Laser additive and subtractive composite forming method and system for capillary micropore metal

Abstract

The invention belongs to the technical field of advanced manufacturing, and particularly relates to a laser additive and subtractive composite forming method and system for capillary micropore metal, and the method comprises the steps that N layers (N is larger than or equal to 1) of capillary micropore metal are continuously formed through the selective laser melting technology, and forming is suspended after the Nth layer is formed and before powder spreading of the (N + 1) th layer begins; full-breadth scanning is conducted on the N forming layers through ultrafast laser, loose powder on the surface layers of the capillary micropores is dispelled through plasma shock waves excited by the ultrafast laser, the ultrafast laser is made to enter the capillary micropores, then the ultrafast laser and the plasma shock waves excited by the ultrafast laser are subjected to multiple reflection in the capillary micropores, and the capillary micropores are formed. Removing powder adhered to the wall surfaces of the capillary micropores; and repeating the steps until the last layer is formed, and performing full-breadth scanning by using ultrafast laser. According to the method and the device, the micro-pore wall surface body can be prevented from being seriously ablated while the powder adhered to the micro-pore wall surface is removed.

Description

Technical Field

[0001] This application belongs to the field of advanced manufacturing technology, and more specifically, relates to a laser additive and subtractive composite forming method and system for capillary microporous metal. Background Art

[0002] Capillary microporous metal generally refers to porous metal with an average pore diameter in the range of 10μm - 200μm. Due to its extremely high specific surface area and permeability, it has important applications in fields such as aerospace, energy chemical engineering, mold manufacturing, and biomedicine. Selective Laser Melting (SLM) technology is one of the fastest-developing laser additive manufacturing technologies. Its working principle is "fine pre-laying of metal powder layer by layer + precise scanning and melting of the laser beam layer by layer", so it is particularly suitable for the high-efficiency and short-cycle manufacturing of complex metal parts. In particular, by adjusting conditions such as the laser scanning trajectory and laser energy input, capillary microporous metal can be flexibly prepared, and the pore characteristics can be flexibly adjusted by changing the laser processing parameters.

[0003] However, due to the existence of the laser heat-affected zone, when preparing capillary microporous metal using SLM technology, there is always adhered powder on the microporous wall surface. Under the action of laser heat, these adhered powders have a certain degree of metallurgical bonding with the microporous wall surface and cannot be removed by simple means such as vibration or air flow flushing. The adhered powder not only causes the actual pore characteristics (such as average pore size and porosity) to deviate from the preset values, but may also cause blockage of the micropores in severe cases, thereby seriously affecting the actual function of the capillary microporous metal. In fact, since the laser heat-affected zone is a common problem of continuous laser processing technology, for other types of metal parts formed by SLM technology, such as various dense solid parts, there is also generally adhered powder on their surfaces, which has a great negative impact on the forming accuracy and product performance. Currently, the adhered powder is mainly removed by post-processing the surface of SLM-formed parts (such as chemical polishing, electrochemical polishing, abrasive flow polishing, sandblasting, shot peening), or only subtractive processing is performed on the forming layer profile using SLM forming technology and ultrafast laser milling additive and subtractive composite forming technology. However, since the micropore diameter of capillary microporous metal is only 10μm - 200μm, and the micropores are densely arranged and extremely numerous, it is very difficult to efficiently remove the adhered powder on the microporous wall surface using the above post-processing methods, which not only causes a significant increase in manufacturing costs but also often fails to achieve the desired effect. Summary of the Invention

[0004] Aiming at the defects of the prior art, the purpose of this application is to provide a laser additive and subtractive composite forming method and system for capillary microporous metal, aiming to solve the problem of powder adhesion on the microporous wall surface of capillary microporous metal formed by existing SLM.

[0005] To achieve the above object, in a first aspect, the present application provides a laser additive and subtractive composite forming method for capillary microporous metal, including: S1 Continuously perform the forming of N layers (N≥1) of capillary microporous metal by laser selective melting technology. After the Nth layer is formed and before the powder spreading of the (N + 1)th layer starts, pause the forming. S2 Use an ultrafast laser to perform full - area scanning on the N formed layers, so as to use the plasma shock wave excited by the ultrafast laser to disperse the loose powder on the surface layer of the capillary micropores, enable the ultrafast laser to enter the interior of the capillary micropores, and then make the ultrafast laser and the plasma shock wave excited by it multiply reflect inside the capillary micropores to remove the powder adhered to the wall surface of the capillary micropores. S3 Repeat steps S1 - S2 until the forming is completed.

[0006] In the present application, the removal of the adhered powder on the micropore wall surface is completed during the SLM forming process of capillary microporous metal, avoiding problems such as low production efficiency and poor powder removal effect caused by subsequent surface treatment.

[0007] Further, the pulse width of the ultrafast laser is greater than or equal to 100 femtoseconds and less than or equal to 10 picoseconds.

[0008] Furthermore, the pulse width of the ultrafast laser is greater than or equal to 1 picosecond and less than 10 picoseconds. The corresponding laser performance parameters are: laser wavelength is 355 nm, pulse repetition frequency is 500 kHz, spot diameter is 10 μm - 30 μm, average power is 10 W - 30 W, laser scanning speed is 50 mm / s - 400 mm / s, and laser scanning pitch is 0.01 mm - 0.03 mm.

[0009] Furthermore, the pulse width of the ultrafast laser is greater than or equal to 100 femtoseconds and less than 1 picosecond. The corresponding laser performance parameters are: laser wavelength is 1070 nm, spot diameter is 10 μm - 30 μm, pulse repetition frequency is 200 kHz - 2 MHz, laser scanning speed is 50 mm / s - 800 mm / s, laser scanning pitch is 0.01 mm - 0.03 mm, and single - pulse energy is 20 μJ - 80 μJ.

[0010] Further, 2≤N≤5.

[0011] Further, in step S2, the ultrafast laser performs full - area scanning on the corresponding formed layer in a sequential raster scanning manner.

[0012] Furthermore, when the ultrafast laser scans sequentially, the scanning directions of adjacent scanning trajectory lines are the same or opposite.

[0013] Further, during each full - area scan, the pulse width of the ultrafast laser is the same as or different from that during the previous full - area scan.

[0014] Further, during each full - area scan, the laser performance parameters of the ultrafast laser are the same as or different from those during the previous full - area scan.

[0015] In a second aspect, the present application provides a system for implementing the laser additive - subtractive composite forming method as described above, including: A selective laser melting device for continuously performing SLM forming of N - layer capillary microporous metal; An ultrafast laser device for performing full - area scanning on the formed layer to use the plasma shock wave excited by the ultrafast laser to disperse the loose powder on the surface layer of the capillary micropores, so that the ultrafast laser enters the interior of the capillary micropores, and then the ultrafast laser and the plasma shock wave excited by it are multiply reflected inside the capillary micropores to remove the powder adhered to the wall surface of the capillary micropores.

[0016] It can be understood that the beneficial effects of the above - mentioned second aspect can be referred to the relevant descriptions in the first aspect above, and will not be elaborated here.

[0017] Generally speaking, compared with the prior art through the above - mentioned technical solutions conceived by the present application, the following beneficial effects are obtained: (1) The present application utilizes the organic combination of SLM forming technology and ultrafast laser milling subtractive manufacturing to remove the adhered powder on the micropore wall surface during the SLM forming process of capillary microporous metal, avoiding problems such as low production efficiency and poor powder removal effect caused by subsequent surface treatment.

[0018] (2) The present application utilizes the characteristics that the laser absorption rate of powder is higher than that of the solid, the thermal conductivity of powder is lower than that of the solid, and the laser absorption rate inside the micropores is further improved due to the multiple reflections of the ultrafast laser inside the micropores. By performing full - area scanning of the ultrafast laser on the formed layer during the SLM forming of capillary microporous metal, it is possible to remove the adhered powder on the micropore wall surface while avoiding serious ablation of the micropore wall surface itself, thus solving the problem of high - efficiency and precise processing of densely arranged micropores with sizes close to the diameter of the ultrafast laser spot.

[0019] (3) In the present application, the timing of using the full - area scanning of the ultrafast laser is after continuously forming N layers, and N is preferably 2 - 5 layers. When N < 2, the number of full - area scans of the ultrafast laser is too large, affecting the production efficiency of capillary microporous metal; when N > 5, the depth of the pore wall that the ultrafast laser needs to process is relatively large, and the photo - induced plasma is likely to accumulate inside the micropores, resulting in a decrease in the powder removal effect.

[0020] (4) In this application, the pulse width of the ultrafast laser used in full-area scanning is 100 femtoseconds to 10 picoseconds. Because when the pulse width is less than 100 femtoseconds, the machining efficiency of ultrafast laser milling is too low, and when the pulse width is greater than 10 picoseconds, spattering is likely to occur in ultrafast laser milling, reducing the machining quality.

[0021] (5) This application is easy to operate, easy to implement, and has strong universality, and is applicable to capillary microporous metals with various pore structures, various compositions, and various external dimensions formed by the SLM technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic flow chart of a method for laser additive and subtractive composite forming of capillary microporous metal provided in Embodiment 1 of this application; Figure 2 is a schematic diagram of a scanning trajectory when an ultrafast laser scans the SLM forming layer of capillary microporous metal in full area provided in Embodiment 1 of this application; Figure 3 is a comparison schematic diagram of a capillary microporous structure scanned by an ultrafast laser in full area and a capillary microporous structure not scanned by an ultrafast laser in full area provided in Embodiment 1 of this application; Figure 4 is a comparison schematic diagram of a capillary microporous structure scanned by an ultrafast laser in full area and a capillary microporous structure not scanned by an ultrafast laser in full area provided in Embodiment 2 of this application.

[0023] In all the drawings, the same reference numerals are used to represent the same elements or structures, where: 1 - SLM forming layer, 2 - scanning trajectory. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] In order to make the objectives, technical solutions, and advantages of this application clearer, the following further details this application in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0025] The term "and / or" in this article is a relationship describing associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The symbol " / " in this article represents an "or" relationship between associated objects. For example, A / B represents A or B.

[0026] The terms "first" and "second" in the specification and claims of this article are used to distinguish different objects, rather than to describe a specific order of the objects. For example, the first response message and the second response message are used to distinguish different response messages, rather than to describe the specific order of the response messages.

[0027] In the embodiments of the present application, words such as "exemplary" or "for example" are used to represent examples, illustrations, or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific manner.

[0028] In the description of the embodiments of the present application, unless otherwise specified, the meaning of "a plurality" refers to two or more. For example, a plurality of processing units refers to two or more processing units, etc.; a plurality of elements refers to two or more elements, etc.

[0029] The embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application.

[0030] Embodiment 1 This embodiment provides a laser additive and subtractive composite forming method for capillary microporous GH4169 precipitation-strengthened nickel-based superalloy, as Figure 1 shown, specifically including the following steps: S1 Continuously perform N-layer (N≥1) capillary microporous metal forming using selective laser melting technology (i.e., SLM forming technology). After the Nth layer is formed and before the powder spreading of the (N + 1)th layer starts, pause the forming. S2 Use an ultrafast laser to perform a full-area scan on the previously formed N layers to utilize the plasma shock wave excited by the ultrafast laser to disperse the loose powder on the surface layer of the capillary micropores, so that the ultrafast laser enters the interior of the capillary micropores, so that the ultrafast laser and the plasma shock wave excited by it are multiply reflected inside the capillary micropores to remove the powder adhering to the wall surface of the capillary micropores. S3 Repeat steps S1~S2 until the last layer is formed and a full-area scan as in step S2 is performed on the last layer.

[0031] Preferably, N is 2-5. When N < 2, the excessive number of full-area scans of the corresponding ultrafast laser will affect the production efficiency of the capillary microporous metal; when N > 5, the depth of the pore wall that the ultrafast laser needs to process is relatively large, and the photoinduced plasma is likely to accumulate inside the micropores, resulting in a decrease in the effect of removing the adhering powder.

[0032] The pulse width of the aforementioned ultrafast laser is greater than or equal to 100 femtoseconds and less than or equal to 10 picoseconds. When the pulse width of the ultrafast laser is greater than or equal to 1 picosecond and less than 10 picoseconds, the laser performance parameters of the ultrafast laser are: the laser wavelength is 355 nm, the pulse repetition frequency is 500 kHz, the spot diameter is 10 μm to 30 μm, the average power is 10 W to 30 W, the laser scanning speed is 50 mm / s to 400 mm / s, and the laser scanning pitch is 0.01 mm to 0.03 mm. When the pulse width of the ultrafast laser is greater than or equal to 100 femtoseconds and less than 1 picosecond, the laser performance parameters of the ultrafast laser are: the laser wavelength is 1070 nm, the spot diameter is 10 μm to 30 μm, the pulse repetition frequency is 200 kHz to 2 MHz, the laser scanning speed is 50 mm / s to 800 mm / s, the laser scanning pitch is 0.01 mm to 0.03 mm, and the single pulse energy is 20 μJ to 80 μJ.

[0033] In this embodiment, in the aforementioned step S1, the SLM forming technology is used to form the capillary microporous GH4169 precipitation-strengthened nickel-based superalloy. Specifically, N is taken as 2, that is, after continuously printing 2 layers, and after the second layer is formed and before the powder spreading of the third layer starts, the SLM forming is paused; In the aforementioned step S2, the ultrafast laser is used to perform full-area scanning on the formed layer; specifically, the ultrafast laser Figure 2 performs full-area scanning on the first 2 layers of the SLM formed layer 1 in the manner of sequential raster filling scanning shown in FIG. a, that is, the scanning directions of adjacent scanning tracks 2 are the same. The specific scanning parameters of the laser during full-area scanning are: the pulse width is 10 ps, the corresponding laser wavelength is 355 nm, the pulse repetition frequency is 500 kHz, the spot diameter is 30 μm, the average power is 16 W, the laser scanning speed is 200 mm / s, and the laser scanning pitch is 0.01 mm.

[0034] In the aforementioned step S3, the SLM forming is continued, and after continuously forming 2 layers, that is, after the fourth layer is formed and before the powder spreading of the fifth layer starts, the SLM forming is paused; then the ultrafast laser is used to perform full-area scanning on the formed layers of the first 4 layers. Specifically, the ultrafast laser Figure 2 performs in the manner of sequential raster filling scanning shown in FIG. a, that is, the scanning directions of adjacent scanning tracks 2 are the same, and the specific performance parameters of the laser are the same as those of the previous full-area scanning, that is: the laser wavelength is 355 nm, the pulse repetition frequency is 500 kHz, the spot diameter is 30 μm, the average power is 16 W, the laser scanning speed is 200 mm / s, and the laser scanning pitch is 0.01 mm.

[0035] Repeat steps S1-S2, alternating between SLM forming of the capillary microporous GH4169 high-temperature alloy and full-scale ultrafast laser scanning of the formed layer until the last layer is formed. Then, the ultrafast laser is used to perform full-scale scanning of the last formed layer. During this full-scale scanning, the performance parameters of the ultrafast laser are the same as those in S2.

[0036] Figure 3 Schematic diagram comparing the capillary pore structure without full-width ultrafast laser scanning and the capillary pore structure with full-width ultrafast laser scanning in this embodiment. Figure 3 As shown in Figure a, when the forming layer is not scanned by ultrafast laser full-width scanning, the micropore wall of the SLM-formed capillary microporous GH4169 superalloy is covered with adhered powder; Figure 3 As shown in Figure b, after the ultrafast laser full-width scanning of the forming layer, the adhering powder on the micropore wall basically disappeared, and the pore wall itself was not severely ablated and damaged.

[0037] Example 2 This embodiment provides a laser additive and subtractive composite forming method for capillary microporous TA15 titanium alloy, which specifically includes the following steps: S1 uses the laser selective melting technology to continuously perform three layers of capillary microporous TA15 titanium alloy SLM forming. After the third layer is formed and before the fourth layer powder coating begins, the SLM forming is paused.

[0038] S2 uses ultrafast laser to perform full-width scanning on the shaping layer; specifically, the ultrafast laser in this embodiment uses the same method as in Example 1. Figure 2 The track-by-track raster filling scanning method shown in b, i.e., the directions of adjacent scanning tracks 2 are opposite; the laser performance parameters during full-width scanning are: pulse width 10 ps, laser wavelength 355 nm, pulse repetition frequency 500 kHz, spot diameter 30 μm, average power 16 W, laser scanning speed 150 mm / s, and laser scanning pitch 0.02 mm.

[0039] S3: Repeat steps S1-S2, continuing SLM for three consecutive layers based on the previous three layers. Pause SLM after the sixth layer is completed and before the seventh layer is applied. Use an ultrafast laser to scan the entire sixth layer. Specifically, the ultrafast laser uses a track-by-track raster fill scan, with adjacent scan tracks 2 in opposite directions. The ultrafast laser scanning parameters are the same as the previous scan: pulse width 10 ps, laser wavelength 355 nm, pulse repetition frequency 500 kHz, spot diameter 30 μm, average power 16 W, laser scanning speed 150 mm / s, and laser scanning pitch 0.02 mm.

[0040] Repeat and alternately perform the SLM forming of capillary microporous TA15 titanium alloy and the full-area scanning of the formed layer with ultrafast laser until the last layer is formed, and then perform the full-area scanning of the last formed layer with ultrafast laser; the full-area scanning parameters are the same as those of any full-area scanning in the previous times.

[0041] Figure 4 It is a schematic comparison diagram of the capillary microporous structure without full-area scanning with ultrafast laser and the capillary microporous structure with full-area scanning with ultrafast laser in this embodiment. As Figure 4 can be seen from Figure a in it, when the full-area scanning of the formed layer with ultrafast laser is not performed, the microporous wall surface of the SLM-formed capillary microporous TA15 titanium alloy is covered with adhered powder; as Figure 4 can be seen from Figure b in it, after the full-area scanning of the formed layer with ultrafast laser, the adhered powder on the microporous wall surface basically disappears, and the main body of the pore wall is not severely ablated and damaged.

[0042] Embodiment 3 This embodiment provides a system for implementing the laser additive and subtractive composite forming method as in Embodiment 1 and Embodiment 2. The system includes: A selective laser melting device for continuously performing SLM forming of N layers of capillary microporous metal; specifically including a laser system, a scanning galvanometer system, a forming station, a control system and other auxiliary structures. The laser system includes a laser and an optical path transmission system arranged along the optical path. The controller controls the laser emitted by the laser to be directed to the forming station through the optical path transmission system, and at the same time controls the scanning galvanometer system to regulate the scanning path.

[0043] An ultrafast laser device for performing full-area scanning on the formed layer to use the plasma shock wave excited by the ultrafast laser to disperse the loose powder on the surface layer of the capillary micropores, so that the ultrafast laser enters the capillary micropores, and then the ultrafast laser and the plasma shock wave excited by it are multiply reflected inside the capillary micropores to remove the powder adhered to the capillary microporous wall surface. The ultrafast laser device includes a femtosecond or picosecond laser, and the laser beam is directed to the formed layer through a composite optical path system.

[0044] The above system can be adaptively improved according to processing requirements, and is not limited to the unit structure mentioned in this embodiment.

[0045] It should be understood that expressions such as "including" and "may include" that can be used in this application indicate the existence of the disclosed functions, operations or constituent elements, and do not limit one or more additional functions, operations and constituent elements. In this application, terms such as "including" and / or "having" can be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components or their combinations, but cannot be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components or their combinations.

[0046] In the description of the embodiments of the present application, it should be noted that unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the two are connected and the relative position relationship after connection remains unchanged. "Rotational connection" means that the two are connected and can rotate relative to each other after connection. "Sliding connection" means that the two are connected and can slide relative to each other after connection. The orientation terms mentioned in the embodiments of the present application, such as "top", "bottom", "inner", "outer", "left", "right", etc., are only with reference to the direction of the accompanying drawings. Therefore, the orientation terms used are for better and clearer description and understanding of the embodiments of the present application, 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 thus cannot be construed as a limitation on the embodiments of the present application.

[0047] In addition, in the embodiments of the present application, mathematical concepts such as symmetry, equality, parallelism, perpendicularity, etc. are mentioned. These limitations are all in view of the current technological level, rather than absolute strict definitions in the mathematical sense. A small deviation is allowed, and being approximately symmetric, approximately equal, approximately parallel, approximately perpendicular, etc. are all acceptable. For example, when A is parallel to B, it means that A is parallel to B or approximately parallel to B, and the included angle between A and B can be between 0 degrees and 10 degrees. When A is perpendicular to B, it means that A is perpendicular to B or approximately perpendicular to B, and the included angle between A and B can be between 80 degrees and 100 degrees.

[0048] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A laser additive and subtractive composite forming method for capillary microporous metal, characterized in that, Including: S1 Continuously perform capillary microporous metal forming for N layers (N≥1) using selective laser melting technology. After the Nth layer is formed and before the powder spreading for the (N + 1)th layer starts, pause the forming. S2 Use an ultrafast laser to perform full - area scanning on the N formed layers, so as to use the plasma shock wave excited by the ultrafast laser to disperse the loose powder on the surface layer of the capillary micropores, make the ultrafast laser enter the interior of the capillary micropores, and then make the ultrafast laser and the plasma shock wave excited by it perform multiple reflections inside the capillary micropores to remove the powder adhering to the wall surface of the capillary micropores. S3 Repeat steps S1 - S2 until the forming is completed.

2. The laser additive and subtractive composite forming method according to claim 1, wherein The pulse width of the ultrafast laser is greater than or equal to 100 femtoseconds and less than or equal to 10 picoseconds.

3. The laser additive and subtractive composite forming method according to claim 2, wherein The pulse width of the ultrafast laser is greater than or equal to 1 picosecond and less than 10 picoseconds. The corresponding laser performance parameters are: laser wavelength is 355 nm, pulse repetition frequency is 500 kHz, spot diameter is 10 μm - 30 μm, average power is 10 W - 30 W, laser scanning speed is 50 mm / s - 400 mm / s, and laser scanning pitch is 0.01 mm - 0.03 mm.

4. The laser additive and subtractive hybrid manufacturing method according to claim 2, characterized in that, The pulse width of the ultrafast laser is greater than or equal to 100 femtoseconds and less than 1 picosecond. The corresponding laser performance parameters are: laser wavelength is 1070 nm, spot diameter is 10 μm - 30 μm, pulse repetition frequency is 200 kHz - 2 MHz, laser scanning speed is 50 mm / s - 800 mm / s, laser scanning pitch is 0.01 mm - 0.03 mm, and single - pulse energy is 20 μJ - 80 μJ.

5. The laser additive and subtractive composite forming method according to claim 1, wherein 2≤N≤5。 6. The laser additive and subtractive composite forming method according to claim 1, characterized in that, In step S2, the ultrafast laser performs full - area scanning on the corresponding formed layer in a sequential raster scanning manner.

7. The laser additive and subtractive hybrid manufacturing method according to claim 6, wherein, When the ultrafast laser scans sequentially, the scanning directions of adjacent scanning trajectory lines are the same or opposite.

8. The laser additive and subtractive composite forming method according to claim 1, characterized in that, During each full - area scanning, the pulse width of the ultrafast laser is the same as or different from that of the previous full - area scanning.

9. The laser additive and subtractive composite forming method according to claim 1, wherein During each full - area scanning, the laser performance parameters of the ultrafast laser are the same as or different from those of the previous full - area scanning.

10. A system for implementing the laser additive and subtractive composite forming method according to any one of claims 1-9, characterized in that, Including: A selective laser melting device for continuously performing capillary microporous metal SLM forming for N layers. An ultrafast laser device for performing full - area scanning on the formed layer, so as to use the plasma shock wave excited by the ultrafast laser to disperse the loose powder on the surface layer of the capillary micropores, make the ultrafast laser enter the interior of the capillary micropores, and then make the ultrafast laser and the plasma shock wave excited by it perform multiple reflections inside the capillary micropores to remove the powder adhering to the wall surface of the capillary micropores.

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