Wall-to-wall protection material for long pulse-ultrafast laser combined drilling and drilling method

Abstract

The invention relates to the technical field of laser processing, particularly provides a wall-aligning protection material for long pulse-ultrafast laser combined hole making, and further provides a preparation method of the wall-aligning protection material and a hole making method. The wall-facing protection material for long pulse-ultrafast laser combined drilling provided by the invention comprises the following preparation raw materials: a bi-component polymer matrix and inorganic particles, the bi-component polymer matrix comprises a component A and a component B; wherein the component A is fluorinated epoxy resin, the component B is a fluorine-containing amine curing agent, and the mass ratio of the component A to the component B is 10: (1-3); the mass ratio of the bi-component polymer matrix to the inorganic particles is (2-1): 1. The wall-to-wall protection material provided by the invention is formed by compounding the bi-component polymer matrix and the inorganic particles, can form a heterogeneous layered structure after being cured, and can effectively block the heat effect of long pulse laser and the high peak power of ultrafast laser.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser processing, in particular to a wall protection material for long pulse-ultrafast laser combined hole making, and a hole making method. BACKGROUND

[0002] Laser processing technology is widely used in hole making, cutting and other industrial manufacturing fields due to its good material universality, high processing flexibility, no contact stress and other advantages. In particular, the combined processing method of using millisecond laser to process initial holes and then using ultrafast laser to process holes can not only ensure excellent hole wall quality, but also significantly improve the hole making efficiency, achieving a good balance between quality and efficiency. Therefore, the research and development of such combined processing equipment and process optimization have become a hot spot in the current industry technology development.

[0003] However, when processing parts with cavity structures such as hollow blades, oil nozzles and double-wall flame tubes, the laser is easy to damage the wall after penetrating the wall to be processed, which seriously affects the fatigue strength and service life of the part. Therefore, the strategy of filling protective materials in the inner cavity of the part is usually used for protection. The existing protective material system is mostly based on single material composition and homogeneous structure design, and can only provide effective protection for specific types of laser processing environment: materials suitable for blocking long pulse laser are often difficult to block ultrafast laser, and materials designed for ultrafast laser cannot effectively resist the impact of long pulse laser. For example, protective materials mainly composed of organic polymers can absorb and dissipate long pulse laser energy through thermal processes such as carbonization and vaporization, but they lack resistance to the high peak power of ultrafast laser; while protective materials mainly composed of high-melting-point inorganic particles can effectively scatter or resist ultrafast laser, but they have limited protection against the sustained heat accumulation effect of long pulse laser.

[0004] When implementing the long pulse-ultrafast laser combined hole making process, the existing homogeneous protective material system cannot meet the general requirements. If two different types of lasers are to be processed on the same workpiece, the original protective material must be removed after long pulse hole making, and another type of material suitable for ultrafast laser must be refilled. This process not only consumes time and effort, significantly reduces production efficiency, but repeated clamping and filling operations also introduce positioning errors, which seriously affect the processing accuracy and consistency of the hole, making it difficult to fully utilize the comprehensive advantages of the combined process. Therefore, it is urgent to develop a wall protection material for long pulse-ultrafast laser combined hole making and a corresponding use method to solve the problem of low universality of existing laser processing anti-wall damage methods and the inability to simultaneously meet the protective requirements of different types of laser energy fields. SUMMARY

[0005] In order to solve the above problems, the application provides a wall-protecting material for long-pulse-ultrafast laser combined drilling, which can form a heterogeneous layered structure after solidification, and can effectively block the thermal effect of long-pulse laser and the high peak power of ultrafast laser. The application also provides a preparation method of the wall-protecting material and a drilling method based on the wall-protecting material.

[0006] In order to achieve the above-mentioned purposes, the application adopts the following technical solutions: In a first aspect, the application provides a wall-protecting material for long-pulse-ultrafast laser combined drilling, which comprises the following raw materials: a two-component polymer matrix and inorganic particles; the two-component polymer matrix comprises component A and component B. The component A is fluorinated epoxy resin, the component B is fluorine-containing amine curing agent, and the mass ratio of the component A to the component B is 10: (1-3). The mass ratio of the two-component polymer matrix to the inorganic particles is (2-1): 1.

[0007] By precisely controlling the addition ratio of the component A (the present adhesive), the component B (the hardener) and the inorganic particles, and controlling the mass ratio of the polymer matrix to the inorganic particles in the range of (2-1): 1, it is ensured that the wall-protecting material has good flowability in the filling stage, can fully fill the complex and narrow cavity, and provides a key condition for forming a stable and functionally gradient layered structure, so as to ensure that the solidified protective body has reliable protective performance. On this basis, the wall-protecting material can spontaneously form a heterogeneous layered structure with the upper layer rich in fluorinated polymer and the lower layer rich in inorganic particles before solidification, thereby having a double blocking function: the upper layer of polymer can effectively absorb and dissipate the thermal energy of long-pulse laser, and the lower layer of inorganic particles can efficiently scatter and resist the high peak power of ultrafast laser, solving the problem that the existing homogeneous protective material cannot simultaneously meet the protection requirements of different types of pulse width laser. In addition, the fluorinated epoxy resin and the fluorine-containing amine curing agent system used in the application significantly improves the thermal stability and laser ablation threshold of the polymer matrix by introducing C-F bonds, so that the formed polymer has excellent thermal stability.

[0008] Preferably, the fluorinated epoxy resin includes but is not limited to hexafluoroisopropylidene diphenylamine type epoxy resin, trifluoromethyl-substituted bisphenol A type epoxy resin, perfluoropolyether chain modified epoxy resin, tetrafluoro-hydroquinone diglycidyl ether, decafluorobiphenyl diglycidyl ether, etc.

[0009] Preferably, the fluorine-containing amine curing agent includes but is not limited to 4,4'-(hexafluoroisopropylidene)diphenylamine, trifluoroethylenediamine, perfluoropolyether diamine, 2,2,3,3,4,4,5,5-octafluorohexanediamine, fluorine-containing aromatic diamine, etc. The preferred fluorine-containing component of the present application significantly improves the thermal stability and laser ablation threshold of the polymer through the strong bond energy of C-F bond, while maintaining appropriate flowability and curing characteristics to meet the requirements of protective materials for composite laser processing. It should be noted that factors such as fluorine content, viscosity matching and curing rate should be considered when selecting to ensure that the final protective material has good process applicability and reliable protective performance.

[0010] Preferably, the inorganic particles include one or more of boron nitride, magnesium hydroxide, aluminum hydroxide, silicon oxide, titanium oxide, zinc oxide, magnesium oxide, aluminum oxide, zirconium oxide, silicon carbide, boron carbide, aluminum nitride.

[0011] The preferred inorganic particles in the present application have high melting point, high hardness and excellent thermal stability, which constitute the core functional phase of the lower layer of the protective body to block ultrafast laser, and can effectively scatter, reflect and absorb the ultra-high peak power of ultrafast laser. At the same time, it has a density difference with the polymer matrix, which ensures that a heterogeneous functional gradient structure of upper layer rich in polymer and lower layer rich in inorganic particles can be stably formed after curing. In addition, preferred inorganic particles such as magnesium hydroxide and aluminum hydroxide can decompose and absorb heat when heated, thereby enhancing the thermal shock resistance of the system, and can produce a synergistic reinforcing effect with the fluorinated polymer matrix, together ensuring the reliability and stability of the performance of the protective body during composite laser processing.

[0012] Preferably, the particle size of the inorganic particles is 10-500 μm.

[0013] In a second aspect, the present application provides a preparation method of the above-mentioned wall-protecting material for long pulse-ultrafast laser combined hole making, which comprises the following steps: Mixing the A component and the B component of the two-component polymer matrix to obtain a mixed glue; adding the inorganic particles to the mixed glue and stirring uniformly to obtain the wall-protecting material.

[0014] In a third aspect, the present application provides a hole making method of the wall-protecting material for long pulse-ultrafast laser combined hole making, which comprises the following steps: S1. Filling the wall-protecting material into the inner cavity corresponding to the hole making part of the workpiece, and then placing the hole making part of the workpiece upwards, so that the wall-protecting material is settled and stratified under the action of gravity, and a protective body is formed after curing; S2. Using a long pulse laser to process an initial hole at the hole-making site of the workpiece, the long pulse laser is blocked by the upper layer of the protective body; then using an ultrafast laser to finish the initial hole, the ultrafast laser is blocked by the lower layer of the protective body; after the hole-making is completed, the protective body is removed.

[0015] Preferably, in step S1, the filling method is selected from one or more of positive pressure injection, negative pressure pumping.

[0016] Preferably, in step S1, the curing method is room temperature standing curing or heating curing.

[0017] Preferably, in step S2, the pulse width of the long pulse laser is 1ms-1ns.

[0018] Preferably, in step S2, the long pulse laser processes the initial hole in a way selected from impact or rotary cutting.

[0019] Preferably, in step S2, the pulse width of the ultrafast laser is <10ps.

[0020] Preferably, in step S2, the ultrafast laser finishes the hole in a way selected from rotary cutting or ring type to remove the heat affected zone of the hole wall and form the final hole type.

[0021] Preferably, the removal method of the protective body is selected from one or more of a debonding agent dissolution or heating decomposition. Further preferably, the debonding agent can be selected from an organic solvent type debonding agent or an alkaline solution type debonding agent, etc., which can effectively dissolve the fluorinated polymer matrix without damaging the workpiece substrate; wherein the organic solvent type debonding agent includes but is not limited to dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), N-methyl pyrrolidone, dichloromethane, trichloroethylene, etc., and the alkaline solution type debonding agent includes but is not limited to sodium hydroxide solution, potassium hydroxide solution, tetramethylammonium hydroxide (TMAH) aqueous solution, etc. The heating decomposition temperature is controlled in the range of 300-500℃, and the failure degradation and removal of the protective body can be achieved by 2-5h of heat preservation. The two removal methods are simple to operate, complete in removal, and do not damage the workpiece body, and are particularly suitable for the machining protection needs of precision parts.

[0022] Compared with the prior art, the present application has the following beneficial effects: (1) The wall protection material provided by the present application is composed of a two-component polymer matrix and inorganic particles, and can spontaneously form a protective body with a layered structure with a upper layer mainly composed of a polymer and a lower layer rich in inorganic fillers in the cavity of the workpiece. The material has good flowability before filling, can fully fill the complex cavity; after standing, it can realize directional layering and curing through gravity settling, and the cured protective material is easy to remove completely.

[0023] (2) In the process of the long pulse-ultrafast laser combined hole making method provided by the present invention, after the long pulse laser penetrates the wall plate to form the initial hole, its remaining energy is effectively blocked by the polymer on the upper layer of the protective body; then, when the ultrafast laser is used for in-situ hole repair, after the ultrafast laser removes the heat-affected zone of the hole wall and the upper polymer material, its energy is reliably blocked by the lower inorganic particle layer until the precision hole repair is completed.

[0024] (3) The wall protection material and hole-making method provided by the present invention successfully solve the problem that traditional single-function protective materials cannot simultaneously meet the wall protection requirements of different types of laser combination or composite processing. Moreover, the wall protection material only needs to be filled once to complete the entire combination hole-making process, avoiding positioning errors caused by repeated clamping, effectively ensuring the processing accuracy of the workpiece, and saving a lot of manpower and material resources. Attached Figure Description

[0025] Figure 1 This is a topographic image of the aperture obtained by using a long pulse-ultrafast laser combination to create a hole after employing a wall-mounted protective material in Embodiment 1 of the present invention. Figure 2 This is a topographic image of the hollow blade after the wall is drilled using a long pulse-ultrafast laser combination after the wall protection material is used in Embodiment 1 of the present invention. Figure 3 This is a metallographic morphology image of the hole wall after long pulse-ultrafast laser combined drilling following the use of a wall-protecting material in Embodiment 1 of the present invention. Figure 4 This is a topographic image of the aperture obtained by long-pulse laser drilling in Comparative Example 1 of the present invention without the use of wall-mounted protective materials; Figure 5 This is a topographic image of the hollow blade after drilling with a long pulse laser in Comparative Example 1 of the present invention, without the use of a protective material against the wall. Figure 6 This is a topographic image of the aperture obtained by ultrafast laser drilling in Comparative Example 2 of the present invention without the use of a wall-mounted protective material; Figure 7 This is a topographic image of the hollow blade after being drilled by an ultrafast laser without the use of a wall-mounted protective material in Comparative Example 2 of the present invention. Figure 8 This is a topographic image of the aperture obtained by long pulse-ultrafast laser combined drilling in Comparative Example 3 of the present invention without the use of wall-mounted protective materials; Figure 9 This is a topographic image of the hollow blade after hole drilling using a long pulse-ultrafast laser combination, without the use of a wall-protecting material in Comparative Example 3 of the present invention. Detailed Implementation

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the specific embodiments will be briefly introduced below. Obviously, the embodiments described below are some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these embodiments without creative effort.

[0027] Where specific experimental steps or conditions are not specified in the embodiments, they can be performed according to the conventional experimental steps or conditions described in the literature in this field. All raw materials or instruments used are commercially available finished products, including but not limited to those used in the embodiments of this application.

[0028] Example 1 This embodiment discloses a wall-protecting material for long-pulse-ultrafast laser combined hole drilling, comprising the following raw materials: a two-component polymer matrix and inorganic particles; the two-component polymer matrix includes component A and component B; Component A is a fluorinated epoxy resin (hexafluoroisopropylidene diphenylamine type epoxy resin), and component B is a fluorinated amine curing agent (trifluoroethylenediamine). The mass ratio of component A to component B is 10:3. The mass ratio of the two-component polymer matrix to the inorganic particles is 2:1; The inorganic particles, by mass percentage, comprise: 40% alumina with a particle size of 200 μm, 30% silica with a particle size of 100 μm, and 30% zirconium dioxide with a particle size of 50 μm. This embodiment provides a method for preparing a wall-protecting material for long-pulse-ultrafast laser combined hole drilling, comprising the following steps: Components A and B of the two-component polymer matrix are mixed and stirred evenly to obtain a mixed adhesive; inorganic particles are added to the mixed adhesive and stirred evenly to obtain a flowable wall protection material.

[0029] This embodiment provides a method for fabricating a wall-protecting material using the above-described method for long-pulse-ultrafast laser combined hole fabrication, comprising the following steps: S1. Using a syringe, the anti-wall protection material prepared in this embodiment is injected under positive pressure into the inner cavity corresponding to the hole to be made on a certain type of hollow blade until the material is fully filled and slightly overflows. Then the opening of the inner cavity is sealed. The hollow blade is placed with the hole to be made facing upwards, so that the anti-wall protection material settles and stratifies naturally under the action of gravity. The upper layer is a polymer layer, and the high-density inorganic particles settle to the middle and lower regions. Allow the material to stand and cure at room temperature for 2 hours to form a protective body with a heterogeneous layered structure. S2. Hole fabrication is performed using a long-pulse-ultrafast laser combined process, as detailed below: A long-pulse laser with a pulse width of 0.3ms, a wavelength of 1064nm, and a power of 100W was used to prepare an initial hole of 0.2mm in size at the hole to be made on the hollow blade using an impact processing method. The impact time was 0.2s. After the long-pulse laser penetrated the wall plate, the remaining energy was effectively blocked by the polymer layer on the upper layer of the protective body. The pulse width was switched to an ultrafast laser with a wavelength of 1030nm and a power of 20W to remove the heat-affected zone of the hole wall by a spin cutting method. The spin cutting time was 30s. After the ultrafast laser removed the residual polymer layer, it was effectively blocked by the inorganic particles in the lower layer of the protective body until the hole repair was completed. After the holes are made, the blades are immersed in a degumming agent (N,N-dimethylformamide) for 12 hours to decompose the polymer matrix. Then, the inorganic particles are removed by high-pressure air blowing, and finally, the protective body is completely removed by ultrasonic cleaning for 1 minute.

[0030] The hollow blades after drilling were inspected. Microscopic observation showed that the orifice morphology was regular, and no defects such as molten accumulation or splashing were observed. Figure 1 After dissecting the leaf, observe the opposite wall, such as... Figure 2 As shown, the surface structure of the wall is intact, with no traces of laser damage, and no residue was found inside the cavity; further metallographic analysis yielded the following results. Figure 3 As shown, the hole wall quality is excellent, with no recast layer, microcracks, or heat-affected zone. These test results fully demonstrate that using this protective material not only provides effective protection for the hole wall but also ensures high-quality machining results in composite hole forming.

[0031] Comparative Example 1 This comparative example provides a hole-making method. Without using an internal cavity-filling protective material, a hole-making experiment is conducted in the same blade area as in Example 1, referring to the long-pulse laser process in Example 1. Specifically: A long-pulse laser with a pulse width of 0.3ms, a wavelength of 1064nm, and a power of 100W was used to prepare an initial hole of 0.2mm in size on the part of the hollow blade to be drilled using an impact processing method, with an impact time of 0.2s.

[0032] Microscopic observation revealed excess material that had melted and accumulated at the orifice opening due to heat. Figure 4 Dissecting the blade and observing the opposite wall, it was found that the inner cavity of the blade showed ablation damage to the opposite wall caused by long-pulse laser irradiation after penetrating the surface wall, including pits and molten spatter. Figure 5 The results show that directly using long-pulse laser drilling without taking protective measures against the wall will cause damage to the wall.

[0033] Comparative Example 2 This comparative example provides a hole-making method. Without using an internal cavity-filling protective material, a hole-making experiment is conducted in the same blade area as in Example 1, referring to the ultrafast laser process in Example 1. Specifically: Using an ultrafast laser with a pulse width of 2ps, a wavelength of 1030nm, and a power of 20W, holes are drilled in a rotary cutting manner, with a processing time of 100s.

[0034] Microscopic observation revealed that the orifice morphology was regular, with no defects such as molten accumulation or splashing observed. Figure 6 Dissecting the blade and observing the opposite wall, non-thermal ablation damage was observed on the opposite wall of the blade's inner cavity, caused by irradiation after the surface wall was penetrated by an ultrafast laser. Figure 7 The results show that, without taking protective measures against the wall, directly using ultrafast laser drilling will cause damage to the wall.

[0035] Comparative Example 3 This comparative example provides a hole-making method. Without using an internal cavity-filling protective material, a hole-making experiment is conducted in the same blade area as in Example 1, referring to the combined laser process in Example 1. Specifically: First, a long-pulse laser with a pulse width of 0.3ms, a wavelength of 1064nm, and a power of 100W was used to prepare an initial hole of 0.2mm using an impact processing method with an impact time of 0.2s. Then, the process was switched to an ultrafast laser with a pulse width of 2ps, a wavelength of 1030nm, and a power of 20W to refine the hole using a rotary cutting method for 30s.

[0036] Microscopic observation revealed that the orifice was relatively regular, without any molten material, splashes, or other excess material. Figure 8 Dissecting the blade and observing the opposite wall, ablation damage caused by a combination of long-pulse laser and ultrafast laser was observed in the blade's inner cavity. Figure 9 The results showed that, without protective measures, the combination of long-pulse laser followed by ultrafast laser drilling caused severe wall damage.

[0037] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A wall-mounting protective material for long-pulse-ultrafast laser combined hole fabrication, characterized in that, The preparation materials include: a two-component polymer matrix and inorganic particles; the two-component polymer matrix includes component A and component B; Component A is a fluorinated epoxy resin, and component B is a fluorinated amine curing agent. The mass ratio of component A to component B is 10:(1-3). The mass ratio of the two-component polymer matrix to the inorganic particles is (2-1):

1.

2. The wall protection material for long-pulse-ultrafast laser combined hole drilling as described in claim 1, characterized in that, The inorganic particles include one or more of boron nitride, magnesium hydroxide, aluminum hydroxide, silicon oxide, titanium oxide, zinc oxide, magnesium oxide, aluminum oxide, zirconium oxide, silicon carbide, boron carbide, and aluminum nitride.

3. The wall protection material for long-pulse-ultrafast laser combined hole drilling as described in claim 1 or 2, characterized in that, The inorganic particles have a particle size of 10μm-500μm.

4. A method for preparing a wall-protecting material for long-pulse-ultrafast laser combined hole drilling as described in any one of claims 1-3, characterized in that, Includes the following steps: The A and B components of the two-component polymer matrix are mixed to obtain a mixed adhesive; the inorganic particles are added to the mixed adhesive and stirred evenly to obtain the wall protection material.

5. A method for fabricating a wall-protecting material using any one of claims 1-3 for combined long-pulse-ultrafast laser hole fabrication, characterized in that, Includes the following steps: S1. Fill the inner cavity corresponding to the hole to be drilled in the workpiece with the wall-mounted protective material, and then place the workpiece with the hole to be drilled facing upwards, so that the wall-mounted protective material settles and layers under the action of gravity, and then solidifies to form a protective body; S2. A long-pulse laser is used to process an initial hole at the location to be drilled on the workpiece, wherein the long-pulse laser is blocked by the upper layer of the protective body; then an ultrafast laser is used to refine the initial hole, wherein the ultrafast laser is blocked by the lower layer of the protective body; after the hole is drilled, the protective body is removed.

6. The hole-making method as described in claim 5, characterized in that, In step S1, the filling method is selected from one or more of positive pressure injection and negative pressure pumping.

7. The hole-making method as described in claim 5, characterized in that, In step S1, the curing method is either room temperature static curing or heat curing.

8. The hole-making method as described in claim 5, characterized in that, In step S2, the pulse width of the long-pulse laser is 1ms-1ns; and / or The method of processing the initial hole with long pulse laser is selected from impact type or rotary cutting type.

9. The hole-making method as described in claim 5, characterized in that, In step S2, the pulse width of the ultrafast laser is <10 ps; and / or The ultrafast laser hole-repairing method is selected from either rotary cutting or ring cutting.

10. The hole-making method as described in claim 5, characterized in that, The method for removing the protective body is selected from one or more of the following: dissolution with a degumming agent and decomposition by heating.

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