Dual-beam SLM forming device and method taking into account both forming efficiency and forming accuracy

Abstract

The present invention belongs to the field of advanced manufacturing technology, and discloses a dual-beam SLM forming device and method that takes into account both forming efficiency and forming accuracy, which includes two laser sources, a beam switching component and a scanning processing component, the two laser sources are respectively used to output medium / low power laser beams and medium / high power laser beams; the beam switching component includes a motion mechanism and two offset reflectors, the two reflectors are driven by the motion mechanism to achieve position adjustment, and are respectively used to reflect the collimated medium / low power laser beam and medium / high power laser beam to the scanning processing component; the scanning processing component is used to focus the medium / low power laser beam or the medium / high power laser beam reflected by the beam switching component on the surface of the metal powder bed to complete the SLM forming of metal parts. The present invention can solve the problems of low beam switching reliability, small forming size and high cost commonly found in existing dual-beam SLM equipment, and at the same time achieve high-efficiency and high-precision SLM forming of metal parts.

Description

Technical Field

[0001] The present invention belongs to the field of advanced manufacturing technology, and more specifically, relates to a dual-beam SLM forming device and method that takes both forming efficiency and forming accuracy into consideration. Background Art

[0002] Selective Laser Melting (SLM) is one of the most promising high-performance metal additive manufacturing technologies. It achieves the overall forming of complex metal components by selectively scanning and melting metal powders layer by layer. However, the common SLM equipment on the market generally uses low-power lasers, and the forming efficiency is low (generally only 5-40cm 3 / h), which cannot meet the needs of mass production. To solve this problem, domestic and foreign research institutions have recently proposed new SLM equipment based on dual-beam collaborative processing. This type of equipment is equipped with both low-power laser source and high-power laser source, and the forming of metal parts is achieved through the cooperation of low-power laser and high-power laser.

[0003] For the dual-beam SLM technology, how to achieve fast and reliable switching between low-power laser beams and high-power laser beams, while taking into account the forming size and equipment cost, is the core problem that must be solved in the development of this technology. However, the existing dual-beam SLM equipment at home and abroad has not yet given an ideal solution. For example, patent CN108580896A discloses a dual-beam SLM equipment including two sets of scanning galvanometer systems, wherein the two sets of galvanometers are installed in parallel above the forming cylinder and are respectively connected to a laser. This not only leads to high equipment costs, but also the dual-beam processing can only be carried out in the overlapping area of ​​the scanning field of the two sets of galvanometers, and the forming size is severely limited. For another example, patent CN103658647B discloses a laser selective melting equipment and processing method based on four laser duplex stations, which can adjust the angle of the total reflection lens so that the high-power laser beam and the low-power laser beam alternately enter the same scanning galvanometer system. This technical solution has the advantages of low equipment cost and large forming size, but it has extremely high requirements for the rotation positioning accuracy of the total reflection lens, and it is difficult to achieve fast and reliable switching of dual beams. For example, patents CN210098969U and CN104708003B proposed a beam switching solution based on a half-mirror (beam splitter), which allows two laser beams to enter the same scanning galvanometer system through reflection and transmission of the half-mirror. This solution does not involve the rotation and positioning of the beam switching device and has strong reliability. However, the half-mirror is expensive and has special requirements for the wavelengths of the two laser beams. It is not suitable for long-term operation of high-power laser beams and is not conducive to application and promotion.

[0004] In summary, it is of great significance to develop a dual-beam SLM equipment with fast beam switching speed, high reliability, large forming size, low manufacturing cost and strong applicability. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides a dual-beam SLM forming device and method that takes into account both forming efficiency and forming accuracy, aiming to solve the problems commonly existing in existing dual-beam SLM equipment, such as low beam switching reliability, small forming size, and high cost.

[0006] To achieve the above object, according to one aspect of the present invention, a dual-beam SLM forming device that takes into account both forming efficiency and forming accuracy is proposed, which includes a first laser source, a second laser source, a beam switching component and a scanning processing component, wherein:

[0007] The first laser source is used to output a medium / low power laser beam to achieve high-precision SLM forming, and the second laser source is used to output a medium / high power laser beam to achieve high-efficiency SLM forming. During the entire forming process, the first laser source and the second laser source work at different times or only one of them works;

[0008] The beam switching assembly includes a first reflector, a second reflector and a motion mechanism. The first reflector and the second reflector are arranged in a staggered manner and can be adjusted in position under the drive of the motion mechanism to ensure that the two work in a staggered manner. The first reflector is used to reflect the collimated medium / low power laser beam to the scanning processing assembly, and the second reflector is used to reflect the collimated medium / high power laser beam to the scanning processing assembly.

[0009] The scanning processing component is used to focus the medium / low power laser beam or medium / high power laser beam reflected by the beam switching component on the surface of the metal powder bed, so as to complete the high-precision and high-efficiency SLM forming of metal parts.

[0010] As a further preference, the first reflector and the second reflector are staggeredly arranged on a reflector support, which is connected to a motion mechanism and slidably cooperates with a guide rail, and the motion mechanism can drive the reflector support and the first reflector and the second reflector thereon to move along the guide rail.

[0011] As a further preference, the output power of the low-power laser beam is less than 500W, the output power of the medium-power laser beam is 500W-1000W, and the output power of the high-power laser beam is greater than 1000W.

[0012] As further preferred, the output power of the high-power laser beam is preferably greater than 1000W and less than or equal to 10000W, and more preferably 2000W to 6000W.

[0013] As a further preference, the scanning processing component is a combination of a two-axis scanning galvanometer and an F-Theta focusing mirror, or a dynamic focusing scanning galvanometer.

[0014] As a further preference, the angle between the mirror surface of the first reflector and the beam output path of the first laser source, as well as the angle between the mirror surface of the first reflector and the beam input path of the scanning processing component are preferably designed to be 45°; preferably, the angle between the mirror surface of the second reflector and the beam output path of the second laser source, as well as the angle between the mirror surface of the second reflector and the beam input path of the scanning processing component are preferably designed to be 45°.

[0015] As a further preference, the intersection of the beam output path of the first laser source and the beam input path of the scanning processing component is preferably located on a vertical line passing through the center of the mirror surface of the first reflector; preferably, the intersection of the beam output path of the second laser source and the beam input path of the scanning processing component is preferably located on a vertical line passing through the center of the mirror surface of the second reflector.

[0016] As a further preference, the motion mechanism is a linear drive mechanism.

[0017] As a further preference, the first reflector, the second reflector and the reflector support are all provided with circulating cooling channels inside, and the cooling channels are externally connected to a liquid cooling device.

[0018] According to another aspect of the present invention, a dual-beam SLM forming method taking into account both forming efficiency and forming accuracy is provided, which comprises the following steps:

[0019] S1 adjusts the position of the reflector according to the laser beam to be used:

[0020] If a medium / low power laser beam is required, the position of the first reflector is adjusted by the motion mechanism so that the intersection of the beam output path of the first laser source and the beam input path of the scanning processing assembly is located on the mirror surface of the first reflector, and the process proceeds to step S2;

[0021] If a medium / high power laser beam is required, the position of the second reflector is adjusted by the motion mechanism so that the intersection of the beam output path of the second laser source and the beam input path of the scanning processing assembly is located on the mirror surface of the second reflector, and the process proceeds to step S3;

[0022] S2: The first laser source emits a medium / low power laser beam which is collimated and then reflected by the first reflector to the scanning processing component and focused on the surface of the metal powder bed to complete the high-precision SLM forming of metal parts.

[0023] The S3 second laser source emits a medium / high power laser beam which is collimated, reflected by the second reflector to the scanning processing component, and focused on the surface of the metal powder bed to complete the efficient SLM forming of metal parts.

[0024] In general, the above technical solutions conceived by the present invention have the following technical advantages compared with the prior art:

[0025] 1. The switching between medium / high power laser and medium / low power laser of the dual-beam SLM forming device of the present invention can be achieved by driving two sets of reflectors to move through a motion mechanism, and only includes one set of scanning processing components, with low manufacturing cost and large forming size.

[0026] 2. The dual-beam SLM forming device of the present invention has low requirements on the movement accuracy of the reflector. It only needs to ensure that the intersection of the laser source beam output path and the scanning processing component beam input path is located on the mirror surface of the reflector to meet the processing requirements. There is no need for the intersection of the two paths to completely coincide with the center of the reflector surface, so that fast and reliable switching of the dual beams can be achieved.

[0027] 3. The present invention indirectly connects the two reflectors with the motion mechanism through the reflector support, so that the positions of the two reflectors can be adjusted through the motion mechanism, thereby realizing the free switching of the two light beams. The two reflectors are staggered. When one reflector is adjusted to a specified position, the other reflector will not interfere with it, thereby ensuring the reliability of transmission.

[0028] 4. The present invention uses a reflector as a transmission component for the laser beam, which has low cost and no special requirements for the laser wavelength. It is particularly suitable for long-term operation of high-power laser beams, especially laser beams with a power of more than 2000W, and is conducive to application and promotion.

[0029] 5. The forming device of the present invention has strong applicability and can provide laser beams of various powers to adapt to the high-efficiency and high-precision SLM forming of metal parts with different processing requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the structure of a dual-beam SLM forming device provided by the present invention that takes both forming efficiency and forming accuracy into consideration;

[0031] Figure 2 Schematic diagram of the relative positions of key components of the dual-beam SLM forming device provided by the present invention that takes both forming efficiency and forming accuracy into consideration, wherein (a) is a front view and (b) is a top view;

[0032] Figure 3 A schematic diagram of the relative positions of key components when the dual-beam SLM forming device provided by the present invention takes both forming efficiency and forming accuracy into consideration adopts medium / low power laser beam forming;

[0033] Figure 4 A schematic diagram of beam transmission when a dual-beam SLM forming device that takes both forming efficiency and forming accuracy into consideration is provided by the present invention and adopts medium / low power laser beam forming;

[0034] Figure 5 A schematic diagram of the relative positions of key components when the dual-beam SLM forming device provided by the present invention takes both forming efficiency and forming accuracy into consideration adopts medium / high power laser beam forming;

[0035] Figure 6 Schematic diagram of beam transmission when the dual-beam SLM forming device provided by the present invention takes both forming efficiency and forming accuracy into consideration adopts medium / high power laser beam forming.

[0036] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0037] 1-first laser source; 2-second laser source; 3-scanning processing assembly; 4-first reflector; 5-second reflector; 6-reflector support; 7-moving mechanism; 8-guide rail; 11-beam output path of the first laser source; 21-beam output path of the second laser source; 31-beam input path of the scanning processing assembly; 40-mirror center of the first reflector; 41-vertical line passing through the mirror center of the first reflector; 50-mirror center of the second reflector; 51-vertical line passing through the mirror center of the second reflector; 311-intersection of the beam output path of the first laser source and the beam input path of the scanning processing assembly; 321-intersection of the beam output path of the second laser source and the beam input path of the scanning processing assembly. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0039] like Figure 1As shown, an embodiment of the present invention provides a dual-beam SLM (selective laser melting) forming device that takes into account both forming efficiency and forming accuracy, which includes a first laser source 1, a second laser source 2, a beam switching component and a scanning processing component 3, wherein the first laser source 1 is used to output a medium / low power laser beam (a medium power laser beam or a low power laser beam), which is input to the scanning processing component through a reflector after collimation to achieve high-precision SLM forming of metal parts (such as its precision parts or contour parts that require high precision), and the second laser source 2 is used to output a medium / high power laser beam (a medium power laser beam or a high power laser beam), which is input to the scanning processing component through a reflector after collimation to achieve high-efficiency SLM forming of metal parts (such as large-sized parts or parts with low precision requirements). Specifically, the output power of the low-power laser beam is less than 500W, and the energy distribution is a Gaussian mode. The output power of the medium-power laser beam is 500W to 1000W, and the energy distribution can be a Gaussian mode, a flat-top mode, a ring mode, and various high-order modes. The output power of the high-power laser beam is greater than 1000W, preferably greater than 1000W and less than or equal to 10000W, and more preferably 2000W to 6000W. The energy distribution can be Gaussian mode, flat-top mode, annular mode and various high-order modes.

[0040] The beam switching component is used to realize the switching between medium / low power beam and medium / high power beam, and includes a first reflector 4, a second reflector 5 and a motion mechanism 7. The first reflector 4 is used to receive the medium / low power laser beam output by the first laser source 1, and transmit the received laser beam to the scanning processing component 3. The second reflector 5 is used to receive the medium / high power laser beam output by the second laser source 2, and transmit the received laser beam to the scanning processing component 3. The first reflector 4 and the second reflector 5 are arranged in a staggered manner, for example, the second reflector 5 is located at the lower right of the first reflector 4. The first reflector 4 and the second reflector 5 can move up and down under the drive of the motion mechanism 7, so that both are adjusted to the required positions and then receive laser beams of corresponding powers, that is, the first reflector 4 is adjusted to the working position to reflect the medium / low power laser beam to the scanning processing component, and the second reflector 5 does not work at this time, or the second reflector 5 is adjusted to the working position to reflect the medium / high power laser beam to the scanning processing component, and the first reflector 4 does not work at this time, that is, the first reflector 4 and the second reflector 5 work at different times to ensure that the scanning processing component 3 always outputs only one laser beam.

[0041] The scanning processing component 3 is used to focus the medium / low power laser beam or medium / high power laser beam reflected by the beam switching component on the surface of the metal powder bed to complete the high-precision and high-efficiency SLM forming of metal parts. Among them, the medium / high power laser beam can be used to process areas that have no specific requirements for forming accuracy or allow subsequent machining, and can be processed by medium / high power lasers to achieve high-efficiency forming in this area. The medium / low power laser beam can be used to form areas that are difficult to process with medium / high power lasers (such as areas with high precision requirements, areas that do not allow subsequent machining, areas with wall thickness less than the diameter of the medium / high power laser beam spot, etc.) to achieve high-precision forming in this area.

[0042] In the whole forming process of the SLM forming device of the present invention, two laser sources (the first laser source 1 and the second laser source 2) work at different times, that is, both laser sources are put into use, but they do not work at the same time but work alternately at different times; or only one of the two laser sources is put into use, for example, only the first laser source 1 works to provide a medium / low power laser beam to achieve high-precision forming of metal parts, and only the second laser source 2 works to provide a medium / high power laser beam to achieve high-efficiency forming of metal parts. Therefore, the forming device of the present invention can not only provide a laser beam of medium / low power and medium / high power combination (i.e., low power + medium power, low power + high power, medium power + medium power, medium power + high power), but also only provide a low power laser beam, a medium power laser beam or a high power laser beam, so as to greatly improve the applicability of the forming device of the present invention, and can be applied to the SLM forming of any metal parts (such as complex structures, simple structures, high precision requirements, low precision requirements, etc.), and has strong applicability and expansibility.

[0043] Specifically, in order to ensure the reliability and stability of the adjustment, the first reflector 4 and the second reflector 5 are connected to the moving mechanism 7 via the reflector support 6, and the reflector support 6 also slides with the guide rail 8, that is, the first reflector 4 and the second reflector 5 are staggered and arranged on the reflector support 6, and the reflector support 6 is connected to the moving mechanism 7. The moving mechanism 7 can drive the reflector support 6 to move up and down along the guide rail 8, thereby driving the first reflector 4 and the second reflector 5 on the reflector support 6 to move up and down together, thereby realizing the adjustment of the upper and lower positions of the first reflector 4 and the second reflector 5.

[0044] As mentioned above, the reflector is used to receive the laser beam output by the laser source and transmit the received laser beam to the scanning processing component, that is, the reflector can receive the laser beam from one component and transmit the received laser beam to another component. In order to achieve the above functions, there must be a certain angle between the beam output path of the laser source and the beam input path of the scanning processing component (that is, non-parallel), that is, the reflector must be arranged at an angle, and the intersection of the beam output path of the laser source and the beam input path of the scanning processing component must be located on the mirror surface of the reflector. That is, the mirror surface of the reflector has a certain angle with the beam output path of the laser source, and the beam output path of the laser source must intersect with the mirror surface of the reflector, so that the laser beam of the laser source can be incident on the mirror surface of the reflector and reflected by the mirror surface of the reflector to the scanning processing component. The specific angle can be set as needed.

[0045] In order to facilitate the arrangement of the laser source, the scanning processing component and the reflector, it is preferred that the angle between the mirror surface of the reflector and the beam output path of the laser source is 45°, and the angle between the mirror surface of the reflector and the beam input path of the scanning processing component is 45°, so that the beam output path of the laser source is perpendicular to the beam input path of the scanning processing component during processing, that is, the laser source, the reflector and the scanning processing component are arranged at the three vertices of a right triangle during processing, and the beam output path of the laser source is perpendicular to the beam input path of the scanning processing component during processing. Such a design facilitates the installation and arrangement of the three, avoids mutual interference and influence during processing, and ensures the quality of laser transmission. In order to ensure the reflection effect and avoid the influence of the mirror on the reflective light source, the intersection of the beam output path of the laser source and the beam input path of the scanning processing component 3 is preferably located on a vertical line passing through the center of the mirror surface of the reflector.

[0046] like Figure 2As shown, the included angle between the mirror surface of the first reflector 4 and the beam output path 11 of the first laser source and the included angle between the mirror surface of the first reflector 4 and the beam input path 31 of the scanning processing component are both 45°. During scanning processing, the first laser source 1, the first reflector 4 and the scanning processing component 3 are arranged at the three vertices of a right triangle, and the beam output path of the first laser source 1 is perpendicular to the beam input path of the scanning processing component 3. The included angle between the mirror surface of the second reflector 5 and the beam output path 21 of the second laser source and the included angle between the mirror surface of the second reflector 5 and the beam input path 31 of the scanning processing component are both 45°. During scanning processing, the second laser source 2, the second reflector 5 and the scanning processing component 3 are arranged at the three vertices of a right triangle, and the beam output path of the second laser source 2 is perpendicular to the beam input path of the scanning processing component 3. The intersection point 311 of the beam output path 11 of the first laser source and the beam input path 31 of the scanning processing component is located on the vertical line 41 passing through the center of the mirror surface 40 of the first reflector, and the intersection point 321 of the beam output path 21 of the second laser source and the beam input path 31 of the scanning processing component is located on the vertical line 51 passing through the center of the mirror surface 50 of the second reflector.

[0047] Furthermore, the motion mechanism 7 is a linear drive mechanism, preferably an electric cylinder or a pneumatic cylinder with low cost, high motion speed and small size. Since the device of the present invention does not require high motion accuracy, the use of an electric cylinder or a pneumatic cylinder can meet the requirements. In order to facilitate the cooling of the reflector, improve its service life and ensure the accuracy of use, a circulating cooling channel is provided inside the first reflector 4, the second reflector 5 and the reflector support 6, and the cooling channel is externally connected to a liquid cooling device. More specifically, the forming device of the present invention performs SLM forming in the form of galvanometer scanning, and the matching scanning processing component 3 is a combination of a two-axis scanning galvanometer and an F-Theta focusing mirror, or a dynamic focusing scanning galvanometer.

[0048] The present invention also provides a dual-beam SLM forming method that takes both forming efficiency and forming accuracy into consideration, which is performed using the dual-beam SLM forming device and specifically comprises the following steps:

[0049] S1 First, adjust the mirror position according to the laser beam to be used:

[0050] If a medium / low power laser beam is required (for example, in areas where medium / high power laser processing is difficult, such as areas with extremely high precision requirements, areas where subsequent machining is not allowed, and areas where the wall thickness is smaller than the spot diameter of the medium / high power laser beam, a medium / low power laser beam is generally required to ensure the forming accuracy), the position of the first reflector 4 is adjusted by the motion mechanism 7 so that the intersection of the beam output path of the first laser source 1 and the beam input path of the scanning processing component is located on the mirror surface of the first reflector 4, and the process goes to step S2;

[0051] If a medium / high power laser beam is required (a medium / high power laser beam is generally used in areas without specific requirements for forming accuracy or where subsequent machining is allowed to be performed to ensure forming efficiency), the position of the second reflector 5 is adjusted by the motion mechanism 7 so that the intersection of the beam output path of the second laser source 2 and the beam input path of the scanning processing assembly is located on the mirror surface of the second reflector 5, and the process proceeds to step S3;

[0052] S2 The first laser source 1 emits a medium / low power laser beam, which is collimated and reflected by the first reflector 4 to the scanning processing component and focused on the surface of the metal powder bed to complete the high-precision SLM forming of the corresponding area of ​​the metal component;

[0053] S3 The second laser source 2 emits a medium / high power laser beam, which is collimated and reflected by the second reflector 5 to the scanning processing component, and is focused on the surface of the metal powder bed to complete the high-efficiency SLM forming of the corresponding area of ​​the metal parts. Specifically, for high-efficiency SLM forming, multiple thin layers of powder can be superimposed and scanned simultaneously, that is, multiple layers of metal powder can be laid, and a medium / high power laser beam can be used to achieve one-time high-efficiency SLM forming, thereby further improving the forming efficiency.

[0054] The following are specific embodiments:

[0055] Example 1

[0056] This embodiment takes a nickel-based high-temperature alloy aviation rocker arm bracket as an example to illustrate the dual-beam SLM forming method of the present invention, which specifically includes the following steps:

[0057] S1 first determines the type of laser beam used to form different areas of the part:

[0058] The part consists of two parts: a base and a cantilever. The base has a simple shape, low precision requirements, and allows for subsequent mechanical processing, so it is formed by a high-power laser beam. The cantilever has a complex structure, high precision requirements, and is difficult to form by a high-power laser beam, so it is formed by a medium-power laser beam.

[0059] S2 slices the three-dimensional model of the part to generate N slice layers (N≥2);

[0060] S3 shapes the cantilever part contained in the first slice layer of the part: adjust the mirror center 40 of the first reflector 4 by the motion mechanism 7 to substantially coincide with the intersection 311 of the beam output path 11 of the first laser source and the beam input path 31 of the scanning processing assembly, such as Figure 3 As shown in Figure 2, the laser beam transmission at this time is as follows: Figure 4 As shown;

[0061] S4 The first laser source 1 emits a laser beam with a power of 800W. After being collimated, it is reflected by the first reflector 4 to the scanning processing component and focused on the surface of the metal powder bed to complete the high-precision forming of the cantilever part contained in the first slice layer;

[0062] S5 shapes the base portion of the first slice layer of the part: adjust the mirror center 50 of the second reflector 5 by the motion mechanism 7 to substantially coincide with the intersection 321 of the beam output path 21 of the second laser source and the beam input path 31 of the scanning processing assembly, such as Figure 5 As shown in Figure 2, the laser beam transmission at this time is as follows: Figure 6 As shown;

[0063] S6 The second laser source 2 emits a 4000W laser beam which is collimated and then reflected by the second reflector 5 to the scanning processing assembly and focused on the surface of the metal powder bed to complete the high-efficiency forming of the base part contained in the first slice layer;

[0064] S7 completes the processing of the subsequent N-1 slice layers according to S3-S6, achieving high-efficiency and high-precision SLM forming of the nickel-based high-temperature alloy aviation rocker arm bracket.

[0065] Example 2

[0066] This embodiment takes a titanium alloy gas turbine stator blade as an example to illustrate the dual-beam SLM forming method of the present invention, which specifically includes the following steps:

[0067] S1 first determines the type of laser beam used to form different areas of the part:

[0068] The part consists of two parts: the base and the blade body. The base has a simple shape, low precision requirements, and allows subsequent mechanical processing, so it is formed by a high-power laser beam; the blade body has a complex structure, high precision requirements, and is difficult to form by a high-power laser beam, so it is formed by a low-power laser beam.

[0069] S2 slices the three-dimensional model of the part to generate N slice layers (N≥2);

[0070] S3 shapes the blade body portion of the first slice layer of the part: adjust the mirror center 40 of the first reflector 4 by the motion mechanism 7 to substantially coincide with the intersection 311 of the beam output path 11 of the first laser source and the beam input path 31 of the scanning processing assembly, such as Figure 3 As shown in Figure 2, the laser beam transmission at this time is as follows: Figure 4 As shown;

[0071] S4 The first laser source 1 emits a laser beam with a power of 300W, which is collimated and then reflected by the first reflector 4 to the scanning processing component and focused on the surface of the metal powder bed to complete the high-precision forming of the blade body part contained in the first slice layer;

[0072] S5 shapes the base portion of the first slice layer of the part: adjust the mirror center 50 of the second reflector 5 by the motion mechanism 7 to substantially coincide with the intersection 321 of the beam output path 21 of the second laser source and the beam input path 31 of the scanning processing assembly, such as Figure 5 As shown in Figure 2, the laser beam transmission at this time is as follows: Figure 6 As shown;

[0073] S6 The second laser source 2 emits a laser beam with a power of 6000W, which is collimated and then reflected by the second reflector 5 to the scanning processing component and focused on the surface of the metal powder bed to complete the high-efficiency forming of the base part contained in the first slice layer;

[0074] S7 completes the processing of the subsequent N-1 slice layers according to S3-S6, achieving high-efficiency and high-precision SLM forming of titanium alloy gas turbine stator blades.

[0075] Example 3

[0076] This embodiment takes a magnesium alloy biological scaffold as an example to illustrate the dual-beam SLM forming method of the present invention, which specifically includes the following steps:

[0077] S1 Determine the laser beam to be used: Due to the complex structure of the magnesium alloy bio-scaffold, it is difficult to use a high-power laser beam to form it, so all its parts are formed by a low-power laser beam;

[0078] S2 adjusts the mirror center 40 of the first reflector 4 to substantially coincide with the intersection 311 of the beam output path 11 of the first laser source and the beam input path 31 of the scanning processing assembly through the motion mechanism 7, as shown in FIG. Figure 3 As shown in Figure 2, the laser beam transmission at this time is as follows: Figure 4 As shown;

[0079] S3 The first laser source 1 emits a laser beam with a power of 180W, which is reflected by the first reflector 4 to the scanning processing component after collimation and focused on the surface of the metal powder bed to complete the high-precision forming of the magnesium alloy bio-scaffold.

[0080] Example 4

[0081] This embodiment takes a stainless steel support beam as an example to illustrate the dual-beam SLM forming method of the present invention, which specifically includes the following steps:

[0082] S1 determines the laser beam to be used. Since the stainless steel support beam has a simple shape, all parts can be formed by high-power laser beams, and the precision requirement is low, allowing subsequent machining, so all parts are formed by high-power laser beams;

[0083] S2 adjusts the mirror center 50 of the second reflector 5 to substantially coincide with the intersection 321 of the beam output path 21 of the second laser source and the beam input path 31 of the scanning processing assembly through the motion mechanism 7, as shown in FIG. Figure 5 As shown in Figure 2, the laser beam transmission at this time is as follows: Figure 6 As shown;

[0084] S5 The second laser source 2 emits a laser beam with a power of 5500W, which is reflected by the second reflector 5 to the scanning processing component after collimation and focused on the surface of the metal powder bed to complete the efficient forming of the stainless steel bracket.

[0085] Example 5

[0086] This embodiment takes a nickel-based high-temperature alloy aircraft engine intake duct as an example to illustrate the dual-beam SLM forming method of the present invention, which specifically includes the following steps:

[0087] S1 first determines the type of laser beam used to form different areas of the part:

[0088] The part consists of two parts: the base and the air inlet. The base has a simple shape, low precision requirements, and allows subsequent mechanical processing, so medium-power laser beam forming is used; the air inlet has a complex structure, high precision requirements, and is difficult to form with medium / high power laser beams, so low-power laser beam forming is used;

[0089] S2 slices the three-dimensional model of the part to generate N slice layers (N≥2);

[0090] S3 shapes the air inlet portion of the first slice layer of the part: adjust the mirror center 40 of the first reflector 4 by the motion mechanism 7 to substantially coincide with the intersection 311 of the beam output path 11 of the first laser source and the beam input path 31 of the scanning processing assembly, such as Figure 3 As shown in Figure 2, the laser beam transmission at this time is as follows: Figure 4 As shown;

[0091] S4 The first laser source 1 emits a 400W laser beam which is collimated and then reflected by the first reflector 4 to the scanning processing assembly and focused on the surface of the metal powder bed to complete the high-precision forming of the air inlet portion contained in the first slice layer;

[0092] S5 shapes the base portion of the first slice layer of the part: adjust the mirror center 50 of the second reflector 5 by the motion mechanism 7 to substantially coincide with the intersection 321 of the beam output path 21 of the second laser source and the beam input path 31 of the scanning processing assembly, such as Figure 5 As shown in Figure 2, the laser beam transmission at this time is as follows: Figure 6 As shown;

[0093] S6 The second laser source 2 emits a 900W laser beam which is collimated and then reflected by the second reflector 5 to the scanning processing assembly and focused on the surface of the metal powder bed to complete the high-efficiency forming of the base part contained in the first slice layer;

[0094] S7 completes the processing of the subsequent N-1 slice layers according to S3-S6, achieving high-efficiency and high-precision SLM forming of the nickel-based high-temperature alloy aircraft engine inlet.

[0095] Example 6

[0096] This embodiment takes a copper alloy conductive shell as an example to illustrate the dual-beam SLM forming method of the present invention, which specifically includes the following steps:

[0097] S1 first determines the type of laser beam used to form different areas of the part:

[0098] The part consists of two parts: a base and a shell surface. The base has a simple shape, low precision requirements, and allows for subsequent mechanical processing, so it is formed by a medium-power laser beam. The shell surface has a complex structure, high precision requirements, and is difficult to form by a high-power laser beam, but can be formed by a medium-power laser beam, so it is formed by a medium-power laser beam.

[0099] S2 slices the three-dimensional model of the part to generate N slice layers (N≥2);

[0100] S3 shapes the shell curved surface portion contained in the first slice layer of the part: adjust the mirror center 40 of the first reflector 4 by the motion mechanism 7 to substantially coincide with the intersection 311 of the beam output path 11 of the first laser source and the beam input path 31 of the scanning processing assembly, such as Figure 3 As shown in Figure 2, the laser beam transmission at this time is as follows: Figure 4 As shown;

[0101] S4 The first laser source 1 emits a 600W laser beam which is collimated and then reflected by the first reflector 4 to the scanning processing assembly and focused on the surface of the metal powder bed to complete the high-precision forming of the shell curved surface part contained in the first slice layer;

[0102] S5 shapes the base portion of the first slice layer of the part: adjust the mirror center 50 of the second reflector 5 by the motion mechanism 7 to substantially coincide with the intersection 321 of the beam output path 21 of the second laser source and the beam input path 31 of the scanning processing assembly, such as Figure 5 As shown in Figure 2, the laser beam transmission at this time is as follows: Figure 6 As shown;

[0103] S6 The second laser source 2 emits a laser beam with a power of 850W. After being collimated, it is reflected by the second reflector 5 to the scanning processing component and focused on the surface of the metal powder bed to complete the high-efficiency forming of the base part contained in the first slice layer;

[0104] S7 completes the processing of the subsequent N-1 slice layers according to S3-S6, achieving high-efficiency and high-precision SLM forming of the copper alloy conductive shell.

[0105] Example 7

[0106] This embodiment takes CoCr alloy artificial spine as an example to illustrate the dual-beam SLM forming method of the present invention, which specifically includes the following steps:

[0107] S1 Determine the laser beam to be used: The structure of the CoCr alloy artificial spine is complex and difficult to be formed by a high-power laser beam, but it can be formed by a medium-power laser beam, so all its parts are formed by a medium-power laser beam;

[0108] S2 adjusts the mirror center 40 of the first reflector 4 to substantially coincide with the intersection 311 of the beam output path 11 of the first laser source and the beam input path 31 of the scanning processing assembly through the motion mechanism 7, as shown in FIG. Figure 3 As shown in Figure 2, the laser beam transmission at this time is as follows: Figure 4 As shown;

[0109] S3 The first laser source 1 emits a laser beam with a power of 600 W, which is reflected by the first reflector 4 to the scanning processing component after collimation and focused on the surface of the metal powder bed to complete the high-precision forming of the CoCr alloy artificial spine.

[0110] The dual-beam SLM forming device of the present invention can solve the problems of low beam switching reliability, small forming size and high cost commonly existing in existing dual-beam SLM equipment, and realize high-efficiency and high-precision SLM forming of metal parts. The device has a simple structure and can be realized by transforming existing SLM equipment. It has strong scalability and can be combined with technologies such as "bidirectional powder spreading" (CN104001915A), "reconfigurable forming cylinder" (CN104668563A), "form-conforming cylinder" (CN106346006A), and "multi-region parallel processing (CN102266942A)" to better realize the improvement of forming efficiency, precision, size and reduction of manufacturing cost.

[0111] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit 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 present invention.

Claims

1. A dual-beam SLM forming device that takes into account both forming efficiency and forming accuracy, characterized in that: The invention comprises a first laser source (1), a second laser source (2), a beam switching component and a scanning processing component (3), wherein: The first laser source (1) is used to output a medium / low power laser beam to achieve high-precision SLM forming, and the second laser source (2) is used to output a medium / high power laser beam to achieve high-efficiency SLM forming. During the entire forming process, the first laser source (1) and the second laser source (2) work at different times or only one of them works; The beam switching assembly comprises a first reflector (4), a second reflector (5) and a motion mechanism (7); the first reflector (4) and the second reflector (5) are arranged in a staggered manner and can be adjusted in position under the drive of the motion mechanism (7) to ensure that the two work in a staggered manner; the first reflector (4) is used to reflect the collimated medium / low power laser beam to the scanning processing assembly (3); and the second reflector (5) is used to reflect the collimated medium / high power laser beam to the scanning processing assembly (3); The scanning processing component (3) is used to focus the medium / low power laser beam or the medium / high power laser beam reflected by the beam switching component on the surface of the metal powder bed, thereby completing high-precision and high-efficiency SLM forming of metal parts.

2. The dual-beam SLM forming device that takes both forming efficiency and forming accuracy into consideration as claimed in claim 1, characterized in that: The first reflector (4) and the second reflector (5) are arranged in a staggered manner on a reflector support (6); the reflector support (6) is connected to the motion mechanism (7) and is slidably matched with a guide rail (8); the reflector support (6) and the first reflector (4) and the second reflector (5) thereon can be driven to move along the guide rail (8) by the motion mechanism (7).

3. The dual-beam SLM forming device that takes both forming efficiency and forming accuracy into consideration as claimed in claim 1, characterized in that: The output power of the low-power laser beam is less than 500W, the output power of the medium-power laser beam is 500W-1000W, and the output power of the high-power laser beam is greater than 1000W.

4. The dual-beam SLM forming device taking both forming efficiency and forming accuracy into consideration as claimed in claim 3, characterized in that: The output power of the high-power laser beam is greater than 1000W and less than or equal to 10000W.

5. The dual-beam SLM forming device that takes both forming efficiency and forming accuracy into consideration as claimed in claim 3, characterized in that: The output power of the high-power laser beam is 2000W to 6000W.

6. The dual-beam SLM forming device that takes both forming efficiency and forming accuracy into consideration as claimed in claim 1, characterized in that: The scanning processing component is a combination of a two-axis scanning galvanometer and an F-Theta focusing mirror, or a dynamic focusing scanning galvanometer.

7. The dual-beam SLM forming device taking both forming efficiency and forming accuracy into consideration as described in any one of claims 1 to 6, characterized in that: The included angle between the mirror surface of the first reflector (4) and the light beam output path of the first laser source (1), as well as the included angle between the mirror surface of the first reflector (4) and the light beam input path of the scanning processing component are both designed to be 45°.

8. The dual-beam SLM forming device taking both forming efficiency and forming accuracy into consideration as described in any one of claims 1 to 6, characterized in that: The included angle between the mirror surface of the second reflector (5) and the light beam output path of the second laser source (2), as well as the included angle between the mirror surface of the second reflector (5) and the light beam input path of the scanning processing component are both designed to be 45°.

9. The dual-beam SLM forming device taking both forming efficiency and forming accuracy into consideration as described in any one of claims 1 to 6, characterized in that: The intersection of the light beam output path of the first laser source (1) and the light beam input path of the scanning processing component (3) is located on a vertical line passing through the center of the mirror surface of the first reflector (4).

10. The dual-beam SLM forming device that takes both forming efficiency and forming accuracy into consideration according to any one of claims 1 to 6, characterized in that: The intersection of the light beam output path of the second laser source (2) and the light beam input path of the scanning processing component (3) is located on a vertical line passing through the center of the mirror surface of the second reflector (5).

11. The dual-beam SLM forming device taking both forming efficiency and forming accuracy into consideration according to any one of claims 1 to 6, characterized in that: The motion mechanism (7) is a linear drive mechanism.

12. The dual-beam SLM forming device that takes both forming efficiency and forming accuracy into consideration according to any one of claims 1 to 6, characterized in that: The first reflector (4), the second reflector (5) and the reflector support (6) are all provided with circulating cooling channels inside, and the circulating cooling channels are externally connected to a liquid cooling device.

13. A dual-beam SLM forming method that takes both forming efficiency and forming accuracy into consideration, which is implemented by using the dual-beam SLM forming device according to any one of claims 1 to 12, characterized in that: The steps include: S1 adjusts the position of the reflector according to the laser beam to be used: If a medium / low power laser beam is required, the position of the first reflector (4) is adjusted by the motion mechanism (7) so that the intersection of the beam output path of the first laser source (1) and the beam input path of the scanning processing component is located on the mirror surface of the first reflector (4), and the process proceeds to step S2; If a medium / high power laser beam is required, the position of the second reflector (5) is adjusted by the motion mechanism (7) so that the intersection of the beam output path of the second laser source (2) and the beam input path of the scanning processing component is located on the mirror surface of the second reflector (5), and the process proceeds to step S3; S2: the first laser source (1) emits a medium / low power laser beam, which is collimated and reflected by a first reflector (4) to a scanning processing component (3), and is focused on the surface of a metal powder bed, thereby completing high-precision SLM forming of metal parts; S3 The second laser source (2) emits a medium / high power laser beam, which is collimated and reflected by the second reflector (5) to the scanning processing component (3), and is focused on the surface of the metal powder bed to complete the high-efficiency SLM forming of metal parts.

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