Ceramic component with decoration and method for manufacturing the same

Abstract

The invention relates to a decorated article comprising a substrate (1) with a surface (1a) defining a first portion with a relief (2) in positive and / or negative relief relative to the plane of the surface (1a) and a second portion extending in the plane of the surface (1a), the first or second portion forming a decoration (4), the decorated article being characterized in that the first portion is formed from the substrate (1) made of an amorphous zirconium-based metal alloy and in that the second portion is formed from a ceramic layer (3) disposed on the substrate (1), or conversely, in that the first portion is formed from said ceramic layer (3) disposed on the substrate (1) and in that the second portion is formed from said substrate (1) made of the amorphous zirconium-based metal alloy. The invention also relates to the method of manufacturing the decorated article.

Description

Technical field of the invention

[0001] The present invention relates to an article, in particular a decorated, two-material watch component, having an amorphous metal alloy substrate with a ceramic layer covering part of its surface. It also relates to the manufacturing process of the article. Technological background

[0002] In earlier art, there are decorated watch components that incorporate amorphous metal and ceramic as their constituent materials. These components are currently made with a ceramic substrate into which an amorphous metal decoration is inlaid. One technique involves engraving the ceramic watch component and then inlaying the amorphous metal.

[0003] Using a ceramic substrate for these watch components presents several disadvantages. First, obtaining the ceramic substrate is a lengthy and expensive process. Second, ceramic is a brittle material that does not withstand bending well. This results in breakage problems during the manufacturing process or when mounting the component onto the case.

[0004] Another technique involves creating positive indices in amorphous metal on ceramic substrates. This requires a galvanic copper growth process, which acts as a matrix during inlay and is subsequently dissolved with acid. This process is very complex and expensive, and therefore reserved for very small production runs. Furthermore, the fragility of the ceramic substrate remains a problem. Summary of the invention

[0005] The invention aims to overcome the aforementioned disadvantages by proposing a decorated, two-material component with an inversion in the arrangement of materials in order to avoid the disadvantages associated with handling fragile ceramics and to facilitate the process.

[0006] To this end, it is proposed to start from an amorphous metallic alloy substrate with a part of the substrate surface comprising a ceramic layer, with either the amorphous metallic alloy or the ceramic forming the decoration.

[0007] More specifically, the invention relates to a decorated article comprising a substrate with a surface defining a first part with a relief in positive and / or negative with respect to the plane of the surface and a second part extending in the plane of the surface, the first or second part forming a decoration, the decorated article being characterized in that the first part is formed of the substrate made in an amorphous zirconium-based metal alloy and in that the second part is formed of a ceramic layer disposed on the substrate or conversely is characterized in that the first part is formed of said ceramic layer disposed on the substrate and in that the second part is formed of said substrate made in the amorphous zirconium-based metal alloy.

[0008] Compared to a one-piece ceramic watch, it's possible to achieve the same aesthetic appeal and surface hardness while eliminating the material's brittleness. For example, with a ceramic case, a lug can easily break in a fall, causing the bracelet to come loose. With an amorphous metal case coated in ceramic, the lugs won't break in a fall.

[0009] The use of amorphous metal as a substrate offers numerous other advantages. Amorphous metal allows for a much more homogeneous current during ceramic plating compared to conventional ceramics or metals, due to the absence of defects in the material. In the case of electrolytic deposition, the quality of the resulting layer will be far superior to that of deposits on conventional metals. It would thus be possible to grow denser layers thicker than with current processes, namely several tenths of a millimeter. Another advantage stems from the fact that the substrate can be produced at a lower cost. Indeed, machining amorphous metals such as zirconium is much simpler and faster than machining ceramics or crystalline zirconium. Furthermore, these materials can be injection-molded or stamped in large quantities to further reduce manufacturing costs.Compared to crystalline zirconium, amorphous zirconium is less expensive because the substrate with the relief can be produced by direct injection or by injection followed by hot pressing, which is impossible with metallic zirconium, which would require 100% machining. Machining zirconium is very costly due to the material's high flammability and the need for expensive tooling.

[0010] Furthermore, the coefficients of thermal expansion of amorphous zirconium and ceramics are very similar, allowing for the growth of thick layers without the risk of shear delamination. Ceramics, particularly ZrO₂, exhibit excellent adhesion to amorphous zirconium-based metal alloys, resulting in good wear resistance. Moreover, corrosion related to potential redox potentials is also very low in the case of the amorphous zirconium-ZrO₂ pair.

[0011] The present invention also relates to the manufacturing process of the article. More specifically, it relates to a manufacturing process for a decorated article comprising the steps of: provision of an amorphous zirconium-based metallic alloy substrate, said substrate comprising a surface defining a first part with a positive and / or negative relief relative to the surface plane and a second part extending in the surface plane, the first or second part being intended to form a decoration, deposition of a ceramic layer on at least a portion of the first and second parts or conversion of the substrate into a ceramic layer on at least a portion of the first and second parts, removal of the excess ceramic layer on said portion to obtain the first part formed of the substrate and the second part formed of a ceramic layer disposed on the substrate or conversely to obtain the first part formed of said ceramic layer disposed on the substrate and the second part formed of said substrate,with the first or second part forming the scenery.

[0012] The range of components to be manufactured is very diverse, and the process according to the invention makes it possible to create complex geometries that would not have been conceivable with ceramic as a substrate. These can include casing components as well as functional movement components requiring the mechanical strength of amorphous metal and the hardness of ceramic.

[0013] Other features and advantages of the invention will become apparent from the detailed description that follows, with reference to the attached drawings. Brief description of the figures

[0014] There figure 1 (a)(b)(c) This schematically represents the successive stages of the manufacturing process for an item with a decoration made of amorphous metal alloy flush with the surface, the amorphous metal alloy decoration being framed by a layer of ceramic. figure 2 (a)(b)(c)This schematically represents the successive stages of the manufacturing process for an item with a ceramic decoration flush with the surface, the ceramic decoration being framed by a layer of amorphous metallic alloy. figure 3 (a)(b)(c) represents a variant of the process of the figure 1 with a positive setting. The figure 4 (a)(b)(c) represents a variant of the process of the figure 2 with a negative background. Detailed description of the invention

[0015] The present invention relates to a method for manufacturing a decorated article and to the decorated article itself. The article is formed from a zirconium-based amorphous metal alloy substrate with a decoration that is either ceramic or made of the same amorphous metal alloy as the substrate. The article may, in particular, be a watch case component such as a case middle, case back, bezel, pusher, bracelet link, flange, dial, hand, dial marker, oscillating weight, etc., or a movement component such as a mainplate, bridge, or balance wheel. The invention will be illustrated below for a bezel. The zirconium-based amorphous metal alloy may be any alloy such as LM1b, LM1b-X-, and Vit106a. The ceramic may be an oxide, a nitride, or a carbide. Preferably, it is zirconium oxide (ZrO2).

[0016] The process allows for the creation of 4-layer surface decorations as illustrated in the diagram. Figures 1 And 2 , in a positive way as illustrated in the figure 3 or in negative as illustrated in the figure 4 It is also possible to create positive and negative decorations on the article. Decoration 4 can be made of a single block of amorphous metal alloy 1 with the substrate as shown in Figures 1 And 3 or in ceramic 3 as shown in figure 2 And 4 The surface 1a of the substrate 1 is provided with at least one decoration 4, said decoration being made of amorphous metal alloy 1 or ceramic 3. In the case of a decoration 4 made of amorphous metal alloy 1, it is surrounded by the ceramic layer 3. It should be noted that the sides of the decoration 4 may be made of ceramic 3, as shown in the example of the figure 3 . In the case of a ceramic decoration 4 3, it is surrounded by the substrate 1 made of amorphous metallic alloy.

[0017] According to the invention, ceramicization is achieved by depositing a ceramic layer (oxides, carbides, or nitrides) or by converting the amorphous zirconium-based metal alloy into a zirconium oxide layer. The conversion is carried out using Micro-Arc Oxidation (MAO) or Electrolytic Plasma Oxidation (PEO) techniques. For these techniques, the oxide layer thickness is typically on the order of 15–20 µm. The ceramic layer can be depositioned by electron beam evaporation ( electron-beam evaporation (in English) and by atomic layer deposition (ALD) with a layer thickness of approximately 10-15 nm or by plasma projection with a thicker layer of approximately 0.10 to 0.20 mm.

[0018] The process for producing the item with decoration 4 is as follows. In a first step (a) visible in Figures 1(a) , 2(a) , 3(a) , 4(a)The substrate 1, made from an amorphous zirconium-based metal alloy, is provided. Preferably, the substrate is produced by injection molding, with or without decorative reliefs. The injection molding process allows for controlled rapid cooling, which ensures the absence of crystallites in the material. If the reliefs are not created during injection molding, they can be formed by hot pressing the substrate onto a die of the desired shape or by conventional milling or grinding.

[0019] In the illustrated examples, the substrate is a rough outline of a spectacle with indexes to be decorated. This substrate 1 has a relief 2 on its surface 1a. In the variants of Figures 1 , 2 And 4 Relief 2 is formed by depressions in the substrate. In other words, relief 2 is negative relative to the plane of surface 1a of the substrate. In the variant of the figure 3Relief 2 forms a structure that overhangs the plane of surface 1a of the substrate. In other words, relief 2 is positive relative to the plane of surface 1a of the substrate.

[0020] In a second step (b), a ceramic layer 3 is deposited or formed by conversion over all or part of the surface 1a, and optionally over the sides of the substrate. During the ceramicization process, it is possible to mask certain areas of the surface so that only the desired areas are ceramicized. Depending on the thickness of the deposited or converted layer, all or part of the cavities can be filled, and if there is a structure overhanging the surface plane, this structure is also covered.

[0021] In a third step (c), the excess ceramic 3 is removed, for example by machining, to reveal the substrate 1 on the surface 1a at the level of the decorations 4 or next to the decorations 4, respectively for a decoration 4 made of an amorphous metal alloy or a ceramic decoration. Optionally, an excess of amorphous metal alloy may also be removed.

[0022] This gives us the article, in particular the bezel 5, with the indices forming the decoration 4 either in ceramic 3 or in amorphous metallic alloy 1.

Claims

1. A decorated article comprising a substrate (1) with a surface (1a) defining a first part with a relief (2) in positive and / or negative relief relative to the plane of the surface (1a) and a second part extending in the plane of the surface (1a), the first part or the second part forming a decoration (4), the decorated article being characterized in that the first part is formed of the substrate (1) made of an amorphous metallic alloy based on zirconium and in that the second part is formed of a ceramic layer (3) placed on the substrate (1) or vice versa in that the first part is formed of said ceramic layer (3) disposed on the substrate (1) and in that the second part is formed of said substrate (1) made in the amorphous zirconium-based metallic alloy.

2. Article decorated according to claim 1, characterized in that the ceramic layer (3) is a zirconium oxide layer.

3. Article decorated according to one of the preceding claims, characterized in that the decoration (4) is flush in the surface plane (1a), is in positive with respect to the surface plane (1a), or is in negative with respect to the surface plane (1a).

4. Article decorated according to one of the preceding claims, characterized in that It is a watch component.

5. Article according to the preceding claim, characterized in that This is a bezel (5) or a dial.

6. A method for manufacturing a decorated article comprising the steps of: - providing a substrate (1) of amorphous zirconium-based metal alloy, said substrate (1) comprising a surface (1a) defining a first part with a relief (2) in positive and / or negative relief relative to the plane of the surface (1a) and a second part extending in the plane of the surface (1a), the first part or the second part being intended to form a decoration (4), - depositing a ceramic layer (3) on at least a portion of the first part and the second part or converting the substrate (1) into a ceramic layer (3) on at least a portion of the first part and the second part,- removal of the excess ceramic layer (3) on said portion to obtain the first part formed of the substrate (1) and the second part formed of the ceramic layer (3) placed on the substrate (1), or conversely to obtain the first part formed of said ceramic layer (3) placed on the substrate (1) and the second part formed of said substrate (1), with the first part or the second part forming the decoration (4).

7. Method according to the preceding claim, characterized in that the ceramic layer (3) is a zirconium oxide layer.

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