Temperature-adjustable laser material reducing device and method

Abstract

The invention relates to a temperature-adjustable laser material reduction device and method.The device comprises a base, a second support, a temperature control part, a moving platform, a first support, a laser emitting part, a temperature adjusting part and the like, and the method comprises the steps of component heating, femtosecond laser material reduction machining, real-time temperature control and evaluation optimization; through the PID temperature controller and the infrared temperature detector, the temperature of the surface of the metal component can be accurately controlled, surface defects and residual stress caused by temperature fluctuation in traditional laser machining are avoided, through dynamic adjustment of laser parameters and the temperature, powder adhesion, the step effect and surface unevenness are remarkably reduced, the surface roughness can be reduced to Ra 0.2 micrometer or below, and the surface quality is improved. Through high-precision machining of femtosecond laser and optimization of a temperature control system, the size precision of the metal component can reach + / -0.01 mm, the high-precision manufacturing requirement is met, and the method is suitable for additive and subtractive composite manufacturing of various metal materials and particularly has remarkable advantages in machining of temperature sensitive materials or multi-layer composite materials.

Description

Technical Field

[0001] The present invention relates to the technical field of laser subtractive manufacturing, and more specifically, to a temperature-adjustable laser subtractive manufacturing device and method. Background Art

[0002] With the wide application of laser processing technology in the field of precision manufacturing, traditional laser subtractive manufacturing processes have shown significant defects in the processing of temperature-sensitive materials. In the prior art, during the subtractive manufacturing process after selective laser melting (SLM) additive manufacturing, due to the lack of timely control of the residual temperature, thermal damage, residual stress accumulation, and powder adhesion phenomena often occur on the material surface. In addition, although traditional femtosecond laser processing has the advantage of non-thermal effects, when processing high-reflectivity metals or complex structures, the following problems still exist:

[0003] Lack of temperature control: There is a lack of a dynamic temperature control mechanism, and the temperature fluctuations in the processing area make it difficult to meet the high-precision requirements for surface roughness (Ra > 0.5 μm) and dimensional errors (±0.05 mm);

[0004] Parameter curing: Parameters such as laser energy density and scanning speed cannot be adjusted in real time according to the material temperature, which easily leads to staircase effects and microcracks;

[0005] Expansion of the heat-affected zone: The superposition of the residual heat after additive manufacturing and the heat generated by laser processing exacerbates the risk of material phase change and deformation.

[0006] Some improvements in the prior art lie in the temperature control system, but its temperature control system only realizes static temperature compensation through preheating and cannot respond to the temperature changes during the processing in real time. Others use a water cooling system for cooling, but this will introduce the problem of stress concentration caused by uneven cooling.

[0007] Therefore, there is an urgent need for a processing solution that integrates dynamic temperature control and collaborative optimization of laser parameters to improve the surface quality and processing accuracy. Summary of the Invention

[0008] For this reason, one object of the present invention is to provide a temperature-adjustable laser subtractive manufacturing device to solve the above problems. Another object is to provide a method based on the temperature-adjustable laser subtractive manufacturing device.

[0009] The technical solution of the present invention is a temperature-adjustable laser subtractive manufacturing device, including:

[0010] A base;

[0011] A second bracket, located on top of the base, which is sequentially connected with a reflecting mirror, a galvanometer scanner, and an f-theta lens from top to bottom;

[0012] A temperature control unit, located below the f-theta lens, on which a metal component is placed;

[0013] A moving platform is located on the base, connected to the temperature control part, and can move the temperature control part within the spatial range of the X-axis, Y-axis, and Z-axis;

[0014] A first bracket is located on one side of the base and opposite to the second bracket. A diode-pumped femtosecond laser, a signal attenuator, a quarter-wave plate, a beam expander, and a diffractive optical element are sequentially arranged and connected thereon from the side far from the second bracket to the side close to the second bracket;

[0015] A temperature regulation part includes an infrared thermometer close to the metal component and located on the moving platform, and a PID temperature controller located on the base. The PID temperature controller maintains the surface temperature of the metal component within a suitable processing temperature range according to the signal detected by the infrared thermometer.

[0016] For the adjustable-temperature laser subtractive manufacturing device according to the present invention, the temperature control part includes an electric furnace plate and a cover body. The electric furnace plate has a resistance wire, and the cover body covers the resistance wire. The metal component is located on the cover body.

[0017] For the adjustable-temperature laser subtractive manufacturing device according to the present invention, a heat-insulating cotton and a fixing shell are sequentially sleeved on the outer wall of the cover body from the inside to the outside.

[0018] For the adjustable-temperature laser subtractive manufacturing device according to the present invention, the temperature regulation part further includes a computer. The PID temperature controller and the infrared thermometer are both electrically connected to the computer. The computer is used to receive infrared temperature measurement data and synchronously adjust laser parameters. The laser energy density range is 0.1 - 10 J / cm 2 , the scanning speed is 10 - 500 mm / s, and the repetition frequency is 10 kHz - 1 MHz.

[0019] For the adjustable-temperature laser subtractive manufacturing device according to the present invention, two fixing plates are parallelly connected in the vertical direction on the side of the base close to the first bracket. A Z-axis moving component is vertically slidably connected to the two fixing plates. A Y-axis moving component is arranged on the Z-axis moving component. An X-axis moving component is arranged on the Y-axis moving component. A fixing seat is connected to the X-axis moving component. The infrared thermometer is fixed to the fixing seat through a third bracket; the temperature control part is fixed to the fixing seat; wherein the Z-axis moving component, the Y-axis moving component, and the X-axis moving component form the moving platform of the temperature control part.

[0020] Another solution of the present invention is a method based on the above adjustable-temperature laser subtractive manufacturing device, including the following steps:

[0021] S1. Place the metal component after additive manufacturing on the temperature control part, and set the target temperature T through the PID temperature controller;

[0022] S2. Set the femtosecond laser energy density E and the scanning speed V according to the type of metal material and the temperature T; start the galvanometer scanning system, and focus the laser beam through the f-theta lens to perform subtractive processing on the metal component.

[0023] S3. The infrared thermometer collects the temperature data of the processed surface of the metal component at a certain frequency; when the detected temperature deviates from the set value, adjust the output power of the PID temperature controller and the laser energy density E to maintain the temperature in the processing area stable within a suitable processing temperature range.

[0024] S4. Use X-ray diffractometer, scanning electron microscope and confocal microscope to perform microscopic detection on the surface of the processed hole, analyze the surface roughness, hole shape and dimensional accuracy, measure the powder adhesion and step effect, and evaluate the influence of temperature on the surface quality and dimensional accuracy by comparing the processing effects at different temperatures; accurately measure the size of the hole with a coordinate measuring instrument, comprehensively analyze the influence of different experimental parameters on the processing effect, and optimize the parameter combination.

[0025] According to the method of the present invention, in S1, the target temperature is set as 100°C ≤ T ≤ 900°C, and the heat insulation cotton and the fixed shell are wrapped on the outer wall of the metal component to reduce the heat dissipation to the outside, ensure that the heat energy is concentrated on the surface of the metal component, keep the temperature of the metal component uniform, and avoid too large temperature gradient.

[0026] According to the method of the present invention, in S2, according to the type of metal material and the temperature T, the femtosecond laser energy density E = K × T is set, where K is the coefficient related to the thermal conductivity of the material, 0.1 ≤ E ≤ 10 J / cm 2 ; the scanning speed V = α / (T - T0), where α is the thermal diffusivity of the material, 10 mm / s ≤ V ≤ 500 mm / s; adjust the position of the metal component in the three-dimensional space by adjusting the Z-axis moving component, the Y-axis moving component and the X-axis moving component.

[0027] According to the method of the present invention, in S3, the infrared thermometer collects the temperature data of the surface of the metal component at a frequency of ≥ 10 Hz.

[0028] According to the method of the present invention, the infrared thermometer continuously collects the temperature data of the surface of the metal component and transmits it to the computer. Combining the thermal physical property data of the material, analyze the influence of the current temperature change on the material deformation, residual stress and surface roughness. When the temperature deviates from the set range, the computer dynamically adjusts the PID temperature controller according to the temperature feedback, and adjusts the output power of the electric furnace plate through the PID algorithm to match the temperature change of the metal material.

[0029] It can be seen from the above technical solutions that compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention is designed with a dynamic temperature control system. Through a PID temperature controller and an infrared thermometer, it can accurately control the temperature of the metal component surface, avoiding surface defects and residual stresses caused by temperature fluctuations in traditional laser processing. Through the dynamic adjustment of laser parameters and temperature, powder adhesion, step effect, and surface unevenness are significantly reduced, and the surface roughness can be reduced to below Ra 0.2μm. Through the high-precision processing of femtosecond lasers and the optimization of the temperature control system, the dimensional accuracy of metal components can reach ±0.01mm, meeting the requirements of high-precision manufacturing, and is applicable to the additive and subtractive composite manufacturing of various metal materials, especially having significant advantages in the processing of temperature-sensitive materials or multi-layer composite materials.

[0031] Specifically:

[0032] 1. Through the cooperation of an f-theta lens and a galvanometer scanner, linear focusing scanning of the laser beam is achieved, with a processing dimensional accuracy of ±0.01mm and a surface roughness of ≤Ra 0.2μm. The positioning accuracy of the moving platform (XYZ three-axis linkage) is ≤5μm, ensuring the geometric consistency of complex structure processing.

[0033] 2. The infrared thermometer monitors the temperature in real time at a frequency of ≥10Hz, and the PID temperature controller adjusts the power of the electric furnace plate to make the temperature fluctuation of the metal component surface ≤±5°C, avoiding the accumulation of thermal stress. The combined design of the heat insulation cotton and the fixed shell reduces the heat dissipation rate to ≤5%, ensuring temperature uniformity (gradient ≤10°C / cm).

[0034] 3. The laser energy density (0.1 - 10J / cm 2 ) and the scanning speed (10 - 500mm / s) can be dynamically adjusted according to the material type (such as titanium alloy, stainless steel) and temperature (100 - 900°C), reducing the powder adhesion rate by ≥50%. The laser energy distribution is homogenized through a diffractive optical element, and the step effect is reduced to ≤5μm / layer.

[0035] 4. Combining the detection data of an X-ray diffractometer and a confocal microscope, the residual stress (≤200MPa) and the aperture tolerance (±5μm) can be quantified, providing closed-loop feedback for parameter optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0037] Figure 1 FIG. is a schematic three-dimensional structure diagram of an adjustable-temperature laser subtractive device provided by the present invention;

[0038] Figure 2 is Figure 1 The enlarged structural schematic diagram of area A in

[0039] Figure 3 is the three-dimensional structural schematic diagram of an adjustable-temperature laser subtractive device provided by the present invention from another perspective;

[0040] Figure 4 is Figure 3 The enlarged structural schematic diagram of area B in

[0041] Figure 5 is the front-view structural schematic diagram of an adjustable-temperature laser subtractive device provided by the present invention;

[0042] Figure 6 is the top-view structural schematic diagram of an adjustable-temperature laser subtractive device provided by the present invention;

[0043] Figure 7 is Figure 6 The enlarged structural schematic diagram of area C in

[0044] Figure 8 is the three-dimensional sectional structural schematic diagram of the temperature adjustment part in the device of the present invention;

[0045] Figure 9 is the method flow chart of the present invention;

[0046] Figure 10 is the process flow chart of the present invention.

[0047] In the figure: 1. Base; 2. First bracket; 3. Diode-pumped femtosecond laser; 4. Signal attenuator; 5. Quarter-wave plate; 6. Beam expander; 7. Diffractive optical element; 8. Second bracket; 9. Mirror; 10. Galvanometer scanning; 11. f-theta lens; 12. Fixed seat; 13. Fixed shell; 14. Electric furnace plate; 15. Resistance wire; 16. Heat insulation cotton; 17. Metal component; 18. Cover body; 19. Third bracket; 20. Infrared temperature detector; 21. PID temperature controller; 22. Computer; 23. Fixed plate; 24. First motor; 25. First pulley; 26. First belt; 27. First slide rail; 28. First slide block; 29. Second slide rail; 30. Second motor; 31. Second pulley; 32. Second slide block; 33. Third slide rail; 34. Third motor; 35. Lead screw; 36. Second belt. Detailed implementation manners

[0048] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0049] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

[0050] Since there are problems in traditional femtosecond laser processing such as lack of temperature control, parameter curing, and expansion of the heat affected zone, in view of this, a technical solution of the present invention is a temperature-adjustable laser subtractive device, see attached Figure 1-8 , including: a base 1, a second bracket 8, a temperature control part, a moving platform, a first bracket 2, a laser emitting part, a temperature adjusting part, etc.

[0051] Among them, the second bracket 8 is located on the top of the base 1, and is successively connected with a reflecting mirror 9, a galvanometer scanner 10, and an f-theta lens 11 from top to bottom; the temperature control part is located below the f-theta lens 11, and a metal member 17 is placed thereon; the moving platform is located on the base 1 and is connected to the temperature control part, and can drive the temperature control part to move within the spatial range of the X-axis, Y-axis, and Z-axis; the first bracket 2 is located on one side of the base 1 and is opposite to the second bracket 8, and is successively arranged and connected with a diode-pumped femtosecond laser 3, a signal attenuator 4, a quarter-wave plate 5, a beam expander 6, and a diffractive optical element 7 from the side far away from the second bracket 8 to the side close to the second bracket 8; the laser emitting part includes a diode-pumped femtosecond laser 3, a signal attenuator 4, a quarter-wave plate 5, a beam expander 6, a diffractive optical element 7, a reflecting mirror 9, a galvanometer scanner 10, and an f-theta lens 11.

[0052] The temperature adjusting part includes an infrared thermometer 20 close to the metal member 17 and located on the moving platform, and a PID temperature controller 21 located on the base 1. The PID temperature controller 21 maintains the surface temperature of the metal member 17 within a suitable processing temperature range according to the signal detected by the infrared thermometer 20.

[0053] In the above solution, see attached Figure 8, the temperature control part includes an electric furnace plate 14 and a cover 18. The electric furnace plate 14 has a resistance wire 15, the cover 18 covers the resistance wire 15, and the metal member 17 is located on the cover 18. The outer wall of the cover 18 is sequentially sleeved with a heat-insulating cotton 16 and a fixing shell 13 from inside to outside.

[0054] Advantageously, the temperature adjustment part further includes a computer 22. The PID temperature controller 21 and the infrared temperature detector 20 are both electrically connected to the computer 22. The computer 22 is used to receive infrared temperature measurement data and synchronously adjust laser parameters. The laser energy density range is 0.1 - 10 J / cm 2 , the scanning speed is 10 - 500 mm / s, and the repetition frequency is 10 kHz - 1 MHz.

[0055] In an embodiment of the present invention, two fixing plates 23 are parallelly connected in the vertical direction on the side of the base 1 close to the first bracket 2. A set of Z-axis moving components are vertically slidably connected to the two fixing plates 23. A Y-axis moving component is arranged on the Z-axis moving components, an X-axis moving component is arranged on the Y-axis moving components, a fixing seat 12 is connected to the X-axis moving components, and the infrared temperature detector 20 is fixed to the fixing seat 12 through a third bracket 19; the temperature control part is fixed to the fixing seat 12; wherein the Z-axis moving components, the Y-axis moving components and the X-axis moving components form a moving platform of the temperature control part.

[0056] In the present invention, unless otherwise clearly defined and limited, terms such as "installation", "connection", "connection", "fixation" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. It can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0057] In the specific implementation manner of the present invention, see the appendix Figure 4 , the Z-axis moving components include: a first motor 24, a first pulley 25, a first belt 26, a first slide rail 27, and a first slide seat 28; a first motor 24 is fixedly connected to the outer wall of one side of the fixing plate 23. The output end of the first motor 24 is fixedly connected to a first pulley 25. A first belt 26 is sleeved on the first pulley 25. A first slide rail 27 is fixedly connected to the outer wall of the other side of the fixing plate 23. A first slide seat 28 is vertically slidably connected to the first slide rail 27, and the first slide seat 28 is fixedly connected to the first belt 26. The first motor 24 is used to drive the first pulley 25 to rotate, and the first pulley 25 drives the first belt 26 to rotate, thereby driving the first slide seat 28 to move in the Z-axis direction along the first slide rail 27.

[0058] The Y-axis moving component includes: a second motor 30, a second pulley 31, a second belt 36, a second slide rail 29, and a second slide block 32. One side of the lower surface of the first slide block 28 is fixedly connected to the second motor 30. The output end of the second motor 30 is fixedly connected to the second pulley 31. The second pulley 31 is sleeved with the second belt 36. The first slide block 28 is fixedly connected to the second slide rail 29. The second slide block 32 is slidably connected to the second slide rail 29, and the second slide block 32 is fixedly connected to the second belt 36. The second motor 30 is used to drive the second pulley 31 to rotate. The second pulley 31 drives the second belt 36 to rotate, thereby driving the second slide block 32 to move in the Y-axis direction along the second slide rail 29. The second slide block 32 is vertically located on the top of the first slide block 28.

[0059] The X-axis moving component includes: a third slide rail 33, a third motor 34, and a lead screw 35. The second slide block 32 is fixedly connected to the third slide rail 33. A fixed seat 12 is slidably connected to the third slide rail 33. The upper surface of the fixed seat 12 is fixedly connected to an electric furnace plate 14. One outer wall of the second slide block 32 is fixedly connected to the third motor 34. The output end of the third motor 34 is fixedly connected to the lead screw 35. The fixed seat 12 is threadedly connected to the lead screw 35. The fixed seat 12 is fixedly connected to a third bracket 19. An infrared temperature detector 20 is fixedly connected to the third bracket 19. The third motor 34 drives the lead screw 35 to rotate, and the lead screw 35 drives the fixed seat 12 to move in the X-axis direction along the third slide rail 33.

[0060] Through the above X-axis moving component, Y-axis moving component, and Z-axis moving component, the position adjustment of the metal component 17 in the three-dimensional space can be realized. The infrared temperature detector 20 is used to monitor the surface temperature of the metal component 17 in real time. The first motor 24, the second motor 30, and the third motor 34 can all be electrically connected to a computer.

[0061] In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", and "third" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0062] See attached Figure 9 and 10 , the present invention provides a method based on the above temperature-adjustable laser subtractive device, including the following steps:

[0063] S1. Place the metal component after additive manufacturing on the temperature control part, and set the target temperature T through the PID temperature controller;

[0064] S2. Set the femtosecond laser energy density E and the scanning speed V according to the type of metal material and the temperature T; start the galvanometer scanning system, and focus the laser beam through the f-theta lens to perform subtractive processing on the metal component.

[0065] S3. The infrared thermometer collects the temperature data of the processed surface of the metal component at a certain frequency; when the detected temperature deviates from the set value, adjust the output power of the PID temperature controller and the laser energy density E to maintain the temperature in the processing area stable within a suitable processing temperature range.

[0066] S4. Use X-ray diffractometer, scanning electron microscope and confocal microscope to perform microscopic detection on the surface of the processed hole, analyze the surface roughness, hole shape and dimensional accuracy, measure the powder adhesion and step effect, and evaluate the influence of temperature on the surface quality and dimensional accuracy by comparing the processing effects at different temperatures; accurately measure the size of the hole with a coordinate measuring instrument, comprehensively analyze the influence of different experimental parameters on the processing effect, and optimize the parameter combination.

[0067] Among them, in the above S1 (Step 1), place the metal component 17 after additive manufacturing on the electric furnace plate 14. The resistance wire 15 on the electric furnace plate 14 is heated by current to generate uniform heat. Set the target temperature through the PID temperature controller 21. The PID temperature controller 21 adjusts the heating temperature by regulating the heating power of the resistance wire 15. The heating temperature is 100°C to 900°C, and the specific temperature value is set according to the material of the metal component 17 and the expected surface quality requirements. The metal component 17 is wrapped with heat-insulating cotton 16 to reduce heat dissipation to the outside, ensure that the heat energy is concentrated on the surface of the component, and can keep the temperature of each part of the component uniform and avoid too large a temperature gradient.

[0068] In the above S2 (Step 2), set the laser parameters of the femtosecond laser according to the material properties and temperature of the metal component 17. The laser energy density is 0.1 J / cm 2 to 10 J / cm 2 , the laser repetition frequency is 10 kHz to 1 MHz, the laser scanning speed is 10 mm / s to 500 mm / s, and the laser scanning times are 1 to 10 times.

[0069] The specific parameters are dynamically adjusted according to the surface temperature of the metal component 17 and the physical properties of the material to be processed. The femtosecond laser is emitted by the diode-pumped femtosecond laser 3, and the intensity of the laser beam is controlled by the signal attenuator 4. The quarter-wave plate 5 converts linearly polarized light into circularly polarized light or performs the reverse conversion. The beam expander 6 expands the diameter of the parallel input beam into a larger parallel output beam, increasing the irradiation area of the laser beam, thereby reducing the energy density per unit area and avoiding excessive damage to the material. The diffractive optical element 7 can shape and homogenize the laser beam through the DOE to improve the processing accuracy and efficiency. The propagation direction of the laser beam is changed by the mirror 9, and the laser beam is guided to the galvanometer scanning 10. By quickly and precisely changing the angle of the laser beam, fine processing of the target object is achieved. Finally, the f-theta lens 11 realizes the precise focusing and linear scanning of the laser beam to perform subtractive processing on the metal component 17. The first motor 24 on the fixed plate 23 drives the first pulley 25 to rotate, the first pulley 25 drives the first belt 26 to rotate, and further drives the first slide 28 to move along the first slide rail 27 in the Z-axis direction. The second motor 30 drives the second pulley 31 to rotate, the second pulley 31 drives the second belt 36 to rotate, and further drives the second slide 32 to move along the second slide rail 29 in the Y-axis direction. The third motor 34 drives the lead screw 35 to rotate, and the lead screw 35 drives the base 12 to move along the third slide rail 33 in the X-axis direction. Through the above control mechanism, the position adjustment of the metal component 17 in three-dimensional space can be realized;

[0070] In S3 (Step 3), the infrared thermometer 20 on the third bracket 19 continuously collects the surface temperature data of the component and transmits it to the computer 22 on the base 1. Combining the thermal physical property data of the material, the influence of the current temperature change on the material deformation, residual stress and surface roughness is analyzed. When the temperature deviates from the set range, the PID temperature controller 21 adjusts the output power of the electric furnace plate 14 through the PID algorithm to ensure that the surface temperature of the component is within the optimal processing range. At the same time, the computer 22 dynamically adjusts according to the temperature feedback to match the temperature change of the material, realizing high-precision subtractive processing. Through continuous adjustment and feedback control, the surface defects, dimensional errors and material property degradation caused by temperature fluctuations during the laser subtractive process can be effectively avoided, thereby improving the overall quality and efficiency of processing;

[0071] In S4 (Step 4), after completing the entire processing, the machined hole surface is microscopically inspected using an X-ray diffractometer, a scanning electron microscope, and a confocal microscope to analyze surface roughness, hole shape, and dimensional accuracy, measure powder adhesion and the step effect. By comparing the processing effects at different temperatures, the influence of temperature on surface quality and dimensional accuracy is evaluated. The dimensions of the hole are accurately measured using a coordinate measuring machine, and the influence of different experimental parameters on the processing effect is comprehensively analyzed to optimize the experimental conditions, reduce powder adhesion and the step effect, and improve the quality of the machined surface.

[0072] When using the present invention for laser subtractive machining:

[0073] Fix the base 1 on the anti-vibration platform, install the first bracket 2 and the second bracket 8 to ensure that the optical paths of the diode-pumped femtosecond laser 3 and the galvanometer scanner 10 are coaxial; place the metal component 17 at the center of the electric furnace plate 14, and adjust the position through the lead screw 35 in the X-axis moving component, the second belt 36 of the Y-axis moving component, and the first belt 26 of the Z-axis moving component to align the machining area with the focus of the f-theta lens 11.

[0074] Set the target temperature through the PID temperature controller 21. The PID temperature controller 21 adjusts the heating temperature by regulating the heating power of the heating wire 15. The heating temperature is 100°C to 900°C, and the specific temperature value is set according to the material of the metal component 17 and the expected surface quality requirements. The outside of the metal component 17 is wrapped with a heat-insulating cotton 16 through a fixed shell 13 to reduce heat dissipation to the outside, ensure that the heat energy is concentrated on the surface of the component, keep the temperature of each part of the component uniform, and avoid excessive temperature gradient. Then, according to the material characteristics and temperature of the metal component 17, set the laser parameters of the femtosecond laser. The laser energy density is 0.1 J / cm 2 to 10 J / cm 2, the laser repetition frequency is from 10 kHz to 1 MHz, the laser scanning speed is from 10 mm / s to 500 mm / s, and the laser scanning times are from 1 to 10 times. The specific parameters are dynamically adjusted according to the surface temperature of the metal component 17 and the physical properties of the material to be processed. The femtosecond laser 3 pumped by the diode on the first bracket 2 emits femtosecond laser, and the intensity of the laser beam is controlled by the signal attenuator 4. The quarter-wave plate 5 converts the linearly polarized light into circularly polarized light, or performs the reverse conversion. The beam expander 6 expands the diameter of the parallel input beam into a larger parallel output beam, increasing the irradiation area of the laser beam, thereby reducing the energy density per unit area and avoiding excessive damage to the material. The diffractive optical element 7 can shape and homogenize the laser beam through DOE to improve the processing accuracy and efficiency. The propagation direction of the laser beam is changed by the mirror 9 on the second bracket 8, and the laser beam is guided to the galvanometer scanning 10. By quickly and precisely changing the angle of the laser beam, fine processing of the target object is achieved. Finally, the f-theta lens 11 realizes the precise focusing and linear scanning of the laser beam to perform subtractive processing on the metal component 17.

[0075] The first motor 24 on the fixed plate 23 drives the first pulley 25 to rotate. The first pulley 25 drives the first belt 26 to rotate, and then drives the first slide 28 to move along the first slide rail 27 in the Z-axis direction. The second motor 30 drives the second pulley 31 to rotate. The second pulley 31 drives the second belt 36 to rotate, and then drives the second slide 32 to move along the second slide rail 29 in the Y-axis direction. The third motor 34 drives the lead screw 35 to rotate. The lead screw 35 drives the base 12 to move along the third slide rail 33 in the X-axis direction. Through the above control mechanism, the position adjustment of the metal component 17 in three-dimensional space can be realized. During the processing, the infrared thermometer 20 on the third bracket 19 continuously collects the surface temperature data of the component and transmits it to the computer 22 on the base 1. Combining with the thermal physical property data of the material, the influence of the current temperature change on the material deformation, residual stress and surface roughness is analyzed. When the temperature deviates from the set range, the PID temperature controller 21 adjusts the output power of the electric furnace plate 14 through the PID algorithm to ensure that the surface temperature of the component is within the optimal processing range. At the same time, the computer 22 dynamically adjusts according to the temperature feedback to match the temperature change of the material, realizing high-precision subtractive processing. Through continuous adjustment and feedback control, the surface defects, dimensional errors and material property degradation caused by temperature fluctuations during the laser subtractive process can be effectively avoided, thereby improving the overall quality and efficiency of the processing.

[0076] After completing the entire machining process, an X-ray diffractometer, a scanning electron microscope, and a confocal microscope are used to microscopically detect the machined hole surface, analyze the surface roughness, hole shape, and dimensional accuracy, measure the powder adhesion and step effect. By comparing the machining effects at different temperatures, the influence of temperature on the surface quality and dimensional accuracy is evaluated. The dimensions of the holes are accurately measured using a coordinate measuring machine, and the influence of different experimental parameters on the machining effect is comprehensively analyzed to optimize the experimental conditions, reduce powder adhesion and step effect, and improve the machining surface quality.

[0077] For example, the galvanometer scanner 10 deflects the laser beam according to the preset air film hole path, focuses the spot diameter to 15 μm through the f-theta lens 11, and completes the machining in the way of single scan + 4 repeated scans (5 scans in total); the infrared thermometer 20 collects temperature data at a frequency of 20 Hz. When it detects that the local temperature rises to 410 °C, the computer dynamically reduces the laser energy density from the initial value of 3.2 J / cm 2 to 2.5 J / cm 2 and reduces the heating power of the PID temperature controller 21. The system stabilizes the temperature at 400 ± 2 °C within 5 seconds through closed-loop feedback to ensure that the heat-affected zone is controllable.

[0078] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification.

[0079] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A temperature-adjustable laser material reduction device, characterized in that: include: Base (1); A second bracket (8) is located on the top of the base (1), and is connected with a reflector (9), a galvanometer scanner (10) and an f-theta lens (11) in sequence from top to bottom; A temperature control unit, located below the f-theta lens (11), on which a metal component (17) is placed; A mobile platform is located on the base (1), connected to the temperature control unit, and capable of moving the temperature control unit within the spatial range of the X-axis, Y-axis and Z-axis; a first bracket (2), located on one side of the base (1) and opposite to the second bracket (8), on which a diode-pumped femtosecond laser (3), a signal attenuator (4), a quarter-wave plate (5), a beam expander (6) and a diffractive optical element (7) are sequentially arranged and connected from the side away from the second bracket (8) to the side close to the second bracket (8); The temperature adjustment unit comprises an infrared temperature detector (20) located on a mobile platform and close to the metal component (17), and a PID temperature controller (21) located on the base (1); the PID temperature controller (21) maintains the surface temperature of the metal component (17) within a suitable processing temperature range based on a signal detected by the infrared temperature detector (20).

2. The temperature-adjustable laser material reduction device according to claim 1, characterized in that: The temperature control unit comprises an electric furnace plate (14) and a cover body (18); the electric furnace plate (14) is provided with a resistance wire (15); the cover body (18) is arranged on the resistance wire (15); and the metal component (17) is located on the cover body (18).

3. The temperature-adjustable laser material reduction device according to claim 2, characterized in that: The outer wall of the cover body (18) is sequentially covered with heat-insulating cotton (16) and a fixing shell (13) from the inside to the outside.

4. The temperature-adjustable laser material reduction device according to claim 2, characterized in that: The temperature adjustment unit also includes a computer (22), the PID temperature controller (21) and the infrared temperature detector (20) are both electrically connected to the computer (22), and the computer (22) is used to receive infrared temperature measurement data and synchronously adjust laser parameters. The laser energy density range is 0.1-10 J / cm 2 , scanning speed 10-500mm / s, repetition frequency 10kHz-1MHz.

5. The temperature-adjustable laser material reduction device according to claim 3 or 4, characterized in that: The base (1) is connected in parallel with two fixing plates (23) in the vertical direction near the first bracket (2); the two fixing plates (23) are vertically slidably connected with Z-axis moving components; the Z-axis moving components are provided with Y-axis moving components; the Y-axis moving components are provided with X-axis moving components; the X-axis moving components are connected with a fixing seat (12); the infrared thermometer (20) is fixed to the fixing seat (12) via a third bracket (19); the temperature control unit is fixed to the fixing seat (12); wherein the Z-axis moving components, the Y-axis moving components and the X-axis moving components form a moving platform of the temperature control unit.

6. A method based on the temperature-adjustable laser material reduction device according to claim 5, characterized in that: The following steps are involved: S1. Place the metal component after additive manufacturing on the temperature control unit and set the target temperature T through the PID temperature controller; S2. According to the type of metal material and temperature T, set the femtosecond laser energy density E and scanning speed V; start the galvanometer scanning system, and focus the laser beam through the f-theta lens to perform subtractive processing on the metal component; S3, the infrared temperature detector collects the surface temperature data of the metal component at a certain frequency; when the detected temperature deviates from the set value, the output power of the PID temperature controller and the laser energy density E are adjusted to maintain the temperature of the processing area stable within the appropriate processing temperature range; S4. Use X-ray diffractometer, scanning electron microscope and confocal microscope to perform microscopic inspection on the surface of the processed holes, analyze the surface roughness, hole shape and dimensional accuracy, measure the powder adhesion and step effect, and evaluate the influence of temperature on surface quality and dimensional accuracy by comparing the processing effects at different temperatures. Use three-coordinate measuring machine to accurately measure the size of the holes, comprehensively analyze the influence of different experimental parameters on the processing effect, and optimize the parameter combination.

7. The method according to claim 6, characterized in that In S1, the target temperature is set to 100℃≤T≤900℃, and the outer wall of the metal component is wrapped with insulation cotton and a fixed shell to reduce heat loss to the outside, ensure that heat energy is concentrated on the surface of the metal component, maintain a uniform temperature of the metal component, and avoid excessive temperature gradients.

8. The method according to claim 6, characterized in that In S2, according to the metal material type and temperature T, the femtosecond laser energy density E = K × T is set, where K is the material thermal conductivity correlation coefficient, 0.1 ≤ E ≤ 10 J / cm 2 ; Scanning speed V = α / (T-T0), α is the thermal diffusion coefficient of the material, 10mm / s≤V≤500mm / s; adjust the position of the metal component in three-dimensional space by adjusting the Z-axis moving component, the Y-axis moving component and the X-axis moving component.

9. The method according to claim 6, characterized in that The S3 mid-infrared temperature sensor collects surface temperature data of metal components at a frequency of ≥10Hz.

10. The method according to claim 9, characterized in that The infrared thermometer continuously collects surface temperature data of metal components and transmits it to the computer. Combined with the material's thermal properties data, it analyzes the impact of current temperature changes on material deformation, residual stress and surface roughness. When the temperature deviates from the set range, the computer dynamically adjusts the PID temperature controller based on temperature feedback and adjusts the output power of the electric furnace plate through the PID algorithm to match the temperature changes of the metal material.

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