Cutting process of metal polymer composite material

Abstract

The invention relates to the technical field of laser processing, and discloses a metal polymer composite material cutting process which comprises the following steps: placing a to-be-cut piece on a cutting platform; the to-be-cut piece comprises a metal layer and a polymer layer which are stacked; adjusting parameters of an output laser beam of the laser; the output wavelength lambda of the laser is controlled, so that the laser generates green laser, and the polymer layer is subjected to cold cutting; the value of the output power P and the value of the output pulse frequency f of the laser are controlled, so that the green laser is emitted in a pulse mode, and laser energy is concentrated and acts on the metal layer at intervals; according to the cutting process of the metal polymer composite material, the two-photon energy of the green laser is sufficient to reach the fracture energy of molecular bonds of the polymer layer, the polymer layer can be directly cut without reaching the melting point of the polymer layer, the energy of the pulse laser is concentrated and spaced, and the heat influence caused by cutting the metal layer is discontinuously generated; therefore, the influence on the interface of the metal layer and the polymer layer is reduced, and the cutting quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of laser processing, and in particular to a cutting process for metal polymer composite materials. Background Art

[0002] Metal polymer composites are usually composed of one or more layers of metal (such as copper, aluminum, etc.) and polymer materials (such as polyvinylidene fluoride, boehmite, etc.). They have the high thermal conductivity and electrical conductivity of metal materials, as well as the light weight and corrosion resistance of polymer materials.

[0003] In actual production, it is often necessary to perform laser cutting on copper-based or aluminum-based polymer composite materials to obtain metal polymer composite materials of a size and shape that meets production requirements.

[0004] However, the current laser cutting process for metal polymer composites generally suffers from poor cutting quality.

[0005] Specifically, infrared lasers are mostly used in the cutting process, but copper or aluminum materials have low absorption rates for infrared lasers, and require ultra-high power lasers and lower cutting speeds for processing. High-power lasers will cause copper and aluminum materials to have stronger thermal radiation and spattering during cutting. Coupled with the slow cutting speed, the metal material radiates a large amount of heat to the surrounding during cutting. In addition, infrared lasers can only perform high-temperature thermal cutting on polymer materials. Under the combined influence of heat, various defects such as expansion, burrs, steps, and pits with a layered appearance will appear at the cutting notch of the composite material and near the interface between the metal layer and the polymer layer, seriously affecting the cutting quality.

[0006] In order to avoid the many problems caused by infrared laser cutting, blue laser and ultraviolet laser are also used for cutting. Both blue laser and ultraviolet laser can perform cold cutting on polymer materials, but the blue laser has a large spot, low energy per unit area, and poor beam quality. It requires very high power to perform cold cutting on polymer materials. High-power blue laser will also generate a lot of heat when cutting metal materials. At the same time, due to the large spot, the cutting quality is also poor. The ultraviolet laser has low power, resulting in a slow cutting speed for metal materials. Long-term high-temperature processing will also cause various defects at the cutting notch. In addition, both blue laser and low-power ultraviolet laser have the problem of difficulty in cutting metal materials such as copper and aluminum. Summary of the invention

[0007] In view of this, the present invention provides a cutting process for metal polymer composite materials to solve the problem of poor cutting quality caused by various defects such as expansion, burrs, and holes occurring at the cutting notch of the composite material under the influence of comprehensive heat and near the interface between the metal layer and the polymer layer.

[0008] The present invention provides a cutting process for a metal polymer composite material, comprising:

[0009] S1: placing a workpiece to be cut on a cutting platform; the workpiece to be cut includes a stacked metal layer and a polymer layer;

[0010] S2: adjust the parameters of the output laser beam of the laser;

[0011] Controlling the output wavelength λ of the laser to be within the range of 500nm≤λ≤550nm, so that the laser generates green laser light to perform cold cutting on the polymer layer;

[0012] Controlling the output power P of the laser to be within the range of 70W≤P≤150W, so that the green laser performs thermal cutting on the metal layer;

[0013] The output pulse frequency f of the laser is controlled to be within the range of 800 khz ≤ f ≤ 2000 khz, and the green laser is emitted in a pulsed manner so that the laser energy is concentrated and acts on the metal layer at intervals;

[0014] S3: confirming the preset cutting line of the workpiece to be cut;

[0015] S4: the laser emits a green pulse laser, and the green pulse laser cuts the workpiece to be cut along the preset cutting line, and the cut of the workpiece to be cut is smooth.

[0016] In an optional embodiment, the polymer layer covers a side of the metal layer close to the laser; or; a plurality of polymer layers are provided, and the plurality of polymer layers cover opposite sides of the metal layer respectively.

[0017] In an optional embodiment, in step S4, the green light pulse laser is focused on the polymer layer, suitable for breaking the molecular bonds of the polymer layer to perform cold cutting on the polymer layer; the green light pulse laser cuts the polymer layer and is focused on the metal layer, and the energy of the green light pulse laser reaches or exceeds the melting point of the metal layer to perform pulsed hot cutting on the metal layer.

[0018] In an optional implementation, step S2 further includes controlling the energy E of the output laser beam of the laser to be within the range of 50uj≤E≤500uj.

[0019] In an optional embodiment, step S2 also includes controlling the diameter D of the focused spot of the output laser beam of the laser to be within the range of 10μm≤D≤50μm, and controlling the cutting speed v of the laser to be within the range of 800mm / s≤v≤3500mm / s, so that the spot overlap rate of the output laser beam of the laser is greater than 80%.

[0020] In an optional implementation, in step S2, the pulse width of the output laser beam of the laser is τ, where 5ns≤τ≤60ns.

[0021] In an optional embodiment, the metal layer is a copper layer, and the temperature at which the green light pulse laser acts on the metal layer is T1, wherein 1090°C≤T1≤1600°C; or; the metal layer is an aluminum layer, and the temperature at which the green light pulse laser acts on the metal layer is T2, wherein 670°C≤T2≤1000°C.

[0022] In an optional embodiment, the thickness of the metal layer is H1, wherein 5 μm≤H1≤30 μm.

[0023] In an optional embodiment, the thickness of the polymer layer is H2, wherein 5 μm≤H2≤30 μm.

[0024] In an optional embodiment, the polymer layer is made of polyvinylidene fluoride or a mixed material of polyvinylidene fluoride and boehmite, that is, the polyvinylidene fluoride material may also be mixed with a portion of boehmite.

[0025] Beneficial effect: In view of the problem of poor cutting quality due to the existence of comprehensive thermal effects in the laser cutting process of metal polymer composite materials, the present embodiment effectively solves the problem of poor cutting quality by setting a pulsed green laser. Specifically, firstly, the two-photon energy of the green laser is sufficient to reach the breaking energy of CC bonds and CH bonds in the polymer layer / polyvinylidene fluoride, and the polymer layer can be cold-cut without reaching the melting point of the polymer layer, thereby avoiding the thermal effect of the polymer layer cutting on the cutting notch; secondly, the energy of the pulsed laser is concentrated and acts at intervals, which ensures the smooth cutting of the metal layer while minimizing the thermal effects caused by the cutting. The pulsed green laser is within the determined technical parameter range, which can perform instantaneous high-temperature melting processing on the metal layer with a thickness of 5 to 30 μm, so that the metal layer is in a molten rather than vaporized state, which can greatly reduce the heat diffusion from the metal layer to the polymer layer and has less thermal impact on the polymer layer. Under the combined effect of the above three aspects, the cutting notch of the metal-polymer composite material is smooth, which effectively eliminates various defects such as expansion, burrs, and pits, and is conducive to ensuring the good morphology near the interface between the metal layer and the polymer layer, thereby greatly improving the cutting quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A schematic diagram of an embodiment of a cutting process of a metal polymer composite material of the present invention;

[0028] Figure 2 FIG. 4 is a schematic diagram of another embodiment of the cutting process of the metal polymer composite material of the present invention.

[0029] Description of reference numerals:

[0030] 1. Metal layer; 2. Polymer layer; 3. Laser. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0035] Combine the following Figure 1 to Figure 2 , describing an embodiment of the present invention.

[0036] According to an embodiment of the present invention, a cutting process for a metal polymer composite material is provided, comprising:

[0037] S1: Place the workpiece to be cut on a cutting platform; the workpiece to be cut includes a stacked metal layer 1 and a polymer layer 2, and the polymer layer 2 covers the side of the metal layer 1 close to the laser 3; the metal layer 1 can be an aluminum layer or a copper layer, and the melting point of the copper layer is higher than that of the aluminum layer. When cutting copper-based polymer composite materials, the energy of the laser 3 can be increased accordingly.

[0038] S2: Adjust the parameters of the output laser beam of laser 3:

[0039] In a first aspect, the output wavelength λ of the laser 3 is controlled to be within the range of 500nm≤λ≤550nm, specifically but not limited to 532nm, where the unit nm is nanometer; the laser 3 generates green laser light to perform cold cutting on the polymer layer 2.

[0040] Specifically, the material of the polymer layer 2 can be but is not limited to polyvinylidene fluoride or a mixture of polyvinylidene fluoride and boehmite. The two-photon energy of the 532nm green laser is sufficient to reach the breaking energy of the CC bond and the CH bond in the polymer layer 2. The CC bond is a covalent bond connecting two carbon atoms, and the CH bond is a covalent bond connecting a carbon atom and a hydrogen atom. The polymer layer 2 can be cold-cut without reaching the melting point of the polymer layer 2, thereby avoiding the thermal impact of the cutting of the polymer layer 2 on the cutting notch.

[0041] Secondly, the output power P of the laser 3 is controlled to be within the range of 70W≤P≤150W, where the unit W is watt; the specific power value can be selected based on the thickness, material and other parameters of the workpiece to be cut in actual production, so that the energy of the green laser reaches the melting point of the metal layer 1 to perform thermal cutting on the metal layer 1.

[0042] Specifically, by using a lower laser power, while ensuring smooth cutting of the metal layer 1, the heat impact caused by cutting is reduced, and undesirable appearances such as expansion, burrs, and pits are effectively eliminated.

[0043] Further on the basis of the second aspect, the output pulse frequency f of the laser 3 is controlled to be within the range of 800khz≤f≤2000khz, with the unit khz being kilohertz, so that the green laser is emitted in pulsed form, and the laser energy is concentrated and acts on the metal layer 1 at intervals. Since laser thermal cutting of the metal layer 1 will inevitably bring thermal effects, this embodiment adopts a pulsed laser, and with the help of the characteristics of pulsed laser energy concentration and intermittent action, while ensuring smooth cutting of the metal layer 1, the thermal effects caused by the cutting are discontinuous, thereby reducing the impact on the interface between the metal layer 1 and the polymer layer 2. At the same time, the green light pulse laser makes the metal layer 1 in a melted rather than vaporized state, which can greatly reduce the diffusion of heat from the metal layer 1 to the polymer layer 2, thereby making the cutting notch smooth, effectively eliminating various defects such as expansion, burrs, and potholes, and is beneficial to ensuring that the morphological characteristics near the interface between the metal layer 1 and the polymer layer 2 are good, thereby greatly improving the cutting quality.

[0044] S3: confirming the preset cutting line of the workpiece to be cut.

[0045] S4: the laser 3 emits a green pulse laser, and the green pulse laser cuts the workpiece to be cut along the preset cutting line, and the cut of the workpiece to be cut is smooth.

[0046] Specifically, the green light pulse laser is first focused on the polymer layer 2, which is suitable for breaking the molecular bonds of the polymer layer 2, and does not generate high temperature during the cutting process, so as to perform cold cutting on the polymer layer 2; after the green light pulse laser cuts the polymer layer 2, it is focused on the metal layer 1, and the energy of the green light pulse laser reaches or exceeds the melting point of the metal layer 1, so as to perform pulsed thermal cutting on the metal layer 1.

[0047] The adjustable ranges of other parameters of the laser 3 are as follows: the diameter D of the focused spot of the output laser beam of the laser 3 is controlled to be within the range of 30μm≤D≤50μm, with the unit μm being micrometer; the cutting speed v of the laser 3 is controlled to be within the range of 800mm / s≤v≤3500mm / s, with the unit mm / s being millimeter per second, so that the spot overlap rate of the output laser beam of the laser 3 is greater than 90% to obtain a relatively smooth incision; the pulse width τ of the output laser beam of the laser 3 is controlled to be within the range of 5ns≤τ≤60ns, with the unit ns being nanosecond; the energy E of the output laser beam of the laser 3 is controlled to be within the range of 50uj≤E≤500uj, with the unit uj being microjoule.

[0048] Preferably, to ensure that the laser can smoothly cut the composite material, the overall thickness of the metal layer 1 and the polymer layer 2 does not exceed 100 μm, the thickness H1 of the metal layer 1 can be selected within the range of 5 μm≤H1≤30 μm, and the thickness H2 of the polymer layer 2 can be selected within the range of 5 μm≤H2≤30 μm, where the unit μm is micrometer.

[0049] Preferably, in the cutting process of the metal polymer composite material, the value range of the above-mentioned laser 3 parameters is obtained through multiple cutting tests.

[0050] Preferably, for workpieces to be cut of different thicknesses and materials, appropriate parameters can be selected within the value range of the above-mentioned laser 3 parameters; for workpieces to be cut in which the metal layer 1 is an aluminum layer with a thickness of 10 μm and the polymer layer 2 has a thickness of 30 μm, when the cutting speed is 3000 mm / s, the pulse frequency is 1200 khz, and the power is in the range of 70W to 133W, the cutting notch is smooth without expansion, burrs, pits, etc., the morphological features near the interface between the metal layer 1 and the polymer layer 2 are good, and the cutting quality is high.

[0051] In view of the problem of poor cutting quality due to the comprehensive thermal effect in the laser cutting process of metal polymer composite materials, in this embodiment, a pulsed green laser is provided to produce the following beneficial effects:

[0052] First, the two-photon energy of the green laser is sufficient to reach the breaking energy of CC bonds and CH bonds in the polymer layer 2, and the polymer layer 2 can be cold-cut without reaching the melting point of the polymer layer 2, thereby avoiding the thermal impact of the cutting of the polymer layer 2 on the cutting notch.

[0053] Secondly, the energy of the pulsed laser is concentrated and acts at intervals, which ensures smooth cutting of the metal layer 1 while discontinuing the heat effect caused by the cutting, thereby reducing the impact on the interface between the metal layer 1 and the polymer layer 2.

[0054] Thirdly, the pulsed green laser is within the determined technical parameter range and can perform instantaneous high-temperature melting processing on the metal layer 1 within the thickness range of 5 to 30 μm, so that the metal layer 1 is in a molten rather than vaporized state, which can greatly reduce the heat diffusion of the metal layer 1 to the polymer layer 2 and has less thermal impact on the polymer layer 2.

[0055] Under the combined effect of the above three aspects, the cutting notch of the metal polymer composite material is smooth, effectively eliminating various defects such as expansion, burrs, and pits, which is conducive to ensuring good morphological characteristics near the interface between the metal layer 1 and the polymer layer 2, thereby greatly improving the cutting quality.

[0056] In some embodiments, in combination Figure 2 As shown, the polymer layer 2 is provided with a plurality of polymer layers 2, which are respectively covered on the opposite sides of the metal layer 1. In this embodiment, two polymer layers 2 are respectively covered on the upper and lower sides of the metal layer 1. During cutting, since the metal layer 1 has a high absorption rate for green light, when the metal layer 1 is in a molten and non-gasified state, the molten metal layer 1 can be reduced from diffusing heat to the polymer layers 2 on both sides under the additional effect of the laser impact force, and the molten metal can be prevented from directly penetrating between the polymer layers 2 on both sides.

[0057] In some embodiments, the metal layer 1 is a copper layer, and the temperature at which the green light pulse laser acts on the metal layer 1 is T1, wherein 1090°C≤T1≤1600°C, and the melting point of the copper layer is 1085°C, and the vaporization temperature is 2562°C, so the green light pulse laser can ensure that the copper layer melts without vaporizing.

[0058] In some embodiments, the metal layer 1 is an aluminum layer, and the temperature at which the green light pulse laser acts on the metal layer 1 is T2, wherein 670°C≤T2≤1000°C, and the melting point of the aluminum layer is 660°C, and the vaporization temperature is 2467°C, so the green light pulse laser can ensure that the aluminum layer melts without vaporizing.

[0059] Obviously, the above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the present invention.

Claims

1. A cutting process for metal polymer composite materials, characterized in that: include: S1: Place the workpiece to be cut on the cutting platform; The workpiece to be cut comprises a stacked metal layer (1) and a polymer layer (2); S2: adjusting the parameters of the output laser beam of the laser (3); Controlling the output wavelength λ of the laser (3) to be within the range of 500nm≤λ≤550nm, so that the laser (3) generates green laser light to perform cold cutting on the polymer layer (2); Controlling the output power P of the laser (3) to a value within the range of 70W≤P≤150W, so that the green laser performs thermal cutting on the metal layer (1); The output pulse frequency f of the laser (3) is controlled to be within the range of 800 khz ≤ f ≤ 2000 khz, and the green laser is emitted in a pulsed manner so that the laser energy is concentrated and acts on the metal layer (1) at intervals; S3: confirming the preset cutting line of the workpiece to be cut; S4: the laser (3) emits a green light pulse laser, and the green light pulse laser cuts the workpiece to be cut along the preset cutting line, and the cut of the workpiece to be cut is smooth.

2. The cutting process of the metal polymer composite material according to claim 1, characterized in that: The polymer layer (2) covers a side of the metal layer (1) close to the laser (3); or; A plurality of polymer layers (2) are provided, and the plurality of polymer layers (2) are respectively covered on two opposite sides of the metal layer (1).

3. The cutting process of the metal polymer composite material according to claim 2, characterized in that: In step S4, The green light pulse laser is focused on the polymer layer (2) and is suitable for breaking the molecular bonds of the polymer layer (2) to perform cold cutting on the polymer layer (2); The green light pulse laser cuts the polymer layer (2) and is focused on the metal layer (1). The energy of the green light pulse laser reaches or exceeds the melting point of the metal layer (1) so as to perform pulsed thermal cutting on the metal layer (1).

4. The cutting process of the metal polymer composite material according to claim 3, characterized in that: Step S2 also includes controlling the energy E of the output laser beam of the laser (3) to be within the range of 50uj≤E≤500uj.

5. The cutting process of the metal polymer composite material according to claim 1, characterized in that: Step S2 also includes controlling the value of the diameter D of the focused spot of the output laser beam of the laser (3) to be within the range of 10 μm ≤ D ≤ 50 μm, controlling the value of the cutting speed v of the laser (3) to be within the range of 800 mm / s ≤ v ≤ 3500 mm / s, and making the spot overlap rate of the output laser beam of the laser (3) greater than 80%.

6. The cutting process of the metal polymer composite material according to claim 1, characterized in that: In step S2, the pulse width of the output laser beam of the laser (3) is τ, wherein 5ns≤τ≤60ns.

7. The cutting process of the metal polymer composite material according to claim 1, characterized in that: The metal layer (1) is a copper layer, and the temperature at which the green light pulse laser acts on the metal layer (1) is T1, wherein 1090° C. ≤ T1 ≤ 1600° C.; or; The metal layer (1) is an aluminum layer, and the temperature at which the green light pulse laser acts on the metal layer (1) is T2, wherein 670°C≤T2≤1000°C.

8. The cutting process of the metal polymer composite material according to claim 7, characterized in that: The thickness of the metal layer (1) is H1, wherein 5 μm≤H1≤30 μm.

9. The cutting process of the metal polymer composite material according to claim 1, characterized in that: The thickness of the polymer layer (2) is H2, wherein 5 μm≤H2≤30 μm.

10. The cutting process of the metal polymer composite material according to claim 9, characterized in that: The material of the polymer layer (2) is polyvinylidene fluoride or a mixed material of polyvinylidene fluoride and boehmite.

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