Green light material increasing device and method based on high-speed rotating polycrystalline ring throwing pressure forced cooling

Abstract

The invention discloses a green light material increasing device and method based on high-speed rotating polycrystalline ring throwing pressure forced cooling, the system comprises two core assemblies, namely a high-speed rotating throwing pressure forced cooling mechanism and an inverted cone total reflection mirror, and the high-speed rotating throwing pressure forced cooling mechanism drives a bevel gear transmission system through a servo motor to drive an LBO crystal to rotate at a high speed; meanwhile, a unique memory springback element is adopted to automatically increase the circulation efficiency of cooling liquid and increase the heat exchange area when the temperature rises, and a reset tension spring is matched to ensure the structural stability of the crystal module in the high-speed operation process; according to the device, the stability of the output power of green laser is remarkably improved by optimizing a thermal management mechanism, the device is particularly suitable for additive manufacturing of high-reflection metal materials such as copper and aluminum, the surface quality and the manufacturing efficiency of a formed part can be effectively improved, and an innovative technical solution is provided for laser processing of the high-reflection materials.

Description

[0001] Authors: Zhan Xiaohong, Zhang Yumeng, Sun Longxiang, Wang Leilei Technical fields:

[0002] This invention relates to the fields of powder material heat treatment and laser forming technology, and in particular to a green light additive manufacturing device and method based on high-speed rotating polycrystalline ring spin-pressure strong cooling. Background Technology

[0003] To improve the quality and efficiency of laser additive manufacturing, the use of green light sources has significant advantages, such as significantly increasing the absorption rate of high-reflectivity and high-conductivity materials like copper, aluminum, and magnesium while reducing reflection losses, and is currently experiencing rapid development. By optimizing process parameters, controlling microstructure, and improving mechanical properties, researchers have successfully fabricated aluminum and magnesium alloy components with high density and excellent mechanical properties.

[0004] However, the high power of green light sources increases the thermal accumulation effect of the crystal, thereby reducing the temperature accuracy and control rate of non-critical phase matching. Achieving rapid thermal equilibrium of the crystal while maintaining high power, high beam quality, and stable polarization of the linearly polarized output fundamental frequency source is a key technical bottleneck restricting the improvement of stability of green lasers at high power. Summary of the Invention

[0005] To address the aforementioned problems in the background technology, this invention proposes a green laser additive manufacturing device and method based on high-speed rotating polycrystalline ring forced cooling. By water-cooling and high-speed rotating the frequency doubling element during laser additive manufacturing, the heat accumulation of the LBO crystal can be controlled more precisely, improving the power stability of the green laser output. Furthermore, the forced cooling device and the additive manufacturing device are coupled together to form an integrated system, reducing the system's energy consumption and enhancing its operability.

[0006] The technical solution of this invention to solve the above problems is: a green light additive manufacturing device and method based on high-speed rotating polycrystalline ring pressure cooling, which is characterized by:

[0007] A rotary pressure cooling mechanism containing a high-speed rotating component and a pressure-spinning cooling component was designed. This mechanism was then combined with a laser source, a powder feeding mechanism, an inverted conical total reflection mirror, and a collimating lens to form an integrated device. The system specifically includes a laser source, a powder feeding mechanism, a high-speed rotating component, and a pressure-spinning cooling mechanism.

[0008] The high-speed rotating pressure cooling device designed above is divided into a high-speed rotating component and a pressure cooling component. The high-speed rotating component consists of a transverse bevel gear, a longitudinal bevel gear and a high-speed rotating motor. The rotational motion of the longitudinal bevel gear and the transverse bevel gear is driven by the high-speed rotating motor.

[0009] The forced-cooling component mainly consists of a copper base, a concave total reflection mirror, an LBO crystal, a shape memory spring-loaded element, a forced-cooling liquid circulation device, and an inverted conical total reflection mirror. The shape memory spring-loaded element is located on the outside of the copper base, covering 30% of its area. It is primarily composed of shape memory metal, which contains a compression spring. When the temperature rises, this spring spring pushes the shape memory metal outwards by 0.5–1 mm. The rebound pressure forces the cooling fluid upwards onto the copper base, accelerating the coolant return flow and thus the coolant circulation process. Simultaneously, it increases the contact area between the copper base and the coolant, causing the temperature of both the copper base and the LBO crystal to rapidly drop to room temperature or even a low temperature. Afterwards, the shape memory spring-loaded element returns to its original position, ensuring the LBO crystal can continue to operate normally.

[0010] Furthermore, the concave total reflection mirror mentioned in the above-mentioned pressure-cooling component is a complete annular structure. The purpose is to ensure that the dispersed green laser light incident in the laser source can be refocused onto the central convex total reflection mirror after being reflected by the mirror, and then transformed back into a parallel laser light that is transmitted downwards.

[0011] The aforementioned forced cooling liquid circulation device is equipped with a pressurized return pipe. This pipe is located outside the copper base, at a height that is basically level with the memory spring-loaded element. When the memory spring-loaded element pops out, it forces the forced cooling liquid to the inlet of the pressurized return pipe. Then, under pressure, it merges with the incoming coolant and accelerates the flow rate of the coolant, thereby speeding up the entire coolant circulation process and achieving a rapid decrease in the temperature of the LBO crystal.

[0012] Advantages of the present invention;

[0013] (1) In this invention, the high-speed rotation causes the heated area of ​​the LBO crystal to be no longer fixed, but swept across at high speed, thereby "dispersing" the concentrated heat source into a uniform and transient heat load in space, which greatly weakens the local thermal lensing effect. At the same time, the centrifugal force generated by the rotation works synergistically with the unique shape memory metal spring structure to achieve "active pumping" of the coolant, rather than the traditional passive flow cooling, so that the coolant impacts the hot spot area of ​​the copper base at a higher flow rate and pressure, thus doubling the heat exchange efficiency;

[0014] (2) This invention is not simply a collection of cooling components, but rather a sophisticated integrated design that combines the cooling system (pressure-driven cooling component), the power system (high-speed rotating mechanism), and the laser optical path (concave total reflection mirror). The annular reflector ensures the integrity and stability of the optical path during high-speed rotation. The memory rebound element automatically pops out to enhance cooling when the temperature rises and automatically resets after the temperature drops, forming a negative feedback closed loop. This eliminates the need for complex external sensors and control systems, thus reducing the overall energy consumption of the system. Attached Figure Description

[0015] Figure 1 This is a cross-sectional front view of the device of the present invention;

[0016] Figure 2 This is a schematic diagram of the laser source components;

[0017] Figure 3 This is a schematic diagram of the high-speed rotating component structure;

[0018] Figure 4 This is a schematic diagram of the structure of the pressure-reducing component;

[0019] Figure 5 This is a schematic diagram of a concave total internal reflection mirror;

[0020] Figure 6 This is a schematic diagram of an LBO crystal;

[0021] Figure 7 This is a schematic diagram of the structure of a forced cooling liquid circulation component;

[0022] In the picture:

[0023] 1. Laser light source,

[0024] 2. Laser scattering component, 201. Scattering crystal support structure, 202. Laser incident scattering crystal,

[0025] 3. Forced cooling component, 301. Copper base, 302. Concave total internal reflection mirror, 303. LBO crystal, 304. Magnetic cladding layer, 305. Reset magnet, 306. Memory springback element.

[0026] 4. Cooling liquid circulation components: 401. Cooling liquid inlet conduit; 402. Cooling liquid outlet conduit; 403. Cooling liquid return conduit; 404. Cooling liquid inlet; 405. Cooling liquid return port.

[0027] 5. Collimating lens; 6. Powder feeding mechanism.

[0028] 7. High-speed rotating components; 701. High-speed rotating servo motor; 702. Longitudinal bevel gear; 703. Horizontal bevel gear.

[0029] 8. Inverted cone total reflection mirror; Detailed implementation method:

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0031] Reference Figure 1A green light additive manufacturing device based on high-speed rotating polycrystalline ring pressure cooling is described. The system consists of a rotating pressure cooling mechanism composed of a laser scattering component (including a scattering crystal support structure 201 and a laser incident scattering crystal 202), a high-speed rotating component (including a high-speed rotating servo motor 701, a longitudinal bevel gear 702 and a horizontal bevel gear 703), a pressure cooling liquid circulation component 4 and a pressure cooling component 3, as well as a collimating lens 5, a powder feeding mechanism 6, and an inverted conical total reflection mirror 8.

[0032] Reference Figure 2 , Laser scattering components It consists of a scattering crystal support structure 1 and a laser incident scattering crystal 7, and is located below the laser source 1;

[0033] Reference Figure 3 The high-speed rotating component mainly consists of a high-speed rotating servo motor 701, a longitudinal bevel gear 702, and a horizontal bevel gear 703;

[0034] Reference Figure 4 and Figure 5 The forced cooling component mainly consists of a copper base 301, a reset spring 302, a concave total reflection mirror 303, an LBO crystal 304, and a memory springback element 305. The forced cooling liquid circulation component 4 mainly consists of a forced cooling liquid inlet conduit 401, a forced cooling liquid outlet conduit 402, and a forced cooling liquid return conduit. The forced cooling liquid circulation component is mainly used to circulate the forced cooling coolant, which cools the LBO crystal during its operation to ensure the stability of the LBO crystal.

[0035] A green light additive manufacturing method based on high-speed rotating polycrystalline ring pressure cooling includes the following steps:

[0036] First, the high-speed rotating servo motor 701 is started, driving the longitudinal bevel gear 702 and the horizontal bevel gear 703 to mesh and transmit power, thereby causing the entire pressure-cooling component 3, composed of the copper base 301 and LBO crystals 304, to start rotating at high speed. During this process, the combined LBO crystal 304 module is subjected to a huge centrifugal force, and its reset spring 302 provides a reverse constraint force to ensure that all crystal modules are always firmly tightened and kept in the preset precise working position under the dynamic condition of high-speed rotation. At the same time, the cooling liquid circulation component 4 is activated, and the coolant enters the system through the cooling liquid inflow conduit 401 and flows over the surface of the copper base 301 for basic cooling.

[0037] Subsequently, the laser source is activated. The fundamental frequency laser is adjusted by the laser incident scattering crystal 202 and then incident on the high-speed rotating LBO crystal 304 for frequency doubling conversion. The resulting high-power green light is reflected by the concave total reflection mirror 303 and forms a parallel laser through the inverted conical total reflection mirror 8. It passes through the collimating lens 5 to form a processing beam. The powder feeding mechanism 6 synchronously transports metal powder to the focal point of the light spot, and the laser additive manufacturing process begins.

[0038] During operation, the LBO crystal 304 generates heat by absorbing laser energy. This heat is conducted to the copper base 301. When the temperature rises to a specific threshold, the shape memory material inside the memory rebound element 305 integrated on the outside of the base expands due to heat, driving its built-in spring mechanism to pop the entire element outward by 0.5–1 mm. This popping action generates an instantaneous pulse pressure, which, on the one hand, accelerates the coolant accumulated on the surface of the copper base 301 through the strong cooling liquid return conduit 403 into the strong cooling liquid inflow conduit 401, increasing the flow speed of the strong cooling liquid in the conduit and accelerating the entire circulation process of the strong cooling liquid, greatly enhancing the heat exchange efficiency. On the other hand, it increases the contact area between the coolant and the base, thereby achieving the effect of "pressure-driven strong cooling," which rapidly suppresses the temperature of the LBO crystal 304.

[0039] When the crystal temperature drops due to forced cooling, the restoring force of the spring inside the memory spring element 305 causes it to contract and reset, awaiting the next thermal activation. Through this intermittent pulsed strong cooling mechanism triggered by temperature under high-speed rotation, the system achieves dynamic and precise control of the LBO crystal temperature, ensuring the long-term power stability of the green laser output and ultimately guaranteeing the additive manufacturing quality of highly reflective metallic materials.

[0040] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. It is neither necessary nor possible to exhaustively describe all possible implementations. The content of this specification should not be construed as a limitation of the present invention. For those skilled in the art, based on the concept of the present invention, other variations or modifications can be made on the basis of the above description. It should be noted that any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A green light additive manufacturing device and method based on high-speed rotating polycrystalline ring pressure cooling, characterized in that: It includes a high-speed rotating pressure-cooling mechanism, which includes a pressure-cooling component (3), a high-speed rotating component (7) and a cooling liquid circulation component (4). In addition, the device is also equipped with a laser light source scattering component (2), a collimating lens (5) and an inverted cone total reflection mirror (8). The high-speed rotating pressure cooling mechanism includes a pressure cooling component (3) and a high-speed rotating device (7). The device consists of a copper base (301), a spring (302), a concave total reflection mirror (303), an LBO crystal (304), and a high-temperature ejection key (305). The concave total reflection mirror (303) is embedded in the copper base (301). The shape memory spring element (306) on the copper base (301) is used to eject and squeeze the cooling water after the temperature rises and increase the side area of ​​the copper base (301) to enhance the cooling effect. The high-speed rotating pressure cooling mechanism includes a high-speed rotating device (7), which includes a high-speed rotating servo motor (701), a longitudinal bevel gear (702), and a horizontal bevel gear (703). The high-speed rotating servo motor (701) has a rotational speed range of 1500r / min-3000r / min. The transmission ratio between the longitudinal bevel gear (702) and the horizontal bevel gear (703) is 5:

1. The rotational speed range of the horizontal bevel gear is set within 300r / min-400r / min, so that the LBO crystal (303) and the concave total reflection mirror (302) generate a high-speed rotation of 5r / s-10r / s. The pressure-cooling component (3) includes a magnetite-coated reset magnet (305), which is disposed on the polycrystalline shell and positioned above the LBO crystal. The pressure-driven cooling component (3) includes an LBO crystal (303) and a concave total reflection mirror (302). The LBO crystal (303) and the concave total reflection mirror (302) are combined. Each combined module adopts an inclined design, forming a 24° angle with the vertical plane. The laser incident in the scattering crystal is reflected by the concave total reflection mirror and converges horizontally onto the inverted cone total reflection mirror (8) at the focal position of the concave total reflection mirror (303) at a 45° angle with the horizontal plane. Then it is converted into a parallel laser and transmitted to the collimating lens (5). The pressure-cooling component (3) contains a shape memory spring element (306). The surface of the shape memory spring element (305) is made of pure copper, and a spring made of shape memory alloy is arranged inside. The surface temperature of the LBO crystal (303) is transferred to the shape memory spring element (306). The spring made of shape memory alloy expands and pops out when heated, popping out the copper shape memory spring element (306). The cooling liquid flows from the cooling liquid return port (405) into the cooling liquid return conduit (403), and then into the cooling liquid inflow conduit (401) to accelerate the cooling liquid circulation speed. The laser source includes an external support platform (201) and a laser incident scattering crystal (202). After the laser light emitted from the laser source passes through the scattering crystal, the laser light is split into multiple beams and enters the LBO crystal (303) and the concave total reflection mirror (302). The inverted cone total reflection mirror (8) in the laser repair system is cone-shaped. When the green laser light is emitted from the concave total reflection mirror (302), the inverted cone total reflection mirror (8) will rescatter the green laser light at the defocused position into a parallel beam.

2. A green light additive manufacturing method based on high-speed rotating polycrystalline ring spin-pressure cooling, characterized in that, This is based on any one of the green light additive manufacturing methods described in claim 1, which utilizes high-speed rotating polycrystalline rings for forced cooling. Includes the following steps: First, the high-speed rotating servo motor (701) is started, and the motor drives the longitudinal bevel gear (702) and the horizontal bevel gear (703) to mesh and transmit power, thereby driving the entire pressure-cooling component (3) composed of the copper base (301), LBO crystal (303), etc. to start rotating at high speed. During this process, the combined LBO crystal (304) module is subjected to huge centrifugal force, and its reset spring (305) provides a reverse constraint force to ensure that all crystal modules are always firmly tightened and kept in the preset precise working position under the dynamic working condition of high-speed rotation. At the same time, the cooling liquid circulation component (4) is turned on, and the coolant enters the system through the cooling liquid inflow conduit (401) and flows over the surface of the copper base (301) for basic cooling. Subsequently, the laser source is activated. The fundamental frequency laser is adjusted by the laser incident scattering crystal (202) and then incident on the high-speed rotating LBO crystal (304) for frequency doubling conversion. The generated high-power green light is reflected by the concave total reflection mirror (303) and forms a parallel laser through the inverted cone total reflection mirror (8). It passes through the collimating lens (5) to form a processing beam. The powder feeding mechanism (6) synchronously transports metal powder to the focal point of the light spot, and the laser additive manufacturing process begins. During operation, the LBO crystal (304) generates heat by absorbing laser energy, which is conducted to the copper base (301). When the temperature rises to a specific threshold, the shape memory material inside the memory rebound element (305) integrated on the outside of the base expands due to heat, driving its built-in spring mechanism to pop the entire element outward by 0.5 to 1 mm. This popping action generates an instantaneous pulse pressure, which on the one hand accelerates the coolant accumulated on the surface of the copper base (301) through the strong cooling liquid return conduit (403) into the strong cooling liquid inlet conduit (401), increases the flow speed of the strong cooling liquid in the conduit, speeds up the entire circulation process of the strong cooling liquid, and greatly enhances the heat exchange efficiency. On the other hand, it increases the contact area between the coolant and the base, thereby achieving the effect of "pressure-driven strong cooling", which rapidly suppresses the temperature of the LBO crystal (304). When the crystal temperature drops due to forced cooling, the restoring force of the spring inside the shape memory spring element (306) causes it to contract and reset, awaiting the next thermal activation. Through this intermittent pulsed strong cooling mechanism triggered by temperature under high-speed rotation, the system achieves dynamic and precise control of the temperature of the LBO crystal (303), ensuring the long-term power stability of the green laser output and ultimately guaranteeing the additive manufacturing quality of highly reflective metallic materials.

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