Laser coaxial fuse wire additive manufacturing device and method based on light splitting heating

Abstract

The invention discloses a laser coaxial fuse wire additive manufacturing device and method based on light splitting heating, and relates to the technical field of laser additive manufacturing. The beam splitting lens is adopted for dividing the annular laser into the inner annular laser beam and the outer annular laser beam, the inner annular laser beam is used for preheating a welding wire, the outer annular laser beam is used for additive manufacturing, and meanwhile the two laser beams can adjust the energy ratio in the additive manufacturing process in real time. The device comprises a beam shaping lens group, a laser, a wire feeding mechanism, a laser splitting component, an energy distribution system and a laser head shell. The beam shaping lens group is used for changing the beam form of the laser beam, and the energy distribution system can change the rotation angle of the beam splitting lens so as to change the distribution proportion of laser energy. According to the laser coaxial fuse wire additive device, the welding wire is preheated, the additive speed is increased on the basis that forming of an additive part is guaranteed, and the additive efficiency is improved.

Description

Technical field:

[0001] The invention relates to a laser coaxial fuse material adding device and method based on split-beam heating, belonging to the technical field of laser material adding. Background technology:

[0002] Additive manufacturing technology, also known as 3D printing technology, has attracted widespread attention from many scholars in recent years. Among the many additive manufacturing methods, laser additive manufacturing is a relatively advanced manufacturing method for preparing metal components with excellent performance. It has been widely used in aerospace, automobile, military equipment, medical and other fields. Laser coaxial fused wire additive technology uses a ring-shaped spot, and the wire is located inside the spot, which reduces the directional limitations of the additive scanning path and improves the process stability and flexibility.

[0003] When laser coaxial fuse additive is used, the laser peak energy is high, which makes the temperature gradient of the molten pool large, and columnar crystals are easily formed, which increases the anisotropy of the additive structure. Not only that, due to the low temperature of the wire, the wire needs to be completely melted after entering the molten pool to ensure good molding quality, which reduces the efficiency of additive. The emergence of hot wire laser additive has reduced the peak energy of the laser to a certain extent, while improving the efficiency of additive. However, the current hot wire laser additive generally adopts the method of applying external current, which increases the complexity of the process. In order to solve the problems of high peak energy and complex hot wire additive process in the laser coaxial fuse additive process. It is urgent to invent a laser coaxial fuse additive device and method based on spectroscopic heating, which uses laser spectrometry to preheat the wire, reduces the peak temperature of the laser during additive, and improves the efficiency of additive. Summary of the invention:

[0004] The purpose of the present invention is to preheat the wire by laser spectrometry, and to propose a laser coaxial fuse additive device and method based on spectroscopic heating, which divides the laser beam into two laser beams, which are used for wire preheating and additive respectively, and accurately controls the wire preheating temperature and the peak temperature of the additive laser, so as to finally obtain a well-formed additive structure and improve the additive efficiency.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A laser coaxial fuse additive device based on split-beam heating, characterized in that it includes a beam shaping lens group, a laser, a wire feeding mechanism, a laser splitting component, an energy distribution system, and a laser head housing;

[0007] Optionally, the energy distribution system includes a computer, a spectroscopic lens, and an insulated temperature measuring wire nozzle. The spectroscopic lens can reflect and transmit laser light. The rotation angle of the spectroscopic lens can be adjusted by computer instructions to change the ratio of laser reflection and transmission, thereby adjusting the power of the heating laser beam and changing the preheating temperature of the welding wire. After heating, the welding wire enters the insulated temperature measuring wire nozzle, which can prevent the high-temperature welding wire from contacting the additive beam focusing lens to avoid damage to the lens. At the same time, the insulated temperature measuring wire nozzle can measure the temperature of the welding wire and feed back the temperature information to the computer. The computer issues instructions to adjust the angle of the spectroscopic lens in real time to keep the welding wire at a constant temperature.

[0008] Optionally, the beam shaping lens group includes a beam shaping lens, a beam splitter prism, a beam bending lens, a reflective lens, a beam splitter lens, a plane lens, and a focusing lens. The laser beam is generated by a laser, emitted by a laser emitter after being transmitted through an optical fiber, and enters a coaxial fuse laser head. The initial unshaped laser beam is a point light source with a Gaussian distribution. Subsequently, the laser beam passes through a beam shaping lens to become a parallel annular light, and then passes through a beam splitter prism to become a symmetrically distributed semi-annular light beam. The semi-annular light beam is reflected by a beam bending lens and reaches a beam splitter lens. The laser beam is divided into two beams after passing through the beam splitter lens; one laser beam continues to be transmitted in a direction parallel to the welding wire through the lens and reaches the beam splitter prism, where it is reintegrated into an annular laser beam, and finally converges through a focusing lens to reach the additive part; the other laser beam is transmitted horizontally to reach the reflective lens and then changes its direction to be parallel to the welding wire, and finally converges through a focusing lens to reach the surface of the welding wire and heat the welding wire;

[0009] Optionally, the reflective lens is located above the plane lens, and the plane lens is mainly used to support the reflective lens;

[0010] Optionally, the energy distribution system can adjust the output power of the laser in real time during the additive process and control the wire feeding speed of the wire feeding mechanism;

[0011] Optionally, the laser coaxial fuse additive method based on split-beam heating comprises the following steps:

[0012] 1). Open the wire feeding mechanism, feed the welding wire into the wire feeder, straighten it through the straightener and then enter the coaxial fuse laser head. Stop feeding the wire after the welding wire passes through the heat-insulating temperature measuring wire nozzle;

[0013] 2). Turn on the energy distribution system, set the additive path, enter the brand or composition of the welding wire in the energy distribution system, call the database, if the selected material is in the database, call the melting point parameters of the material in the database; if the selected material is not in the database, call the melting point parameters of the material with the closest composition in the database; the energy distribution system controls the angle of the reflective lens according to the material properties to achieve the energy ratio of the heating beam and the additive beam;

[0014] 3). Turn on the laser and print according to the preset additive path. The wire feeding mechanism runs synchronously at the preset wire feeding speed. During the printing process, the energy distribution system adjusts the energy distribution of the heating beam and the additive beam in real time according to the molding quality of the additive part until the additive process is completed.

[0015] Beneficial effects of the present invention

[0016] 1. The annular laser beam is split, and the energy ratio of the two beams can be adjusted in real time, which optimizes the energy utilization ratio of the additive process. The inner annular beam is used for heating the wire, and the outer annular beam is used for the additive process, which improves the microstructure of the additive part.

[0017] 2. The addition of hot wire makes the wire melt at a faster speed inside the molten pool. On the basis of ensuring the molding of additive parts, the additive speed is increased, and the additive efficiency is improved.

[0018] 3. The device of the present invention has a high degree of intelligence and can adjust the energy ratio of the additive process in real time to obtain a good additive molding effect. Description of the drawings:

[0019] Figure 1 It is an overall schematic diagram of a coaxial fuse device based on spectroscopic heating;

[0020] Figure 2 It is a schematic diagram of laser spots at different positions;

[0021] In the figure:

[0022] 1-Laser transmitter head;

[0023] 21-unshaped laser beam, 22-annular beam, 23-semi-annular beam, 24-double semi-annular beam, 25-double annular beam, 26-heating annular beam, 27-additive annular beam;

[0024] 3-Laser head housing;

[0025] 41-beam shaping lens, 42-beam splitter prism, 43-beam bending lens, 44-reflecting lens, 45-beam splitter lens, 46-planar lens, 47-beam splitter prism, 48-heating beam focusing lens, 49-additive beam focusing lens;

[0026] 5- welding wire;

[0027] 6- Insulated temperature measuring nozzle;

[0028] 7- straightener;

[0029] 8-wire feeding mechanism;

[0030] 9-Energy distribution system;

[0031] 10-Laser;

[0032] 11- Additive parts. Specific implementation method:

[0033] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0034] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0036] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0037] When laser coaxial fused wire is used for additive manufacturing, the laser peak energy is high, which makes the temperature gradient of the molten pool large, and columnar crystals are easily formed, which increases the anisotropy of the additive structure. In addition, due to the low temperature of the wire, the wire needs to be completely melted after entering the molten pool to ensure good molding quality, which reduces the efficiency of additive manufacturing.

[0038] In view of the above problems, the present embodiment provides a laser coaxial fuse additive device and method based on spectroscopic heating, which can be used in the field of laser additive.

[0039] like Figure 1 As shown, the laser coaxial fuse additive device based on spectroscopic heating described in the present invention includes a beam shaping lens group, a laser, a wire feeding mechanism, a laser spectroscopic component, an energy distribution system, and a laser head housing. The energy distribution system includes a computer, a spectroscopic lens, and a heat-insulating temperature measuring wire nozzle. The spectroscopic lens can reflect and transmit the laser. By adjusting the rotation angle of the spectroscopic lens through computer instructions, the proportion of laser reflection and transmission can be changed, thereby adjusting the power of the heating laser beam and changing the preheating temperature of the welding wire. After heating, the welding wire enters the heat-insulating temperature measuring wire nozzle, which can prevent the high-temperature welding wire from contacting the additive beam focusing lens to avoid damage to the lens. At the same time, the heat-insulating temperature measuring wire nozzle can measure the temperature of the welding wire and feed back the temperature information to the computer. The computer issues instructions to adjust the angle of the spectroscopic lens in real time to keep the welding wire at a constant temperature.

[0040] The beam shaping lens group comprises a beam shaping lens, a beam splitter prism, a beam bending lens, a reflective lens, a beam splitter lens, a plane lens, and a focusing lens. The laser beam is generated by a laser, emitted by a laser emitter after being transmitted through an optical fiber, and enters a coaxial fuse laser head. The initial unshaped laser beam is a point light source with a Gaussian distribution. Subsequently, the laser beam passes through the beam shaping lens to become a parallel annular light, and then passes through the beam splitter prism to become a symmetrically distributed semi-annular light beam. The semi-annular light beam is reflected by the beam bending lens and reaches the beam splitter lens. The laser beam is divided into two beams after passing through the beam splitter lens; one laser beam continues to be transmitted in a direction parallel to the welding wire through the lens and reaches the beam splitter prism, where it is reintegrated into an annular laser beam, and finally converges through a focusing lens to reach the additive part; the other laser beam is horizontally transmitted to reach the reflective lens and then changes its direction to be parallel to the welding wire, and finally converges through a focusing lens to reach the surface of the welding wire and heat the welding wire.

[0041] The reflective lens is located above the plane lens, and the plane lens is mainly used to support the reflective lens. The energy distribution system can adjust the output power of the laser in real time during the additive process and control the wire feeding speed of the wire feeding mechanism at the same time.

[0042] The laser coaxial fuse additive method based on split-beam heating includes the following steps:

[0043] (1) Open the wire feeding mechanism and feed the DP800 high-strength steel welding wire with a wire diameter of 1.0 mm into the wire feeder. After being straightened by the straightener, it enters the coaxial fused wire laser head. Stop feeding the wire after the welding wire passes through the heat-insulating temperature measuring wire nozzle;

[0044] (2) Turn on the energy distribution system, import the additive path designed by the layered slicing software into the computer, enter the brand of DP800 high-strength steel welding wire in the energy distribution system, call the database, and select the laser output power of 2500W and the welding wire preheating temperature of 700℃ according to the composition and properties of DP800 high-strength steel welding wire in the database. The energy distribution system automatically calculates the angle of the beam splitter lens based on the material properties, laser energy, and preheating temperature information in the database to ensure that the welding wire preheating temperature can reach the preset temperature when the additive process starts;

[0045] (3) Turn on the laser and print according to the preset additive path. The wire feeding mechanism runs synchronously at the preset wire feeding speed. During the printing process, the energy distribution system adjusts the energy distribution of the heating beam and the additive beam in real time according to the molding quality of the additive part until the additive process is completed.

[0046] Obviously, the above embodiments of the present invention are only examples for clearly explaining the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation and application scope, and the content of this specification should not be understood as limiting the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A laser coaxial fuse additive device based on split-beam heating, characterized in that: It comprises a beam shaping lens group, a laser (10), a wire feeding mechanism (8), a laser beam splitting component, an energy distribution system (9), and a laser head housing (3); The energy distribution system (9) comprises a computer, a spectroscopic lens (45), and a heat-insulating temperature measuring wire nozzle (6). The spectroscopic lens (45) can reflect and transmit laser light. The rotation angle of the spectroscopic lens (45) can be adjusted by computer instructions to change the ratio of laser reflection and transmission, thereby adjusting the power of the heating laser beam and changing the preheating temperature of the welding wire (5). After heating, the welding wire (5) enters the heat-insulating temperature measuring wire nozzle (6). The heat-insulating temperature measuring wire nozzle (6) can prevent the high-temperature welding wire (5) from contacting the additive beam focusing lens (49) to avoid damage to the lens. At the same time, the heat-insulating temperature measuring wire nozzle (6) can measure the temperature of the welding wire (5) and feed back the temperature information to the computer. The computer issues instructions to adjust the angle of the spectroscopic lens (45) in real time to keep the welding wire (5) at a constant temperature. The beam shaping lens assembly comprises a beam shaping lens (41, 46), a beam splitter prism (42, 47), a beam bending lens (3), a reflective lens (44), a beam splitter lens (45), a plane lens (46), and a focusing lens (48, 49). The laser beam is generated by a laser (10), and is emitted by a laser emission head (1) after being transmitted through an optical fiber, and enters a coaxial fuse laser head. The initial unshaped laser beam (21) is a point light source with a Gaussian distribution, and then the laser beam passes through the beam shaping lens (41) to become a parallel annular light, and then passes through the beam splitter prism (42) to become a symmetrically distributed A semi-annular light beam is reflected by a beam bending lens (43) and reaches a beam splitting lens (45). The laser beam is split into two beams after passing through the beam splitting lens (45); one laser beam continues to be transmitted in a direction parallel to the welding wire (5) through the lens and reaches a beam splitting prism (47) and is then reintegrated into an annular laser beam, and finally converges through a focusing lens (49) and reaches the additive component (11); the other laser beam is horizontally transmitted and reaches a reflecting lens (44), and then changes its direction to be parallel to the welding wire (5), and finally converges through a focusing lens (48) and reaches the surface of the welding wire (5) and heats the welding wire (5).

2. The laser coaxial fuse additive device based on split-beam heating according to claim 1, characterized in that: The reflective lens (44) is located above the plane lens (46), and the plane lens (46) is mainly used to support the reflective lens (44).

3. The laser coaxial fuse additive device based on split-beam heating according to claim 1, characterized in that: The energy distribution system (9) is capable of adjusting the output power of the laser (10) in real time during the material addition process, while controlling the wire feeding speed of the wire feeding mechanism (8).

4. The laser coaxial fuse additive method based on split-beam heating as claimed in claim 1, characterized in that: The following steps are involved: 1). Open the wire feeding mechanism (8), feed the welding wire (5) into the wire feeder, straighten it through the straightener (7), and then enter the coaxial fuse laser head. Stop feeding the wire after the welding wire passes through the heat-insulating temperature measuring wire nozzle (6); 2). Turn on the energy distribution system (9), set the additive path, input the brand or composition of the welding wire in the energy distribution system (9), call the database, if the selected material is in the database, call the melting point parameter of the material in the database; if the selected material is not in the database, call the melting point parameter of the material with the closest composition in the database; the energy distribution system (9) controls the angle of the reflective lens (44) according to the material properties to achieve the energy ratio of the heating beam and the additive beam; 3). Turn on the laser (10), print according to the preset additive path, and the wire feeding mechanism (8) operates synchronously at a preset wire feeding speed; during the printing process, the energy distribution system (9) adjusts the energy distribution of the heating beam and the additive beam in real time according to the molding quality of the additive part (11) until the additive process is completed.

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