of large middle powder amount and small powder amount of the two sides in the traditional broadband powder feeding mode are solved, the section shapes of the coating obtained by cladding processing are not the traditional section shapes of the middle, the two sides of the coating are thin, and the section shapes are close to rectangles, therefore, the overlapping amount is reduced, the later-stage processing efficiency is improved, and the cost is also saved.

Referring to fig. 9A and 9B, the end portions of the coating prepared by laser cladding with the powder feeding device of the present invention have different curvatures of the arc surfaces compared to the conventional method. The process implementation link needs to be at the effective coating thickness h₀The overlap is set on this reference line, and the coating prepared in the conventional way is from the coating boundary to h₀Horizontal dimension w of this height value₁Is significantly larger than the coating w prepared by the invention₀The value w is the size of the overlapping area, so that the overlapping area required by cladding processing is reduced, and correspondingly, the number of single-pass cladding required by powder feeding treatment is small under the conditions of the same cladding area and the same single-pass width, so that the coating preparation time is shortAnd accordingly, the efficiency is improved.

Meanwhile, the overlapping area is a secondary remelting area, secondary remelting can cause burning loss of some trace elements of the coating, so that corresponding performance is influenced, meanwhile, secondary remelting also aggravates oxidation of the coating elements to a certain extent, and oxides can be introduced secondarily, so that the corrosion resistance of the coating can be reduced. In the unit length direction, after the powder feeding control adopted by the invention, the lapping amount and the lapping frequency of cladding processing are reduced, a secondary heating area is reduced, and the preparation efficiency and the quality of a corresponding coating are improved.

Corrosion resistance test of coating

Referring to fig. 10, after the surface of the pipe with the same specification is machined by adopting the traditional broadband cladding and the single-layer coating prepared by the method of the invention, the surface neutral salt spray performance test (280h neutral salt spray test) is carried out, the corrosion rust spots of the coating prepared by the method are obviously less than those of the coating prepared by the traditional broadband cladding, wherein the left part is the surface appearance of the corrosion resistance test of the coating prepared by the method of the invention, the right part is the surface appearance of the corrosion resistance test of the coating prepared by the traditional broadband cladding, and the corrosion resistance of the two parts is greatly different, so that the corrosion resistance of the single-layer coating prepared by the method of the invention is obviously better than that of the traditional coating.

In the coating preparation method, carrier gas type powder feeding is adopted, particularly argon is used, compared with the traditional gravity powder feeding, the argon protection effect of a molten pool is increased, the molten metal oxidation phenomenon of the molten pool is reduced, meanwhile, because the width and the cross section appearance of single-channel cladding are adjustable, the number of overlapping areas in a unit area and the overlapping rate between single-channel cladding layers are reduced, because the overlapping areas are secondary remelting areas, secondary remelting can cause burning loss of certain trace elements or functional elements of the coating, the corresponding performance is influenced, meanwhile, the oxidation of the coating elements is also aggravated to a certain degree, oxides can be introduced secondarily, and the corrosion resistance of the coating is reduced. Under the conditions of the same cladding area and the same single-pass width, the overlapping amount of cladding processing by adopting the powder feeding mode is small, the generation of the defects of oxide slag inclusion, non-fusion and the like in the coating is further reduced, the corresponding performance weakening area of the coating is small, and the performance of the coating is improved.

Variable light spot and variable powder spot 3D printing

(1) Clamping a workpiece: clamping a 45 steel flat plate on a working platform, and pretreating the surface of the plate by using a laser cleaning machine, such as removing oxide skin and oil stain;

the inner diameters of powder pipes of the first lateral powder feeding assembly and the second lateral powder feeding assembly are selected to be 1.7mm, the distance between the lower end part of each powder pipe and a molten pool is 35mm, the size of a powder convergence point at the position of 35mm is actually measured to be 3.0mm, and the lap joint quantity of each powder beam at an action point is 1 mm;

(4) the control signal determines: the single-channel wall printing test of three light spot sizes is carried out on the surface of the flat plate, and the test length of each section is 100 mm:

the width of the first wall is 7mm, namely, a powder spot control signal S is started₃And S₄According to the principle that the size of the powder spot is smaller than about 1mm of the size of the light spot, the long edge of the size of the light spot is 8mm, and the control signal is K₁；

The second wall printing width is 11mm, namely, a powder spot control signal S is started₂、S₃、S₄And S₅The long side of the light spot size is 12mm, and the control signal is K₃；

The third wall prints 15mm in width, namely starts the chalk mark control signal S₁、S₂、S₃、S₄、S₅And S₆The long side of the light spot size is 16mm, and the control signal is K₂；

(5) Setting printing parameters: the laser power of three-wall printing is sequentially set to be 4000W, 5000W and 6500W, the scanning speed is 600mm/min, the powder outlet amount of each powder pipe is set to be 16g/min, and the rotation number of a powder disc is set on each powder feeding barrel control interface of a powder feeder according to a combination mode;

(6) writing a printing track program through RAY-CAM software, adding control signals S and K into the printing track program, performing trial operation, and performing light printing after determining no error.

Dissimilar material partition synchronous powder feeding printing under same light spot condition

In this embodiment, the powder feeding device and the laser cladding system of the foregoing embodiments are used to perform partition-synchronous powder feeding and printing on different materials under the same light spot condition. The powder feeding device adopts a bilateral powder feeding mode of array independent powder tubes, the length and/or width of a powder spot are adjusted through a powder feeding control signal, the light spot and the powder spot are optimally matched, high-efficiency and high-quality heterogeneous material synchronous subarea printing is realized, powder tubes on two sides synchronously feed powder to a laser light spot position in a one-to-one symmetrical mode, at least one pair of powder tubes feeding powder to the same position respectively convey different powder, melting metallurgical reaction of the two powder tubes is realized in a powder convergence point area, a metallurgical bonding area is formed to serve as a transition area, so that broadband adjustable multi-tube synchronous powder feeding is realized, synchronous subarea paraxial powder feeding 3D printing under the same light spot is favorably carried out at high efficiency, and cladding efficiency and quality are improved.

The method for synchronously and sectionally feeding the powder to the different materials with the same light spot in the laser cladding process as the preferred embodiment comprises the following steps:

firstly, determining the size of a coating preparation area, the width of a printing track and the preparation width of a single-channel coating according to the size of a cladding layer on the surface of a workpiece to be printed, and planning a printing path; setting a powder feeding path according to the planned printing path, designing the powder feeding width, the number of the powder tubes and the spacing distance of the powder tubes, and determining the size of the powder spot; then selecting powder tubes with proper inner diameter according to the set powder feeding path, determining the number of the powder tubes required to be fed, and connecting the powder tubes through different types of powder distributorsDetermining a powder feeding control signal S according to the set powder feeding path_i(i＝1，2……N)；

Wherein, when the powder feeding path is set, the plurality of powder tubes of the first lateral powder feeding assembly and the second lateral powder feeding assembly are set to:

1) the p powder pipes of the first lateral powder feeding assembly and the p +1 powder pipes of the second lateral powder feeding assembly are arranged to synchronously convey the first powder; p is less than or equal to P, wherein P represents the total number of powder pipes of the first lateral powder feeding assembly and the second lateral powder feeding assembly;

2) q +1 powder pipes of the first lateral powder feeding assembly and q powder pipes of the second lateral powder feeding assembly are arranged to synchronously convey the second powder; the powder conveyed by the (q + 1) th powder pipe of the first lateral powder feeding assembly and the (p + 1) th powder pipe of the second lateral powder feeding assembly can be melted by laser spots in a powder convergence point area to realize metallurgical reaction, and a metallurgical bonding area is formed and is used as a transition area; wherein P + q + 1;

finally, setting cladding parameters, compiling a printing program, and starting a corresponding powder feeding control signal S according to the planned powder spot size_iSynchronous powder feeding, i is 1, 2 … … N, and the spot control signal K corresponding to the spot size required by starting_jJ is 1, 2 … … N; and i is not equal to j, obtaining the light spot with the required size, and carrying out cladding printing.

An exemplary printing process is as follows:

(3) powder feeding connection of a powder pipe: the powder pipes, the powder distributors and the powder feeding barrels of the powder feeders are connected according to the mode of FIG. 7A, and the powder feeding control signals of the combination modes are marked as S₁、S₂、S₃、S₄、S₅、S₆The on-off of different powder feeding barrels of the powder feeder is realized through the on-off of different powder feeding control signals;

(4) the control signal determines: carrying out dissimilar material T on the surface of a rigid flat plate₁And T₂The metallurgical bonding composite board single wall printing test:

testing the length of 200mm, starting the powder spot control signal S₁、S₂And S₄、S₅Co-delivery of powder T after activation of four signals₁Starting a light spot control signal K₃(ii) a Start the chalk mark control signal S₃And S₆Two signals co-deliver powder T₂Starting a light spot control signal K₁；

Powder tube delivery T labeled E and L in FIG. 7A, respectively₂And T₁Powder, in which the two powder materials undergo a metallurgical melting reaction, T₁+T₂Forming a metallurgical bonding area to provide a transition area for high-performance connection of dissimilar metals on two sides;

(5) setting printing parameters: the laser power is 5400W, the scanning speed is 730mm/min, the powder output of each powder tube is set at 16g/min, and the rotation number of a powder disc is set on each powder feeding barrel control interface of the powder feeder according to a combination mode;

Referring to fig. 7A and 7B, laser cladding processing of two different materials is performed, in which the powder tubes of the first lateral powder feeding assembly 401 and the second lateral powder feeding assembly 402 are symmetrical to each other and synchronously feed powder to the laser spot position; at least one pair of powder pipes (i.e. powder pipes E and powder pipes L in the figure) which send powder to the same position respectively send different powders, and the two powders realize melting metallurgical reaction in the area of the powder convergence point to form a metallurgical bonding area.

Therefore, synchronous printing and powder feeding of dissimilar materials in different areas can be achieved under the same light spot condition, the powder pipe combination mode of the dissimilar materials can be obtained according to the printing path, regulation and control are conducted, synchronous printing and powder feeding of the dissimilar materials in different areas can be achieved, and different powder T is shown in FIG. 7B₁And T₂Schematic of printing a composite layer, T₁+T₂The metallurgical bonding area is formed, the transition area is provided for high-performance connection of dissimilar metals on two sides, the printing is not required to be respectively carried out in the whole printing process, the defects of cladding layer accumulation and layering caused by powder separation and layering in the processes of powder mixing and powder conveying and printing of dissimilar materials in the traditional printing process can be overcome, a better coating forming profile can be obtained through the subarea synchronous powder conveying control and cladding processing, and the printing efficiency is improved.

In the examples of the present invention, the powder T₁And T₂Titanium alloy (TC4) and stainless steel (316 stainless steel) powders.

In further embodiments, combinations of different powders in other types of titanium alloys, superalloys, stainless steels may also be implemented, including but not limited to: the subarea synchronous powder feeding printing of steel powder with different grades, such as the mixing of stainless steel powder with grades 316 and 235; the partition synchronous powder feeding printing of the titanium alloy and the high-temperature alloy powder, such as the mixing of TC4 titanium alloy powder and IN625/IN718 nickel-based high-temperature alloy; the partition synchronous powder feeding printing of the titanium alloy and the stainless steel powder is carried out, for example, TC4 titanium alloy powder is mixed with 316-grade stainless steel powder; and zoned simultaneous powder feed printing of superalloys and stainless steel powders, such as a mix of N625/IN718 grade nickel-base superalloy and 316 stainless steel powder.

Under different printing combinations, process parameters such as laser power, scanning speed, powder output and the like can be determined according to the selected material and the cladding layer requirement.

Synchronous powder feeding printing of three kinds of powder with large difference in physical properties

In the prior art, aiming at the problems that three kinds of powder with large physical property difference cannot be synchronously fed and printed in a premixing mode, the powder feeding device provided by the embodiment of the invention is used for feeding powder, so that the synchronous powder feeding and printing of the three kinds of powder with large physical property difference is realized.

As an exemplary implementation, copper (Cu), tungsten carbide (WC), silicon dioxide (SiO) are used₂) Three kinds of powder are taken as examples, high-strength, wear-resisting and corrosion-resisting tungsten carbide ceramic composite material coating materials are printed, namely powder 1, powder 2 and powder 3 respectively, and the specific printing process is as follows:

(3) powder feeding connection of a powder pipe: connecting each powder pipe, the powder distributor and each powder conveying barrel of the powder feeder according to the mode of figure 8A, wherein three adjacent powder pipes connected in the mode convey three different powders, adjusting the position relation among the powder pipes to enable three beams of powders to exist in a mixing area shown in figure 8B at an action point, the mixing mode can realize effective mixing of powder materials under the action of high-temperature liquid flow of a laser molten pool, and start-stop control signals of all combination modes are marked as S₁、S₂、S₃、S₄、S₅、S₆(ii) a The on-off of different powder feeding barrels of the powder feeder is realized through the on-off of different powder feeding control signals;

(4) the control signal determines: three kinds of

powder

1, 2 and 3 which have large physical property difference and can not be premixed are synchronously fed and printed on the surface of a flat plate to test a single wall, the test length is 200mm, and a starting signal S is used₃And S₅Conveying the powder 1; start signal S₂And S₆Conveying the powder 2; start signal S₁And S₄Conveying the powder 3; s₁—S₆When all signals are started, the powder feeding width is 12mm, and the light spot control signal is started K₄；

(5) Setting printing parameters: the laser power is 5000W, the scanning speed is 750mm/min, the powder output of each powder tube is set at 16g/min, and the rotation number of a powder disc is set on each powder feeding barrel control interface of the powder feeder according to a combination mode;

Referring to fig. 9A and 9B, three powder pipes form a group to feed powder, and three kinds of powder are melted and metallurgically reacted in the powder gathering point area to form a metallurgical bonding area. In the combined illustration, the three powder tubes are distributed, and the first powder tube and the second powder tube are located in the first lateral powder feeding assembly 401, and the third powder tube is located in the second lateral powder feeding assembly, and in the opposite position, it is located between the first powder tube and the second powder tube, i.e. in the staggered position, rather than in the one-to-one correspondence with the position of one of the powder tubes. Three powder tubes are used for conveying different powders respectively.

In this embodiment, the difference with respect to the embodiment of fig. 7A, 7B and 8A, 8B that the powder tube of the first lateral powder feeding assembly 401 and the powder tube of the second lateral powder feeding assembly 402 are symmetrically arranged one by one to synchronously feed the powder to the laser spot position is that in the example shown in fig. 9A and 8B, the powder tube of the first lateral powder feeding assembly 401 and the powder tube of the second lateral powder feeding assembly 402 are arranged in a relatively staggered manner to synchronously feed the powder to the laser spot position, and the three kinds of powders are effectively and uniformly mixed at the mixing position by the connection arrangement and the powder feeding control of the powder tube powder feeder.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. A powder feeding device for laser cladding additive manufacturing is characterized by comprising:

at least one powder feeder having a powder feed barrel;

2. The powder feeding device for laser cladding additive manufacturing according to claim 1, wherein the powder tubes of the first lateral powder feeding assembly and the powder tubes of the second lateral powder feeding assembly are provided in a one-to-one correspondence in number and position distribution.

3. The powder feeding apparatus for laser cladding additive manufacturing according to claim 1, wherein the first lateral powder feeding assembly and the second lateral powder feeding assembly adopt the same structural design.

4. The powder feeding device for laser cladding additive manufacturing according to claim 1, wherein the first lateral powder feeding assembly comprises a first housing having a flat shape and a plurality of powder tubes mounted in the first housing and distributed in an array, and the distances between adjacent powder tubes are equal.

5. The powder feeding device for laser cladding additive manufacturing according to claim 4, wherein the first lateral powder feeding assembly includes a second housing having a flat shape and a water cooling pipe provided in the second housing, the water cooling pipe having a cooling medium inlet and a cooling medium outlet; the second housing is mounted on the first housing and the second housing is closer to the laser cladding process head than the first housing.

6. The powder feeding device for laser cladding additive manufacturing according to claim 5, wherein a sectional area of the second housing is larger than a sectional area of the first housing.

7. The powder feeding device for laser cladding additive manufacturing according to claim 1, wherein the powder tube of the first lateral powder feeding assembly is a copper tube in which a quartz glass tube is nested.

8. The powder feeding device for laser cladding additive manufacturing according to claim 1, wherein the powder distributor assembly comprises at least one powder distributor connected with the first lateral powder feeding assembly in a matching manner, and at least one powder distributor connected with the second lateral powder feeding assembly in a matching manner.

9. A laser-clad additive manufacturing system, comprising:

a laser spot controller configured to adjust the laser spot;

the powder delivery apparatus of any one of claims 1-8, configured to deliver powder to the location of the laser spot; and

a powder feed controller configured to control powder feed.

10. The laser cladding additive manufacturing system of claim 9 wherein the laser spot controller is configured to control a width and/or a length of the laser spot and the powder feed forms a powder spot size that is smaller than the spot size.

11. The laser cladding additive manufacturing system of claim 9 wherein the powder tubes of the first lateral powder feed assembly are arranged to feed powder to the laser spot locations synchronously in a one-to-one symmetrical manner with the powder tubes of the second lateral powder feed assembly.

12. The laser cladding additive manufacturing system of claim 9 wherein the powder tube of the first lateral powder feed assembly is configured to feed powder to the laser spot location synchronously in a relatively staggered manner with respect to the powder tube of the second lateral powder feed assembly.

13. The laser cladding additive manufacturing system of claim 9 wherein the first and second lateral powder feed assemblies are configured to feed powder through multiple powder feed barrels of the same powder feeder.

14. The laser clad additive manufacturing system of claim 9 wherein the first and second lateral powder feed assemblies are configured to feed powder through powder feed barrels of different powder feeders.

15. The laser cladding additive manufacturing system of claim 9 wherein the powder feed controller is configured to control a powder feed speed of the powder feeder to control a powder feed amount within each powder tube.

16. A laser cladding additive manufacturing method based on the laser cladding additive manufacturing system of any one of claims 10-15, comprising the steps of:

firstly, determining the size of a coating preparation area, the width of a printing track and the preparation width of a single-channel coating according to the size of a cladding layer on the surface of a workpiece to be printed, and planning a printing path; then according to the planned typingSetting a powder feeding path for the printing path, designing the powder feeding width, the number of the powder tubes and the spacing distance of the powder tubes, and determining the size of the powder spot; selecting powder tubes with proper inner diameter according to the set powder feeding path, determining the number of the powder tubes to be fed, connecting the powder tubes through different types of powder dividers, and determining a powder feeding control signal S according to the set powder feeding path_i(i＝1，2……N)；

17. The laser-clad additive manufacturing method of claim 16 wherein the spot size is greater than 1mm of the spot size.

18. The application of the laser cladding additive manufacturing system based on claim 10 in the synchronous subarea powder feeding laser cladding of the same spot dissimilar material, which is used for the laser cladding processing of two different materials, wherein the powder pipes of the first lateral powder feeding assembly are arranged to synchronously feed powder to the laser spot position in a one-to-one symmetrical manner with the powder pipes of the second lateral powder feeding assembly;

19. The application of the laser cladding additive manufacturing system based on claim 10 in synchronous powder feeding and printing of three kinds of powder with larger difference in physical properties, which is used for laser cladding processing of the three kinds of powder with larger difference in physical properties, wherein the powder pipe of the first lateral powder feeding assembly is arranged to synchronously feed powder to the laser spot position in a relatively staggered manner with the powder pipe of the second lateral powder feeding assembly;