CN101942659A - Laser cladding nozzle convenient for cooling and manufacturing method thereof - Google Patents

Abstract

The invention discloses a laser cladding nozzle which is convenient for cooling, comprising a nozzle core and a connection head connected above it for an external laser system, the nozzle core is provided with a beam channel, a cooling cavity and several powder feeding The cooling cavity is a cavity formed between the outer circumference of the beam channel and the outer circumference of each powder feeding channel; the outer wall of the upper end of the nozzle core is respectively opened with a powder inlet connected with the powder feeding channel and a cooling cavity. A connected water outlet, the lower end of the nozzle core is provided with a powder outlet connected to the powder feeding channel and a water inlet connected to the cooling cavity, and the water inlet and the water outlet are respectively externally connected to the cooling system. The invention also discloses the manufacturing method of the above-mentioned nozzle, which includes the steps of constructing a model, slicing processing, rapid prototyping, post-processing and the like. The invention has the advantages of simple structure, high cooling effect and good powder feeding quality, and is directly manufactured by a rapid prototyping method, so that the design of the nozzle is not restricted by the traditional processing method, and the structure is more diversified.

Description

A laser cladding nozzle convenient for cooling and its manufacturing method

technical field

The invention belongs to the technical field of laser processing, and in particular relates to a laser cladding nozzle which is convenient for cooling and a manufacturing method thereof.

Background technique

The basic principle of laser cladding technology is: add cladding material on the surface of the substrate, use a laser beam with a certain power density to scan it to completely melt it, and quickly solidify it to form a surface coating that is metallurgically bonded to the substrate. Laser cladding technology has attracted more and more attention due to its advantages of saving strategic metals, protecting the environment, improving the surface properties of materials, and reducing energy consumption.

In the laser cladding system, most of the laser cladding powder feeding systems currently use laser cladding nozzles for powder feeding. The uniformity of powder feeding has a great influence on the cladding quality. The distance is very close, and it is greatly affected by the thermal radiation of the molten pool, so the nozzle must have a very good cooling effect.

The publication number is CN 1570190A, the publication date is January 26, 2005, and the application number is the Chinese invention patent of 200410013108.0. The name of the invention is a built-in laser cladding nozzle, which discloses a built-in laser cladding nozzle. The cylinder body is composed of upper and lower cones, and there are powder passages, cooling water passages and protective gas passages in the cylinder wall. The entrances of these powder passages, water passages and air passages are all located on the top of the nozzle. Tube, compact structure. Its disadvantage is that the powder channel is a uniform pipe up and down, and the quality of powder feeding is not high; although the cooling water ring is placed in the bottom wall of the conical cylinder, its inlet is set at the upper end of the conical cylinder, which is not suitable for heat radiation. The cooling effect of the lower edge of the nozzle that affects the most is not very good; the entire nozzle is assembled from multiple parts, the overall structure is complex, and it is easy to affect the powder feeding effect or cause water leakage due to improper assembly. The Chinese utility model patent with the application number "200420046953.3" discloses a hole-type coaxial laser cladding nozzle, which uses 3 or 6 small holes as powder feeding channels to achieve coaxial and powder focusing and laser focusing coincidence, and When inclined at a large angle (90-180 degrees), there will be no powder segregation phenomenon, and the uniformity of the sent powder can still be ensured. However, this structure is embedded with a water-cooled jacket to achieve its cooling effect. Due to the processing method Due to the limitations of the water cooling jacket, it is necessary to process the water cooling jacket separately, and then assemble it with the nozzle by welding, etc., which has defects such as cumbersome processing and limited cooling area.

In summary, the existing technologies generally have the following deficiencies: (1) Limited by the processing method, the water cooling jacket needs to be processed separately, and then combined with the nozzle by welding. This method is not only cumbersome, but also It is easy to cause water leakage due to weld quality problems; (2) The cooling area is limited, and the cooling effect on the lower edge of the nozzle that is most affected by heat radiation is not very good; (3) As mentioned earlier, the nozzle is composed of multiple parts The overall structure is complicated, and it is easy to affect the powder feeding effect or cause water leakage due to improper assembly and other problems.

Therefore, it is necessary to provide a laser cladding nozzle which can ensure the uniformity of powder feeding and has a high-efficiency cooling effect, and does not require assembly, and a manufacturing method thereof.

Contents of the invention

The primary purpose of the present invention is to overcome the disadvantages and deficiencies of the prior art, and to provide a laser cladding nozzle that can ensure uniform powder feeding and has high-efficiency cooling effect, and does not need to be assembled for easy cooling.

Another object of the present invention is to provide a method for manufacturing a laser cladding nozzle that is convenient for cooling.

In order to achieve the above purpose, the present invention adopts the following technical solution: a laser cladding nozzle that is convenient for cooling, including a nozzle core and a connecting head for an external laser system connected above it, and a beam channel is provided in the nozzle core , a cooling cavity and several powder feeding channels, the cooling cavity is the cavity formed between the outer circumference of the beam channel, the outer circumference of each powder feeding channel and the inner wall of the nozzle core; the outer wall of the upper end of the nozzle core is respectively opened with A powder inlet connected to the powder feeding channel and a water outlet connected to the cooling cavity. The lower end of the nozzle core is provided with a powder outlet connected to the powder feeding channel and a water inlet connected to the cooling cavity. The water inlet and the water outlet Both are externally connected to the cooling system. When working, the external cooling system sends cooling water from the water inlet at the lower end of the nozzle core to the cooling cavity of the nozzle core. cooling system recovery.

The beam channel is a through hole opened at the center of the nozzle core, and the through hole is preferably a conical hole or a cylindrical hole.

The connecting head is a cylinder provided with external threads, and a through hole communicated with the beam channel is opened at the center thereof;

Alternatively, the connecting head is an annular convex body integrally formed with the nozzle core, and several through holes for externally connecting the laser system are opened on its side wall. As a preference, each through hole surrounds the central axis of the nozzle core Evenly distributed.

The powder feeding channel is a channel with a smooth inner wall, and the aperture of the channel gradually becomes smaller from the powder inlet to the powder outlet; each powder feeding channel is evenly distributed around the central axis of the nozzle core, and each powder feeding channel is along the direction of the powder outlet. The extension cords converge at one point.

The number of powder feeding channels is three to six, and the number of powder inlets and powder outlets is consistent with the number of powder feeding channels. As a preference, the powder inlets, powder outlets and powder feeding channels are in one-to-one correspondence; the nozzle core The thickness of the outer wall is 2-5mm; the wall thickness of the beam channel is 2-5mm; the wall thickness of the powder feeding channel is 2-5mm.

The above-mentioned manufacturing method of the laser cladding nozzle convenient for cooling comprises the following steps:

(1) Constructing a model: establishing a three-dimensional model of the laser cladding nozzle in the host computer according to the structure of the laser cladding nozzle;

(2) Slicing processing: Slicing the obtained three-dimensional model of the laser cladding nozzle along the forming direction to obtain slice data of its layered section, and then import the slice data into the laser rapid prototyping device;

(3) Rapid prototyping: set the rapid prototyping parameters, send the manufactured raw material powder into the laser rapid prototyping device, scan the raw material powder according to the imported slice data and accumulate layer by layer until the accumulation is formed, and the formed laser cladding is obtained nozzle;

(4) Post-processing: Post-processing the formed laser cladding nozzle.

In the step (3), the rapid prototyping is laser selective melting/sintering; the raw material powder is stainless steel, copper or copper alloy, and copper or copper alloy is used as the raw material powder for the best cooling effect.

In the step (4), the post-processing specifically includes: cutting the formed laser cladding nozzle from the substrate, grinding, sandblasting, and blowing the surface and interior of the laser cladding nozzle to remove the bond Powder on the surface of the laser cladding nozzle or trapped in the powder feeding channel and cooling cavity inside it.

The working principle of the present invention: during processing, the external laser system emits laser light, and the laser light is emitted to the lower end of the nozzle core along the beam channel. At the same time, the raw material powder enters each powder inlet and moves along the powder feeding channel to the powder outlet. The powder outlet reaches the lower end of the nozzle core, and under the action of the laser, operations such as cladding are realized. Since each powder feeding channel adopts a channel with a smooth inner wall, the aperture of the channel gradually becomes smaller from the powder inlet to the powder outlet. , and each powder feeding channel is evenly distributed around the central axis of the nozzle core, so the raw material powder can be uniformly delivered to the lower end of the nozzle core. While processing, the external cooling system sends cooling water from the water inlet at the lower end of the nozzle core to the cooling cavity of the nozzle core. After the nozzle is cooled, the cooling system pumps the cooling water out from the water outlet at the upper end of the nozzle core to Fully realize the effect of efficiently cooling the nozzle core.

The invention can be applied to laser processing fields such as laser cladding, laser three-dimensional manufacturing, material synthesis, and laser repair.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

1. The powder feeding channel in the nozzle of the present invention is a channel with a smooth inner wall, and the aperture of the channel gradually becomes smaller from the powder inlet to the powder outlet, which can achieve a better powder feeding effect and improve the powder feeding quality.

2. The nozzle itself of the present invention has a cooling effect, and does not need to be combined with a water cooling jacket or to open a water cooling channel, so there is no problem of water leakage caused by poor sealing, and the quality of powder delivery will not be affected by improper assembly.

3. The nozzle of the present invention only retains the powder feeding channel and the beam channel, and the rest of the cavity (that is, the cavity between the powder feeding channel and the beam channel) is used as a cooling cavity, which greatly reduces the quality of the entire nozzle and The overall structure is simple; moreover, compared with the prior art, the cooling chamber has a large cooling area and has a very good cooling effect, especially the water inlet of the cooling chamber is located at the lower end of the nozzle core, which can better cool the nozzle most affected by heat radiation Core lower edge.

4. The nozzle of the present invention can be manufactured directly without combining or assembling with other parts, eliminating the assembly process, and there is no problem of poor powder feeding effect or water leakage due to assembly problems.

5. The present invention uses laser scanning to directly manufacture the nozzle by rapid prototyping, so it is not limited by traditional processing methods, and the structure of the nozzle is more diverse.

Description of drawings

Fig. 1 is the schematic diagram of the three-dimensional structure of the nozzle of the present invention in Embodiment 1;

Fig. 2 is A-A sectional view of the nozzle shown in Fig. 1;

Fig. 3 is a B-B sectional view of the nozzle shown in Fig. 1;

Fig. 4 is the structural representation of nozzle of the present invention in embodiment 2;

Fig. 5 is a schematic structural view of the nozzle of the present invention in Embodiment 3;

Fig. 6 is a schematic flow chart of the manufacturing method of the nozzle shown in Fig. 1 .

Detailed ways

The present invention will be further described below in conjunction with the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

Example 1

As shown in Figure 1, the laser cladding nozzle that is convenient for cooling includes a nozzle core 10 and a connecting head 9 connected above it for an external laser system. The nozzle core 10 is provided with a beam channel 3 and a cooling cavity 8 and three powder feeding passages 4, the cooling cavity 8 is the outer periphery of the beam passage 3, the outer periphery of each powder feeding passage 4 and the cavity formed between the inner wall of the nozzle core 10 (that is, in the nozzle core 10, the beam passage 3 is removed and the remaining cavity part behind the powder feeding channel 4 all constitute the cooling cavity 8); as shown in Figure 2 and Figure 3, the upper end outer wall of the nozzle core 10 is respectively provided with a powder inlet communicating with the powder feeding channel 4 2 and the water outlet 7 communicating with the cooling cavity 8, the lower end of the nozzle core 10 has a powder outlet 5 communicating with the powder feeding channel 4 and a water inlet 6 communicating with the cooling cavity 8, the water inlet 6 and the outlet The water outlets 7 are respectively connected to the external cooling system, so that the cooling cavity 8 is connected with the external cooling system. When working, the external cooling system sends cooling water from the water inlet 6 at the lower end of the nozzle core 10 to the cooling cavity 8 of the nozzle core 10. After cooling the nozzle, the cooling system sends the cooling water from the outlet at the upper end of the nozzle core Water port 7 is drawn out and recycled through the external cooling system.

As shown in FIG. 2 , the beam channel 3 is a through hole opened at the center of the nozzle core 10 , and the through hole is a conical hole.

As shown in Figure 1, the connector 9 is an annular convex body integrally formed with the nozzle core 10, and three through holes 1 for externally connecting the laser system are opened on its side wall, and the three through holes 1 are located at The upper end of the nozzle core 10 is evenly distributed around the central axis of the nozzle core 10 .

As shown in Figure 2, the powder feeding channel 4 is a channel with a smooth inner wall, and the aperture of the channel gradually becomes smaller from the powder inlet 2 to the powder outlet 5; each powder feeding channel 4 is evenly distributed around the central axis of the nozzle core 10, And each powder feeding channel 4 converges at one point along the extension line of the powder discharging direction.

The number of powder inlets 2 and powder outlets 5 is the same as the number of powder feeding channels 4, which are three respectively, and the three powder inlets 2 and three powder outlets 5 are respectively connected to the three powder feeding channels 4, The powder inlet 2, the powder outlet 5 and the powder feeding channel 4 correspond one by one; the outer wall thickness of the nozzle core 10 is 2 mm; the wall thickness of the beam channel 3 is 2 mm; the wall thickness of the powder feeding channel 4 is 2 mm.

As shown in Figure 6, the above-mentioned method for manufacturing the laser cladding nozzle that is convenient for cooling includes the following steps:

(1) Constructing a model: establishing a three-dimensional model of the laser cladding nozzle in the host computer according to the structure of the laser cladding nozzle;

(2) Slicing processing: Slicing the obtained three-dimensional model of the laser cladding nozzle along the forming direction to obtain slice data of its layered section, and then import the slice data into the laser rapid prototyping device;

(3) Rapid prototyping: set the rapid prototyping parameters, send the manufactured raw material powder into the laser rapid prototyping device, scan the raw material powder according to the imported slice data and accumulate layer by layer until the accumulation is formed, and the formed laser cladding is obtained nozzle;

(4) Post-processing: Post-processing the formed laser cladding nozzle.

In the step (3), the rapid prototyping is laser selective melting/sintering; the raw material powder is copper alloy.

In the step (4), the post-processing specifically includes: cutting the laser cladding nozzle away from the substrate, and performing grinding, sandblasting, and air blowing on the surface and interior of the laser cladding nozzle to remove the laser cladding nozzle. Cladding the surface of the nozzle or the powder remaining in the powder feeding channel 4 and the cooling cavity 8 inside it.

The working principle of this embodiment: during processing, the external laser system emits laser light, and the laser light is emitted to the lower end of the nozzle core 10 along the beam channel 3. At the same time, the raw material powder enters each powder inlet 2 and moves along the powder feeding channel 4 to the The powder outlet 5 reaches the lower end of the nozzle core 10 from the powder outlet 5, and under the action of the laser, operations such as cladding are realized. Since each powder feeding channel 4 adopts a channel with a smooth inner wall, the aperture of the channel is from the inlet The powder opening 2 to the powder outlet 5 gradually becomes smaller, and each powder feeding channel 4 is evenly distributed around the central axis of the nozzle core 10 , so the raw material powder can be uniformly delivered to the lower end of the nozzle core 10 . While processing, the external cooling system sends cooling water from the water inlet 6 located at the lower end of the nozzle core 10 to the cooling cavity 8 of the nozzle core 10. After cooling the nozzle, the cooling system sends the cooling water from the upper end of the nozzle core 10 The water outlet 7 is drawn out to fully realize the effect of efficiently cooling the nozzle core 10 .

This embodiment can be applied to laser processing fields such as laser cladding, laser three-dimensional manufacturing, material synthesis, and laser repair.

Example 2

The structure of this embodiment is the same as that of Embodiment 1 except for the following features: as shown in FIG. 4 , the beam channel 3 is a through hole opened at the center of the nozzle core, and the through hole is a cylindrical hole.

In the step (3), the raw material powder is copper.

Example 3

The structure of this embodiment is the same as that of Embodiment 1 except for the following features: As shown in FIG. 5 , the connecting head is a cylinder provided with an external thread 11 , and a through hole 12 communicating with the beam channel is opened at the center.

The number of powder feeding channels 4 is six; the number of powder inlets 2 and powder outlets 5 is the same as the number of powder feeding channels 4, which are six respectively, and six powder inlets 2 and six powder outlets 5 They are respectively connected with six powder feeding channels 4, and the powder inlet 2, powder outlet 5 and powder feeding channel 4 correspond one by one; the outer wall thickness of the nozzle core is 5 mm; the wall thickness of the beam channel is 5 mm; the powder feeding channel 4 The wall thickness is 5mm.

Example 4

The structure of this embodiment is the same as that of Embodiment 1 except for the following features: the powder feeding channels are five; the number of powder inlets and powder outlets is the same as the number of powder feeding channels, which are five respectively, and five The powder inlet 2 and the five powder outlets 5 are respectively connected with the five powder feeding channels, and the powder inlet 2, the powder outlet 5 and the powder feeding channels 4 correspond one by one; the outer wall thickness of the nozzle core is 4 mm; the beam channel The wall thickness is 3mm; the wall thickness of the powder feeding channel is 3mm.

In the step (3), the raw material powder is stainless steel.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (10)

1. A laser cladding nozzle that is convenient for cooling, including a nozzle core and a connection head connected above it for an external laser system, characterized in that: the nozzle core is provided with a beam channel, a cooling cavity and several The powder feeding channel, the cooling cavity is the cavity formed between the outer circumference of the beam channel, the outer circumference of each powder feeding channel, and the inner wall of the nozzle core; the outer wall of the upper end of the nozzle core is respectively provided with a powder feeding channel connected to the powder feeding channel. A mouth and a water outlet communicated with the cooling cavity. The lower end of the nozzle core is provided with a powder outlet communicated with the powder feeding channel and a water inlet communicated with the cooling cavity. The water inlet and the water outlet are respectively externally connected to the cooling system. 2. The laser cladding nozzle for easy cooling according to claim 1, characterized in that: the beam channel is a through hole opened at the center of the nozzle core. 3. The cooling laser cladding nozzle according to claim 2, characterized in that: the through hole is a conical hole or a cylindrical hole. 4. The laser cladding nozzle that is convenient for cooling according to claim 2, characterized in that: the connecting head is a cylinder provided with external threads, and a through hole communicating with the beam channel is opened at the center thereof. 5. The laser cladding nozzle convenient for cooling according to claim 2, characterized in that: the connecting head is an annular convex body integrally formed with the nozzle core, and there are several holes on its side wall for The through holes of the external laser system are connected, and the through holes are evenly distributed around the central axis of the nozzle core. 6. The laser cladding nozzle convenient for cooling according to claim 2, 4 or 5, characterized in that: the powder feeding channel is a channel with a smooth inner wall, and the aperture of the channel gradually becomes smaller from the powder inlet to the powder outlet ; Each powder feeding channel is evenly distributed around the central axis of the nozzle core, and each powder feeding channel converges at one point along the extension line of the powder output direction. 7. The laser cladding nozzle convenient for cooling according to claim 6, characterized in that: the number of powder feeding channels is three to six, and the number of powder inlets and powder outlets is consistent with the number of powder feeding channels; The outer wall thickness of the nozzle core is 2-5 mm; the wall thickness of the beam channel is 2-5 mm; the wall thickness of the powder feeding channel is 2-5 mm. 8. The method for manufacturing a laser cladding nozzle that is convenient for cooling according to any one of claims 1 to 7, characterized in that it comprises the following steps: (1) Constructing a model: establishing a three-dimensional model of the laser cladding nozzle in the host computer according to the structure of the laser cladding nozzle; (2) Slicing processing: Slicing the obtained three-dimensional model of the laser cladding nozzle along the forming direction to obtain slice data of its layered section, and then import the slice data into the laser rapid prototyping device; (3) Rapid prototyping: set the rapid prototyping parameters, send the manufactured raw material powder into the laser rapid prototyping device, scan the raw material powder according to the imported slice data and accumulate layer by layer until the accumulation is formed, and the formed laser cladding is obtained nozzle; (4) Post-processing: Post-processing the formed laser cladding nozzle. 9. the manufacturing method of the laser cladding nozzle that is convenient to cooling according to claim 8 is characterized in that, in described step (3), described rapid prototyping is laser selective melting/sintering forming; Described raw material powder is Stainless steel, copper or copper alloys. 10. The method for manufacturing a laser cladding nozzle that is convenient for cooling according to claim 8 or 9, characterized in that in the step (4), the post-processing is specifically: cutting the formed laser cladding nozzle from the substrate, The surface and inside of the laser cladding nozzle are ground, sand blasted and air blown.

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