阅读说明：本技术 一种用于增材制造的载气混粉式同轴送粉喷嘴 (Carrier gas powder mixing type coaxial powder feeding nozzle for additive manufacturing ) 是由 罗怡 彭延睿 张福源 阳树青 阳涛 刘娟 邓小俊 梁乙夫 兰红雨 于 2021-09-29 设计创作，主要内容包括：本发明公开了一种用于增材制造的载气混粉式同轴送粉喷嘴,包括喷嘴本体,喷嘴本体包括转换接头、喷嘴基座筒、导流套筒、内喷嘴和外喷嘴；转换接头下端与喷嘴基座筒连接,喷嘴基座筒下端与外喷嘴连接；导流套筒呈倒锥形,装在喷嘴基座筒内,导流套筒外侧壁与喷嘴基座筒内侧壁之间合围形成混粉导流腔；内喷嘴位于外喷嘴内且两者之间形成出粉通道,内喷嘴上端与导流套筒小径端螺纹连接,混粉导流腔的径向尺寸大于出粉通道宽度；喷嘴基座筒下部设有主体粉末送粉口和掺杂粉末送粉口。其能够在激光聚焦状态发生变化时相应地对粉末汇聚状态、光斑粉斑相对位置作出调整,在输送粉末过程中同步为主体粉末掺杂极细的掺杂粉末,避免产生粉末团聚体。(The invention discloses a carrier gas powder mixing type coaxial powder feeding nozzle for additive manufacturing, which comprises a nozzle body, wherein the nozzle body comprises a conversion joint, a nozzle base barrel, a flow guide sleeve, an inner nozzle and an outer nozzle; the lower end of the adapter is connected with the nozzle base barrel, and the lower end of the nozzle base barrel is connected with the outer nozzle; the guide sleeve is in an inverted cone shape and is arranged in the nozzle base barrel, and the outer side wall of the guide sleeve and the inner side wall of the nozzle base barrel are enclosed to form a powder mixing guide cavity; the inner nozzle is positioned in the outer nozzle, a powder outlet channel is formed between the inner nozzle and the outer nozzle, the upper end of the inner nozzle is in threaded connection with the small-diameter end of the flow guide sleeve, and the radial size of the powder mixing flow guide cavity is larger than the width of the powder outlet channel; the lower part of the nozzle base cylinder is provided with a main powder feeding port and a doped powder feeding port. The laser focusing device can correspondingly adjust the powder convergence state and the relative position of the light spot and the powder spot when the laser focusing state changes, and can synchronously dope the superfine doping powder for the main powder in the powder conveying process, thereby avoiding the generation of powder aggregates.)

1. The utility model provides a carrier gas mixes coaxial powder feeding nozzle of powder formula for additive manufacturing, includes that the hole is the nozzle body of laser channel, its characterized in that: the nozzle body comprises a conversion joint (1), a nozzle base barrel (3), a flow guide sleeve (4), an inner nozzle (5) and an outer nozzle (6); the upper end of the adapter (1) is used for connecting a laser emitting head, the lower end of the adapter is connected with the nozzle base barrel (3), and the lower end of the nozzle base barrel (3) is connected with the outer nozzle (6);

the guide sleeve (4) is in an inverted cone shape and is arranged in the nozzle base barrel (3), the section of the inner side wall of the nozzle base barrel (3) corresponding to the guide sleeve (4) is in a cone shape, a mixed powder guide cavity (7) is formed by surrounding the outer side wall of the guide sleeve (4) and the inner side wall of the nozzle base barrel (3),

the inner nozzle (5) is positioned in the outer nozzle (6), a powder outlet channel is formed between the inner nozzle and the outer nozzle and is communicated with the upper powder mixing guide cavity (7); the upper end of the inner nozzle (5) is in threaded connection with the small-diameter end of the flow guide sleeve (4), the size of a powder outlet channel between the inner nozzle (5) and the outer nozzle (6) is adjusted by adjusting the threaded screwing distance of the inner nozzle (5), and the radial size of the powder mixing flow guide cavity is larger than the width of the powder outlet channel;

the upper part of the nozzle base barrel (3) is provided with an inert gas interface (31) communicated with a laser channel, and the lower part of the nozzle base barrel is provided with at least one main powder feeding port (32) and at least one doped powder feeding port (33) communicated with the powder mixing guide cavity (7);

powder entering from the main powder feeding port (32) and the doped powder feeding port (33) forms circulating reflux in the powder mixing guide cavity (7), is conveyed into a powder outlet channel formed between the inner nozzle (5) and the outer nozzle (6) along the surface of the guide sleeve (4), and forms powder spots on the surface of a workpiece to be processed by taking inert gas in the laser channel as a powder feeding carrier.

2. The carrier gas powder mixing type coaxial powder feeding nozzle for additive manufacturing according to claim 1, characterized in that: the nozzle base barrel is characterized by further comprising a position adjusting assembly (2), and the lower end of the conversion joint (1) is connected with the nozzle base barrel (3) through the position adjusting assembly (2).

3. The carrier gas powder mixing type coaxial powder feeding nozzle for additive manufacturing according to claim 2, characterized in that: the position adjusting assembly (2) comprises an axial adjusting assembly and a radial adjusting assembly, the axial adjusting assembly is used for achieving axial position adjustment of the nozzle base barrel (3) relative to the conversion joint (1), and the radial adjusting assembly is used for achieving radial position adjustment of the nozzle base barrel (3) relative to the conversion joint (1) and is matched with the conversion joint to adjust the relative position between a laser beam focusing light spot generated by the laser emitting head and a powder flow convergence point.

4. The carrier gas powder mixing type coaxial powder feeding nozzle for additive manufacturing according to claim 3, characterized in that: the axial adjusting assembly comprises a first axial adjusting cylinder (21) and a second axial adjusting cylinder (22), and the longitudinal adjusting assembly comprises an inverted T-shaped connecting cylinder (23);

the outer side wall of the first axial adjusting cylinder (21) is in threaded connection with a first axial positioning ring (25), the upper end of the first axial adjusting cylinder (21) is in threaded connection with the inner side wall of the adapter (1), and the lower end of the first axial adjusting cylinder is in threaded connection with the inner side wall of the upper end of the connecting cylinder (23);

a plurality of radial adjusting screws (24) are uniformly arranged on the circumferential direction of the horizontal part of the connecting cylinder (23),

the second axial adjusting cylinder (22) is in an inverted cone shape, the large-diameter end is inserted into the connecting cylinder (23), the conical surface of the second axial adjusting cylinder (22) is in contact with the end part of the radial adjusting screw (24), and the small-diameter end is in threaded connection with the inner side wall of the upper end of the nozzle base cylinder (3).

5. The carrier gas powder mixing type coaxial powder feeding nozzle for additive manufacturing according to claim 4, characterized in that: the outer side wall of the second axial adjusting cylinder (22) is in threaded connection with a second axial positioning ring (26) and a third axial positioning ring (27), the second axial adjusting cylinder (22) is axially positioned through the second axial positioning ring (26), and the nozzle base cylinder (3) is axially positioned through the third axial positioning ring (27).

6. The carrier gas powder mixing type coaxial powder feeding nozzle for additive manufacturing according to claim 4, characterized in that: and a protective lens is arranged in an inner hole of the connecting cylinder (23).

7. The carrier gas-powder mixing type coaxial powder feeding nozzle for additive manufacturing according to claim 1 or 2, characterized in that: the outer side wall of the small-diameter end of the flow guide sleeve (4) is in threaded connection with a fourth axial positioning ring (51), and the inner nozzle (5) is axially positioned through the fourth axial positioning ring (51).

8. The carrier gas-powder mixing type coaxial powder feeding nozzle for additive manufacturing according to claim 1 or 2, characterized in that: interior nozzle (5) and outer nozzle (6) all are the back taper, and the play powder passageway conical surface inclination that forms between the two is 50 ~ 70, and play powder passageway clearance width is 0.5 ~ 2.0 mm.

9. The carrier gas-powder mixing type coaxial powder feeding nozzle for additive manufacturing according to claim 1 or 2, characterized in that: the nozzle base barrel (3) is provided with three main powder feeding ports (32) and three doped powder feeding ports (33), the main powder feeding ports (32) and the doped powder feeding ports (33) are uniformly distributed on the same circumference of the barrel wall of the nozzle base barrel (3), and the main powder feeding ports (32) and the doped powder feeding ports (33) are arranged at intervals.

10. The carrier gas-powder mixing type coaxial powder feeding nozzle for additive manufacturing according to claim 1 or 2, characterized in that: a plurality of axial diversion grooves (41) are uniformly distributed on the periphery of the diversion sleeve (4).

Technical Field

The invention relates to laser additive manufacturing, in particular to a carrier gas powder mixing type coaxial powder feeding nozzle for additive manufacturing.

Background

The laser additive manufacturing technology becomes a new advanced manufacturing method for directly and rapidly manufacturing three-dimensional solid metal parts and repairing precious metal parts, and is widely applied to the industries of aerospace, petrochemical engineering, electronic information, energy environment and the like. In a laser additive manufacturing technology system, a high-power laser is used for directly forming a compact metal part in a laser melting deposition manufacturing technology, and the compact metal part is paid more and more attention to the related industrial field due to low cost and good controllability.

The powder feeding system is a very important system in a laser fused deposition manufacturing and forming system. The powder delivery nozzle, as a component of the powder delivery system, directly affects the quality and accuracy of the formed part. In a typical laser fused deposition fabrication forming system, the following characteristics are often required for the powder delivery nozzle: 1. the powder flow delivered has good stability and uniformity to ensure good surface formation. 2. The powder flow conveyed has good convergence so as to ensure the powder utilization rate and good forming precision. 3. The end of the powder feeding nozzle is far away from the laser molten pool so as to avoid the phenomenon that molten splashes or powder are adhered to the outlet of the nozzle to have adverse effects on the powder feeding state and the heat dissipation of the nozzle.

Commonly used powder feeding nozzles include both paraxial and coaxial powder feeding nozzles. The paraxial powder feeding nozzle is widely applied in the initial stage of the application of the laser fused deposition manufacturing technology, but the paraxial powder feeding nozzle is only suitable for the movement of a simple track and is not suitable for the movement of a complex track, and the forming size and the performance of an additive layer in each direction cannot be ensured, so that the paraxial powder feeding nozzle cannot meet the use requirement of the development of the laser fused deposition manufacturing technology. The coaxial powder feeding nozzle enables the powder flow and the laser beam to be coaxially output, is symmetrical in all directions of the circumference, has no directional limitation, has good isotropic property of the powder flow, and can realize two-dimensional plane additive forming and three-dimensional forming manufacturing. However, the characteristics of the powder flow, such as stability, uniformity, convergence and isotropy, greatly depend on the structure of the coaxial powder feeding nozzle, so that researchers at home and abroad are always dedicated to the design and development of the high-performance coaxial powder feeding nozzle.

At present, although the powder feeding stability, uniformity and convergence performance of a coaxial powder feeding nozzle which is widely used can meet the requirements, the problem of difficulty in matching and adjusting with laser focusing parameters generally exists. When the size of the laser spot is changed due to the process adjustment or the laser focusing position is changed, the powder flow convergence state and the powder spot position are difficult to correspondingly adjust. Moreover, the laser melting deposition manufacturing technology needs to mix and uniformly configure the powder in advance, and if the powder has very fine particle size or the main powder needs to be doped with alloy powder with very fine particle size, the agglomeration phenomenon is very easy to occur in the secondary mixing configuration process or the use process of the powder to form powder agglomerates, so that the powder feeding state and the powder melting behavior are extremely adversely affected. Therefore, a coaxial powder feeding nozzle which can not only facilitate the matching and adjustment of light and powder, but also effectively ensure the uniform delivery of powder is needed.

Disclosure of Invention

The invention aims to provide a carrier gas powder mixing type coaxial powder feeding nozzle for additive manufacturing, which can correspondingly adjust the powder convergence state and the relative position of light spot powder spots when the laser focusing state changes, and can synchronously dope superfine doping powder for main powder in the powder conveying process, thereby effectively avoiding the generation of powder aggregates.

The carrier gas powder mixing type coaxial powder feeding nozzle for additive manufacturing comprises a nozzle body, wherein an inner hole of the nozzle body is a laser channel, and the nozzle body comprises a conversion joint, a nozzle base barrel, a flow guide sleeve, an inner nozzle and an outer nozzle; the upper end of the adapter is used for connecting a laser emitting head, the lower end of the adapter is connected with a nozzle base barrel, and the lower end of the nozzle base barrel is connected with an outer nozzle; the guide sleeve is in an inverted cone shape and is arranged in the nozzle base barrel, the section of the inner side wall of the nozzle base barrel corresponding to the guide sleeve is in a cone shape, and a powder mixing guide cavity is formed by surrounding the outer side wall of the guide sleeve and the inner side wall of the nozzle base barrel; the inner nozzle is positioned in the outer nozzle, a powder outlet channel is formed between the inner nozzle and the outer nozzle and is communicated with the upper powder mixing guide cavity; the upper end of the inner nozzle is in threaded connection with the small-diameter end of the flow guide sleeve, the size of a powder outlet channel between the inner nozzle and the outer nozzle is adjusted by adjusting the threaded screwing distance of the inner nozzle, and the radial size of the powder mixing flow guide cavity is larger than the width of the powder outlet channel; the upper part of the nozzle base barrel is provided with an inert gas interface communicated with the laser channel, and the lower part of the nozzle base barrel is provided with at least one main powder feeding port and at least one doped powder feeding port communicated with the powder mixing guide cavity; powder entering from the main powder feeding port and the doped powder feeding port forms circulating reflux in the powder mixing guide cavity, is conveyed into a powder outlet channel formed between the inner nozzle and the outer nozzle along the surface of the guide sleeve, and forms powder spots on the surface of a workpiece to be processed by taking inert gas in the laser channel as a powder feeding carrier.

Further, still include position control assembly, the crossover sub lower extreme passes through position control assembly and is connected with nozzle base section of thick bamboo.

Further, the position adjusting assembly comprises an axial adjusting assembly and a radial adjusting assembly, the axial adjusting assembly is used for achieving axial position adjustment of the nozzle base barrel relative to the adapter, and the radial adjusting assembly is used for achieving radial position adjustment of the nozzle base barrel relative to the adapter so as to adjust the relative position between a laser beam focusing spot generated by the laser emitting head and a powder flow converging point.

Further, the axial adjusting assembly comprises a first axial adjusting cylinder and a second axial adjusting cylinder, and the longitudinal adjusting assembly comprises an inverted T-shaped connecting cylinder; the outer side wall of the first axial adjusting cylinder is in threaded connection with a first axial positioning ring, the upper end of the first axial adjusting cylinder is in threaded connection with the inner side wall of the adapter, and the lower end of the first axial adjusting cylinder is in threaded connection with the inner side wall of the upper end of the connecting cylinder; the horizontal part circumference of connecting cylinder evenly is equipped with a plurality of radial adjusting screw, and the second axial is adjusted a section of thick bamboo and is the back taper, and big footpath end is inserted in the connecting cylinder and the conical surface and the radial adjusting screw tip contact of a second axial adjustment section of thick bamboo, and the footpath end is held and nozzle base section of thick bamboo upper end inside wall threaded connection.

Furthermore, the outer side wall of the second axial adjusting cylinder is in threaded connection with a second axial positioning ring and a third axial positioning ring, the second axial positioning ring is used for achieving axial positioning of the second axial adjusting cylinder, and the third axial positioning ring is used for achieving axial positioning of the nozzle base cylinder.

Furthermore, a protective lens is arranged in an inner hole of the connecting cylinder.

Furthermore, the outer side wall of the small-diameter end of the flow guide sleeve is in threaded connection with a fourth axial positioning ring, and the inner nozzle is axially positioned through the fourth axial positioning ring.

Further, interior nozzle and outer nozzle all are the back taper, and the play powder passageway conical surface inclination that forms between the two is 50 ~ 70, and play powder passageway clearance width is 0.5 ~ 2.0 mm.

Furthermore, the nozzle base barrel is provided with three main powder feeding ports and three doped powder feeding ports, the main powder feeding ports and the doped powder feeding ports are uniformly distributed on the same circumference of the barrel wall of the nozzle base barrel, and the main powder feeding ports and the doped powder feeding ports are arranged at intervals.

Furthermore, a plurality of axial diversion grooves are uniformly distributed on the periphery of the diversion sleeve.

Compared with the prior art, the invention has the following beneficial effects.

1. According to the invention, the main powder feeding port and the doped powder feeding port which are communicated with the powder mixing guide cavity are arranged at the lower part of the nozzle base cylinder, the outer side wall of the guide sleeve and the inner side wall of the nozzle base cylinder surround to form the powder mixing guide cavity, so that the uniformity and stability of powder conveying are better ensured, the powder mixing and powder feeding are synchronously carried out, the procedure of mixing the main powder and the doped powder before additive manufacturing is reduced, the powder aggregate formation caused by the aggregation phenomenon in the secondary mixing and configuration process or the use process of the powder is effectively avoided, and the powder feeding state and the powder melting behavior are ensured to meet the requirements.

2. According to the invention, the position of the first axial positioning ring on the first axial adjusting cylinder is adjusted, so that the nozzle base cylinder can axially move in a large range relative to the adapter, and the relative positions of the powder flow powder spot and the laser spot in the axial direction can be conveniently adjusted in a large range. The position of the third axial positioning ring on the second axial adjusting cylinder is adjusted, so that the nozzle base cylinder can axially move in a small range relative to the second axial adjusting cylinder, and the relative positions of the powder flow powder spot and the laser spot in the axial direction can be finely adjusted conveniently. The radial position of the nozzle base barrel relative to the connecting barrel is adjusted through the plurality of radial adjusting screws uniformly arranged on the horizontal part of the connecting barrel, so that the adjustment of the radial positions of powder flow powder spots and laser light spots is realized.

3. The invention realizes the clearance adjustment between the inner nozzle and the outer nozzle by adjusting the screwing distance of the screw thread of the inner nozzle, even if the relative position of the inner nozzle and the outer nozzle and the width of the slit of the powder outlet channel are changed, thereby finely adjusting the powder flow convergence state, the axial position of powder flow powder spots and the size of the powder spots. When the inner nozzle is adjusted to be retracted into the outer nozzle, the axial position of the powder flow powder spot tends to be close to the center of the nozzle, the powder flow tends to converge, and the size of the powder spot is reduced; when the inner nozzle is adjusted to extend out of the outer nozzle, the axial position of the powder flow powder spot tends to be far away from the center of the nozzle, the powder flow tends to diverge, and the powder spot size becomes larger.

4. The invention realizes the adjustment of the axial and radial relative positions of the powder flow powder spot and the laser spot by using the position adjusting component, and realizes the adjustment of the powder flow convergence state by using the adjustment of the screwing distance of the inner nozzle thread, and has high use flexibility and strong functional practicability.

Drawings

FIG. 1 is a schematic structural view of a nozzle body according to the present invention;

FIG. 2 is a schematic internal view of the nozzle body of the present invention;

FIG. 3 is a schematic diagram showing the distribution of the powder feeding ports for the bulk powder and the doped powder according to the present invention.

In the figure, 1-adapter, 2-position adjusting component, 21-first axial adjusting cylinder, 22-second axial adjusting cylinder, 23-connecting cylinder, 24-radial adjusting screw, 25-first axial positioning ring, 26-second axial positioning ring, 27-third axial positioning ring, 3-nozzle base cylinder, 31-inert gas interface, 32-main powder feeding port, 33-doped powder feeding port, 4-flow guiding sleeve, 41-flow guiding groove, 5-inner nozzle, 51-fourth axial positioning ring, 6-outer nozzle, 61-cooling cavity, 7-mixed powder flow guiding cavity, and 8-protective lens drawer.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

Referring to fig. 1 and 2, the carrier gas powder mixing type coaxial powder feeding nozzle for additive manufacturing includes a nozzle body with an inner hole as a laser channel, and the nozzle body includes a conversion joint 1, a position adjusting assembly 2, a nozzle base barrel 3, a flow guide sleeve 4, an inner nozzle 5 and an outer nozzle 6.

The upper end of the adapter 1 is connected with the laser emitting head, the lower end of the adapter is connected with the nozzle base barrel 3 through the position adjusting assembly 2, the lower end of the nozzle base barrel 3 is connected with the outer nozzle 6, and the inner ring of the outer nozzle 6 is provided with a cooling cavity. The guide sleeve 4 is an inverted cone, a plurality of axial guide grooves 4 are uniformly distributed on the periphery of the guide sleeve, the cross section of the inner side wall of the nozzle base barrel 3 corresponding to the guide sleeve 4 is conical, and a mixed powder guide cavity 7 is formed by surrounding the outer side wall of the guide sleeve 4 and the inner side wall of the nozzle base barrel 3. The inner nozzle 5 is positioned in the outer nozzle 6, a powder outlet channel is formed between the inner nozzle and the outer nozzle, and the powder outlet channel is communicated with the upper powder mixing guide cavity 7; the upper end of the inner nozzle 5 is in threaded connection with the small-diameter end of the flow guide sleeve 4, the size of a powder outlet channel between the inner nozzle 5 and the outer nozzle 6 is adjusted by adjusting the threaded screwing-in distance of the inner nozzle 5, and the radial size of the powder mixing flow guide cavity is larger than the width of the powder outlet channel. In order to adjust the axial position of the inner nozzle 5 more accurately, a fourth axial positioning ring 51 is connected to the outer side wall of the small-diameter end of the flow guide sleeve 4 in a threaded manner, and the axial positioning of the inner nozzle 4 is realized through the fourth axial positioning ring 51.

Interior nozzle 5 and outer nozzle 6 all are the back taper, and the play powder passageway conical surface inclination that forms between the two is 50 ~ 70, and play powder passageway clearance width is 0.5 ~ 2.0 mm. The adjustment of the screwing distance of the inner nozzle 5 changes the relative position of the inner nozzle 5 and the outer nozzle 6 and the slit width of the powder outlet channel, thereby finely adjusting the powder flow convergence state, the axial position of the powder flow powder spot and the size of the powder spot. When the inner nozzle 5 is adjusted to be retracted inside the outer nozzle 6, the axial position of the powder flow powder spot tends to be close to the center of the nozzle, the powder flow tends to converge, and the size of the powder spot is reduced; when the inner nozzle 5 is adjusted to extend beyond the outer nozzle 6, the powder flow powder spot tends to be located away from the nozzle center in the axial direction, the powder flow tends to diverge, and the powder spot becomes larger in size.

The upper part of the nozzle base barrel 3 is provided with an inert gas interface 31 communicated with the laser channel, and the lower part is provided with three main body powder feeding ports 32 and three doped powder feeding ports 33 communicated with the powder mixing diversion cavity 7. In order to ensure the powder feeding uniformity and the mixing uniformity of the main powder and the doping powder, referring to fig. 3, three main powder feeding ports 32 and three doping powder feeding ports 33 are uniformly distributed on the same circumference of the wall of the nozzle base cylinder 3, and the main powder feeding ports 32 and the doping powder feeding ports 33 are arranged at intervals.

As a preferred embodiment of the present invention, the position adjusting assembly 2 includes an axial adjusting assembly for adjusting the axial position of the nozzle base cylinder 3 relative to the adapter, and a radial adjusting assembly for adjusting the radial position of the nozzle base cylinder relative to the adapter, so as to adjust the relative position between the focused spot of the laser beam generated by the laser emitting head and the converging point of the powder flow.

The axial adjustment assembly comprises a first axial adjustment barrel 21 and a second axial adjustment barrel 22, and the longitudinal adjustment assembly comprises a connecting barrel 23 in an inverted T shape. The outer side wall of the first axial adjusting cylinder 21 is in threaded connection with a first axial positioning ring 25, the upper end of the first axial adjusting cylinder is in threaded connection with the inner side wall of the adapter 1, and the lower end of the first axial adjusting cylinder is in threaded connection with the inner side wall of the upper end of the connecting cylinder 23. By adjusting the position of the first axial positioning ring 25 on the first axial adjustment cylinder 21, the nozzle base cylinder 3 can axially move in a large range relative to the adapter 1, so that the relative positions of the powder flow powder spot and the laser spot in the axial direction can be adjusted in a large range conveniently.

The horizontal part circumference of connecting cylinder 23 evenly is equipped with four radial adjusting screw 24, second axial adjustment cylinder 22 is the back taper, and big footpath end is inserted in connecting cylinder 23 and the conical surface and the radial adjusting screw 24 tip contact of second axial adjustment cylinder 22, and the minor diameter end is connected with nozzle base section of thick bamboo 3 upper end inside wall threaded connection. The radial position of the nozzle base cylinder 3 relative to the connecting cylinder 23 is adjusted by four radial adjusting screws 24 uniformly arranged on the horizontal part of the connecting cylinder 23 in the circumferential direction, so that the adjustment of the radial positions of the powder flow powder spots and the laser light spots is realized.

The outer side wall of the second axial adjusting cylinder 22 is in threaded connection with a second axial positioning ring 26 and a third axial positioning ring 27, the second axial positioning ring 26 is used for realizing the axial positioning of the second axial adjusting cylinder 22, and the third axial positioning ring 27 is used for realizing the axial positioning of the nozzle base cylinder 3. By adjusting the position of the third axial positioning ring 27 on the second axial adjusting cylinder 22, the nozzle base cylinder 3 can axially move in a small range relative to the second axial adjusting cylinder 22, so that the relative positions of the powder flow powder spot and the laser spot in the axial direction can be finely adjusted.

The connecting cylinder 23 is provided with a protective lens drawer 8, when in use, a protective lens is arranged in the protective lens drawer 8, and the protective lens is quickly installed and uninstalled by radially pushing and pulling the protective lens drawer 8.

During specific work, the main powder feeding port 32 and the doped powder feeding port 32 which are uniformly distributed on the nozzle base barrel 3 directly feed the main powder and the doped powder into the mixed powder guide cavity 7, the inner side wall cross section corresponding to the guide sleeve 4 of the nozzle base barrel 3 is conical, the width of a powder outlet channel gap formed between the inner nozzle 5 and the outer nozzle 6 is 0.5-2.0 mm smaller than the radial dimension of the mixed powder guide cavity 7, so that the main powder and the doped powder form circulating reflux in the mixed powder guide cavity 7, the main powder and the doped powder with different components or particle sizes are fully mixed, the main powder and the doped powder are conveyed into a powder outlet channel formed between the inner nozzle 5 and the outer nozzle 6 along the guide groove 41, and inert gas in a laser channel is used as a powder feeding carrier to form powder spots on the surface of a workpiece to be processed. The powder mixing and guiding structure can ensure that the powder is uniformly and stably conveyed, and can also ensure that powder aggregates are prevented from being formed while powder components with different particle sizes are uniformly mixed when the nano-scale alloy powder is doped.

The above-mentioned embodiments are descriptions of typical preferred embodiments of the present invention, but the technical solution of the present invention is not limited thereto, and any changes and modifications made by those skilled in the art based on the main technical concept of the present invention will fall within the technical scope of the present invention.

The carrier gas powder mixing type coaxial powder feeding nozzle for laser additive manufacturing, provided by the invention, can ensure the uniformity, stability and convergence of the powder to be conveyed, can realize matching adjustment with the focusing state of a laser beam, is convenient to use, has strong functionality, is beneficial to improving the efficiency and quality of laser additive manufacturing, and has wide popularization and application prospects.