Methods for improving aerosol-based cold deposition (Aerosol Deposition Method, ADM)

Abstract

The invention relates to a device for improving layer production by means of aerosol-based cold deposition. In particular, this allows the homogeneity of the layers to be increased. This is achieved by using a spot nozzle whose deposit spot is at least 5 times smaller in both dimensions than the dimensions of the surface to be coated, and by moving the spot nozzle and substrate relative to each other at a speed of at least 20 cm / s, whereby each point on the coating must be passed over at least five times.

Description

Technical field

[0001] The invention relates to a device for improving layer production by means of aerosol-based cold deposition. Technical background

[0002] The production of ceramic or ceramic-like layers or bodies typically requires a sintering temperature above 1000 °C. Consequently, the integration or combination of ceramics or ceramic-like materials with low-melting-point plastics, glasses, or metals is difficult or even impossible. Ceramics or ceramic-like materials with a high covalent bonding content present a further challenge. In these cases, the coating material decomposes before densification, making the production of dense components or layers impossible or only achievable with considerable effort.

[0003] A novel approach is based on a known method of aerosol- and vacuum-based layer deposition [1], [2]. This method is also referred to in the literature as aerosol deposition method (ADM) or, more recently, as "aerosol-based cold deposition" or, more recently, as powder aerosol deposition method (PAD or PADM). Here, dense layers can be deposited directly from the starting powders onto a wide variety of substrate materials at room temperature. These coatings are characterized by strong adhesion to the substrate, very high density, and material properties similar to those of the starting powders used.

[0004] The process is based on the following: particles are transferred into an aerosol 5 using appropriate devices (described below), then accelerated, and finally directed onto a substrate 7 to be coated, which is moved on a substrate carrier 8. The high kinetic energy of the particles in the aerosol 5 presumably leads to a local increase in pressure and temperature upon impact with the substrate 7 [1], as well as to plastic deformation and the breaking up of the particles. This, in turn, ensures adhesion both between the particles and between the particles and the substrate 7, thus forming a layer 6.

[0005] According to current knowledge [2], [3], the process of layer deposition begins with the formation of an anchoring layer on the substrate 7 and continues with a continuous build-up and densification of the layer. In the literature, this layer formation process is also frequently referred to as "Room Temperature Impact Consolidation" (RTIC) [1]. State of the art regarding a device for aerosol-based cold separation

[0006] The prior art and the invention are described below with reference to figures.

[0007] Figs. Figure 1 shows an exemplary device for the deposition of layers using the aerosol-based cold deposition of powders with a coating chamber (state of the art).

[0008] The main components of a device for aerosol-based cold deposition of powders are, as shown in Figs.1 shown, a vacuum chamber 1, an evacuation device 2, an aerosol-generating device 3, which for example as in [2] (there Figs. 2) or as in [4] there Figs. 2 can be implemented, and a nozzle apparatus 4, consisting of a connecting line 4.1 and a nozzle 4.2. Publications regarding the apparatus design, which represent the state of the art in this respect, can be found, for example, in US 7,553,376 B2.

[0009] The principle of a device for the aerosol-based cold deposition of powders is based on the creation of a vacuum within the vacuum chamber 1 via an evacuation device 2 [1], [3]. A gas stream 10, which can consist of a single gas such as oxygen, nitrogen, helium, or the like, as well as mixtures of several gases, is guided through a gas supply line 9 and mixed with the coating powder (not described in detail here) in the aerosol-generating device 3. This produces a powder aerosol, hereinafter referred to simply as aerosol 5, i.e., a mixture of the particles of the coating powder and the carrier gas flow 10. As a result of the pressure drop occurring between the aerosol-generating device 3 and the vacuum chamber 1, the powder aerosol 5 is transported from the aerosol-generating device 3 into the vacuum chamber 1 via a connecting line 4.1. The connecting line 4.1 terminates in a nozzle 4.2, in which the carrier gas used, and thus the particles in the powder aerosol 5, are further accelerated by changing the cross-section. In the vacuum chamber 1, the particles collide with a reciprocating substrate 7 and form a dense, adhesive, and scratch-resistant coating 6 [1], [2], [3]. A slot nozzle 4.2 is typically used, and the layer thickness increases with each pass. In some applications, it is suggested that the nozzle 4.2, rather than the substrate 7, is moved. Furthermore, so-called de Laval nozzles are used in some applications [5], but these usually only result in point deposition, or, if the nozzle or substrate is moved, in line-like deposition. Disadvantages of the state of the art

[0010] When using a slot nozzle, the layer is approximately the width of the slot nozzle. While very wide nozzles are conceivable, the resulting layer thickness is often not constant because the particle loading of the gas stream is not homogeneous across the nozzle width. This leads to the layer being thicker in areas with particularly high particle loading than in areas with low particle loading of the aerosol gas stream. Adapted process paths have so far only been used in cold spraying [8, 9], a thermally induced spraying process based on a completely different deposition physics and applied to metals, in contrast to the powder aerosol deposition method, which can be used for brittle materials.

[0011] Furthermore, relatively low or even very low traverse speeds in the range of 0.05 to 100 mm / s are typically selected, as shown in the following overview in Table 1. These low traverse speeds allow for reasonably high layer deposition rates per pass. Table 1 Verfahrgeschwindigkeitin mm / s Arbeitsgroup Those with Angabe from the DOI: 5 Fan et al.

[10] 10.1361 / 105996306X146901 1 Piechowiak et al.

[11] https: / / doi.org / 10.1016 / j.jeurceramsoc.2013.11.019 1 Seo et al.

[12] https: / / doi.org / 10.1166 / jnn.2015.10437 0,05 - 0,65 Johnson et al.

[13] 10.1117 / 12.2029717 10 Bae et al.

[14] 10.1016 / j.ssi.2013.01.022 5 Yang et al.

[15] 10.1007 / s11666-012-974 1-6 5 Eckstein et al.

[16] 10.1007 / s10853-022-07467-3 10 Goto et al.

[17] https: / / doi.org / 10.1016 / j.ceramint.2023.10.173 70 Park et al.

[18] 10.1016 / j.ceramint.2024.02.037 100 Jang et al.

[19] https: / / doi.org / 10.3390 / ceramics5040083 16 Furuya et al.

[20] https: / / doi.org / 10.1016 / j.surfcoat.2023.129362 20 Elsenberg et al.

[21] 10.1007 / s11666-023-01550-0

[0012] High traverse speeds up to 400 mm / s -1 are known from cold spraying

[22] , but since this is a thermally induced spraying process, this does not represent the state of the art in powder aerosol deposition.

[0013] For a substrate 7, which is to be coated with a coating area A with dimensions axb and is to receive a layer thickness h, a slot nozzle of width a is required, which is moved over a distance b with as many passes as necessary until the layer thickness h is reached. With a coating rate per pass of r (i.e., 1 nm / pass), n = hlr passes would therefore be necessary.

[0014] The complexity of slot nozzles makes their manufacture difficult, and blockages within the nozzle can lead to flow instabilities. Furthermore, the high flow velocity of the powder particles can cause material wear, which can also lead to temperature gradients. These types of nozzles therefore require regular maintenance, resulting in high operating costs. Basic idea of ​​the invention

[0015] The basic idea of ​​the invention is a method for using nozzles 4.2, in particular those with a round nozzle opening, to achieve a particularly uniform coating, i.e., a deposited layer 6 with a very homogeneous layer thickness. The method according to the invention provides for the use of a nozzle that deposits a layer (spot) while stationary, which is significantly smaller in both dimensions than the dimensions of the coating area A. "Significantly smaller" here means a factor of 5 or more. In the following, deposition with such a nozzle is referred to as "spotting" deposition, i.e., the nozzle deposits only spot by spot (as long as it is stationary). The term "spot" within the meaning of the invention is understood to mean an area that can be circular, oval, square, rectangular, or otherwise shaped.In a simple example according to the invention, the deposited spot can be round and, for example, have a diameter of 1 mm. Generally, the deposition profile within the spot (within the diameter of the spot for circular spots) does not have to be constant; rather, deposition with a Gaussian profile can also occur, as described, for example, in work [7], therein. Figs. 2, shown. Therefore, the term "spot nozzle" will be used in the following.

[0016] When this invention refers to a travel path, it means a relative movement between nozzle 4.2 (here, a spot nozzle) and substrate 7. Substrate 7 can also be understood to be a movable substrate 7 or a belt, for example, for roll-to-roll coating. Generally, either the nozzle 4.2 or the substrate 7, or both, can be moved. The crucial factor is the relative movement. For the sake of simplicity, however, the term "travel path" will be used in the following, even though it refers to a relative movement.

[0017] The basic concept of the invention is that the traverse speed of the spot nozzle is very high in at least one dimension, at least twice as fast as the highest value of 100 mm / s mentioned in the overview. This means at least 20 cm / s, preferably at least 50 cm / s. Unexpectedly, it has been found that the faster the spot nozzle travels, the more uniformly and homogeneously the substrate 7 is coated. The presumed effect behind this is that the significantly higher traverse speeds result in a correspondingly lower layer thickness per pass (r), since less powder is deposited per pass. This significantly reduces the absolute peaks in an uneven coating profile within a spot.

[0018] This must be combined with a correspondingly larger number of crossings, which, however, must comply with the other conditions of the invention. These can be derived from Figs.See Figure 2. For the following explanation, it is assumed that a spot nozzle produces a profile resembling a Gaussian profile (curve 1). However, the teaching of the invention applies to all layer profiles, regardless of their shape. If such a spot nozzle is moved at a constant speed, a deposition profile is obtained that looks approximately like a ridge, with a constant height in the direction of travel and an approximately Gaussian-shaped profile perpendicular to it (the shape also corresponds to curve 1). If a larger area is to be coated as homogeneously as possible, these individual profiles must be combined, i.e., the travel path must be staggered, with the stagger being chosen so that the overlaps fill the valleys. This is shown schematically in curve 2 using the example of a cross-section when an area has been traversed three times. If the same area has been traversed ten times, the valleys are hardly recognizable anymore (curve 3).With each additional pass, the homogeneity improves. According to the invention, this effect is amplified when the traversing speed is very high, since the height of a spot (i.e., the maximum of curve 1) is then lower. A non-linear relationship even appears to exist here, as experiments have shown that doubling the traversing speed reduces the height of a spot by less than half. It has been found that a spot must be traversed at least five times to achieve a reasonably homogeneous coating (n ≥ 5). Advantages of the invention

[0019] The invention offers the advantage that, on the one hand, the layers are significantly more homogeneous than with a conventional slot nozzle. Furthermore, by using a nozzle with a smaller deposition spot, the mass flow rate of the pumps in the evacuation device 2 can also be reduced, which significantly lowers operating and acquisition costs for the pump. The invention also makes it easier to use Laval nozzles for the powder aerosol deposition method. Moreover, a redesign of a wider slot nozzle is not required for thicker layers. Embodiments of the invention

[0020] A first advantageous embodiment is shown below. Instead of using a conventional nozzle for the spot nozzle, which allows the powder aerosol 5 to be accelerated to a maximum of supersonic speed within the nozzle (often also referred to as a convergent nozzle), a nozzle 4.2 is used, which allows the powder aerosol 5 to be accelerated to supersonic speeds within the nozzle (often also referred to as a convergent-divergent nozzle). This could, for example, be a so-called Laval nozzle.

[0021] Another particularly preferred embodiment provides that the spot nozzle has a circular or oval diameter. However, the aforementioned requirements for spot size and travel speeds must still be observed.

[0022] For the measured travel path, there are two preferred embodiments: Firstly, traversing a zigzag pattern, i.e., multiple changes of direction at acute angles, whereby care must be taken to ensure that, when traversing the path multiple times, the points of the change of direction at acute angles do not overlap, see schematic representation in Figs. 3, Curve 1, with crossings 11.1 and 11.2.

[0023] Furthermore, tracing a meandering pattern with straight or rounded lines is a preferred embodiment, whereby it also applies that all longitudinal sections are not completely congruent when the substrate is crossed several times, see schematic representations in Figs. 3, Curve 2, Curve 3 and Curve 4.

[0024] Furthermore, it is advantageous to use a very high traversing speed (> 20 cm / s, preferably > 50 cm / s) when traversing a zigzag pattern. Tests have shown that this is particularly effective at compensating for defects.

[0025] The method disclosed here can also be applied to conventional convergent or convergent-divergent slot nozzles, particularly when their width is smaller than the required layer width or the layer thickness is inhomogeneous across the layer width (for example, due to uneven aerosol distribution or defects in the nozzle). By traversing the patterns described above, the defects or the uneven layer thickness can be compensated for.

[0026] The use of a multi-axial, i.e., a biaxial, preferably a triaxial, substrate support system also allows the coating of more complex surfaces, such as convex or concave ones. By scanning the surface as described and adjusting the distance between the nozzle and the substrate using the additional axes of the substrate support, it is particularly possible to coat non-planar surfaces where the distance between the nozzle and the substrate would change in a biaxial system, such as large concave or convex surfaces like lenses. Similarly, the combination of concave and convex surfaces, as is the case with corrugated substrates, is possible.

[0027] The traverse speed is directly related to the amount of particles interacting with substrate 7 and can be varied to improve coating homogeneity. A higher traverse speed means that fewer powder particles impact substrate 7 and contribute to deposition. By varying the traverse speed, the powder deposition on the surface can be adjusted to compensate for inhomogeneities in the layer profile and ensure homogeneity of the layer cross-section. This is shown schematically in Figs. Figure 4, Curve 1 is shown. In this figure, n means A the number of particles that strike the nozzle area projected onto substrate 7 per unit of time and v Dthe traverse speed. On the other hand, increasing the traverse speed drastically reduces the overall coating time without compromising the homogeneity of the coating. The variation of the traverse speed to compensate for inhomogeneous layer profiles from previous depositions is shown schematically in Figs. 4, curve 2 and curve 3 are shown.

[0028] In addition to the travel speed, another adjustable parameter is the aerosol concentration (particle load of the aerosol). The relationship between the number of particles in the aerosol and the aerosol concentration is described in Figs.Figure 5, curve 1, is shown schematically. Increasing the aerosol concentration locally increases the layer thickness, while decreasing it reduces it. Valleys that formed during deposition due to the Gaussian profile of the deposited layers would be filled in by repeated scanning across the coating if the aerosol concentration is locally increased. This relationship is shown in Figure 5. Figs. 5, Curve 2 and Curve 3 are shown schematically.

[0029] Another embodiment involves using mathematical random functions or modified functions to control the moving axes of the coating system. These functions calculate random coordinates for the movement of the substrate or the nozzle. The exact travel path cannot be predicted before the calculation. Boundary conditions, such as a maximum travel path, define the boundaries of the coordinate system for the possible movement. A high number of passes and / or the modification of such random functions ensures a largely uniform powder coating. Figs. Figure 6 shows a schematic representation of such a process. Cited non-patent literature [1] J. Akedo: Room Temperature Impact Consolidation (RTIC) of Fine Ceramic Powder by Aerosol Deposition Method and Applications to Microdevices, J. Therm. Spray Technol., 17, 181-198 (2008), doi: 10.1007 / s11666-008-9163-7 [2] M. Schubert, D. Hanft, T. Nazarenus, J. Exner, M. Schubert, P. Nieke, P. Glosse, N. Leupold, J. Kita, R. Moos: Powder aerosol deposition method - novel applications in the field of sensing and energy technology, Funct. Mater. Lett., 12, 1930005 (2019), doi: 10.1142 / S1793604719300056 [3] D. Hanft, J. Exner, M. Schubert, T. Stöcker, P. Fuierer, R. Moos: An Overview of the Aerosol Deposition Method: Process Fundamentals and New Trends in Materials Applications, J. Ceram. Sci. Technol., 6, 147-182 (2015), doi: 10.4416 / JCST2015-00018 [4] D. Hanft, P. Glosse, S. Denneler, T. Berthold, M. Oomen, S. Kauffmann-Weiss, F. Weis, W. Häßler, B. Holzapfel, R. Moos: The Aerosol Deposition Method: A Modified Aerosol Generation Unit to Improve Coating Quality, Materials, 11, 1572 (2018), doi: 10.3390 / ma11091572 [5] M. Lee, J. Park, D. Kim, S. Yoon, H. Kim, D. Kim, S. James, S. Chandra, T. Coyle, J. Ryu; et al.: Optimization of supersonic nozzle flow for titanium dioxide thin-film coating by aerosol deposition, J. Aerosol Sci., 42, 771-780 (2011), doi: 10.1016 / j.jaerosci.2011.07.006 [7] M. Linz, J. Exner, J. Kita, F. Bühner, M. Seipenbusch, R. Moos: Discontinuous Powder Aerosol Deposition: An Approach to Prepare Films Using Smallest Powder Quantities, Coatings, 11, 844 (2021), doi: 10.3390 / coatings11070844 [8] R.F. Vaz, V. Albaladejo-Fuentes, J. Sanchez, U. Ocaña, Z.G. Corral, H. Canales, I.G. Cano: Metal Knitting: A New Strategy for Cold Gas Spray Additive Manufacturing, Materials, 15 (2022), doi: 10.3390 / ma15196785 [9] H. Wu, C. Huang, X. Xie, S. Liu, T. Wu, T. Niendorf, Y. Xie, C. Deng, M. Liu, H. Liao; et al.: Influence of spray trajectories on characteristics of cold-sprayed copper deposits, Surf. Coat. Technol., 405, 126703 (2021), doi: 10.1016 / j.surfcoat.2020.126703

[10] S.Q. Fan, G.J. Yang, C.J. Li, G.J. Liu, C.X. Li, L.Z. Zhang: Characterization of microstructure of Nano-TiO2 coating deposited by vacuum cold spraying. J. Therm. Spray Tech. 15, 513-517 (2006). doi: 10.1361 / 105996306X146901

[11] M.A. Piechowiak, J. Henon, O. Durand-Panteix, G. Etchegoyen, V. Coudert, P. Marchet, F. Rossignol: Growth of dense Ti3SiC2 MAX phase films elaborated at room temperature by aerosol deposition method, J. Eur. Ceram. Soc., 34, 1063-1072 (2014), doi: 10.1016 / j.jeurceramsoc.2013.11.019

[12] D.S. Seo, J.K. Lee, K.H. Hwang, B.-D. Hahn, S.Y. Yoon: Influence of Starting Powders on Hydroxyapatite Coatings Fabricated by Room Temperature Spraying Method, J. Nanosci. Nanotechnol., 15, 6032-6038 (2015), doi: 1 0.1166 / jnn.2015.1 0437

[13] S.D. Johnson, F.J. Kub, C.R. Eddy Jr.: ZnS / Diamond Composite Coatings for Infrared Transmission Applications Formed by the Aerosol Deposition Method, Proc. SPIE, 8708, 87080T (2013), doi: 10.1117 / 12.2029717

[14] H. Bae, J. Choi, G.M. Choi: Electrical conductivity of Gd-doped ceria film fabricated by aerosol deposition method, Solid State lon., 236, 16-21 (2013), doi: 10.1016 / j.ssi.2013.01.022

[15] G.-J. Yang, K.-X. Liao, C.-J. Li, S.-Q. Fan, C.-X. Li, S. Li: Formation of Pore Structure and Its Influence on the Mass Transport Property of Vacuum Cold Sprayed TiO2 Coatings Using Strengthened Nanostructured Powder, J. Therm. Spray Technol., 21, 505-513 (2012), doi: 10.1007 / s11666-012-9741-6

[16] U. Eckstein, N.H. Khansur, M. Bergler, D. Urushihara, T. Asaka, K. Kakimoto, M. Sadl, M. Dragomir, H. Uršič, D. de Ligny; et al.: Room temperature deposition of freestanding BaTiOs films: temperature-induced irreversible structural and chemical relaxation, J. Mater. Sci., 57, 13264-13286 (2022), doi: 10.1007 / s1 0853-022-07467-3

[17] T. Goto, Y. Matsubayashi, J. Akedo: Ceramic coating on rubber by aerosol deposition with cryogenic substrate cooling, Ceram. Int., (2023), doi: 10.1016 / j.ceramint.2023.10.173

[18] H. Park, H. Kwon, T.-H. Lee, C. Lee: Deposition mechanism in vacuum-kineticsprayed alumina film: First weak bonding and bonding consolidation, Ceram. Int. (2024), doi: 10.1016 / j.ceramint.2024.02.037

[19] S.O. Jang, C. Cho, J.H. Kim, I.J. Kang, H. Chang, H. Park, K. Lee, D.G. Kim, H.W. Seok: Microwave Plasma Assisted Aerosol Deposition (µ-PAD) for Ceramic Coating Applications, Ceramics, 5, 1174-1184 (2022), doi: 10.3390 / ceramics5040083

[20] Y. Furuya, S. Konuma, M. Hasegawa: Deposition mechanism of alumina particles in aerosol deposition based on the kinetic energy of particles, Surf. Coat. Technol., 458, 129362 (2023), doi: 10.1016 / j.surfcoat.2023.129362

[21] A. Elsenberg, T. Emmler, M. Schieda, F. Gärtner, T. Klassen: Tuning Aerosol Deposition of BiVO4 Films for Effective Sunlight Harvesting, J. Therm. Spray Tech., 32, 352-362 (2023), doi: 10.1007 / s11666-023-01550-0

[22] RA Seraj, A. Abdollah-zadeh, S. Dosta, H. Canales, H. Assadi, IG Cano: The effect of traverse speed on deposition efficiency of cold sprayed Stellite 21, Surf. Coat. Technol., 366, 24-34 (2019), doi: 10.1016 / j.surfcoat.2019.03.012 Reference sign 1 vacuum chamber 2 Evacuation device 3 Aerosol-generating device 4 nozzle apparatus 4.1 Connecting cable 4.2 Nozzle 5 Aerosol, also known as powder aerosol 6. Deposited layer, also called coating 7 Substrat 8 substrate carriers 9 Gas supply line 10 Gas supply 11.1 Previous crossing 11.2 Subsequent crossing after 11.1 12.1 Inhomogeneous layer profile 12.2 Layer profile according to 12.1 after reduction of inhomogeneities 12.3 Layer profile according to 12.2 after reduction of inhomogeneities 12.4 Layer profile according to 12.3 after reduction of inhomogeneities QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 7,553,376 B2

[0008] Cited non-patent literature

[0000] J. Akedo: Room Temperature Impact Consolidation (RTIC) of Fine Ceramic Powder by Aerosol Deposition Method and Applications to Microdevices, J. Therm. Spray Technol., 17, 181-198 (2008), doi: 10.1007 / s11666-008-9163-7

[0029] M. Schubert, D. Hanft, T. Nazarenus, J. Exner, M. Schubert, P. Nieke, P. Glosse, N. Leupold, J. Kita, R. Moos: Powder aerosol deposition method - novel applications in the field of sensing and energy technology, Funct. Mater. Lett., 12, 1930005 (2019), doi: 10.1142 / S1793604719300056

[0029] D. Hanft, J. Exner, M. Schubert, T. Stöcker, P. Fuierer, R. Moos: An Overview of the Aerosol Deposition Method: Process Fundamentals and New Trends in Materials Applications, J. Ceram. Sci. Technol., 6, 147-182 (2015), doi: 10.4416 / JCST2015-00018

[0029] D. Hanft, P. Glosse, S. Denneler, T. Berthold, M. Oomen, S. Kauffmann-Weiss, F. Weis, W. Häßler, B. Holzapfel, R. Moos: The Aerosol Deposition Method: A Modified Aerosol Generation Unit to Improve Coating Quality, Materials, 11, 1572 (2018), doi: 10.3390 / ma11091572

[0029] M. Lee, J. Park, D. Kim, S. Yoon, H. Kim, D. Kim, S. James, S. Chandra, T. Coyle, J. Ryu; et al.: Optimization of supersonic nozzle flow for titanium dioxide thin-film coating by aerosol deposition, J. Aerosol Sci., 42, 771-780 (2011), doi: 10.1016 / j.jaerosci.2011.07.006

[0029] M. Linz, J. Exner, J. Kita, F. Bühner, M. Seipenbusch, R. Moos: Discontinuous Powder Aerosol Deposition: An Approach to Prepare Films Using Smallest Powder Quantities, Coatings, 11, 844 (2021), doi: 10.3390 / coatings11070844

[0029] R.F. Vaz, V. Albaladejo-Fuentes, J. Sanchez, U. Ocaña, Z.G. Corral, H. Canales, I.G. Cano: Metal Knitting: A New Strategy for Cold Gas Spray Additive Manufacturing, Materials, 15 (2022), doi: 10.3390 / ma15196785

[0029] H. Wu, C. Huang, X. Xie, S. Liu, T. Wu, T. Niendorf, Y. Xie, C. Deng, M. Liu, H. Liao; et al.: Influence of spray trajectories on characteristics of cold-sprayed copper deposits, Surf. Coat. Technol., 405, 126703 (2021), doi: 10.1016 / j.surfcoat.2020.126703

[0029] S.Q. Fan, G.J. Yang, C.J. Li, G.J. Liu, C.X. Li, L.Z. Zhang: Characterization of microstructure of Nano-TiO2 coating deposited by vacuum cold spraying. J. Therm. Spray Tech. 15, 513-517 (2006). doi: 10.1361 / 105996306X146901

[0029] M.A. Piechowiak, J. Henon, O. Durand-Panteix, G. Etchegoyen, V. Coudert, P. Marchet, F. Rossignol: Growth of dense Ti3SiC2 MAX phase films elaborated at room temperature by aerosol deposition method, J. Eur. Ceram. Soc., 34, 1063-1072 (2014), doi: 10.1016 / j.jeurceramsoc.2013.11.019

[0029] D.S. Seo, J.K. Lee, K.H. Hwang, B.-D. Hahn, S.Y. Yoon: Influence of Starting Powders on Hydroxyapatite Coatings Fabricated by Room Temperature Spraying Method, J. Nanosci. Nanotechnol., 15, 6032-6038 (2015), doi: 1 0.1166 / jnn.2015.1 0437

[0029] S.D. Johnson, F.J. Kub, C.R. Eddy Jr.: ZnS / Diamond Composite Coatings for Infrared Transmission Applications Formed by the Aerosol Deposition Method, Proc. SPIE, 8708, 87080T (2013), doi: 10.1117 / 12.2029717

[0029] H. Bae, J. Choi, G.M. Choi: Electrical conductivity of Gd-doped ceria film fabricated by aerosol deposition method, Solid State lon., 236, 16-21 (2013), doi: 10.1016 / j.ssi.2013.01.022

[0029] G.-J. Yang, K.-X. Liao, C.-J. Li, S.-Q. Fan, C.-X. Li, S. Li: Formation of Pore Structure and Its Influence on the Mass Transport Property of Vacuum Cold Sprayed TiO2 Coatings Using Strengthened Nanostructured Powder, J. Therm. Spray Technol., 21, 505-513 (2012), doi: 10.1007 / s11666-012-9741-6

[0029] U. Eckstein, N.H. Khansur, M. Bergler, D. Urushihara, T. Asaka, K. Kakimoto, M. Sadl, M. Dragomir, H. Uršič, D. de Ligny; et al.: Room temperature deposition of freestanding BaTiOs films: temperature-induced irreversible structural and chemical relaxation, J. Mater. Sci., 57, 13264-13286 (2022), doi: 10.1007 / s1 0853-022-07467-3

[0029] T. Goto, Y. Matsubayashi, J. Akedo: Ceramic coating on rubber by aerosol deposition with cryogenic substrate cooling, Ceram. Int., (2023), doi: 10.1016 / j.ceramint.2023.10.173

[0029] H. Park, H. Kwon, T.-H. Lee, C. Lee: Deposition mechanism in vacuum-kineticsprayed alumina film: First weak bonding and bonding consolidation, Ceram. Int. (2024), doi: 10.1016 / j.ceramint.2024.02.037

[0029] S.O. Jang, C. Cho, J.H. Kim, I.J. Kang, H. Chang, H. Park, K. Lee, D.G. Kim, H.W. Seok: Microwave Plasma Assisted Aerosol Deposition (µ-PAD) for Ceramic Coating Applications, Ceramics, 5, 1174-1184 (2022), doi: 10.3390 / ceramics5040083

[0029] Y. Furuya, S. Konuma, M. Hasegawa: Deposition mechanism of alumina particles in aerosol deposition based on the kinetic energy of particles, Surf. Coat. Technol., 458, 129362 (2023), doi: 10.1016 / j.surfcoat.2023.129362

[0029] A. Elsenberg, T. Emmler, M. Schieda, F. Gärtner, T. Klassen: Tuning Aerosol Deposition of BiVO4 Films for Effective Sunlight Harvesting, J. Therm. Spray Tech., 32, 352-362 (2023), doi: 10.1007 / s11666-023-01550-0

[0029] R.A. Seraj, A. Abdollah-zadeh, S. Dosta, H. Canales, H. Assadi, I.G. Cano: The effect of traverse speed on deposition efficiency of cold sprayed Stellite 21, Surf. Coat. Technol., 366, 24-34 (2019), doi: 10.1016 / j.surfcoat.2019.03.012

[0029]

Claims

Method for producing a layer by means of aerosol-based cold deposition, characterized in that a slot nozzle is used, the slot of which is at least 5 times smaller in one dimension than the dimensions of the surface to be coated, and that the nozzle and substrate are moved relative to each other at a speed of at least 20 cm / s, whereby each point on the coating must be passed over at least 5 times. Method for producing a layer by means of aerosol-based cold deposition according to the aforementioned claim, characterized in that a spot nozzle is used whose deposit spot is at least 5 times smaller in both dimensions than the dimensions of the surface to be coated, and that the nozzle and substrate are moved relative to each other at a speed of at least 20 cm / s, whereby each point on the coating must be passed over at least 5 times. Method according to one of the preceding claims, characterized in that the nozzle and substrate are moved relative to each other at a speed of at least 50 cm / s. Method according to one of the preceding claims, characterized in that the nozzle is designed such that the powder aerosol is accelerated to supersonic speeds. Method according to the aforementioned claim, characterized in that the nozzle is designed as a convergent nozzle and the gas velocity remains largely below the speed of sound in the respective medium and at the respective pressure. Method according to one of the preceding claims, characterized in that the spot nozzle has a circular or oval diameter. Method according to one of the preceding claims, characterized in that the spot nozzle has a slotted outlet and the two- or multi-axis movement is used to obtain a homogeneous layer thickness or a layer that is wider than the slot width. Method according to one of the aforementioned claims, characterized in that a multi-axis support system is used to move the nozzle or the substrate, which allows the coating of complex geometries. Method according to one of the preceding claims, characterized in that the spot nozzle or the substrate is moved relative to each other in a zigzag pattern or a meander pattern, or that a parabolic pattern is traced, or that a meandering pattern with rounded or straight lines is traced. Method for moving the nozzle or the substrate according to one of the preceding claims, characterized in that the center point of the nozzle is not located at an identical position during several passes.

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