Orange zirconia-based clock component and method for manufacturing an orange clock component

Abstract

The invention relates to an orange ceramic timepiece component comprising 87 to 98.8% by weight of zirconium oxide, 1 to 6% by weight of yttrium oxide, 0.1 to 5% by weight of aluminium oxide, 0.05 to 1% by weight of cerium oxide and 0.05 to 1% by weight of magnesium oxide.

Description

Technical Field

[0001] This invention relates to a method for manufacturing orange zirconia-based components by sintering.

[0002] The present invention also relates to orange zirconia-based components specifically produced according to the above method. Background Technology

[0003] Colorants or pigments, such as cadmium sulfide (CdS), cadmium selenide (CdSe), and cadmium sulfide selenide, have been commonly added to ceramic materials to produce orange / red ceramic parts, such as those used in the manufacture of household enamels, glazes, containers, or floor coverings.

[0004] There are some drawbacks to the use of such colorants when they are added to industrial ceramics, especially those based on sintered zirconia.

[0005] In fact, these colorants lack stability at high temperatures and only exhibit their coloring properties at temperatures as high as 1000 or 1200°C. This greatly limits the use of such colorants, especially making them unsuitable for the production of sintered zirconia-based products, since the sintering temperature of zirconia is always above 1100°C.

[0006] Furthermore, even if it is not prohibited by law, it is strongly discouraged to use such colorants containing heavy metals in items intended to come into contact with the user's skin, such as watch cases.

[0007] Furthermore, the particle size of commercially available colorants of this type is incompatible with the homogeneous mixture used in the production of zirconium oxide powder. Summary of the Invention

[0008] The present invention aims to overcome the above-mentioned shortcomings by proposing a method for manufacturing orange components based on sintered zirconia, and on the other hand, particularly using such components produced by this method, which have satisfactory mechanical properties while exhibiting an orange color in both the core and the surface.

[0009] Therefore, the present invention relates to an orange ceramic watch component comprising 87% to 98.8% zirconium oxide, 1% to 6% yttrium oxide, 0.1% to 5% aluminum oxide, 0.05% to 1% cerium oxide and 0.05% to 1% magnesium oxide.

[0010] The present invention also relates to a method for manufacturing orange ceramic components.

[0011] More specifically, according to a first embodiment, the method for manufacturing an orange zirconia-based watch component according to the present invention includes the following steps: - Prepare a first mixture comprising zirconium oxide powder, 1 wt% to 6 wt% yttrium oxide, 0.1 wt% to 5 wt% aluminum oxide, 0.05 wt% to 1 wt% cerium oxide and 0.05 wt% to 1 wt% magnesium oxide; - Prepare a second mixture comprising the first mixture and at least one adhesive; - To prepare the second mixture as a powder mixture or a granular mixture; - Green blanks are formed from the powder mixture or granular mixture; - Debinding the green body to produce a brown body; - The brown blank is sintered in a neutral gas atmosphere to form an orange semi-finished product; - The resulting semi-finished product is machined to produce orange ceramic clock components.

[0012] According to a second embodiment, the method for manufacturing an orange zirconium oxide-based watch component according to the present invention includes the following steps: - Prepare a mixture comprising zirconium oxide powder, 1 wt% to 6 wt% yttrium oxide, 0.1 wt% to 5 wt% aluminum oxide, 0.05 wt% to 1 wt% cerium oxide and 0.05 wt% to 1 wt% magnesium oxide; - Prepare the mold; - Pour the powder mixture into the mold; - Under a neutral gas atmosphere, at 5 N / mm 2 Up to 250 N / mm 2 Rapid sintering or SPS sintering is carried out under sintering pressure, with a complete cycle time of 10 to 180 minutes, to form orange ceramic components; - Demold the resulting orange component; - Finish the orange ceramic components; - The resulting semi-finished product is machined to produce orange ceramic clock components.

[0013] The present invention also relates to an orange ceramic clock assembly produced by the manufacturing method described above.

[0014] Other advantageous variations according to the invention: - The sintering step according to the first embodiment is carried out at a temperature of 1250°C to 1650°C for 30 minutes to 4 hours; - The sintering step according to the second embodiment is carried out at a temperature of 600°C to 1,650°C for 10 minutes to 180 minutes. - The neutral gas is selected from argon, nitrogen or helium, or a mixture of at least two of these neutral gases; - The debonding step can be thermal debonding or solvent debonding; - The thermal debonding step is carried out in air.

[0015] The present invention also relates to orange ceramic components.

[0016] This type of watch component is used as an external part or as a watch component in the movement, and it is selected from the following list: middle, case back, bezel, bezel insert, pushers, crown, bracelet links, clasp, dial, hands, dial hour markers, oscillating mass, and mainplate.

[0017] Other features and advantages of the invention will become apparent from the following description of preferred embodiments, which are given by way of non-limiting example.

[0018] Detailed description This invention relates to ceramic watch components, such as external parts for watches or jewelry, or watch components whose entirety (or core) and surface are orange.

[0019] By incorporating cerium oxide (CeO2) powder into the sintering mixture, the method of the present invention can lower the sintering temperature and improve mechanical properties (impact resistance). Cerium oxide is also one of the elements that determines the desired orange color of the component.

[0020] According to the present invention, the first mixture comprises 0.05% to 1% by weight of cerium oxide powder (Ce+4O2).

[0021] The present invention also relates to an orange zirconia-based watch component, which is produced in particular by the method of the present invention. The component is made of a part formed by sintering a molded part comprising a zirconia matrix, 1 wt% to 6 wt% yttrium oxide, 0.1 wt% to 5 wt% aluminum oxide, 0.05 wt% to 1 wt% cerium oxide and 0.05 wt% to 1 wt% magnesium oxide.

[0022] The advantage of these components is their high gloss after polishing, making them particularly suitable for manufacturing watch components such as the center, bezel, crown, pushers, balance wheel, lever, mainplate, and bracelet links.

[0023] Other features and advantages of the present invention will become apparent from the following description of exemplary embodiments of the method of the present invention.

[0024] The manufacturing method of the present invention, which will now be described in detail, is capable of producing bright orange components based on sintered zirconium oxide, whose appearance and mechanical properties are particularly suitable for use as components in the production of wristwatches or for the production of any other decorative parts.

[0025] The bright orange zirconia components produced by this method contain 87% to 98.8% by weight of stabilized zirconia, with the remainder being: 1.2% to 13% by weight of a glass phase (made from alumina and yttrium oxide alone or in combination), 0.05% to 1% by weight of cerium oxide, and 0.05% to 1% by weight of magnesium oxide.

[0026] Traditionally, zirconium oxide is stabilized in a tetragonal phase using at least one stabilizer selected from oxides containing yttrium oxide, magnesium oxide, and calcium oxide, used alone or in combination.

[0027] Magnesium oxide increases the transparency of the components produced, resulting in a brighter, more vibrant orange color.

[0028] To produce this component, the method according to the first embodiment of the present invention includes the following steps: a) Prepare a first mixture comprising zirconium oxide powder, 1 wt% to 6 wt% yttrium oxide, 0.1 wt% to 5 wt% aluminum oxide, 0.05 wt% to 1 wt% cerium oxide and 0.05 wt% to 1 wt% magnesium oxide; b) Prepare a second mixture comprising the first mixture and at least one adhesive; c) Prepare a powder mixture or particulate mixture of the second mixture; d) Forming a green body from the powder mixture or granular mixture; e) Debonding the green blank to produce a palm blank; f) Sinter the brown blank in a neutral gas atmosphere at a temperature of 1250°C to 1650°C for 30 minutes to 4 hours to form an orange semi-finished product; g) The resulting semi-finished product is machined to produce orange ceramic components of the required size.

[0029] It should be noted that the purity of all these powders should preferably be greater than 95%.

[0030] After the powder is weighed, it is mixed and homogenized in a humid environment, for example, using a slip agent. In the final homogenization stage, a binder is added.

[0031] The mixture is then dried, for example, in a conventional atomizer.

[0032] The resulting powder is sieved to retain particles smaller than 200 µm. Those skilled in the art can also prepare these particles without difficulty.

[0033] The powder is then pressed into a mold with the structure of the component to be produced to form a green component.

[0034] The green body is then debonded to remove any residual adhesive. Debonding is typically performed by heat or solvent. In the case of heat debonding, it is carried out in air. The debonded green body yields a brown blank.

[0035] The palm fiber blanks are then placed in a sintering furnace. It is important to note that sintering is carried out under a neutral gas partial pressure. In the first stage, the palm fiber blanks are heated to a target temperature of 1250°C to 1650°C at a heating rate of 100°C to 300°C per hour. In the second stage, the palm fiber blanks are held at this target temperature for 30 minutes to 4 hours.

[0036] The neutral gas is selected from argon, nitrogen, or helium, or a mixture of at least two of these neutral gases.

[0037] After sintering, the temperature is gradually reduced at a rate of 100°C to 400°C per hour. This produces a semi-finished product or component that is close to the final monolithic form, and the semi-finished product produced by the sintering operation is orange in color. It is important to note that the coloring occurs throughout the entire object, so that machining the component will not change its color.

[0038] Depending on the desired orange color, the brown blank is sintered in an argon or nitrogen atmosphere. In fact, the inventors were surprised to find that the orange hue of the final component varied depending on the gas used.

[0039] This orange clock component can also be obtained through SPS sintering (or rapid sintering).

[0040] Therefore, the orange ceramic component can be produced using a method according to a second embodiment of the present invention, the method comprising the following steps: - Prepare a first mixture comprising zirconium oxide powder, 1 wt% to 6 wt% yttrium oxide, 0.1 wt% to 5 wt% aluminum oxide, 0.05 wt% to 1 wt% cerium oxide and 0.05 wt% to 1 wt% magnesium oxide; - Prepare the mold; - Pour the powder mixture into the mold; - In a neutral gas atmosphere, at 5 N / mm 2 Up to 250 N / mm 2 Rapid sintering or SPS sintering is carried out under sintering pressure, with a complete cycle time of 10 to 180 minutes, to form orange ceramic components; - Demold the resulting orange component; - Finishing the orange ceramic components; - Optionally, the resulting semi-finished product can be machined to produce an orange ceramic clock assembly of the desired size.

[0041] Preferably, the sintering step is carried out at a temperature of 600°C to 1650°C for 10 minutes to 180 minutes.

[0042] The semi-finished product is machined to the required component size.

[0043] This method may include laser ablation to form decorations on the component. For example, decorations may include hour markers, scale lines, or logos.

[0044] After laser ablation, the manufacturing method includes finishing (or finishing) steps, such as polishing, satin finishing, matte finishing, etc.

[0045] The resulting semi-finished product can be optionally machined to produce orange ceramic clock components of the required size. Detailed Implementation

[0046] The following examples illustrate the method and the resulting materials according to the present invention.

[0047] Example 1 (by weight) The powder mixture contains 93.95 wt% zirconium oxide, 5 wt% yttrium oxide, 0.25 wt% alumina, 0.6 wt% cerium oxide, and 0.2 wt% magnesium oxide. The semi-finished product was sintered at 1400°C for 60 minutes under an argon atmosphere, resulting in an orange-colored component.

[0048] Example 2 (by weight) The powder mixture contains 88.65 wt% zirconium oxide, 6 wt% yttrium oxide, 5 wt% alumina, 0.25 wt% cerium oxide, and 0.1 wt% magnesium oxide. The semi-finished product was sintered at 1650 °C for 90 minutes under a nitrogen atmosphere, and the resulting component was orange in color.

Claims

1. An orange ceramic watch component comprising 87% to 98.8% zirconium oxide, 1% to 6% yttrium oxide, 0.1% to 5% aluminum oxide, 0.05% to 1% cerium oxide and 0.05% to 1% magnesium oxide.

2. A method for manufacturing an orange ceramic clock assembly according to claim 1, the method comprising the following steps: - Prepare a first mixture comprising zirconium oxide powder, 1 wt% to 6 wt% yttrium oxide, 0.1 wt% to 5 wt% aluminum oxide, 0.05 wt% to 1 wt% cerium oxide and 0.05 wt% to 1 wt% magnesium oxide; - Prepare a second mixture comprising the first mixture and at least one adhesive; - To prepare the second mixture as a powder mixture or a granular mixture; - Green blanks are formed from the powder mixture or granular mixture; - Debonding the green blank to produce a palm blank; - The brown blank is sintered in a neutral gas atmosphere to form an orange semi-finished product; - The resulting semi-finished product is machined to produce orange ceramic clock components.

3. A method for manufacturing an orange ceramic clock assembly according to claim 1, the method comprising the following steps: - Prepare a first mixture comprising zirconium oxide powder, 1 wt% to 6 wt% yttrium oxide, 0.1 wt% to 5 wt% aluminum oxide, 0.05 wt% to 1 wt% cerium oxide and 0.05 wt% to 1 wt% magnesium oxide; - Prepare the mold; - Pour the powder mixture into the mold; - Under a neutral gas atmosphere, at 5 N / mm 2 Up to 250 N / mm 2 Rapid sintering or SPS sintering is carried out under sintering pressure, with a complete cycle time of 10 to 180 minutes, to form orange ceramic components; - Demold the resulting orange component; - Finishing the orange ceramic components; - The resulting semi-finished product is machined to produce orange ceramic clock components.

4. The method according to claim 2, characterized in that, The sintering process is carried out at a temperature of 1,250°C to 1,650°C for 30 minutes to 4 hours.

5. The method according to claim 3, characterized in that, The sintering process is carried out at a temperature of 600°C to 1,650°C for 10 to 180 minutes.

6. The method according to any one of claims 2 to 5, characterized in that, The neutral gas is selected from argon, nitrogen, or helium, or a mixture of at least two of these neutral gases.

7. The method according to claim 2, characterized in that, The debonding process can be either thermal debonding or solvent debonding.

8. The method according to claim 7, characterized in that, The thermal debonding process is carried out in air.

9. The orange ceramic clock assembly according to claim 1, characterized in that, The watch components are used as external parts or as components in the movement.

10. The orange ceramic clock assembly according to claim 9, characterized in that, Watch components used as external parts or in the movement are selected from the following list: center, case back, bezel, bezel insert, pushers, crown, bracelet links, clasp, dial, hands, dial hour markers, balance wheel, and mainplate.