Method for manufacturing a functional component and the functional component obtained

Abstract

A method for manufacturing a functional component capable of obtaining a functional component made of a metallic material, all or part of which defines a fluid-permeable filter medium and defines a first main surface and a second main surface for preferred circulation of gas through the filter medium. The method includes a main stage comprised of an additive manufacturing process implemented in a manner of continuous passage from a support tray. Each pass includes depositing at least one layer of the metallic material, the deposited material adhering to at least one previously deposited layer of metallic material. Deposition is controlled during each pass such that the stacking of metallic material deposited during continuous passes forms the functional component. The filter medium includes a coalesced network of interconnected structures according to a three-dimensional spatial distribution between the first and second main surfaces, the interconnected structures defining pores therebetween, these pores being spatially distributed within the filter medium in three dimensions between the first and second main surfaces.

Description

Technical Field

[0001] The present invention relates to a manufacturing method capable of obtaining a functional component made of substantially metallic material, which defines, wholly or partially, a fluid-permeable filter medium and defines a first main surface and a second main surface such that fluid preferably circulates through the filter medium between the first main surface and the second main surface.

[0002] The present invention also relates to a functional component obtained by implementing this manufacturing method.

[0003] This invention can be applied to any system requiring fluid filtration, regardless of whether the fluid is composed of gas or liquid, such as air. One possible application involves manufacturing or supplying masks conforming to FFP1 or FFP2 standards, as well as other highly efficient filter media. Applications can be extended to various industrial sectors and for the general public. The resulting functional components can also be used as supports for catalysts or battery electrodes. More generally, this invention can be applied to any device requiring filter media with a large exchange surface for personal or collective protection. Background Technology

[0004] In the realm of personal or collective protection, particularly for the protection of people from the proliferation and spread of viruses, microorganisms, bacteria, or dust in their environment or the air, there are known masks worn by people.

[0005] It is known that almost all protective equipment (such as surgical masks, FFP2 masks, and ordinary public masks) is disposable.

[0006] Besides supply issues, current protective equipment has several shortcomings.

[0007] The main drawback of ordinary public masks, surgical masks, or FFP2 masks is their short-lived and non-reusable nature. Since their use is limited to around 3 hours, a considerable number of masks are inevitably consumed; for example, medical and paramedic personnel in France alone require at least 24 million masks per week. This, of course, creates a real ecological problem, especially during large-scale disease outbreaks.

[0008] Furthermore, the fact that masks are discarded means there is a significant risk to others who may handle the discarded masks or, more generally, come into contact with them.

[0009] An alternative solution is to use protective masks made of washable fabric. The drawbacks of these short-lived masks are the large accumulation of contaminated waste and the potential risks associated with their management. Furthermore, it should not be forgotten that washing a large number of masks (millions daily) can have environmental impacts due to the effluent from washing.

[0010] Metal filters manufactured by sintering powders already exist, but these methods are very expensive, complex, and result in filters with non-uniform porosity. The achievable shapes are also limited. Furthermore, it has unfortunately been demonstrated in practice that the pressure drop experienced by the filtered fluid through the filter increases with filtration efficiency. Therefore, obtaining highly efficient filters means that the required pressure drop level may be prohibitive in some applications. Summary of the Invention

[0011] The present invention aims to provide a manufacturing method of the type described above, which allows for the resolution of the problems listed above related to the mentioned prior art.

[0012] In particular, the present invention aims to provide a solution that achieves the following objectives:

[0013] -Provides filter media with very high durability (i.e., their service life and duration of use), especially filter media that can be reused throughout their entire lifespan.

[0014] - Essentially, limiting the amount of waste to better align with the perspective of sustainable development.

[0015] - Provides filter media with high filtration efficiency.

[0016] - Obtain filter media with low pressure drop for the filtered fluid.

[0017] - Provides filter media that meet the standards for FFP1 or FF2 category masks, or meets the standards for highly efficient filter media typically according to European classification EN 1822:2009 or standard EN 779:2012, particularly allowing a filtration efficiency higher than 99% for particles larger than 100nm.

[0018] - Simple and inexpensive to manufacture

[0019] -This enables the production of filter media with complex shapes.

[0020] - Allows the pores to be evenly distributed within the filter medium.

[0021] This objective can be achieved by implementing a manufacturing method capable of obtaining a functional component made entirely or partially of a metallic material, which defines a fluid-permeable filter medium and defines a first and a second main surface for preferred circulation of gas through the filter medium between the first and second main surfaces. The manufacturing method includes a main stage comprised of an additive manufacturing process implemented in a continuous pass from a support tray, each pass comprising depositing at least one layer of the metallic material, the deposited material adhering to a previously deposited layer of metallic material, controlling the deposition of metallic material at the level of each layer during each pass such that the metallic material deposited during the continuous pass stacks to form the functional component. The filter medium of the functional component comprises a coalesced network of interconnected structures according to a three-dimensional spatial distribution between the first and second main surfaces, the interconnected structures defining pores therebetween, these pores being spatially distributed within the filter medium in three dimensions between the first and second main surfaces.

[0022] The advantages of this manufacturing method are its simplicity and economy. Furthermore, it allows for the easy fabrication of components with simple or complex shapes, whether they consist of planar surfaces (discs, squares, rectangles, triangles, polygons) or complex surfaces (tubes, spheres, cylinders, pyramids, masks). Controlled porosity can be easily achieved, meaning the architecture, size, and distribution of the pores can be perfectly controlled, as can the architecture, length, and thickness of the metal coalescing network's interconnects. Filter media with thicknesses ranging from 400 μm to 500 μm can be readily obtained. Uniformly distributed pores within the filter media can be readily achieved, ensuring good efficiency and reliability. Unlike powder sintering solutions, very high filtration efficiency can be achieved while maintaining a relatively low pressure drop level. In addition to the above advantages, filter media manufactured in this manner are particularly advantageous due to their high durability throughout almost their entire lifespan and minimal environmental impact.

[0023] Some preferred but non-limiting aspects of this manufacturing method are as follows, and these features can be considered individually or in combination.

[0024] The filter media obtained during the main stage is contained in the main plane, which forms an angle of 30° to 90° with the support tray.

[0025] The thickness of the filter medium (considered to be the thickness between the first and second main surfaces) is 400 μm to 500 mm.

[0026] The functional components are made of metallic materials including at least one of the following materials in the form of pure metals, alloys or oxides: aluminum, stainless steel, nickel, cobalt, iron, copper, palladium, titanium, tungsten, silver, and platinum.

[0027] During each pass, the support tray is heated to a temperature between ambient temperature and 250°C, specifically equal to 200°C with a tolerance within 10%.

[0028] Each pass includes the step of depositing at least one powder layer formed of the said metallic material, followed by the step of selectively melting the previously deposited powder via localized energy input using a laser beam. The selective melting of the metallic material is controlled using a pre-established computer database, which is controlled by a computer program during each pass. This computer program controls the spatial displacement of the laser beam relative to the previously deposited metallic powder, at least one of which is selected from: the relative path between the laser beam and the previously deposited powder, the displacement velocity corresponding to the relative velocity between the laser beam and the previously deposited powder, the laser beam power, and the laser beam power density.

[0029] The thickness of each powder layer ranges from 20 μm to 100 μm.

[0030] In each selective melting step, the path followed by the laser beam includes a displacement vector, which is spatially offset in pairs according to an offset value, and wherein, for a given laser beam power and a given layer thickness, the porosity of the pores within the filter medium is adjusted by adapting the offset value, which increases as the offset value increases.

[0031] At the level of the filter medium, during the selective melting step, the laser beam power used each time is 30% to 90% of the laser beam power value that is capable of obtaining a non-porous block that does not form holes in the metal material.

[0032] In each selective melting step, for a given laser beam power and a given layer thickness, the porosity of the pores in the filter medium is adjusted by adapting the displacement velocity. Above a lower threshold of the displacement velocity, the porosity increases with increasing displacement velocity.

[0033] The laser beam power is 275W, the layer thickness is 50μm, and the lower threshold of the displacement velocity is 1500mm / s to 6000mm / s.

[0034] In each selective melting step, for a given laser beam power and a given layer thickness, the porosity of the pores in the filter medium is adjusted by adapting the laser beam power density. Below the upper threshold of the power density, the porosity increases as the laser beam power density decreases.

[0035] The laser beam power is 275W, the layer thickness is 50μm, and the upper threshold of power density is 7J / mm². 3 Up to 20J / mm 3 .

[0036] In each selective melting step, the porosity of the pores in the filter medium is adjusted by adapting both the laser beam power and the displacement velocity, while maintaining a constant ratio between the displacement velocity and the laser beam power within a tolerance of 20%. As both the laser beam power and the displacement velocity increase, the porosity increases.

[0037] Laser beam power density equals 13 J / mm 3 At the level where the filter media is manufactured, the ratio between the displacement velocity in mm / s and the laser beam power in W is 15 to 24 in each selective melting step.

[0038] The main stages are parameterized such that the functional components derived from the main stages include an enhanced profile arranged on all or part of the peripheral boundary of the filter medium.

[0039] In the plane of the first main surface and / or the second main surface, the reinforcing profile has an overlap with the filter medium, particularly an overlap of 1 mm in width with a tolerance of 10%.

[0040] At the level of the manufactured reinforced profile, the porosity is equal to 0.

[0041] Laser beam power density equals 13 J / mm 3 Furthermore, at the level of the fabricated enhanced profile, the ratio between the displacement velocity in mm / s and the laser beam power in W is 2.5 to 3.5 at each selective melting step.

[0042] The main stages are parameterized so that the functional components are connected to the support tray via a support made of the same metal material as the functional components and obtained by the same additive manufacturing method as the functional components.

[0043] The present invention also covers functional components obtained by implementing this manufacturing method.

[0044] Some preferred but non-limiting aspects of this functional component are as follows, and these features may be considered individually or in combination.

[0045] The network of connections and pores present in the filter medium ensures that, for fluids passing through the filter medium in the direction from the first main surface to the second main surface, or in the direction from the second main surface to the first main surface, the permeability is 11 l m when the pressure drop between the first and second main surfaces is 100 Pa. -2 .s -1 Up to 200l.m -2 .s -1 .

[0046] At the horizontal level of the filter medium, the porosity of the pores present in the filter medium is 10% to 70%.

[0047] The filter medium is intended for use as a filter mask with a thickness of 600 μm to 2 mm. The thickness of the filter mask is considered to be the thickness between the first and second main surfaces.

[0048] The filter media of the functional component has an overall disc shape in the form of a planar surface or a complex surface, and the diameter of the disc is 8 mm to 120 mm. Attached Figure Description

[0049] Other aspects, objects, advantages, and features of the invention will become more apparent after reading the following detailed description of preferred embodiments of the invention, given as non-limiting examples and made with reference to the accompanying drawings, in which:

[0050] Figure 1 It is a flowchart illustrating different stages and steps of an example of a manufacturing method according to the present invention.

[0051] Figure 2 The principle of the additive manufacturing method during step E2 is illustrated schematically.

[0052] Figure 3 An example of manufacturing multiple functional components on a support tray using manufacturing methods is presented.

[0053] Figure 4 It is a table showing the setup parameters during the first set of tests, denoted as Test 1.

[0054] Figure 5 It shows Figure 4 The example of functional component 10, number 17 in the table.

[0055] Figure 6 For Experiment 1, the porosity (%) on the vertical axis is shown to change according to the displacement velocity V (mm / s) on the horizontal axis.

[0056] Figure 7 For Experiment 1, the porosity (%) on the ordinate is presented based on the laser beam power density E (J / mm²). 3 ) changes.

[0057] Figure 8 It is a table showing the setup parameters during the second group of tests, denoted as Test 2.

[0058] Figure 9 It is a table showing the setup parameters during the third group of tests, denoted as Test 3.

[0059] Figure 10It is a table showing the setup parameters during the fourth group of tests, denoted as Test 4.

[0060] Figure 11 It is a table showing the setup parameters during the fifth group of tests, denoted as Test 5.

[0061] Figure 12 It is a table showing the setup parameters during the sixth group of tests, denoted as Test 6.

[0062] Figure 13 This indicates three configurations of the functional component 10 manufactured in Experiment 5, wherein the reinforcing profile has different widths from one configuration to another. Detailed Implementation

[0063] In the accompanying drawings and the following description, the same reference numerals denote the same or similar elements. Additionally, to enhance clarity, different elements are not drawn to scale. Furthermore, different embodiments and variations are not mutually exclusive; on the contrary, they can be combined together.

[0064] The present invention described below is intended to solve the problems listed above that relate to the mentioned prior art.

[0065] In particular, the ultimate goal is to manufacture a functional component 10 integrally formed of metal, which can be used as a filter and a mask, and, without excluding and for this purpose, aluminum can prove to be a very promising material as a manufacturing material, due to its lightweight nature.

[0066] In general, the object of the present invention relates firstly to a manufacturing method capable of obtaining a functional component 10 made of substantially metallic material, which allows all or part of the functional component to define a fluid-permeable filter medium 12 (which may be a gas and / or a liquid), thereby allowing for anisotropic or isotropic porosity, the filter medium 12 defining a first principal surface 14 and a second principal surface 16 such that the fluid preferably circulates through the filter medium 12 between the first principal surface 14 and the second principal surface 16.

[0067] The present invention also relates to a functional component 10 obtained by implementing this manufacturing method.

[0068] Advantageously, the manufacturing method includes a main stage P1, which is constituted by an additive manufacturing method implemented in a manner that continuously passes through a support tray 18 via a FS, each pass through the FS including the deposition of at least one layer of metal material, the deposited metal material adhering to the previously deposited at least one layer of metal material during the deposition of a given layer. The deposition of metal material at the level of each layer is controlled during each pass through the FS, such that the metal material deposited during continuous passes through the FS stacks to form the desired functional component 10, the filter medium 2 of which advantageously includes a coalesced network of interconnected structures according to a three-dimensional spatial distribution between the first main surface 14 and the second main surface 16 after the completion of the main stage P1, the interconnected structures of this network defining pores therebetween, these pores being spatially distributed within the filter medium 12 in three dimensions between the first main surface 14 and the second main surface 16.

[0069] Returning to the manufactured functional component 10, the network and pores of the connecting structure present in the filter medium 12 advantageously enable that, for fluid passing through the filter medium 12 in the direction from the first main surface 14 to the second main surface 16 or in the direction from the second main surface 16 to the first main surface 14, the permeability is 11 l m when the pressure drop between the first main surface 14 and the second main surface 16 is 100 Pa. -2 .s -1 and 200l.m -2 .s -1 Between. In particular, this pressure drop depends on the thickness of the filter medium 12 and on the porosity and pore size.

[0070] Therefore, according to a particularly advantageous embodiment, the thickness of the filter medium 12 intended to be used as a filter mask (considered to be the thickness between the first main surface 14 and the second main surface 16) is between 600 μm and 2 mm.

[0071] Therefore, one difficulty lies in finding the parameters of an additive manufacturing method suitable for obtaining a functional component 10 with such a small thickness (in order to limit the pressure drop) while maintaining manufacturability, durability and strength; this is an even more difficult challenge when the goal is to achieve the main surfaces 14, 16 between 8 mm and 120 mm.

[0072] According to an advantageous embodiment, each pass through FS includes step E1 of depositing at least one layer of metallic material powder 20, followed by step E2 of selectively melting the previously deposited powder via a localized energy input through the action of a laser beam 22. The selective melting of the metallic material is controlled using a pre-established computer database, which is controlled by a computer program during each pass. This computer program controls the spatial displacement of the laser beam 22 relative to the previously deposited metallic material powder 20, at least one of which is selected from:

[0073] - The relative path between the laser beam 22 and the previously deposited metallic powder 20,

[0074] - The displacement velocity "V" corresponding to the relative velocity between the laser beam 22 and the previously deposited metallic powder 20.

[0075] -Laser beam power "P"

[0076] - Laser beam power density "E".

[0077] The 3D printing technique known as "SLM" (which is an abbreviation for "Selective Laser Melting") is itself a known approach, involving the deposition of continuous layers followed by selective melting via a laser beam along a pre-established path controlled by a computer.

[0078] In SLM additive manufacturing, it is known to operate in a neutral gas environment (typically argon), particularly when a thin layer of metal powder is deposited on a metal substrate. A laser beam then delivers the required energy to the powder, selectively melting and adhering it to the underlying layer according to the geometry of the part. Repeating these actions enables the fabrication of metal parts with complex three-dimensional geometries. For this, a computer-aided control file for the part must be prepared by slicing it into pieces with desired thicknesses for the fabrication layers to form a set of two-dimensional planes. Additionally, holding supports must be created for the part, and a set of parameters must be assigned to define the path of the laser beam across the powder. All these operations allow for the acquisition of the transmitted file and the guidance of the manufacturing machine.

[0079] The unit is J / mm 3 The laser beam power density E is defined by the following mathematical expression:

[0080] [Expression 1]

[0081]

[0082] in:

[0083] P is the laser beam power, measured in watts (W).

[0084] V is the displacement velocity, with units of mm / s.

[0085] HD is the offset between two adjacent vectors from which the laser is applied, measured in mm.

[0086] e represents the layer thickness, in mm.

[0087] E is the laser beam power density.

[0088] Therefore, at each selective melting step E2, the path followed by the laser beam 22 includes a displacement vector, wherein the displacement vector is spatially offset in pairs according to the offset value HD that affects the manufactured functional component 10.

[0089] However, other methods for additive manufacturing of metallic materials can still be considered, such as the so-called "SLS" (which is an abbreviation for "selective laser sintering") technology, or by "binder jetting" or by "electron beam melting," etc.

[0090] The applicant is committed to developing such a functional component and has conducted a series of experiments, described in detail below, to determine the advantageous parameters preferred for the specific case of the SLM additive manufacturing method proposed above, which are particularly promising but not limiting.

[0091] It should be understood that many parameters can actually have a direct impact on the manufacturing quality of functional components, particularly the laser beam power P, displacement velocity V, offset value HD between two adjacent vectors applying the laser, layer thickness e, laser beam power density E, and also parameters known as “beam compensation” (which compensates for the molten pool width by offset relative to the actual contour of the component), parameters related to shielding strategies (with melting interruption locations and / or areas that may have different shielding strategies and / or rotation from one layer to another), parameters known as “limit rotation” and “limit window” (these parameters depend on the limit rotation from one layer to another according to the airflow direction), parameters known as “boundary” (which defines one or more contours between the edge of the component and the shielding portion), and “fill contour”, a parameter that allows defining at least one additional contour between the contour and the shielding portion with another setting.

[0092] The metallic material used to make the functional component 10 includes at least one of the following materials in the form of pure metal, alloy or oxide: aluminum, stainless steel, nickel, cobalt, iron, copper, palladium, titanium, tungsten, silver, platinum.

[0093] Therefore, as an example, SLM was used. All tests were conducted on the 316L stainless steel powder sold. However, the metallic material may specifically be composed of aluminum or aluminum alloys, which have the advantages of being lightweight and thermally stable at sterilization temperatures. Furthermore, materials can be selected from the list indicated in the preceding paragraph.

[0094] For all support trays 18 in different experiments, the stage P0 for preparing the metallic powder was the same. The new powder was sieved through a 200 μm sieve to deagglomerate it. Then, these powders were steam-treated at 63°C for at least 24 hours to achieve a relative humidity below 10%. After this, the powder was ready for feeding into the manufacturing machine. After each manufacturing process, the powder was recovered by sieving it through a 50 μm sieve and by steam-treating it at 63°C for more than 24 hours.

[0095] Several experiments have been conducted to manufacture a functional component 10 in the form of a disc, the central portion of which is a circular filter medium 12 with a diameter ranging from 30 mm to 96 mm. The 96 mm diameter corresponds to the circular filter medium 12 suitable for a mask with a filter cartridge developed in the context of a health crisis. Other experiments have been conducted to directly manufacture protective masks.

[0096] More generally and beyond the case of mere experimentation, the filter medium 12 may advantageously have a disc-shaped overall shape in the form of a planar surface or a complex surface, wherein the disc has a diameter between 8 mm and 120 mm.

[0097] In the case of a disc-shaped filter medium 12, it should be understood that the first main surface 14 and the second main surface 16 are formed by the circular surface of the disc.

[0098] Advantageously, for reasons of limiting pressure drop in relation to manufacturing, mechanical strength and filtration quality, the thickness of the filter medium 12 (considered to be the thickness between the first main surface 14 and the second main surface 16) is between 400 μm and 500 mm.

[0099] For all tests, it has been determined that the filter media 12 obtained during the main stage P1 is contained within a main plane that forms an angle between 30° and 90° with the support tray 18 and a tolerance within 5°. This feature has the advantage of limiting the dimensions of the heel (the part of the functional component 10 that contacts the support 24, described later), which advantageously means limiting the machining required to separate the manufactured functional component 10 from the support 24.

[0100] For these tests, it was also decided to work without any profile and without any scanning strategy, and to conduct these tests such that, each time the FS is passed, the support tray 18 is heated to a temperature between ambient temperature and 250°C, specifically equal to 200°C and within a tolerance of 10%.

[0101] According to one particular embodiment, the thickness of each powder layer is between 20 μm and 100 μm. Therefore, a layer thickness of 50 μm is preferred for all experiments, but some functional parts 10 have been fabricated using layer thicknesses of 30 μm or 100 μm.

[0102] According to a particular embodiment, the main stage P1 is parameterized such that the functional component 10 is connected to the support tray 18 via a support member 24, which is made of the same metal material as the functional component 10 and obtained by the same additive manufacturing method as the functional component 10. Thus, during manufacturing, the connection between the support tray 18 and each disc-shaped functional component 10 has been experimentally established in the form of the support member 24, the characteristics of which will be described in detail later. This support member 24 is also manufactured using the same additive manufacturing method, even though different manufacturing parameters can be provided between those parameters used to manufacture the support member 24 and those used to manufacture the functional component 10 (particularly those used for the filter media 12).

[0103] Experiment 1

[0104] This experiment involved manufacturing 60 disc-shaped functional components 10, each with a diameter of 30 mm and a thickness of 3 mm. The angle between each component and the support tray 18 was 90° with a tolerance within 5°. The thickness e of each deposited material layer was 50 μm.

[0105] Figure 4 This indicates the corresponding values ​​of P, V, HD, e, and E used for the 60 manufactured functional components 10.

[0106] For a speed of 300 mm / s and a scan value of 100 W, the "boundary" number is 2 and the "beam compensation" is 0.08 mm. For a speed of 400 mm / s and a scan value of 150 W, the "fill profile" value is 1, the initial angle is 10°, the angle step from one layer to another is 33°, "limit rotation" is activated and "limit window" is 90°. The laser beam is applied to each deposited metal material layer, and the scan parameter of the laser beam at the level of the support 24 is parameterized such that the displacement speed V is equal to 700 mm / s and the power is equal to 150 W.

[0107] Therefore, for a given laser power P, the effects of layer thickness e, HD, and the increase of V may have been studied.

[0108] Visually, there is a significant difference between the functional components 10 at the exit of the manufacturing machine: the functional components manufactured at very high speeds (above 7000 mm / s) are more brittle.

[0109] After the manufactured functional components 10 are removed from the support tray 18, these components (except for the most brittle ones) are sucked in, blown with compressed air, and held at 40°C under ultrasound for 15 minutes in an attempt to remove as much of the easily separable powder as possible that has not melted or has just burned off from the functional components 10. The filter media 12 is then cut, wrapped, and optically inspected. Figure 5 It shows Figure 4 An example of functional component 10, numbered 17 in the table. It can be noted that in the filter medium 12, the coalescing network of the connecting structure is interconnected according to a three-dimensional spatial distribution, and the connecting structure of the network defines pores distributed in the internal space of the filter medium 12.

[0110] Figure 6 The graph shows the change in porosity (%) on the ordinate according to the displacement velocity V (mm / s) on the abscissa. The top curve corresponds to the point established for an HD value of 0.12 mm, while the bottom curve corresponds to the point established for an HD value of 0.10 mm. Therefore, in each selective melting step E2, for a given laser beam power P and a given layer thickness e, the porosity of the pores within the filter medium 12 can be adjusted by adapting the displacement velocity V; above a lower threshold displacement velocity, the porosity increases as the displacement velocity V increases. Figure 6 The diagram shows a laser beam power P of 275 W, a layer thickness e of 50 μm, and a lower threshold displacement velocity between 1500 mm / s and 2000 mm / s. At the two points enclosed by the two lines, the displacement velocity V corresponds to 27 J / mm². 3 The laser beam power density E increases from these two points. More generally, the lower threshold of displacement velocity is between 1500 mm / s and 6000 mm / s.

[0111] Figure 7 The vertical axis represents porosity (%), while the horizontal axis represents laser beam power density E (J / mm²). 3 The curve at the top corresponds to the point established for an HD value of 0.12 mm, while the curve at the bottom corresponds to the point established for an HD value of 0.10 mm. Therefore, in each selective melting step E2, for a given laser beam power P and a given layer thickness e, the porosity of the pores within the filter medium 12 can be adjusted by adapting the laser beam power density E; below an upper threshold of power density, the porosity increases as the laser beam power density E decreases. Figure 7 The laser beam shown has a power of 275 W, a thickness e of 50 μm, and an upper threshold power density of 7 J / mm. 3 and 20J / mm 3 Between the two points encircling the two curves, the laser beam power density E corresponds to 27 J / mm².3 Furthermore, as the laser beam power density E decreases, the porosity increases from both points.

[0112] Finally, Experiment 1 has shown that, for the filter medium 12 forming a 90° angle with a tolerance within 5° relative to the support tray 18, preferably, the laser beam power P used during each pass at the level of the filter medium 12 in the selective melting step E2 is between 30% and 90% of the laser beam power value that would yield a poreless block made of the same metallic material. At the level of the filter medium 12, the porosity of the pores present in the filter medium 12 is between 10% and 70%.

[0113] Experiment 2

[0114] This experiment 2 involved manufacturing 37 disc-shaped functional components 10, each with a diameter of 30 mm and a thickness of 3 mm. The angle formed between the support tray 18 and each functional component was 90° with a tolerance within 5°. The thickness e of each deposited material layer was 30 μm.

[0115] Figure 8 This indicates the corresponding values ​​of P, V, HD, e, and E used for the 37 manufactured functional components 10.

[0116] For a speed of 550 mm / s and a scan value of 100 W, the "boundary" value is 1 and the "beam compensation" is 0.08 mm. For a speed of 500 mm / s and a scan value of 150 W, the "fill profile" value is 0, the initial angle is 10°, the angle step from one layer to another is 33°, "limit rotation" is activated and "limit window" is 90°, the laser beam is applied to every 2 deposited metal material layers (i.e., for each 60 μm deposition slice), and the scan parameter of the laser beam at the level of support 24 is parameterized with a displacement speed of 875 mm / s and a power P of 200 W.

[0117] On the same support tray 18, three functional components 10 are manufactured simultaneously using the same method and the same setup, each of which has the shape of a filter mask ready to be worn on the user's head.

[0118] Experiment 3

[0119] Test 3 involved conducting the same tests as Test 1, but with higher P values ​​set for HD values ​​of 100 μm and 120 μm, namely 300 W, 325 W, 350 W, and 375 W. The aim was to maintain the E value relative to Test 1 by correspondingly adapting the displacement velocity V, specifically by making it higher than 3500 mm / s.

[0120] Figure 9 This indicates the corresponding values ​​of P, V, HD, e, and E used for the manufactured functional component 10.

[0121] In the same experiment 3, disc-shaped functional components 10 were fabricated on the same support tray 18. These functional components were filter masks with a diameter of 60 mm, a thickness of 0.6 mm, and a thickness of 1 mm. The parameters were set as follows: for an HD value of 100 μm, P equals 275 W, and the displacement velocity V equals 3501 mm / s. A laser beam was applied to every two deposited metal material layers (i.e., every 100 μm deposition slice).

[0122] Therefore, after analyzing the functional component 10 manufactured in this manner, it has been determined that, in each selective melting step E2, the porosity of the pores within the filter medium 12 can be adjusted by adapting both the laser beam power P and the displacement velocity V, while maintaining a constant ratio between the displacement velocity V and the laser beam power P (within a tolerance of 20%). The porosity increases together with the increase of both the laser beam power P and the displacement velocity V. This appears to be truly independent of the HD value.

[0123] Additionally, for a value equal to 13 J / mm 3 At the manufacturing level of filter medium 12, the ratio between the displacement velocity V (in mm / s) and the laser beam power P (in W) in each selective melting step E2 is between 15 and 24.

[0124] It has also been noted that for the disc-shaped functional components 10 with a diameter of 60 mm, these functional components have fluctuations in height from their middle, which may be due to marking issues and / or problems held by the support 24 and / or residual stress.

[0125] Experiment 4

[0126] This experiment 4 aims to determine the values ​​of parameters P, V, and HD by a factor of three to obtain the desired filtration standards in terms of air and liquid permeability and efficiency at different particle sizes.

[0127] This experiment 4 includes the fabrication of disc-shaped functional components 10 with a diameter of 96 mm, wherein 8 macro-energy components are 0.6 mm thick and the remaining 20 functional components are 1 mm thick, forming a 90° angle between the support tray 18 and each functional component 10 with a tolerance within 5°. The thickness e of each deposited material layer is 50 μm.

[0128] For the functional component 10 manufactured in this manner, Figure 10 The corresponding values ​​of P, V, HD, e, and E used are presented.

[0129] Specifically, for 13 J / mm 3 At the manufacturing level of filter medium 12, the ratio between the displacement velocity V (in mm / s) and the laser beam power P (in W) in each selective melting step E2 is between 15 and 24.

[0130] It has been noted that if all functional components 10 were manufactured at least partially during test 4, all functional components were characterized by numerous deformations. Functional component 10 with a thickness of 0.6 mm could not be fully manufactured because its thickness was too thin compared to its diameter, and deformation and fluctuations began to appear from a few centimeters away from the support tray 18. Functional component 10 with a thickness of 1 mm exhibited the same problem, although it was less noticeable.

[0131] Experiment 5

[0132] This experiment 5 was conducted to address the deformation and fluctuation issues that had already emerged in experiment 4.

[0133] For this purpose, the functional component 10 to be manufactured has been modified to have an enhanced profile 26. More specifically, the main stage P1 has been parameterized such that the functional component 10 produced by the main stage P1 includes an enhanced profile 26 arranged on all or part of the outer boundary of the filter medium 12, that is, in the specific case of the disc-shaped filter medium 12, as in Experiment 4, arranged on the outer boundary of the disc.

[0134] In this experiment, reference Figure 13 Some functional components 10 have a disc-shaped filter medium 12 with a thickness of 0.6 mm, and the reinforcing profile 26 has a width of 8 mm in the plane of the first main surface 14 and / or the second main surface 16. Other functional components 10 have a disc-shaped filter medium 12 with a thickness of 1 mm, and the reinforcing profile 26 has a width of 5 mm in the plane of the first main surface 14 and / or the second main surface 16. Still other functional components 10 have a disc-shaped filter medium 12 with a thickness of 1.5 mm, and the reinforcing profile 26 has a width of 3 mm in the plane of the first main surface 14 and / or the second main surface 16.

[0135] The parameters used ensure that the porosity is zero at the level of the manufactured reinforced profile 26, for example, by providing a power P equal to 100 W and a velocity V equal to 300 mm / s. Therefore, the reinforced profile 26 is much denser than at the level of the filter medium 12. More generally, the laser beam power density E is equal to 13 J / mm². 3Furthermore, at the level of the manufactured enhanced profile 26, in each selective melting step E2, the ratio between the displacement velocity V (in mm / s) and the laser beam power P (in W) is between 2.5 and 3.5.

[0136] Figure 11 The corresponding values ​​of P, V, HD, e, and E at the level of the filter medium 12 are presented for the functional component 10 manufactured in this manner. Specifically, for a value equal to 13 J / mm... 3 The power density E, at the level of manufacturing filter media 12, in each selective melting step E2, the ratio between the displacement velocity V (in mm / s) and the laser beam power P (in W) is between 15 and 24.

[0137] The parameters used to manufacture support 24 are the same as those used in test 4.

[0138] It can be noted that in some areas there is separation in the form of no contact between the enhanced profile 26 and the filter medium 12.

[0139] Conversely, it can be noted that, due to the presence of the reinforced profile 26, the fluctuations are essentially not noticeable and / or occur at higher heights compared to the case in Experiment 4. Only the functional component 10 with a thickness of 1.5 mm exhibits the characteristic of almost no deformation, and this is independent of the parameters used.

[0140] Experiment 6

[0141] This experiment 6 repeats experiment 5, while retaining only the functional component 10 with a thickness of 1 mm and the functional component 10 manufactured with other parameter combinations.

[0142] Figure 12 This indicates the corresponding values ​​of P, HD, e, and E used at the level of the filter medium 12 for the manufactured functional component 10.

[0143] The parameters used to manufacture the support member 24 are different from those used in Test 5. In Test 5, each support member 24 included a set of connecting lines linking the supported functional component 10 and the support tray 18. In Test 6, each support member 24 was in the form of a block.

[0144] In addition, to address the separation issue between the reinforcing profile 26 and the filter medium 12 that occurred in Experiment 5, the reinforcing profile 26 has an overlap of 0.4 mm with the filter medium 12 in the plane of the first main surface 14 and / or the plane of the second main surface 16.

[0145] Because there is a 0.4 mm overlap between the reinforcing profile 26 and the filter medium 12, no separation occurs between the two parts. However, deformation still exists.

[0146] Furthermore, due to the change in the shape of the support 24, the fluctuation of the filter medium 12 has been significantly reduced and appears at a substantially higher height (considering the tray 18). Therefore, the functional component 10 still lacks stability during manufacturing, but it is much worse than in test 5.

[0147] Finally, the filter media 12 manufactured using a P value of 275W, an HD value of 0.2mm, and a velocity V of 3501mm / s has the best visual appearance, despite the filter media having a strong tendency to tear.

[0148] Experiment 7

[0149] In this experiment 7, different parameters for the support 24 were tested while maintaining a laser beam power of 275 W P, a displacement velocity of 2000 mm / s V, and an HD value of 0.12 μm. Additionally, different configurations of the support 24 were tested by switching between block and tree-like shapes. The tree-like support laterally supports the functional component 10 at a given height, thus supporting the functional component 10 rather than just at its lower part. For some block-like supports 24, reinforcement was achieved by increasing the thickness at their periphery to 0.7 mm, while the thickness at the center remained at 0.5 mm.

[0150] In addition, the reinforced profile 26 has an overlap with the filter medium 12 in the plane of the first main surface 14 and / or the plane of the second main surface 16, the overlap having a width of 2 mm, and thus being wider than the overlap present in test 6.

[0151] In this experiment 7, the effect of varying HD values ​​between 120 μm, 150 μm, 180 μm, and 200 μm was also investigated for a manufactured disc with a diameter of 96 mm and a filter medium 12 with a thickness of 1.5 mm.

[0152] Finally, a disc-shaped functional component 10 with a diameter of 50 mm has been manufactured, while the value of the rotation parameter is varied between 5° and 90°, with the "limiting window" being 90°.

[0153] Therefore, it has been noted that for a given laser beam power P and a given layer thickness e, the porosity of the pores in the filter medium 12 can be adjusted by adapting the offset value HD, and the porosity increases as the offset value HD increases.

[0154] Regarding the rotation parameters, when the "limit window" is 90°, the porosity is constant and remains between 35% and 36%. Except for rotation values ​​of 5° and 66°, at which rotation values ​​the porosity is higher, thus becoming between 39% and 40%.

[0155] Furthermore, it has been determined that the presence of the tree-shaped support 24 is redundant compared to the block-shaped support 24 that reinforces the periphery.

[0156] Finally, the presence of an overlap with a width of 1 mm and a tolerance within 10% is particularly advantageous for avoiding deformation.

[0157] Experiment 8

[0158] This test 8 is the same as test 7, except that the block-shaped support 24 with a thickness of 0.5 mm and reinforced at the periphery by increasing the thickness to 0.7 mm has been replaced by a block-shaped support 24 with a thickness of 0.4 mm and reinforced at the periphery by increasing the thickness to 0.6 mm.

[0159] It has been noted that the manufactured functional component 10 is characterized by deformation on its top, which was not the case in test 7. Therefore, the support 24 has been shown to have the mechanical strength to withstand the functional component 10 manufactured on its top.

Claims

1. A method for manufacturing a functional component capable of obtaining a functional component (10) made substantially of a metallic material, all or part of said functional component (10) defining a fluid-permeable filter medium (12) and defining a first main surface and a second main surface (14, 16) for preferred circulation of gas through said filter medium (12) located between the first main surface and the second main surface (14, 16), said manufacturing method comprising a main stage (P1) consisting of an additive manufacturing method implemented in a manner of continuous pass (FS) from a support tray (18), each pass (FS) comprising depositing at least one layer of said metallic material. The deposited material adheres to at least one layer of previously deposited metal material, and the deposition of metal material at the level of each layer is controlled during each pass (FS) such that the metal material deposited during the continuous pass (FS) stacks to form the functional component (10). The filter medium (12) of the functional component includes a coalescing network of interconnected structures according to a three-dimensional spatial distribution between the first main surface and the second main surface (14, 16), the interconnected structures of the network defining pores between them, which are spatially distributed in the filter medium (12) in three dimensions between the first main surface and the second main surface (14, 16). in, Each pass (FS) includes a step (E1) of depositing at least one powder layer (20) formed of the metal material, followed by a step (E2) of selectively melting the previously deposited powder by means of a local energy input via a laser beam (22), wherein the selective melting of the metal material is controlled using a pre-established computer database controlled by a computer program during each pass (FS), the computer program controlling the spatial displacement of the laser beam (22) relative to the previously deposited metal material powder, at least one of the parameters being selected from: the relative path between the laser beam (22) and the previously deposited powder, the displacement velocity (V) corresponding to the relative velocity between the laser beam (22) and the previously deposited powder, the laser beam power (P), and the laser beam power density (E); In each selective melting step (E2), the path followed by the laser beam (22) includes a displacement vector, wherein the displacement vector is spatially offset in pairs according to an offset value (HD), and wherein, for a given laser beam power (P) and a given layer thickness (e), the porosity of the pores within the filter medium (12) is adjusted by adapting the offset value (HD), which increases as the offset value (HD) increases; In each selective melting step (E2), for a given laser beam power (P) and a given layer thickness (e), the porosity of the pores in the filter medium (12) is adjusted by adapting the displacement velocity (V), and the porosity increases as the displacement velocity (V) increases above a lower threshold of the displacement velocity. In each selective melting step (E2), for a given laser beam power (P) and a given layer thickness (e), the porosity of the pores in the filter medium (12) is adjusted by adapting the laser beam power density (E), and the porosity increases as the laser beam power density (E) decreases below the upper threshold of the power density. Wherein, the laser beam power (P) is 275 W, the layer thickness (e) is 50 μm, and the upper threshold of the power density is 7 J / mm. 3 Up to 20 J / mm 3 .

2. The manufacturing method according to claim 1, wherein, The filter medium (12) obtained during the main stage (P1) is contained in a main plane that forms an angle of 30° to 90° with the support tray (18).

3. The manufacturing method according to any one of claims 1 and 2, wherein, The thickness of the filter medium (12) is 400 μm to 500 mm, and the thickness of the filter medium is considered to be the thickness between the first main surface and the second main surface (14, 16).

4. The manufacturing method according to any one of claims 1 to 2, wherein, The metallic material used to make the functional component (10) includes at least one of the following materials in the form of pure metal, alloy or oxide: aluminum, stainless steel, nickel, cobalt, iron, copper, palladium, titanium, tungsten, silver, platinum.

5. The manufacturing method according to any one of claims 1 to 2, wherein, During each pass (FS), the support tray (18) is heated to a temperature between ambient temperature and 250°C.

6. The manufacturing method according to claim 5, wherein, During each pass (FS), the support tray (18) is heated to 200°C with a tolerance of 10%.

7. The manufacturing method according to claim 1, wherein, The thickness (e) of each powder layer (20) is 20 μm to 100 μm.

8. The manufacturing method according to claim 1 or 7, wherein, At the level of the filter medium (12), during the selective melting step (E2), the laser beam power (P) used for each pass (FS) is 30% to 90% of the laser beam power value (P) that can obtain a non-porous block that does not form a hole in the metal material.

9. The manufacturing method according to claim 1, wherein, The laser beam power (P) is 275 W, the layer thickness (e) is 50 μm, and the lower threshold of the displacement velocity is 1500 mm / s to 6000 mm / s.

10. The manufacturing method according to claim 1, wherein, The main stage (P1) is parameterized such that the functional component (10) derived from the main stage (P1) includes an enhanced profile (26) arranged on all or part of the peripheral boundary of the filter medium (12).

11. The manufacturing method according to claim 10, wherein, In the plane of the first main surface (14) and / or the plane of the second main surface (16), the enhanced profile (26) has an overlap with the filter medium (12).

12. The manufacturing method according to claim 11, wherein, The overlapping portion is 1 mm wide and the tolerance is within 10%.

13. The manufacturing method according to any one of claims 10-12, wherein, At the level of the manufactured reinforced profile (26), the porosity is equal to 0.

14. The manufacturing method according to any one of claims 10-12, wherein, The laser beam power density (E) is equal to 13 J / mm². 3 And in which, at the level of the manufactured enhanced profile (26), the ratio between the displacement velocity (V) in mm / s and the laser beam power (P) in W is 2.5 to 3.5 in each selective melting step (E2).

15. The manufacturing method according to any one of claims 1 to 2, wherein, The main stage (P1) is parameterized such that the functional component (10) is connected to the support tray (18) via a support member (24) made of the same metal material as the functional component (10) and obtained by the same additive manufacturing method as the functional component (10).

16. A functional component (10) obtained by implementing the manufacturing method according to any one of claims 1 to 15.

17. The functional component (10) according to claim 16, wherein, The network of connections and the pores present in the filter medium (12) enable a permeability of 11 m for fluid passing through the filter medium (12) in the direction from the first main surface (14) toward the second main surface (16) or in the direction from the second main surface (16) toward the first main surface (14), provided that the pressure drop between the first and second main surfaces (14, 16) is 100 Pa. -2 .s -1 Up to 200 lm -2 .s -1 .

18. The functional component (10) according to any one of claims 16 and 17, wherein, At the level of the filter medium (12), the porosity of the pores present in the filter medium (12) is 10% to 70%.

19. The functional component (10) according to any one of claims 16 to 17, wherein, The filter medium (12) is intended to be used as a filter mask (12) with a thickness of 600 μm to 2 mm, the thickness of which is considered to be the thickness between the first main surface and the second main surface (14, 16).

20. The functional component (10) according to claim 19, wherein the filter medium (12) of the functional component has an overall disc-shaped form in the form of a planar surface or a complex surface, the diameter of the disc being 8 mm to 120 mm.

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