DE102020103232A1 - Method for applying particles to a substrate - Google Patents

Abstract

Method for applying particles (3) to a substrate (2), in particular to a substrate surface (2a) of the substrate (2), the method comprises the following method steps: Providing a quantity of particles (3) in a gas stream (4, 45 ) at an inlet end (E1) of a device (1), wherein the gas flow (4, 45) comprises in particular a carrier gas flow and / or a jacket gas flow, accelerating the gas flow (45) while heating the gas flow (45) in the direction of an outlet end (E2 ) of the device, focusing the particles (3) on an axis (M) which is aligned parallel to the gas flow, during which the particles are accelerated and heated, aligning the outlet end (E2) of the device (1) on the substrate ( 2), in particular on the surface (2a) of the substrate (2).

Description

The invention relates to a method for applying particles to a substrate.

In the area of additive manufacturing, the established processes can be divided into powder bed processes and free-space processes. In the powder bed process, powder is distributed in layers on a base and melted in defined areas, e.g. using a laser, so that a component is created in the entirety of many layers. The free space method is based on the addition of solid or liquid particles to a substrate, with the particles entering into a particularly cohesive bond with the substrate as a result of the curing, which results in a structure through curing, fusing or “clamping” on the substrate.

The manufacturing process dealt with in the context of the present invention is to be assigned to the free space process.

the US 2009/0056620 A1 discloses a thermal spray process in which particles are brought to a speed above the speed of sound ( US 2009/0056620 A1 , Claim 1). The particles are heated by a laser device in such a way that they are melted. In a pipe section, the melted particulate material is accelerated by the carrier gas flowing around it, and atomization should take place. Since the carrier gas is colder than the particles, the particles are rapidly cooled in the pipe section. In addition, there is a defocusing ( US 2009/0056620 A1 , 9-11 ). As a result, the particles are atomized, which favors the production of very fine, two-dimensional layers.

With laser beam deposition welding, a powder jet is directed onto a substrate. A laser beam is used to heat the powder. The powder is melted by the laser beam in an interaction zone between the powder jet and the laser beam. The substrate lies directly in the interaction zone so that the melted powder can form a bond with the substrate.

It is the object of the present invention to provide an improved manufacturing method, in particular to provide an alternative to the aforementioned method. It is particularly desirable to apply fine structures to substrates, the structure width should be a maximum of 500 micrometers, in particular a maximum of 50 micrometers, in particular a maximum of 10 micrometers. The thermal load on the substrate should be as low as possible.

The object on which the invention is based is achieved by a method and a device according to the main claims; Refinements are the subject of the subclaims and the description.

The subject of the method is in particular the focusing and simultaneous heating and acceleration of particles within a device. In particular, this is made possible by using a device with a heated gas line. After the particles are focused, heated and accelerated in this device, they can be applied to a substrate, whereby manufacturing is carried out. Due to the focusing, it is possible to produce very fine structures on the substrate surface.

If a particle moves through a shear flow, asymmetrical pressure distributions and friction components arise on its particle surface. An integration of these asymmetrical relationships over the particle surface provides a force component perpendicular to the relative speed between the fluid and the particle. This force is called the Saffman force.

In the process, the particles are focused with the help of the Saffman force. This is achieved through the laminar and rotationally symmetrical flow profile within the pipe, which is generated during the implementation of the method. For this purpose, the axial velocity component of the particle is smaller than that of the flow. In this case the Saffman force acts in the direction of the greater flow velocity and thus in the center of the pipe. By heating the gas flow, the flow is accelerated and the focusing effect is intensified.

As a result of the heating of the gas flow and an increased dwell time of the particles in the hot gas flow, the particles are also heated and accelerated in the device, which is a prerequisite for the direct application of the particles.

Optionally, the particles can be additionally heated at the outlet end. This can be done by another heating device, e.g. by a laser. In this way, particles made of a material with a very high melting temperature can also be heated accordingly.

Optionally, the gas, carrier gas and / or jacket gas can be preheated before flowing into one of the sections. Consequently, the first section can be preceded by a section.

In one embodiment, the substrate, in particular the substrate surface, is tempered, in particular to a temperature above the ambient temperature around the substrate.

In one embodiment, a so-called protective gas, in particular argon, nitrogen or carbon dioxide, is used as the carrier gas and / or jacket gas. In one embodiment, compressed air is also possible as jacket gas and / or carrier gas, in particular if it is ensured that no unwanted chemical reactions take place under the conditions prevailing in the device. Compressed air is comparatively cheap to provide.

In one embodiment, the particles comprise a metal, in particular more than 50%.

In one embodiment, the particles comprise a plastic, in particular more than 50%. In this case, within the scope of the present disclosure, the solidus temperature is understood to mean the melting temperature of the plastic.

In one embodiment, the carrier gas and / or the jacket gas is aerosol-free. It goes without saying that the particles are not considered to be part of an aerosol. Rather, what is meant by this is that apart from the particles that are part of the additive material application, no further solid and / or liquid components are included in the gases.

The manufacturing process enables the defined application of different materials to the substrate. This opens up the possibility of expanding existing additive manufacturing processes, especially in the area of multi-material components. Multi-material components are in particular those components in which different materials are materially and / or positively connected to one another.

In one embodiment, different particle materials can be selectively alternately supplied to the inlet end. This allows the material to be applied to be changed while the additive process is running.

In the context of the present disclosure, percentages relating to the composition relate to the respective weight fraction.

In addition to the possible multi-material application, the invention is distinguished in particular by one or more of the following advantages. Due to the comparatively low speed of the particles when they leave the device, the production of fine structures with a small scatter width is possible, since due to the comparatively low kinetic energy the particles are only slightly destroyed or and thus atomized when they hit the device. The use of soft substrates is also possible. The comparatively low temperature on the substrate, which can be below the solidus temperature or only slightly above the solidus temperature, enables the use of thermally sensitive substrate materials. Under certain circumstances, the substrate can even remain cold, since only the particles are melted. Compared to aerosol jet printing processes, no binding material is required to create a composite material and therefore no further process cuts are required.

• 1 eine Vorrichtung zur Verwendung für ein erfindungsgemäßes Verfahren in perspektivischer Darstellung, teilweise aufgeschnitten dargestellt;
• 2 schematisch die Vorrichtung nach 1 im Längsschnitt;
• 3 zwei Strömungsquerschnitte des Gasstroms während des erfindungsgemäßen Verfahrens;
• 4 schematisch die Vorrichtung nach 1 im Längsschnitt mit beispielhaften Maßangaben.

The invention is explained in more detail below with reference to the figures; here shows:

• 1 a device for use for a method according to the invention in a perspective view, shown partially cut away;
• 2 schematically the device according to 1 in longitudinal section;
• 3 two flow cross-sections of the gas stream during the method according to the invention;
• 4th schematically the device according to 1 in longitudinal section with exemplary dimensions.

The process according to the invention results in particles 3 onto a substrate surface 2a of a substrate 2 (e.g. workpiece) applied. A device is used for this 1 is used, the function of which is explained below. All of the following speed information is the average speed, unless otherwise stated.

The device 1 comprises a tubular outer wall 11 with an inlet end E1 and an outlet end E2 . The tubular outer wall 11 defines a central axis M. Gases can be inside the outer wall 11 from the inlet end E1 towards the outlet end E2 along a, in particular straight, main flow direction R. stream.

At the inlet end E1 becomes a carrier gas 4th which one with the particle 3 is provided, let in. Inside the device 1 become the particles 3 accelerated and heated so that the particles 2 then the device with high energy 1 at the outlet end E2 rely on the substrate 2 to be applied.

The device 1 comprises a first section A1, a second section A2 and a third section A3, which are in the main flow direction R. viewed one after the other. In this example the main flow direction is R. in the third section A3 straight and the outer wall 11 in the third section A3 parallel to the central axis M. Alternatively, a device is conceivable in which the outer wall 11 in the third section A3 is conical or free-form. In particular, the second section A2 is therefore optional and can therefore be omitted; in particular, the function of the second section can be integrated into the first and / or second section.

The first section A1 comprises an, in particular cylindrical, core space 21a in which the carrier gas 4th with the particles 3 is led. Around the core room 21a around it is a shell space, in particular a hollow cylindrical one 21b arranged. The coat room 21b surrounds the core space 2 ring-shaped. In the coat room 21b becomes a jacket gas 5 in the main flow direction R. guided. The coat room 21b is from the core room 21a through a cylindrical partition 12th Cut. The jacket gas is thus in the first section A1 5 separated from the carrier gas 4th and the particle 3 guided.

The jacket gas or carrier gas introduced in the first section can be preheated, in particular to a temperature above 50.degree.

In the first section A1 are the particles 3 in the carrier gas 4th randomly arranged. At the end of the first section A1, the particles point 3 together with the carrier gas 4th a first particle velocity vp1 in the main flow direction R. a first carrier gas velocity of the carrier gas 4th is equivalent to. The jacket gas 5 points in the main flow direction R. a first jacket gas velocity at the end of the first section A1 vm1 on.

The partition ends at the transition from the first section A1 to the second section A2 12th . The coat room 21b and the core space 21 thus open into a common connecting space 22nd , in the carrier gas 4th and with it the particles 3 with the jacket gas 5 be merged. This is in detail in 2 shown.

Due to the low Reynolds numbers, there is a mixing of the carrier gas 4th and the jacket gas 5 also avoided in the second and third sections A2, A3. The carrier gas 4th is located in the middle of the line system until it leaves the device and is surrounded by the jacket gas. Since a distinction between the two gases is unimportant in the further course, the following is only about the gas 45 spoken. By tapering the flow cross-section in the connection space 22nd there is an acceleration of the gas 45 so that the gas 45 at the end of the second section A2 at one speed vg2 flows. Already in the connecting room 22nd hydrodynamic focusing results. In particular, this focus can be traced back on the one hand to the Saffman force and / or on the other hand to the tapering of the flow.

The second section A2 is basically optional, but simplifies the process because the section has small radii 3 with larger geometries in the section 1 can be combined. The small radii in the section 3 ensure good focus due to the high Saffman force. The larger geometries in section 1 at the same time ensure a large core space 21a so that the speed of the carrier gas 4th can be lower. (At the same speed of the gas 45 are the speeds in section 1 for reasons of continuity with a larger geometry - and thus larger diameters - in section 1 lower) This in turn leads to lower particle velocities in the core space 21a so that any radial particle velocities in the direction of the outer wall 11 or particle rotations due to collisions with the cylindrical partition 12th are lower. The transverse velocities and rotations of the particles after leaving the core space 21a can also through a wider jacket space 21b and thus a larger geometry in the section 1 be better intercepted.

The particles 3 remain for the most part in the radially inner area and do not flow radially outwards. At the end of the second section A2, the particles have a second particle velocity vp2 that is greater than the first particle velocity vp1 . The second speed of the gas vg2 is greater than the second particle velocity vp2 and the first particle velocity vp1 .

The gas continues to flow 45 further in the main flow direction R. into the third section A3. Section A3 is the core of the device 1 . Here, the particles are focused on the central axis M, accelerated to a particle speed sufficient for application to the substrate, and the particle temperature is heated. A heating device is located on the third section A3 13th provided that the gas 45 heated. The gas 45 thereby expands and is consequently further accelerated.

Thereby the particles 3 in particular due to gravitational and flow forces, again less accelerated than the gas 45 so that the relative velocity between the gas and the particles is maintained. Therefore, the Saffmann force F acts on the particles, which the particles 45 always applied inwards and thus focused on the central axis M. Possible disturbances of the focus such as radial particle velocities outwards or rotations due to particle-particle collisions or turbulent flows also compensated by the Saffman force, so that the trajectory of the particles is stabilized despite disturbances. In addition to the decrease in density due to the gas heating, the gas density decreases in the direction of flow due to the decrease in pressure. The pressure decrease is the result of wall friction and dissipation of the flow in the device. As a result of this effect, the gas in the capillary tube is accelerated even if the gas temperature is slightly reduced at the end of the third section in the practical implementation of a plant.

Heating reduces the density of the gas and increases its viscosity. As a result, the Reynolds number of the gas flow is lowered. This reduces the tendency of the gas flow to form turbulence, although the gas flow is accelerated.

When leaving the device at the outlet end E2 the heated particles move within the still heated gas and hit after a short distance L4 (a few millimeters) on the substrate 2 on. The distance L4 between the outlet end E2 and the substrate surface is shown in the figures as fourth section A4.

Based on 3 the Saffmann force is described, which is used to focus the particles in section 3 is being used. The device is designed in such a way that the gas flow is laminar due to the low Reynolds numbers. In a laminar flow, layers are parallel to the direction of flow R. each formed with different flow velocities. On the outside wall 22nd the speed is the lowest due to the friction with the wall; As the distance between the layers and the wall increases, the layers of the flow have a greater velocity. At the central axis M, the distance to the wall is greatest and thus the speed of the gas is greatest. The gradient of the speed profile is therefore directed towards the central axis M from each side.

The direction of the Saffmann force is perpendicular to the relative speed of particles 3 and flow and thus transverse to the main flow direction R. . In the case of particle Reynolds numbers less than 50, the sign of the Saffman force depends on whether the particle velocity or the gas flow in the immediate vicinity of a particle is greater. The Saffmann force F now acts on those particles 3 in the direction of the central axis M, which have a slower speed than the gas. A particle which is consequently arranged eccentrically to the central axis M is inevitably acted upon towards the central axis M due to the conditions described above. This can lead to a transient process, since individual particles are moved beyond the central axis M. On the other side of the central axis M, however, the Saffmann force also has the effect that the respective particle is applied back in the direction of the central axis M again.

• - dem Partikeldurchmesser,
• - der Dichte des Gases, das das Partikel umgibt,
• - die Viskosität des Gases, das das Partikel umgibt,
• . die Relativgeschwindigkeit zwischen dem Partikel und dem Gas, das das Partikel umgibt,
• - der Gradient in der Strömung, die das Partikel umgibt.

The amount of the Saffman force on a particle depends on:

• - the particle diameter,
• - the density of the gas surrounding the particle,
• - the viscosity of the gas surrounding the particle,
• . the relative speed between the particle and the gas surrounding the particle,
• - the gradient in the flow surrounding the particle.

The changes in gas density and viscosity due to increases in temperature generally increases the magnitude of the Saffman force. The same applies to the particle diameter and the gradient of the shear flow. Since the speed level is increased by heating, the gradient of the flow and thus the Saffman force also increase with the increase in temperature.

For illustration, the 3a and 3b Particles 3a and 3b are shown in each case. The temperature of the gas is in 3b larger than in 3a , where the relative speed between gas 45 and particle is the same. In the 3b the gradient is higher than in due to the overall higher speed level 3 . Thus, the Saffmann force is on the respective in 3b larger at identical radial positions than in the 3a .

Because the speed of the particles in the section 3 is always smaller than the flow velocity, the Saffman force acts in the direction of the central axis M. This leads - together with the increased amount of the Saffman force through temperature control in the section 3 along the main flow direction R. - to a focusing of the particles 3 on the central axis M.

In order to apply particles to the substrate, a combination of particle velocity and particle temperature is required at the outlet of the device. In addition to focusing, the heating device in the third section A3 heats and accelerates the particles so that a form-fitting connection with the substrate is made possible. In particular, the particles are heated to a temperature that at least fuses the particles 3 has the consequence. The magnitudes of the velocities of the particles at the exit end A2 correspond in the case of metallic particles at least to those in powder flame spraying.

Based on 4th (not true to scale) an exemplary device is described with exemplary dimensions. The core room 11 has a diameter D11 of 1.1 mm. An annular gap that runs through the shell space 12th is formed has a width B12 of 1 mm.

At the end of the second section A2, the particles point 3 a second speed vp2 that is greater than the first speed vp1 the particles at the end of the first section A1.

At the end of the second section A2, the particles point 3 a second speed vp2 on that is less than a second speed vg2 of the gas 45 at the end of the second section A2.

In the third section A3, the flow cross section has a constant diameter D3 of 1 mm. The third section A1 points in the main flow direction R. a length L3 from 750mm up. A length of L3 = 750 mm, especially at a pipe temperature of 900 ° C, enables sufficient heating and acceleration of the particles (AlSi10Mg, 10-40 µm), since the time the particles stay in the heated section 3 is sufficiently high despite high particle velocities. In the case of the exemplary dimensions, argon is used as the gas.

Shortly after the particles enter 3 in the third section A3 the particles are focused on the M axis. In the further course of the third section A3, the precision of the focusing is further increased, in particular since oscillation around the central axis subsides.

In one embodiment, the particles are 3 at the outlet end E2 arranged around the axis M within a tolerance band of less than 10 micrometers.

The following optional value ranges are basically suitable for characterizing the invention and further restricting the claims and / or in any combination with other features:

The pipe diameter D3 in the third section A3 has a diameter of preferably a maximum of 4 mm and / or the pipe diameter D3 in the third section A3 has a diameter of preferably at least 0.5 mm.

An outlet diameter DE2 at the outlet end E2 has a minimum of 0.5 mm and / or a maximum of 3 mm. The outlet diameter DE2 may differ from the pipe diameter D3 of the third section A3.

The third speed vp3 the particle 3 at the outlet end E2 is in particular less than the speed of the gas vg3 at the outlet end E2 . The speed vp3 the particle 3 at the outlet end E2 is greater than the first and second velocities of the particles vp1 , vp2 .

The third speed vp3 the particle 3 at the outlet end E2 is in particular a maximum of 200 m / s. The third speed vg3 of the gas flow 45 at the outlet end E2 is in particular a maximum of 200 m / s.

The third speed vp3 the particle 3 at the outlet end E2 is in particular at least 5 m / s for particles made of plastic 5 m / s and / or particularly preferably at least 50 m / s for particles made of metal.

The diameter D11 of the core space 21a is preferably to be dimensioned as small as possible so that particles 3 can still be added. The diameter is preferably D11 of the core space min 0.5 mm, since with smaller diameters the carrier gas flow is reduced and the particles can no longer be brought into the flow. The diameter is preferably D11 of the core space max. 2 mm,

The temperature Tg1 of the gas at the end of the first section A1 and / or the temperature of the wall of the partition 12th at the end of the first section is in particular lower than the solidus temperature of the particles.

The temperature Rg3 of the gas at the end of the third section A3 and / or the temperature of the wall of the partition 12th at the end of the third section is in particular greater than the solidus temperature of the particles.

The partition has in particular a wall thickness D12 of max.0.2mm.

The smaller the diameter D11 of the core space, the shorter the length can be L2 of the second section 2 fail. One could bring in the particles very finely and the diameter D11 of the core room 21a reduce, a device would be conceivable in which a diameter (= D11 + 2 x B12) of the outer wall 11 the diameter D3 of the third section A3, whereby the second section A2 could be omitted. The second section A2 is therefore required to control the flow from the core space 21b of the first section A1 to be transferred to the third section A3.

The gap width B12 of the jacket room 12th is preferably a maximum of 5 mm and / or a minimum of 0.5 mm. The jacket gas flow serves in particular to " Outliers ”of particles again, especially before the third section, and leads in particular to the particles in the section 3 do not come into contact with the heated walls.

The temperature Tp1 the particle 3 at the end of the section 1 is lower than the temperature Tp3 the particle at the end of the third section.

The temperature Tp3 the particle 3 at the end of the third section is in particular higher than the solidus temperature of the particle. This promotes a connection between the particle and the substrate surface.

The temperature Tg1 of the gas 45 at the end of the first section A1 is lower than the temperature Rg3 of the gas at the end of the third section A3.

The pipe length L1 of the first section A1 is in particular at least 10 mm. The pipe length L2 of the second section A2 is in particular a maximum of 150 mm. The pipe length L3 of the third section A3 is in particular at least 100 mm and / or at most 1000 mm.

The distance L4 between the outlet end E2 and the substrate / the substrate surface is in particular a maximum of 5 mm and / or a minimum of 1 mm.

The temperature of the substrate surface is in particular lower than the temperature of the particles hitting the substrate surface.

In particular, the particles have a density of at least 1000 kg / m ³ (for metal particles) and / or at least 300 kg / m ³ (for plastic particles).

A diameter of the particles at the inlet end is in particular at least 1 micrometer, preferably at least 5 micrometers, and / or at most 50 micrometers.

The ratio of the total diameter of the first section ( B12 + D12 + D11 + D12 + B12 ) to pipe diameter D3 of the third section is in particular a maximum of 5 and / or a minimum of 1.

The designation “first”, “second”, “third” and “fourth” section is used in particular to individualize the individual sections and does not require a minimum number. The provision of a third section therefore does not necessarily mean that a second or first section is also provided. The designation of the first section consequently also allows further sections to be provided before the first section.

List of reference symbols

1

contraption

2

Substrate

2a

Substrate surface

3

Particles

4th

Carrier gas

5

Jacket gas

45

Total gas

11

Outer wall, in particular outer tube

12th

Partition, in particular intermediate pipe

13th

Heating device

21a

Core room

21b

Cloakroom

22nd

Connecting room

23

Focus space

E1

Inlet end

E2

Outlet end

R.

Main flow direction

S.

Feed direction

vp1

Average speed of the particles when leaving the first section

vt1

mean velocity of the carrier gas when leaving the first section

vm1

mean velocity of the jacket gas when leaving the first section

vp2

Average speed of the particles when leaving the second section

vg2

mean speed of the gas when leaving the second section

vp3

Average speed of the particles when leaving the third section

vg3

mean speed of the gas when leaving the third section

D11

Diameter of the core space 11

B12

Gap width of the shell space 12th

D12

Wall thickness of the partition 12th

D3

Pipe diameter of the third section A3

DE2

Outlet diameter at outlet end E2

L1

Pipe length of the first section A1

L2

Pipe length of the second section A2

L3

Pipe length of the third section A3

L4

Distance between outlet end E2 and substrate surface 2a (= max. 5mm)

Tp1

Temperature of the particles at the end of the first section

Tp3

Temperature of the particles at the end of the third section

Rg3

Temperature of the gas at the end of the third section

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 2009/0056620 A1 [0004]

Claims (16)

Method for applying particles (3) to a substrate (2), in particular to a substrate surface (2a) of the substrate (2), the method comprises the following method steps: Providing a quantity of particles (3) in a gas stream (4, 45) at an inlet end (E1) of a device (1), the gas stream (4, 45) in particular comprising a carrier gas stream and / or a jacket gas stream, Accelerating the gas flow (45) while heating the gas flow (45) in the direction of an outlet end (E2) of the device, Focusing the particles (3) on an axis (M) which is aligned parallel to the gas flow, with the particles being accelerated and heated by the accelerated gas flow during the focusing, Alignment of the outlet end (E2) of the device (1) on the substrate (2), in particular on the surface (2a) of the substrate (2). Method according to the preceding claim, characterized in that, in particular in a first phase, the particles (3) are received in a carrier gas flow (4), the carrier gas (4) being surrounded in a ring shape by a jacket gas flow (4), the jacket gas flow (5) flows at a first jacket gas velocity (vm1) which is in particular greater than a first carrier gas velocity (vt1) at which the carrier gas flow flows. Method according to one of the preceding claims, characterized in that, in particular in a second phase, the carrier gas flow (4) is combined with the jacket gas flow (5) to form a common gas flow (45). Method according to one of the preceding claims, characterized in that, in particular in a third phase, the gas flow (45) is accelerated by heating the gas flow (45) in such a way that a speed difference (vg3 - vp3) between the gas flow (45) and the Particles (3) is formed. Method according to one of the preceding claims, characterized in that the gas flow provided before the acceleration, in particular the carrier gas flow and / or the jacket gas flow, is preheated to a temperature above the ambient temperature, in particular before the first phase, and / or in particular to a Temperature above 50 ° C. Method according to one of the preceding claims, characterized in that a centering force (F) is formed by generating a speed difference (vg3 - vp3) between the gas flow (45) and the particles (3), in particular a Saffmann force (F), which centers the particles on the axis (M). Method according to one of the preceding claims, characterized in that the particles when leaving the outlet end (E2) have a particle speed (vp3) which is at least 5 m / s, in particular at least 50 m / s, in particular 100 m / s, and / or that on leaving the outlet end (E2) the particles have a particle velocity (vp3) which is a maximum of 300 m / s, in particular a maximum of 200 m / s. Method according to one of the preceding claims, characterized in that the particles (3) when they leave the outlet end (E2) have a temperature which corresponds at least to the solidus temperature of the particles. Method according to one of the preceding claims, characterized in that the focusing of the particles (3) on the axis (M) is adjusted by deliberately varying the heating of the gas flow (45), in particular by deliberately changing a heating power. Method according to one of the preceding claims, characterized in that the gas flow (45) is aerosol-free. Method according to one of the preceding claims, characterized in that the particles (3) comprise first particles made of a first material and second particles made of a second material, the first and the second material being different from one another. Method according to one of the preceding claims, characterized in that the substrate and / or the substrate surface is tempered, in particular is heated to a temperature which is above the ambient temperature around the substrate. Method according to one of the preceding claims, characterized in that the particles pass the outlet end, then fly to the substrate, then hit the substrate, and then enter into a connection with the substrate, in particular the particles not falling below their solidus temperature when they hit the substrate cooling down. Device (1) for performing the method according to one of the preceding claims, comprising a tubular outer wall (11), the outer wall extending along a main flow direction (R), the device having: - an inlet end (E1) for providing a quantity of Particles (3) in a gas stream (4, 45); - An outlet end (E2), in particular after a third section (A3), for delivering the quantity of particles (3) onto a substrate (2), in particular onto a substrate surface (2a); the device (1) comprises, in particular in a third section (A3), a heating device (13) set up for targeted heating and acceleration of the gas flow (45) and focusing the particles (3) on a central axis (M). Device according to the preceding claim, further comprising, in particular in a first section (A1), an intermediate wall which separates a core space (11) for receiving a carrier gas (4) with particles (3) from a shell space (5), wherein the Shell space (5) surrounds the core space (4) in a ring shape. Device according to the preceding claim, further comprising, in particular in a second section (A2), a connecting space (22) into which the core space (11) and the jacket space (5) open in the main flow direction (R).

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