KR102553387B1 - Method for laser drilling or laser cutting a workpiece and system for laser drilling or laser cutting - Google Patents

Abstract

The present invention proposes a method for laser drilling or laser cutting of a workpiece, wherein in a first method step a workpiece, an inlet device and a laser source emitting laser light are provided, and in a second method step,
- A bore is formed in the workpiece by laser light,
- a liquid containing particles is placed in the bore using an inlet device;
The laser light and the particles in the liquid are selected such that the laser light is scattered and/or absorbed by the particles in the liquid for shaping the inner surface of the bore or the edge region.

Description

A method for laser drilling or laser cutting of a workpiece and a system for laser drilling or laser cutting

The present invention relates to laser drilling or laser cutting of workpieces and systems for laser drilling and laser cutting.

Methods for forming bores or cuts in workpieces using laser light are well known. Generally, the edges of the bores have to be deburred or rounded, in which case the edges to be rounded or deburred are often in inaccessible positions, interrupting the machining. An example of such a bore is an injection hole or throttle bore in an injection system. In this case, the edge is usually rounded only after the bore is implemented.

Edge areas are usually rounded by hydro erosive grinding (HE-grinding). In this case the abrasive oil is mixed with a small amount of abrasive medium and compressed by means of a pump through the bore to be rounded at a pressure of approximately 100 bar. In this case, the abrasive medium must always be kept in a moving state to prevent sedimentation and clogging of the abrasive medium. In addition, since the abrasive medium grinds the parts of the circuit through which the polishing oil is conveyed, regular replacement of the parts of the circuit is necessary. What is also needed is a high-performance pump for circulation of the abrasive oil to achieve the desired pressure, and a corresponding seal to ensure that the abrasive oil follows a predetermined path through the workpiece. Another disadvantage is that in the case of asymmetric inflow, non-uniform removal is achieved by the non-uniform velocity distribution in the flow, which also results in less or too heavy removal.

Further, in the prior art, for example in publication DE 10 2013 212 665, a liquid containing nanoparticles is disposed on the rear side of the bore, and the liquid prevents erroneous processing of objects disposed on the rear side of the bore when viewed in the direction of propagation of light. Initiate how to become

The object of the present invention is to provide a method for laser drilling or laser cutting that is improved compared to the methods disclosed in the prior art, in particular with respect to the efficiency and quality of rounding of the edge region of a bore.

The object is solved by a method for laser drilling or laser cutting of a workpiece, wherein in a first method step a workpiece, an inlet device and a laser source emitting laser light are provided. According to the invention, in a second method step, a bore is formed in the workpiece by means of laser light, and a liquid containing particles is placed in the bore by means of an inlet device, thereby preferably rounding or deburring in the edge region or in the inner surface of the bore. Shaping is controlled as intended. The laser light and the particles in the liquid are in this case selected such that the laser light is scattered and/or absorbed by the particles in the liquid for the shaping of the edge region or inner surface of the bore, i.e. for rounding or deburring, for example, thereby in particular Grain-initiated heat generation is provided, resulting in removal of the inner surface or edge region of the bore.

Unlike the prior art, the method according to the invention offers the advantage that the shaping is effected by the laser light used for the production of the bore. Thus, the subsequent machining of the edge region can be omitted, similar to the use of abrasives commonly used in the prior art. The placement of the liquid, in particular in the bore, allows targeted and controlled shaping of the edge region or inner surface besides the above improvement in terms of time and cost efficiency, which also has a positive effect on the quality of the laser drilling. Also, the asymmetric influx of liquid does not adversely affect the symmetry, as is the case with the use of abrasive oil mixed with the abrasive.

In particular, a workpiece is provided with a preliminary bore, for example in the form of a core bore, and the preliminary bore is enlarged to a predetermined diameter by laser drilling according to the invention. Furthermore, with particular preference, collective excitation of electrons, for example in the form of plasmons or surface plasmons, is used for absorption of the laser light. It is also possible according to the invention that the method is used to modify the inner surface of a bore, for example to change the cross section along the bore.

Preferred embodiments and refinements of the invention are presented in the detailed description with reference to the dependent claims and drawings.

According to another preferred embodiment of the invention, the partial section of the bore is filled with a liquid containing particles, in which case the depth of penetration of the liquid into the bore remains at least temporarily constant during the second method step. The penetration depth is also determined in particular by the length of the filled partial section of the bore. Preferably the depth of penetration of the liquid into the bore is controlled or regulated. It is also possible that the penetration depth is varied during the second method step. For adjustment of the depth of penetration, a counter pressure caused by, for example, the gas surrounding the workpiece is used, or a laser plasma is used to limit the presence of a liquid to a given partial section to determine the depth of penetration. In this way, the shaping of the inner surface, in particular of the edge region, can be advantageously controlled.

According to another embodiment of the present invention, in the second method step

- liquid containing particles enters the end of the bore,

- Laser light is introduced into the second end of the bore. In this case, the first end and the second end are in particular arranged opposite each other. By virtue of this structural arrangement, in an uncomplicated manner, the liquid entering the first end and the laser light entering the second end collide with each other within the bore.

According to another preferred embodiment of the present invention, in the second method step

- pulsed laser light, in particular laser light with picosecond or nanosecond pulses, and/or

- Liquids containing nanoparticles, in particular metal nanoparticles, are used. Preferably, the nanoparticles have an elliptical shape, a rod shape, an octahedral or decahedral shape, or a rectangular parallelepiped shape. By elliptical shape we mean in this case all spherical shapes, i.e. ball, egg and ellipse. The excitation energy required for the formation of the collective excitation is in this case determined in particular by the spatial extension of the nanoparticle concerned. It is possible to give rise to different collective excitations if the excitation energies in the same nanoparticle are apparently different, especially if the spatial extensions are distinctly different for two different spatial directions. This provides the advantage that the two laser wavelengths are simultaneously absorbed by the nanoparticles, especially if they are processed with two different laser wavelengths, for example.

Usually the ratio of spatial extension in two different spatial directions is decisive for the excitation energy of the collective excitation. In the case of rod-shaped nanoparticles, in particular, the ratio of the longitudinal extension along the longitudinal direction of the rod to the direction perpendicular to the longitudinal extension, the so-called transverse extension, should be given. For example, when such rod-shaped nanoparticles made of gold are used, the ratio of spatial extension in the longitudinal direction to the transverse direction of 4 causes excitation energy of the surface plasma, and infrared laser light can be absorbed by the energy. Thus, for example, rod-shaped nanoparticles having an extension of 10 nm in the longitudinal direction and 2.5 nm in the transverse direction perpendicular thereto can be used.

Of course, it is also possible to mix differently formed nanoparticles for broadband absorption as much as possible. Nanoparticles with essentially the same shape and different spatial extensions can also be mixed in this way, whereby light of different energies and wavelengths can be absorbed.

Nanoparticles can be made today in different shapes and sizes. As mentioned above, in particular the elongation of the nanoparticles and/or the so-called aspect ratio, i.e. the ratio of the length to the width of the nanoparticles, is of critical importance to the excitation energy of the collective excitation and the wavelength of the most absorbed electromagnetic radiation. At the same time, the wavelength depends on the material used. As a result of the experiment, it was shown that the resonance of the wavelength of the absorbed electromagnetic radiation can be shifted by the fluctuation of the size of the nanoparticles. In the case of spherical silver-nanoparticles in water, it has been shown that nanoparticles with a radius of 3 nm have a resonance of 380 nm, and thus can absorb light of this wavelength. For spherical silver-nanoparticles, a radius of 10 nm causes a resonance of 390 nm, a radius of 25 nm causes a resonance of 410 nm, a radius of 50 nm causes a resonance of 480 nm, and a radius of 100 nm causes a resonance of 410 nm. The radius causes a resonance of 770 nm. Therefore, it can be seen that the location of resonance and the wavelength of laser radiation that can be absorbed can be clearly shifted by changing the size of the spherical silver-nanoparticles.

The same applies to, for example, spherical gold-nanoparticles in water. In this case a radius of 3 nm leads to a resonance of 515 nm, while an extension of the radius to 10 nm leads to a resonance of 530 nm. A further extension of the radius also results in an extension of the wavelength of the electromagnetic radiation absorbed in this case. A radius of 25 nm causes absorption of 540 nm wavelength, a radius of 50 nm causes absorption of 575 nm wavelength, a radius of 100 nm causes absorption of 770 nm wavelength, and a radius of 150 nm causes absorption of 1100 nm wavelength causes absorption of

Considering that typical laser wavelengths for cutting and drilling are 800 nm, 1030 nm or 1064 nm, for each selected wavelength, for example, due to its diameter or radius, a spherical gold underwater suitable for absorbing the incident laser wavelength exactly. -Can detect nanoparticles. Alternatively, the laser frequency may be doubled, and the wavelength of the laser radiation may be halved. Accordingly, a laser wavelength of 400 nm, 515 nm, or 532 nm may be used, and the laser wavelength may be absorbed by, for example, very small spherical gold-nanoparticles or spherical silver-nanoparticles in water.

When so-called nanorods, i.e., rod-shaped underwater nanoparticles, are used instead of spherical nanoparticles, the aspect ratio of the nanoparticles, i.e., the ratio of the length to the width of the rod, is particularly important. In the case of gold, this aspect ratio of 1 causes absorption of a wavelength of 530 nm. When the aspect ratio increases to 2.5, the absorbed wavelength fluctuates to 700 nm, to 800 nm when the aspect ratio is 4, to 850 nm when the aspect ratio is 4.5, and to 900 nm when the aspect ratio is 5.5. do. In the academic paper "Preparation and Growth Mechanism of Gold Nanorods Using Seed-Mediated Growth Method" (Journal Chemistry of Materials. 2003, 15, 1957-1962), 700 nm, 760 nm, 790 nm, 880 nm, 1130 nm and 1250 nm Different rod-shaped gold-nanoparticles with aspect ratios that cause resonance are disclosed. An aspect ratio of 6.5 results in an absorption wavelength of 1000 nm in this case, while an aspect ratio of 9 results in an absorption wavelength of 1300 nm. Since the aspect ratio of the individual nanoparticles can in this case be controlled very precisely and precisely, the wavelength of the electromagnetic radiation that is absorbed can also be controlled so that it can be matched precisely and desirably for each laser wavelength.

Of course, the shapes of nanoparticles are not limited to spherical, elliptical or rod shapes. In the review paper "Modeling the optical response of gold nanoparticles" (published by Chemical Society Reviews, 2008, 37, 1792-1805) different shapes of rods with e.g. circular or square cross sections or various sizes of nano-octahedrons are analyzed. there is. Nanodecahedrons can also be made and used. In this case too, the spatial extensions and the ratio between them have a decisive influence on the wavelength of the electromagnetic radiation absorbed.

When electromagnetic laser radiation is incident on these nanoparticles, these photons are absorbed by the nanoparticles. In this case, it has been found that nanoparticles can be pulverized by such laser irradiation. This crushing is due to melting and vaporization by laser radiation. This process, however, ends with, for example, gold particles of an average size of about 5 nm, since the absorption cross section of the small nanoparticles is too small to absorb by the laser radiation the amount of energy required for further comminution. The size at which the pulverization of the nanoparticles by laser irradiation ends is referred to as the final size below. If nanoparticles of this final size, which cannot be reduced by further laser irradiation, contain a collective excitation having an excitation energy suitable for the incident electromagnetic laser radiation, especially in the case of spherical nanoparticles, the liquid is mixed with the nanoparticles contained therein. Together, they can be reused with little wear and tear. If the nanoparticles have other shapes, for example in the form of rods or cuboids, this does not apply unconditionally, since the nanoparticles are also broken and pulverized during laser irradiation, whereby spatial extensions in different spatial directions may be obtained. Rain changes.

The pulverization of nanoparticles is performed especially when irradiated with a pulsed laser. In this case, the local energy density of each pulse is high enough to achieve nanoparticle pulverization. These pulsed lasers are needed to be able to machine a small number of materials in a particular workpiece. In the case of other materials, eg plastics, a lower energy density is sufficient, so that the material can be processed eg by a cw-laser, ie a continuous beam laser. The local energy density of the laser radiation in this case is too small to cause fracture in the nanoparticles. This provides the advantage that nanoparticles that are not spherically formed are not split and pulverized, so that these nanoparticles matched to a given wavelength of laser radiation can be used again and again with little restriction. It is therefore unnecessary in this case to provide each new nanoparticle in a new liquid for the processing of multiple workpieces.

In particular the laser light has a wavelength of 380 nm to 650 nm, preferably 500 nm to 530 nm, in particular 515 nm.

As described above, by selecting the size of the nanoparticles used, the excitation energy required for the formation of collective excitations can be controlled. Particularly in the case of spherical gold particles, such particles of a final size of about 5 nm, which cannot be reduced by further laser irradiation, were found to have excitation energies corresponding to photons with a wavelength of 515 nm. If this wavelength is used for a light source, ie a laser source, an optimal absorption cross section of the nanoparticles for the laser light is ensured even in this “fixed” state in which the size distribution of the nanoparticles no longer changes. If nanoparticles of a different shape or material are used, the final size and "final" excitation energy may differ from the above values. However, in general, the wavelength of the incident laser light is selected so that the selected nanoparticles contain a collective excitation having an excitation energy even during long-term operation, and the excitation energy corresponds to the energy of a photon having an incident wavelength.

Therefore, gold particles having a particularly spherical shape and a laser having a wavelength of 515 nm are preferably used.

It has been shown to be advantageous if the spatial extension of the nanoparticles in at least one spatial direction is selected such that the excitation energy of the collective excitation corresponds to the energy of the laser light. Since the absorption cross-section of the nanoparticles is optimized in this way, a particularly large amount of laser light can be absorbed.

Preferably at least a minority of the nanoparticles are metal particles, in particular consisting of gold, silver, copper, palladium or an alloy of a number of the foregoing elements. Of course, it is also possible to implement all nanoparticles in this form. These nanoparticles can be formed directly into the liquid, for example by laser radiation. This is a very safe manufacturing process, since it prevents nanoparticles from reaching the air, which can pose a health risk to, for example, a person who inhales the nanoparticles. Also, this process is very flexible because nanoparticles can be formed in this way from many metals or alloys. At the same time, the combination of nanoparticles with other substances in the liquid can be achieved. Of course, the nanoparticles may be prepared in other ways and then provided in a liquid, for example water or acetone.

A number of metals, particularly noble and light metals, can make plasmonic resonance possible. The excitation energy of the plasmon can be controlled by appropriate selection of the material, shape, size and ambient conditions of the nanoparticle, and can be selected almost freely. In this way, it is possible to select nanoparticles according to a given laser light. Alternatively, the laser source can also be tailored to a given nanoparticle. It is preferable if the shape, size and material of the nanoparticles are matched to the incident laser wavelength so that plasmon resonance or other collective excitation resonance is formed at the wavelength of the incident laser light. It is also possible to use a laser source which is adjustable with respect to the wavelength, in which the wavelength is adjusted by, for example, a frequency conversion process.

For example, metallic spherical gold particles having an average diameter of about 30 nm (±10 nm) can be used. Since this causes a plasmon resonance of about 530 nm, laser light of this wavelength can be absorbed particularly well by these nanoparticles. As described above, the nanoparticles are reduced to an average size of about 5 nm by laser irradiation, and in this case, the excitation energy of each plasmon collective excitation slightly increases to correspond to the energy including photons having a wavelength of 515 nm. Depending on the manufacturing method, nanoparticles of different sizes may be produced. Thus, nanoparticles having a size of 100 nm to about 300 nm can be used, for example to absorb long-wave photons.

As mentioned above, the use of an incident wavelength of 515 nm is particularly preferred in the case of gold particles, since this corresponds to the plasma resonance of gold particles with a diameter of 5 nm. Since nanoparticles of the above size cannot be made smaller by irradiation with laser light, such a gold-nanoparticle dispersion can be used for an almost unlimited time range, in which case there is no effect on the shaping of the inner surface of the bore or the edge region. does not decrease or disappear

Preferably at least a few of the nanoparticles are disposed on the surface of the microparticles. Of course, it is also possible to place all nanoparticles on the surface of microparticles. The use of microparticles in the liquid causes scattering of the laser radiation, thereby reducing the energy density of the laser radiation. When nanoparticles are absorbed at the surface of microparticles, as described herein, the different effects caused by the microparticles and nanoparticles are combined. This results in absorption of the electromagnetic laser radiation by the nanoparticles and scattering of the radiation by the microparticles having a surface on which the nanoparticles are absorbed.

In a preferred embodiment of the method at least a minority of the nanoparticles are carbon nanotubes. Of course, all nanoparticles can also be formed as carbon nanotubes. Collective excitation can also be induced in these carbon nanotubes. Since the length, wall thickness and diameter of the nanotubes can be manufactured to be almost freely adjustable, even in this case, the excitation energy required for the formation of collective excitation can be adjusted almost freely. Even in this case, the nanotube can be optimally adjusted to the incident laser wavelength. Carbon nanotubes, unlike metal particles, for example, exist as black powders and thus offer the further advantage of having a relatively large absorption cross section by means of electronic excitation in addition to a large absorption cross section by collective excitation. Thereby, carbon nanotubes combine the advantages of dyes with those of nanoparticles with collective excitation.

Preferably at least a minority of the nanoparticles contain a photosensitive material on their surface. Of course, such a photosensitive material may be provided on the surface of all nanoparticles. A photosensitive material is a dye or pigment suitable for absorbing light of a particular wavelength. When such a dye is placed on the surface of a nanoparticle, the dye enhances the absorption cross section of the provided nanoparticle, because, similar to the carbon nanotubes described above, the effect of the collective excitation of the nanoparticle correlates with the electronic excitation of the photosensitive material. because it is combined.

It has been found to be preferable if the liquid comprises nanoparticles at a concentration of less than 4 g/l, preferably less than 2 g/l and particularly preferably less than 1 g/l. The concentration actually used depends in this case on a number of different parameters and can be selected according to the experimental or production system's characteristics and the desired target setting. Unlike the excitation energy of the collective excitation, the actual concentration in this case depends in particular on the intensity of the incident laser radiation and on the wavelength of the laser radiation.

The liquid used is not so critical as long as the nanoparticles used are stable in the liquid.

According to another embodiment of the invention, in a second method step for controlling the shaping of the inner surface or edge region of the bore

- the concentration of particles in the liquid,

- particle size and/or

- The flow speed of the liquid is controlled. This advantageously allows the shaping of the bore to be controlled.

According to another embodiment of the invention, the bore is implemented in a part of an injection valve for the injection device, in particular in a valve seat, nozzle or throttle plate of the injection device.

Another object of the invention is a system for laser drilling or laser cutting of workpieces, in particular according to the method according to the invention, said system having a laser source emitting laser light and capable of introducing a liquid containing particles into a bore. Includes an inlet device. The laser light and the particles in the liquid are in this case selected such that the laser light scatters off the particles and/or the particles at least partially absorb the laser light. Heat is generated from the particles by absorption or scattering, which contributes to the removal of the inner surface or edge region of the bore.

According to another preferred embodiment of the present invention, the system comprises a circuit for guiding the liquid, said circuit comprising a reservoir for collecting the liquid containing particles, a pump for dispensing the liquid, and a circuit for introducing the liquid into the bore. It includes an inlet device and/or a return for discharging liquid introduced into the workpiece.

1 shows schematically a system for a method for rounding an edge in the area of a bore according to the prior art;
Fig. 2 schematically shows the respective edge areas of a bore formed in a workpiece, wherein the edge areas are rounded by a method of the prior art;
3 schematically illustrates a system for a method for laser drilling in a workpiece according to an exemplary embodiment of the present invention;
Fig. 4 schematically shows the respective edge areas of a bore formed in a workpiece, wherein the edge areas are rounded by a method according to an exemplary embodiment of the present invention;

Like parts in the various drawings are always denoted by like reference numerals and, therefore, are generally each described only once.

1 shows schematically a system for a method for rounding an edge in the area of a bore according to the prior art. In general, the workpiece 1 requires bores depending on their function, and after completion of the bores, the bores must be deburred or rounded on the inner surface. Usually the area to be machined of the workpiece 1 is difficult to access, so mechanical methods are discontinued. The bores are for example bores 11 for an inlet system, in particular for an inlet hole in an injection system for an internal combustion engine, for a throttle bore or for parts subjected to relatively high mechanical loads. Generally, the bores 11 are rounded only after being formed according to the prior art.

A commonly used method for rounding is hydroerodible grinding (HE-grinding), in which grinding oil is mixed with an abrasive medium, and a bore (11) to be rounded using a pump (3) under a pressure of about 100 bar compressed by The size of the rounding in the edge region 12 can be adjusted within limits determined by the grinding duration, grinding pressure, amount and type of abrasive, and viscosity of the abrasive oil. In this case, the disadvantage is that the grinding medium must be constantly kept in motion, in order to prevent settling and clogging of the grinding medium in the circuit which guides the grinding oil. The abrasive medium also unintentionally abrades parts of the circuit or the reinforcement itself, which makes regular replacement of the parts of the circuit or the reinforcement material necessary. The high pressure also presupposes a pump for the circuit or a special drive, which creates additional costs. In addition, in order for the lubricant to follow a predetermined path through the work piece 1, a special seal 2 is required.

Figure 2 schematically shows the edge areas 12 of the bores 11 formed in the workpiece 1, respectively, which edge areas 12 have been rounded by a method of the prior art. In particular, a two-bore profile is present, which profile causes an asymmetric inflow of the abrasive oil and an uneven removal due to an uneven velocity distribution in the flow. Thus, either too little (Fig. 2 left) or too much (Fig. 2 right) is removed.

3 shows a system for a method of laser drilling in a workpiece 1 according to an exemplary embodiment of the invention. The system in this case comprises a laser source which emits laser light 7 and an input device. In this case, a bore 11 is realized in the workpiece 1 by the laser light 7, and at the same time, for drilling, a liquid 4 containing particles is introduced into the bore 11, and the particles and the laser light are introduced into the bore 11. (7) In particular, the wavelengths of the laser light 7 are selected or matched to each other such that the laser light 7 is scattered at and/or absorbed by the particles in the liquid 4. The removal of the workpiece is thereby assisted by the particle-containing liquid 4, which in this case results in rounding of the edge region 12 of the bore 1. In particular for this purpose, liquid 4 is introduced into bore 11 during laser drilling, and bore 11 is flushed with liquid 4 . The realization of the bore 11 and the shaping of the bore 11 , in particular of the edge region 12 or the inner surface of the bore 11 , can thus advantageously save time on the production line. For cleaning the bores (11), the system comprises a circuit with a pump (3), an inlet device (6) and a reservoir (14) for liquid (4) containing particles. In particular, the inlet device 6 is designed to be inserted as precisely as possible into a recess 13 formed in the workpiece 1 , for example in the form of a pre-chamber or cavity in front of the bore 11 . In particular, the liquid 4 is discharged from the opening of the inlet device 6, in which case when the inlet device 6 is inserted into the recess 13, the opening of the inlet device 6 is inside the workpiece 11. are placed It is also possible for the inlet device 6 to be formed such that upon insertion of the inlet device 6 into the recess 13 , the workpiece 1 and the inlet device 6 are sealed. It is also possible for the inlet device 6 to be fixed to the workpiece 1 . In particular, for example, the opening of the inlet device 6 faces the bore 11 or is arranged directly in front of the bore, so that the liquid 4 is directed directly into the bore 11 by means of the pump 3 and the inlet device 6 ) or into the bore 11 through an injection device. The return part 15 is preferably integrated into the inlet device 6 . The liquid 4 injected into the workpiece 1 through the return unit 15 is returned into the reservoir 14 . Furthermore, the liquid 4 discharged from the bore 11 is preferably returned via a further return 16 back into the reservoir 14 and collected there. In particular the reservoir 14 , the pump 3 , the return part 15 , the further return part 16 and/or the injection device 6 form part of the circuit. Also preferably, the laser light 7 is a pulsed laser light, for example a nanosecond, picosecond or femtosecond pulse. In this case, it is possible for the laser light 7 to be focused to increase the intensity. Also, the size of the shaping of the edge area or inner surface of the bore is controllable or can be controlled by adjusting the laser intensity. It is also possible that the particles are, for example, gold-nanoparticles having an average diameter of less than 50 nm, preferably less than 20 nm, particularly preferably less than about 10 nm. Further, the circumference or size of the rounding is controlled by the intended adjustment of the concentration of the particles in the liquid 4 , the particle size and/or the flow rate of the liquid 4 .

Figure 4 schematically shows two edge regions 12, each of which is formed using a method according to an exemplary embodiment of the present invention. It can be seen that in both cases the symmetrical edge regions 12 are formed by the above method. This is because the effect of rounding is critically influenced by the laser light, and the method is less sensitive to asymmetric influx compared to hydroerosion grinding (HE-grinding).

1 workpiece
4 liquid
7 laser light
11 bore
12 edge area

Claims (10)

As a method for laser drilling or laser cutting of a workpiece (1),
In a first method step, the workpiece (1), an inlet device (6) and a laser source emitting laser light (7) are provided,
In a second method step,
- a bore (11) is formed in the workpiece (1) by means of the laser light (7);
- liquid (4) containing particles is placed in the bore by means of the inlet device (6);
The laser light 7 and the particles in the liquid 4 are such that the laser light 7 is formed by the particles in the liquid 4 for shaping the edge area 12 or inner surface of the bore 11. A method for laser drilling or laser cutting of a workpiece, selected to be either scattering, or absorption, or both scattering and absorption. 2. The method according to claim 1, wherein a partial section of the bore (11) is filled with the liquid (4) containing the particles, and the penetration depth of the liquid (4) into the bore (11) is increased during the second method step. A method for laser drilling or laser cutting of a workpiece, which is held constant at least temporarily. 3. The method according to claim 1 or 2, wherein in the second method step,
- the liquid (4) containing particles enters the first end of the bore (11),
- a method for laser drilling or laser cutting of a workpiece, wherein the laser light (7) is introduced into the second end of the bore (11). 3. The method according to claim 1 or 2, wherein in the second method step,
- pulsed laser light (7) and
- a method for laser drilling or laser cutting of a workpiece, in which at least one of the liquids (4) containing nanoparticles is used. 3. The method according to claim 1 or 2, wherein in the second method step to control the shaping of the inner surface or the edge region,
- the concentration of particles in the liquid,
- depth of penetration of the liquid into the bore,
- particle size, and
- a method for laser drilling or laser cutting of a workpiece, wherein at least one of the flow rates of the liquid is regulated. 3. Method according to claim 1 or 2, wherein the bore (11) is embodied in part of an injection valve for an injection device. A system for laser drilling or laser cutting of a workpiece (1), comprising a laser source that emits laser light (7) and a liquid (4) containing particles through a bore (11) formed in the workpiece (1). Including an inlet device (6) that can be introduced into the
The laser light 7 and the particles in the liquid 4,
so that the laser light 7 is scattered at the particles, or
so that the particles at least partially absorb the laser light 7, or
A system for laser drilling or laser cutting of a workpiece, wherein the laser light (7) is selected such that it is scattered at the particles and the particles at least partially absorb the laser light (7). 8. The system according to claim 7, comprising a gas counterpressure device for controlling the depth of penetration of the liquid into the bore. 9. The method according to claim 7 or 8, wherein the system comprises a circuit for guiding the liquid (4), said circuit comprising a reservoir (14) for collection of the liquid (4) comprising the particles, the Pump 3 for delivery of liquid 4, inlet device 6 for introduction of liquid 4 into bore 11, and discharge of liquid 4 introduced into workpiece 1 A system for laser drilling or laser cutting of a workpiece (1), comprising at least one of the return parts (15) for 9. The method according to claim 8, wherein the inlet device (6) is insertable into a recess (13) in the workpiece (1), or
The return part 15 is integrated into the inlet device 6, or
The inlet device 6 is insertable into a recess 13 in the workpiece 1 , and the return part 15 is incorporated in the inlet device 6 , laser drilling or laser cutting of the workpiece 1 . system for.

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