INLATED CLOCK COMPONENTS AND METHOD FOR THEIR MANUFACTURE

Abstract

The invention relates to an inlaid watch component (1) comprising a body (10) made of metallic and / or ceramic material having at least one recess (11) forming the impression of a decoration (12). According to the invention, said at least one recess is entirely filled by successive layers (13, 14, 15) formed by an agglomeration of particles (16) via cold metallization in order to form a watch component (1) inlaid with at least one decoration (12).

Description

Technical field of the invention

[0001] The invention relates to a watch component inlaid with at least one metallic and / or ceramic decoration and to its manufacturing method. Technological background

[0002] It is known to form watch components such as watch bezels at least partially in ceramic, metal or composite to show a deposit made in a hollow under the bezel forming for example a graduation or a commercial name. This configuration has the advantage of protecting the deposit from any mechanical degradation by completely covering the sapphire part. However, this configuration can make it difficult to read the decoration due to the altered transmission of the coloring of the deposit but also by the lack of difference in the shade of the sapphire compared to that of the deposit.

[0003] To overcome these drawbacks, an inlaid ceramic element has been proposed comprising a ceramic body comprising at least one recess forming the imprint of a decoration, said at least one recess being entirely filled with a first and a second electrically conductive layer of substantially 50 nm and a metallic galvanic deposit in order to form a ceramic element inlaid with at least one metallic decoration with improved visual quality.

[0004] However, the production of such a part remains complex, expensive, time-consuming and it is necessary to put in place a bonding layer (conductive layer) to create the decorations. In addition, it is complicated to perfectly fill the cavities forming a decoration or a graduation while obtaining an impeccable visual appearance. Summary of the invention

[0005] The invention aims in particular to overcome the various drawbacks of the prior art.

[0006] To this end, the invention relates to an inlaid watch component comprising a body made of metallic and / or ceramic material comprising at least one recess forming the imprint of a decoration. According to the invention, said at least one recess is entirely filled by successive layers formed by an agglomeration of particles via cold metallization in order to form a watch component inlaid with at least one decoration.

[0007] According to other advantageous variants of the invention: the particles forming the layers are metallic and / or at least partially ceramic and are chosen from: copper, zinc, tin, titanium, niobium, zirconium, tantalum, chromium, iron and its alloys, zirconia or alumina; each at least one recess has a depth of at least 100 µm, and preferably 200 µm; the at least one decoration is covered with a colored metallic layer by means of anodization; the watch component is a decorative element such as a bezel, a back, a dial, a case middle, a bracelet link, a crown, a pusher.

[0008] The invention also relates to a timepiece comprising at least one inlaid timepiece component in accordance with the invention.

[0009] The invention also relates to a method of manufacturing an inlaid watch component comprising the following steps: a) forming a body made of metallic and / or ceramic material; b) etching at least one recess in a face of the body, each at least one recess forming the imprint of a decoration; c) depositing a first layer of a coating with a thickness of at least 10 µm on the entire face comprising said at least one recess by cold spraying of a flow comprising a carrier gas and particles forming the coating; d) repeating step c) one or more times to deposit one or more additional layers of 20 µm each on the entire face comprising said at least one recess covering the first layer in order to completely fill said at least one recess and form an inlaid decoration; e) carrying out polishing to remove all deposits from the layers of the surface of the body in order to leave only in the at least one recess.

[0010] According to other advantageous variants of the method according to the invention: the flow of the carrier gas has a flow rate of between 85 and 90m3 / h, at a pressure of between 45 and 60 bar and at a temperature of between 800 and 1000°C; the particles are made of metal or metal alloy, ceramic or cermets; the mass flow rate of the particles is between 70 and 80g / min; the particle size is at most 45µm; the particle size is between 1 and 25µm; the method comprises an optional step between step b) and c) during which the recess is engraved or textured via a laser to improve the adhesion of the particles; the method comprises an optional step after step e) during which anodization of the decorations is carried out to color said decorations. Brief description of the figures

[0011] Other characteristics and advantages of the invention will appear on reading the following detailed description given by way of non-limiting example, with reference to the appended drawings in which: there figure 1 represents a sectional view of a watch component covered with several layers; the figure 2 represents a sectional view of a watch component according to the invention figure 3 represents a top view of a bezel for a timepiece obtained via a method according to the invention. Detailed description of the invention

[0012] In the example shown in figure 1, we can see a watch component 1. The inlaid watch component 1 comprises a body 10 made of metallic and / or ceramic material comprising at least one recess 11 forming the imprint of a decoration 12. The at least one recess 11 is entirely filled by successive layers 13, 14, 15 formed by an agglomeration of particles 16 via cold metallization, more commonly called “cold spray” in order to form a watch component 1 inlaid with at least one decoration 12.

[0013] The cold metallization technique or "cold spray" consists of accelerating a filler material (300 to 1500 m / s) in the form of powder or particles beyond a critical speed. These speeds cause plastic deformation and / or fragmentation upon impact of this material on a substrate to be treated, which is significant enough to form a dense and adherent coating. The temperatures of the projection gases are low (typically between 300 and 1100 °C) compared to the temperatures used in other processes. The material before impact is therefore not melted. Ceramic materials can also be projected.

[0014] In the remainder of the description, only the case of a bezel 1 will be described, but it goes without saying that the description is applicable to any other watch component, and more particularly the exterior parts of a timepiece such as a back, a dial, a case middle, a crown, an oscillating weight or even a pusher.

[0015] In the example illustrated below, the explanation of the invention will therefore be given based on a ring 10 made of ceramic material comprising inlaid metal decorations 12 forming the graduations of a bezel 4. Obviously a bezel made of metal or metal alloy, cermet or even composite material is also possible.

[0016] The inlaid bezel 1 is intended to form a very wear-resistant part comprising at least one metallic decoration presenting excellent visual quality and whose durability over time is improved.

[0017] As illustrated in the figure 2 , the inlaid watch component 1 comprises a ceramic body 10 comprising at least one recess 11 forming the imprint of a decoration 12. At the figure 3, it can be seen that each decoration 12 can be of any shape, such as, for example, a geometric figure or an alphanumeric character. According to the invention, each recess 11 is entirely filled by a plurality of layers 13, 14, 15 with a thickness of between 10 and 50 µm. This configuration makes it possible to protect each metal decoration 12 in the ceramic body 11 which is very resistant to wear.

[0018] Each recess 11 has a depth P of between 100 and 200 µm and their internal surface can have a varied geometric shape. For example, one can imagine a recess in the form of a star, a rectangle or a triangle, or even a letter.

[0019] The body 10 is obtained from a wide variety of materials, including ceramics. A zirconia-based ceramic is preferably used for its mechanical properties, its polishing capacity and, to a lesser extent, for its ability to offer a wide range of colors. It is of course obvious that other ceramics are possible, such as, for example, titanium carbide-based ceramics, or transparent polycrystalline ceramics based on alumina or spinel.

[0020] According to another embodiment, the body 10 is obtained from a metallic material or a metallic alloy.

[0021] The particles forming the layers are metallic and / or at least partially ceramic and are chosen from: copper, zinc, tin, titanium, niobium, zirconium, tantalum, chromium, iron, zirconia or alumina. According to a variant of the invention, layers made of different materials are used, for example a first part of the layers can be made of zinc then the second part of titanium. Such an alternative makes it possible to reduce manufacturing costs.

[0022] The first layer 13 has a thickness of substantially 20 µm and is located in the bottom of the recess 11. Similarly, the second layer 15 and the following layers have an increasing or identical thickness according to the needs of the person skilled in the art. The first layer may for example have a thickness of 20 µm, the second layer 30 µm, the third 30 µm, the fourth 40 µm, the fifth 50 µm ... The succession of layers continues until the recess is completely filled.

[0023] Furthermore, according to the invention, the visual rendering of each decoration 12 can be modified locally by coloring the last layer, namely the layer flush with the surface of the watch component, via anodization 16 for example, when the body 10 is made of ceramic.

[0024] In this respect, to facilitate anodization, at least the last of the metal layers is preferably made of aluminum or titanium.

[0025] In the case of a metallic body 10, the filling part will not pose a problem, but coloring via a local coloring anodic oxidation will not be feasible, the body 10 and the last layer being both conductive. It is then possible to deposit the last layer with a slight withdrawal from the surface of the body 10, then to carry out a coloring anodic oxidation on the entire part and finally to remove the surplus on the surface of the body via a polishing operation for example. (another option: put in place a mask via a LIGA process).

[0026] The invention also relates to a method of manufacturing an inlaid watch component.

[0027] The method of manufacturing an inlaid watch component 10 will now be explained. In the remainder of the description, only the case of the manufacture of a bezel 1 will be described, but it goes without saying that the description is applicable to any other watch component as detailed previously. The explanation of the method according to the invention will therefore be given based on a ring 10 made of ceramic material comprising inlaid metal decorations 12 forming the graduations of a bezel 1.

[0028] In a first step a), the method consists of forming the body 10 from ceramic, for example, from zirconia. In the case of a ceramic-based component, the latter is preferably obtained by sintering. At the end of step a), the body 10 has its final dimensions.

[0029] The method comprises a second step b) intended to engrave at least one recess 11 which may be blind in a face F of the body 10, the recesses 11 forming the imprint of the future decorations 12 as visible in the figure 1 . Each recess 11 has a minimum depth P of 100 µm, and preferably a depth of 200 µm. Each recess 11 may have a varied geometric shape depending on the needs of the person skilled in the art. For example, it is possible to imagine a recess in the form of a star, a rectangle or a triangle, or even an alphanumeric character.

[0030] Step b) is generally obtained by means of laser ablation allowing good precision of the engravings. According to an optional step, at the end of step b) the at least one recess is engraved or textured via a laser to improve the adhesion of the particles in the rest of the process.

[0031] The method continues according to a third step c) intended to deposit a first layer 13 with a thickness equal to 20 µm over the entire face F, that is to say including in each of the recesses 11 as visible in the figure 1 .

[0032] The third step c) of the process consists of coating the face F by cold metallization more commonly called “cold spray”. It is thus possible to deposit a layer of particles which adheres perfectly to the body 10 without the presence of an adhesion layer.

[0033] The projected particles are made of metal or metal alloy, ceramic or even cermets.

[0034] To form the deposit on the substrate 10, the particles are projected by means of a carrier gas through a de Laval type spray nozzle to accelerate them and project them at high speed to make them adhere to the substrate.

[0035] In the illustrated example, titanium particles of a size between 1 and 50 µm are projected, and preferably a particle size in the range of 5 to 25 µm, and even more preferably a size of 20 µm.

[0036] The main gas is sent through the nozzle at a flow rate of between 80 and 90m 3 / hour, the flow rate being able to vary depending on the nozzle and the gas used. Generally helium and nitrogen are used alone or in combination. Helium has the advantage of allowing work at lower temperatures than nitrogen, and nitrogen has the advantage of being cheaper.

[0037] The carrier gas temperature is in the range of 900°C to 1000°C, and the spray pressure is in the range of 45 to 60 bar.

[0038] In the case of titanium particles, a temperature of 1000°C and a pressure of 50 bar allow very good results to be obtained.

[0039] The particles are fed into the nozzle at a flow rate of 70 to 80g / min, preferably 75g / h. The particle speed is thus between 800 and 1000m / s.

[0040] The spray nozzle is kept at a distance of around 50mm from the surface F of the telescope 1 and progresses at a speed of 0.15m / sec during the deposit of each layer.

[0041] In the case of a ceramic substrate, the skilled person will take care to adapt the process parameters when depositing the first layer. The ceramic material is relatively fragile and the particles must be projected at a lower speed to avoid cracking and / or breaking the substrate. Thus, during the deposition of the first layer, the particles are sent into the nozzle at a flow rate of 20g / min, the pressure, flow rate and temperature of the carrier gas remaining the same.

[0042] The method continues with a fourth step d) during which step c) is repeated one or more times to deposit one or more additional layers 14, 15 of at least 20 µm each on the entire face F comprising the at least one recess 11 covering the first layer 13. Step c) is repeated until the at least one recess 11 is completely filled and a decoration 12 is formed in the bezel 1.

[0043] Finally, in a fifth step e), the method ends by removing the layers 13, 14 and 15 deposited on the surface F of the body 10 in order to leave only at the level of each recess 11 as visible at the figure 2 . The inlaid watch component 10 is thus finished and only has, possibly, to be mounted on a final part. This step can be obtained by a usual surfacing method such as grinding or lapping to remove the excess material followed by polishing.

[0044] The method according to the invention may also provide a final optional step intended to deposit a metallization in order to color the decorations 12. Such a layer may, for example, be produced via anodization.

[0045] Of course, the present invention is not limited to the illustrated example and is susceptible to various variants and modifications which will appear to those skilled in the art, without departing from the scope of the invention as defined by the claims.

Claims

1. Inlaid watch component (1) comprising a body (10) made of metallic and / or ceramic material comprising at least one recess (11) forming the imprint of a decoration (12) characterized in that said at least one recess is entirely filled by successive layers (13, 14, 15) formed by an agglomeration of particles (16) via cold metallization in order to form a watch component (1) encrusted with at least one decoration (12).

2. Inlaid watch component (1) according to claim 1, in which the particles (16) forming the layers are metallic and / or at least partially ceramic and are chosen from: copper, zinc, tin, titanium, niobium, zirconium, tantalum, chromium, iron, zirconia or alumina.

3. Inlaid watch component (1) according to one of claims 1 to 3, in which each at least one recess (11) has a depth of 200 µm.

4. Inlaid watch component (1) according to one of claims 1 to 4, characterized in that the at least one decoration (12) is covered with a colored metallic layer (18) by means of anodization.

5. Inlaid watch component (1) according to one of claims 1 to 6, characterized in that the watch component is a decorative element such as a bezel, a back, a dial, a case middle, a bracelet link, a crown, a pusher.

6. Timepiece (1) characterized in that it comprises at least one inlaid watch component (10) in accordance with one of the preceding claims.

7. Method for manufacturing an inlaid watch component (10) comprising the following steps: a) forming a body (10) made of metallic and / or ceramic material; b) engraving at least one recess (11) in a face (F) of the body (10) in, each at least one recess forming the imprint of a decoration (12); c) depositing a first layer (13) of a coating with a thickness of at least 10 µm on the entire face (F) comprising said at least one recess by cold spraying process, called "cold spray", of a flow comprising a carrier gas and particles (16) forming said coating; d) repeating step c) one or more times (14) to deposit one or more additional layers of 20µm each on the entire face (F) comprising said at least one recess covering the first layer (14) in order to completely fill said at least one recess and form an inlaid decoration (12);e) performing a polishing to remove all deposits from the strata of the surface of the body (10) so as to leave only in the at least one recess.; 8. Method according to claim 8, characterized in that the flow of the carrier gas has a flow rate between 85 and 90m 3 / h, at a pressure of between 45 and 60 bar and at a temperature between 900 and 1000°C.

9. Method according to claim 8 or 9, characterized in that the particles are made of metal or metal alloy, ceramic or cermets.

10. Method according to one of claims 8 to 10, characterized in that the mass flow rate of particles is 70 to 80g / min.

11. Method according to one of claims 8 to 11, characterized in that the particle size is a maximum of 45µm.

12. Method according to one of claims 8 to 12, characterized in that the particle size is preferably between 1 and 25µm.

13. Method according to one of claims 8 to 13, characterized in that it includes an optional step between step b) and c) during which the recess is etched or textured via a laser to improve particle adhesion.

14. Method according to one of claims 8 to 14, characterized in that it includes an optional step after step f) during which anodization of the decorations is carried out to color said decorations.