CN217709642U

CN217709642U - Novel laser spraying device

Info

Publication number: CN217709642U
Application number: CN202221604326.1U
Authority: CN
Inventors: 龙雨; 刁鹏源; 谢迎春; 周柱坤; 周俊; 邓春明
Original assignee: Guangxi University
Current assignee: Guangxi University
Priority date: 2022-06-24
Filing date: 2022-06-24
Publication date: 2022-11-01
Anticipated expiration: 2032-06-24

Abstract

The utility model discloses a novel laser spraying device includes the nozzle, install respectively at the inside both ends of casing at the nozzle both ends, send the setting of powder pipe to locate at the entry end center pin of nozzle, the nozzle is by the entry section that connects gradually, contraction section and export section are constituteed, high-pressurepipe passes casing and entry section intercommunication, laser head and laser outgoing pipe connect gradually, and tilt up installs between casing inboard and export section, the laser incoming pipe entry end is installed on the casing is inboard, the optical fiber head is installed on the casing, and with laser incoming pipe entry end intercommunication, be equipped with the speculum in the laser beam direction through the optical fiber head transmission, the speculum is installed on the laser incoming pipe inner wall, laser beam through the speculum reflection gets into the laser head, the exit end of laser outgoing pipe communicates with export section's exit end one side. The device can preheat the softening matrix better, reduces the critical deposition speed of powder, improves the bonding strength of the coating, and the design of the nozzle can reduce the manufacturing cost.

Description

Novel laser spraying device

Technical Field

The utility model relates to a spraying coating preparation technical field, concretely relates to novel laser spraying device.

Background

Thermal spraying technology is one of the technologies for surface protection and strengthening, and is an important subject in surface engineering. The thermal spraying is a technique of heating a powdered or wire-like metallic or non-metallic coating material to a molten or semi-molten state by using a heat source such as an electric arc, a plasma arc, a combustion flame, etc., and then atomizing and spraying the atomized material at a constant speed onto the surface of a pretreated substrate by the power of a flame flow itself or an applied high-speed gas flow to combine the atomized material with the substrate to form a surface coating having various functions. However, the heating exists in the thermal spraying process, the spraying material has the defects of high-temperature oxidation, dissolution, peeling, gas evaporation and the like, so that the coating also has inevitable defects, for example, the high temperature can oxidize and melt the matrix, the matrix has large thermal stress, the coating is not uniformly formed, pores are generated, and the problems of insufficient bonding, insufficient strength and the like of the coating are caused.

In view of the above-mentioned shortcomings of conventional thermal spraying, the concept of cold spraying was proposed in the middle and late 80 s of the 20 th century. Cold Spray, also called Cold Gas Dynamic Spray (CS for short), is a process in which supersonic speed is achieved by preheating compressed Gas, which passes through a Laval nozzle at a certain pressure, powder particles impact a substrate at high speed by Gas acceleration, and the particles are deposited on the substrate by plastic deformation to form a coating. The cold spraying coating preparation process does not generate oxidation and phase change, and the coating has high deposition efficiency and thick coating, thereby being very suitable for large-scale production. However, since the cold spraying process is a plastic deformation process, pores generated by poor bonding are easily formed in the cold spraying layer, particularly at the bottom of the coating, so that the bonding between the cold spraying substrate and the coating is mostly mechanical bonding, i.e. mechanical interlocking between particles, and the bonding performance between the coating and the substrate is poor, and the bonding strength is low. Particularly, for metals with low hardness such as Cu and Ag, it is difficult to achieve effective deposition of particles. Therefore, a method for preheating a substrate by using laser is provided, so that the deposition efficiency of the first layer of metal powder is improved.

Chinese patent CN103920626a proposes a coaxial laser-assisted cold spray nozzle device. In the device, a carrier gas heating device is eliminated, powder particles are fed in a nozzle diffusion part, powder softening, condensation and blockage of a contraction section are avoided, and uniform laser preheating of powder, gas and a matrix in the nozzle is realized. However, the nozzle of the device is too small in size, so that a reflector is difficult to mount; the laser heats the powder after passing through the throat part of the nozzle, the powder is in a molten or semi-molten state and is easily bonded on the expansion section of the nozzle under the action of the carrier gas; in addition, laser cannot be reflected through a reflector in the expansion section due to the influence of powder, so that the center of a laser spot ejected cannot be ensured to fall on the center of a powder beam.

At present, laser preheating cold spraying equipment is mostly placed by adopting a single laser head paraxial mode, namely, single laser side irradiation. This results in the difficulty in handling the movement of the laser preheating whole device in actual production and the light beam and the powder spot have slight errors in the actual movement process. In addition, the temperature cannot be fully controlled due to the cold spray chamber temperature effect. This limits the development and practical application of cold spray.

SUMMERY OF THE UTILITY MODEL

The utility model provides a novel laser spraying device, concrete scheme as follows:

the utility model provides a novel laser spraying device, includes casing, nozzle, send whitewashed pipe, high-pressurepipe, laser incident tube, laser head, laser outgoing pipe and optical fiber head, install respectively at the inside both ends of casing at the nozzle both ends, send whitewashed pipe setting in the entry end center pin department of nozzle, the nozzle comprises entry section, shrink section and the export section that connects gradually, high-pressurepipe passes casing and entry section intercommunication, laser incident tube, laser head and laser outgoing pipe connect gradually, and tilt up installs between the inboard and export section of casing, the laser incident tube entry end is installed on the casing is inboard, the optical fiber head is installed on the casing, and with laser incident tube entry end intercommunication, be equipped with the speculum along the laser beam direction of passing through the optical fiber head transmission, the speculum is installed on the laser incident tube inner wall, laser beam through the speculum reflection gets into the laser head, laser outgoing pipe exit end communicates with export end one side of export section.

Further, the powder feeding device comprises a laser, wherein the laser is connected with the optical fiber head, and the diameter of a laser beam emitted by the laser is larger than that of the powder feeding pipe.

Further, the inlet section and the outlet section are both circular straight tubular.

Furthermore, the contraction angle of the contraction section of the nozzle is 30-60 degrees, and the angle formed by the intersection of the central axis of the nozzle and the central axis of the laser emitting tube is 10-20 degrees.

Further, the diameter of the powder feeding pipe is smaller than that of the outlet end of the contraction section.

Furthermore, a collimating lens, a first focusing lens, a second focusing lens, a third focusing lens and a protective lens are sequentially arranged in the laser head from the incident end to the emergent end, a laser beam transmitted by the optical fiber head is focused by the laser head and then is irradiated to the surface of the substrate from the laser emergent pipe, and the irradiation area of the laser beam on the surface of the substrate is overlapped with the spraying area of the powder beam conveyed by high-pressure gas on the surface of the substrate.

Furthermore, a pure phase spatial light modulator is arranged in the laser head, so that the laser beam emitted by the laser head is a flat-top beam or an inverse Gaussian beam.

Further, the reflecting mirror is a plane mirror or a concave mirror.

The advantages of the utility model

1. The utility model discloses a novel laser spraying device passes through the speculum and enters into the laser head with the laser beam reflection of optical fiber head transmission, focuses on the base member after becoming the laser facula through the laser head, through adjusting speculum angle adjustment facula position, guarantees to erupt the laser facula center and falls on transporting the pencil center of the exit end to the export section through high-pressure gas. Compared with the traditional paraxial laser auxiliary cold spraying device, the device is convenient to operate, the Laval nozzle in the prior art is changed into a contraction nozzle, the manufacturing cost of the nozzle can be reduced, the internal structure of the laser head can be exchanged, and the shape and the size of the formed laser spot can be changed; in addition, because the laser irradiates the basal body and can produce the reflected light, the structural design mode of the device can protect the laser head and the nozzle structure, prevent dust from entering the nozzle, and ensure that the reflected light can not melt the equipment.

2. The utility model provides a pair of novel laser spraying device compares with the supplementary cold spray nozzle of coaxial laser, and the light beam is put with the powder branch, and better preheating base member and softening base member are of value to the deposit of powder granule, can promote the efficiency of deposit metal alloy effectively, make the bonding strength of coating and base member promote by a wide margin, form the coating of high performance.

3. The utility model provides a pair of novel laser spraying device compares traditional cold spraying, can more effectively preheat softening coating and base member, reduces the critical deposition rate of powder, has increased substantially deposition efficiency and binding rate, has widened the used material scope of ultrasonic speed cold spraying, and can better improve the bonding strength of coating. The change of the nozzle structure is beneficial to saving materials and cost and facilitating manufacturing and processing.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is an external structural schematic diagram of the laser spraying device of the present invention.

Fig. 3 is a cross-sectional view of the coating sprayed by the device of the present invention.

In the figure:

1-powder feeding pipe; 2-central axis of nozzle; 3-high-pressure air pipe; 4-an inlet section; 5-a contraction section, 6-an outlet section; 7-a substrate; 8-a mirror; 9-a fiber optic head; 10-a collimating lens, 11-a laser head, 12-a focusing lens I, 13-a focusing lens II and 14-a focusing lens III; 15-protective lens; 16-a laser incident tube; 17-a laser emission tube; 18. a housing; 19. and (4) a nozzle.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings and specific embodiments, it should be noted that the present invention is not limited to the specific embodiments.

As shown in fig. 1 to 2, the novel laser spraying device provided by this embodiment includes a housing 18, a nozzle 19 disposed in the housing 18, a powder feeding pipe 1, a high pressure gas pipe 3, a laser incident pipe 16, a laser head 11, a laser emitting pipe 17, a fiber head 9, and a laser (not shown).

The two ends of the nozzle 19 are respectively arranged at the two ends inside the shell 18, the powder feeding pipe 1 is arranged at the central axis of the inlet end of the nozzle 18, the nozzle 18 consists of the inlet section 4, the contraction section 5 and the outlet section 6 which are sequentially connected, and preferably, the inlet section 4 and the outlet section 6 are both in a circular straight pipe shape, so that the cost for manufacturing the nozzle 18 can be reduced. The contraction angle of the contraction section 5 of the nozzle 18 is 30-60 degrees. The diameter of the powder feeding pipe 1 is smaller than that of the outlet end of the contraction section 5.

The high pressure gas pipe 3 communicates with the inlet section 4 through the housing 18. The powder is accelerated in the nozzle 19 and deposited on the surface of the matrix 7 through high-pressure gas after entering the inlet section 4 and the contraction section 5, and the end of the outlet section 6 is connected with the laser emitting tube 16, so that the problem that in the prior art, the powder is in a molten or semi-molten state due to the fact that the laser beam heats the powder after passing through the throat of the nozzle, and is easy to bond or block at the expansion section of the nozzle under the action of carrier gas can be solved, and the technical problem that the center of a laser spot ejected cannot be ensured to fall at the center of the powder beam due to the fact that the laser beam cannot be reflected through a reflector at the expansion section due to the influence of the powder in the prior art can also be solved.

The laser device comprises a laser incident pipe 16, a laser head 11 and a laser emergent pipe 17 which are sequentially connected and are obliquely and detachably mounted between the inner side of a shell 18 and an outlet section 6, the inlet end of the laser incident pipe 16 is mounted on the inner side of the shell 18, an optical fiber head 9 is mounted on the shell 18 through an inner angle nut and is communicated with the inlet end of the laser incident pipe 16, the laser device is connected with the optical fiber head 9, a laser beam emitted by the laser device is transmitted through the optical fiber head 9, a reflecting mirror 8 is arranged along the direction of transmitting the laser beam by the optical fiber head 9, the reflecting mirror 8 is a plane mirror or a concave mirror, the reflecting mirror 8 is mounted on the inner wall of the laser incident pipe 16, the laser beam reflected by the reflecting mirror 8 enters the laser head 11, a collimating mirror 10, a focusing mirror 12, a focusing mirror 13, a focusing mirror three 14 and a protective mirror 15 are sequentially arranged in the laser head 11 from the incident end to the emergent end, the outlet end of the laser emergent pipe 17 is communicated with one side of the outlet end of the outlet section 6, the central axis of the nozzle is intersected with the central axis to form an angle of 10-20 degrees, the central axis, the laser beam emitted by the laser head 9 is transmitted to the laser head 9, and then reflected by the central axis of the reflecting mirror 8 to enter the laser head 11, the central axis of the laser head 17, and then irradiate a high-pressure gas-emitting area of a substrate 7, and the substrate is transmitted by the high-emitting area of the high-pressure gas-emitting area.

The laser is a fiber laser or a semiconductor laser. The diameter of the laser beam emitted by the laser is larger than that of the powder feeding pipe 1, and a pure phase spatial light modulator is arranged in the laser head 11, so that the laser beam emitted by the laser head 11 is a flat-top beam or an inverse Gaussian beam.

The working principle is as follows:

before use, a first focusing lens 12, a second focusing lens 13, a third focusing lens 14 and a protective lens 15 which are suitable are selected according to requirements and are sequentially installed in a laser head 11, and powder particles sequentially enter an inlet section 4, a contraction section 5 and an outlet section 6 from a powder feeding pipe 1 and are carried by high-pressure gas to form powder beams to be sprayed to the surface of a base body 7; laser beams emitted by a laser enter a laser incident tube 16 through an optical fiber head 9, are reflected by a reflector 8 arranged on the inner wall of the laser incident tube 16 to enter a laser head 11 to be focused into laser spots, and then are emitted from a laser emitting tube 17 to irradiate the surface of a matrix 7 so as to preheat and soften the matrix 7; the center of a laser spot formed by focusing by the laser head 11 can be controlled to coincide with the center of a powder beam transmitted by high-pressure gas by adjusting the angle of the reflector 8 arranged on the inner wall of the laser incidence tube 16. The carrier gas transports the powder particles under the action of pressure to pass through the contraction section 5 of the nozzle 18 to realize sonic velocity, and the laser beam is mixed with the powder at the outlet section 6 of the nozzle 18 for heating, and simultaneously heats the matrix 7, so that the critical speed required by powder deposition can be reduced, effective deposition is realized, the efficiency of metal alloy deposition is improved, and the bonding strength of the coating and the matrix 7 is greatly improved. In addition, the nozzle 19 and the laser head 11 are integrally arranged in the shell 18, so that when the operation is convenient, the spraying device is integrally controlled to move left and right to irradiate laser spots and powder on the surface of the pre-sprayed substrate 7, the substrate is preheated and softened, meanwhile, the deposition of powder particles is facilitated, the deposition efficiency and the bonding rate are greatly improved, and a high-performance coating is formed. The size, focal length and beam distribution of the laser spot can be adjusted by adjusting the lens structure in the laser head 11. If the laser selects the blue laser, the blue laser can improve the laser absorption rate of the copper alloy powder and broaden the range of materials used in the ultrasonic rapid cold spraying. In addition, because the laser facula irradiates the basal body 7 and can produce the reflected light, install the nozzle 19 and laser head 11 in the body 18 integrally, not only simple to operate, and can protect the structure of laser head 11 and nozzle 19, prevent that the dust from getting into nozzle 19, and can avoid the reflected light can not melt the equipment.

The internal structure of the laser head 11 of the present embodiment can be exchanged as needed, and the shape and the spot size of the forming laser can be changed by exchanging the internal structure. A pure phase spatial light modulator can be installed inside the laser head 11, so that the laser beam emitted by the laser head 11 is a flat-top beam or an inverse gaussian beam.

The novel laser spraying device is used for carrying out the laser cold spraying method, high-pressure gas enters the nozzle 18 from the high-pressure gas pipe 3, sequentially passes through the inlet section 4, the contraction section 5 and the outlet section 6 and then is sprayed to the surface of the matrix 7; powder particles sequentially enter the inlet section 4, the contraction section 5 and the outlet section 6 from the powder feeding pipe 1 and are carried by high-pressure gas to form powder beams which are sprayed on the surface of the matrix 7; laser beams emitted by a laser enter a laser incidence pipe 16 through an optical fiber head 9, the laser beams are reflected by a reflecting mirror 8 arranged on the inner wall of the laser incidence pipe 16 to enter a laser head 11 to be focused into laser spots, then the laser spots are emitted from a laser emitting pipe 17 to irradiate the surface of a substrate 7, the substrate 7 is preheated and softened, the center of the laser spots formed after the laser head 11 is focused is controlled to coincide with the center of a powder beam transmitted by high-pressure gas by adjusting the angle of the reflecting mirror 8 arranged on the inner wall of the laser incidence pipe 16, and a high-performance coating is formed.

Next, the PCS 1000 cold spraying equipment in the prior art and the spraying device of the present embodiment are used to respectively spray and compare the stainless steel round tube substrate:

the high-pressure gas selected for spraying is N₂Pure copper powder is adopted, the particle size of the powder is 25-53 mu m, and the shape of the powder is spherical. The setting basal body is all 304 stainless steel round tubes. The temperature of the gun chamber during spraying is set to be 800 ℃, and the pressure of the high-pressure gas is set to be 5MPa.

By adopting PCS 1000 cold spraying equipment in the prior art, the cold spraying deposition particle speed is 719m/s, the coating sprayed by the cold spraying equipment is difficult to effectively deposit, the coating is easy to fall off, the bonding strength is about 4MPa, and the deposition efficiency of pure copper sprayed by the cold spraying equipment on the matrix is 12%.

By adopting the spraying device of the embodiment, the light beam is adjusted to be blue light through each focusing lens, and the shape of the light spot is adjusted to be rectangular through adjusting the distance between the focusing lenses. The center of a laser spot jetted out by the laser emitting tube 16 falls at the center of the powder beam by adjusting the angle of the reflector 8, the laser power is 8kw, and the speed of jetted particles is 340m/s, which is far lower than the speed of cold spray deposited particles. Before spraying, the surface substrate 7 is heated by laser, as shown in fig. 3, the sprayed coating of the present embodiment has no obvious pores inside, and is 0.11% after Image J measurement, which is far lower than that of other coatings sprayed by cold spraying, and the powder particle deposition efficiency of the spraying device of the present embodiment is 96% and higher than that of the cold spraying pure copper on the soft substrate 7 of the PCS 1000 cold spraying equipment of the prior art. The interface of the substrate 7 has no heat affected zone and still maintains the advantages of cold spraying. The result of the FM1000 glue tensile test is glue break, which proves that the internal bonding strength of the coating in this embodiment is above 80 MPa.

Claims

1. Novel laser spraying device, a serial communication port, including casing, nozzle, send whitewashed pipe, high-pressurepipe, laser incident pipe, laser head, laser outgoing pipe and optical fiber head, the inside both ends of casing are installed respectively at the nozzle both ends, send whitewashed pipe setting in the entry end center pin department of nozzle, the nozzle comprises entry section, contraction section and the export section that connects gradually, high-pressurepipe passes casing and entry section intercommunication, laser incident pipe, laser head and laser outgoing pipe connect gradually, and tilt up installs between casing inboard and export section, the laser incident pipe entry end is installed on the casing inboard, the optical fiber head is installed on the casing, and with laser incident pipe entry end intercommunication, be equipped with the speculum along the laser beam direction of passing through the optical fiber head transmission, the speculum is installed on the laser incident pipe inner wall, laser beam through the speculum reflection gets into the laser head, laser outgoing pipe exit end and export end one side intercommunication of export section.

2. The novel laser spraying device according to claim 1, comprising a laser, wherein the laser is connected with a fiber head, and the diameter of a laser beam emitted by the laser is larger than that of the powder feeding pipe.

3. The novel laser spraying device of claim 1, wherein the inlet section and the outlet section are both circular and straight tubular.

4. The novel laser spraying device as claimed in claim 1, wherein the contraction angle of the contraction section of the nozzle is 30-60 °, and the angle formed by the intersection of the central axis of the nozzle and the central axis of the laser emitting tube is 10-20 °.

5. The novel laser spraying device of claim 1, wherein the diameter of the powder feeding pipe is smaller than the diameter of the outlet end of the contraction section.

6. The novel laser spraying device according to claim 1, wherein a collimating lens, a first focusing lens, a second focusing lens, a third focusing lens and a protective lens are sequentially arranged in the laser head from the incident end to the exit end, a laser beam transmitted through the optical fiber head is focused by the laser head and then irradiated onto the surface of the substrate from the laser exit tube, and the laser beam is overlapped with the powder beam conveyed by the high-pressure gas in the irradiation area of the surface of the substrate in the injection area of the surface of the substrate.

7. A novel laser spraying device as claimed in claim 1, characterized in that a pure phase spatial light modulator is installed in the laser head, so that the laser beam emitted by the laser head is a flat-top beam or an inverse Gaussian beam.

8. The novel laser spraying device of claim 1, wherein the reflecting mirror is a plane mirror or a concave mirror.