阅读说明：本技术 陶瓷组件的制造 (manufacture of ceramic components ) 是由 西里亚克·博卡尔 奥利维耶·皮若尔 于 2018-04-16 设计创作，主要内容包括：一种用于制造粘结的陶瓷粉末的方法,该粘结的陶瓷粉末包含至少一种添加的元素或化合物,所述粘结的陶瓷粉末尤其是基于氧化锆和/或氧化铝和/或铝酸锶,其特征在于,该方法包括通过物理气相沉积(PVD)和/或通过化学气相沉积(CVD)和/或通过原子层沉积(ALD)在粘结的陶瓷粉末上沉积至少一种添加的元素或化合物的步骤(E3)。(Method for manufacturing a bonded ceramic powder comprising at least one added element or compound, in particular based on zirconia and/or alumina and/or strontium aluminate, characterized in that it comprises a step (E3) of depositing at least one added element or compound on the bonded ceramic powder by Physical Vapour Deposition (PVD) and/or by Chemical Vapour Deposition (CVD) and/or by Atomic Layer Deposition (ALD).)

1. Method for manufacturing a ceramic powder with a binder, comprising at least one added element or compound, in particular based on zirconium oxide and/or aluminum oxide and/or strontium aluminate, wherein the method comprises the step of depositing (E3) at least one added element or compound on the ceramic powder with a binder by Physical Vapor Deposition (PVD) and/or by Chemical Vapor Deposition (CVD) and/or by Atomic Layer Deposition (ALD).

2. The method for manufacturing a ceramic powder with a binder according to the preceding claim, wherein the deposition step (E3) comprises the addition of less than or equal to 5 wt. -%, or less than or equal to 3 wt. -%, or less than or equal to 1 wt. -%, or less than or equal to 0.05 wt. -%, or less than or equal to 0.01 wt. -% of said at least one added element or compound, based on the total amount of ceramic powder excluding organic compounds.

3. The method for manufacturing a ceramic powder with a binder according to any of the preceding claims, wherein the deposition step (E3) comprises adding the at least one added element or compound in an amount of greater than or equal to 1ppm in total, or greater than or equal to 10ppm, the at least one added element or compound not comprising an organic compound.

4. the method for manufacturing a ceramic powder with a binder according to claim 1, wherein the depositing step (E3) comprises depositing at least one added element or compound in an amount of 0.01 to 5 wt. -%, or 0.01 to 3 wt. -%, or 0.01 to 1 wt. -% onto the ceramic powder with a binder by Physical Vapor Deposition (PVD) and/or by Chemical Vapor Deposition (CVD), the at least one added element or compound not comprising an organic compound.

5. The method for manufacturing a ceramic powder with a binder according to claim 1, wherein the depositing step (E3) comprises depositing by Atomic Layer Deposition (ALD) at least one added element or compound on the ceramic powder with a binder in an amount of 1ppm to 5 wt. -%, or even 1ppm to 3 wt. -%, or even 1ppm to 0.05 wt. -%, or even 1ppm to 0.01 wt. -%, the at least one added element or compound not comprising an organic compound.

6. Method for manufacturing a ceramic powder with a binder according to any of the preceding claims, wherein the deposition step (E3) comprises the deposition of an added element or compound selected from metals, and/or metal alloys, and/or oxides, and/or nitrides, and/or carbides.

7. Method for manufacturing a ceramic powder with a binder according to the preceding claim, wherein the added element or compound is or comprises a metal selected from one of the following four lists:

-a high melting noble metal selected from platinum, rhodium, osmium, palladium, ruthenium or iridium; or

-any other metal selected from gold, aluminum, silver, rhenium, titanium, tantalum or niobium; or

-a transition metal selected from aluminium, iron, chromium, vanadium, manganese, cobalt, nickel or copper;

-a lanthanide selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium or lutetium.

8. Method for manufacturing a ceramic powder with a binder according to any of the previous claims, wherein the added compound is a metal alloy obtained by direct deposition of a metal alloy on the ceramic powder with a binder or by a combination of sequential or simultaneous deposition of a plurality of elements of a metal alloy on the ceramic powder with a binder.

9. The method for manufacturing a ceramic powder with a binder according to any of claims 1 to 7, wherein the added compound is an oxide, carbide or nitride of one or more metals obtained by direct deposition of the metal oxide, carbide or nitride on the ceramic powder with a binder or by reacting the metal deposit with a reactive atmosphere, in particular in a deposition chamber or after deposition, for example during the step of sintering the ceramic compound.

10. The method for manufacturing a ceramic powder with a binder according to any of the preceding claims, wherein the deposition step (E3) comprises the simultaneous deposition or the successive deposition of a plurality of different added elements or compounds.

11. The method for manufacturing a ceramic powder with a binder according to any of the preceding claims, wherein the depositing step (E3) comprises adding at least one added element or compound to the ceramic powder with a binder comprising 1 to 4 wt% or 12 to 25 wt% of an organic compound.

12. The method for manufacturing a ceramic powder with a binder according to any of the preceding claims, wherein the method comprises:

-a first stage (P1) consisting in preparing ceramic powders, in particular based on zirconia and/or alumina and/or strontium aluminate, and then in

-optionally, a deposition step (E1) comprising depositing at least one additional element or compound on the ceramic powder by Atomic Layer Deposition (ALD), and then

-a second stage (P2) consisting in integrating a binder of the organic material type into the ceramic powder comprising said at least one added element or compound; then the

-a deposition step (E3) comprising depositing at least one additional element or compound on the ceramic powder with binder.

13. A method for manufacturing a ceramic component, wherein the method comprises a stage for manufacturing a ceramic powder with a binder according to any of the preceding claims.

14. method for manufacturing a ceramic component according to the preceding claim, wherein, after the deposition step (E3) comprising the deposition of at least one additional element or compound, the manufacturing method proceeds:

-a third stage (P3) of temporarily shaping the ceramic powder with binder comprising at least one added element or compound, and then

-a fourth phase (P4) comprising the step of degreasing the temporarily shaped ceramic component, in particular comprising the elimination of organic compounds, and then sintering said ceramic component.

15. the method for manufacturing a ceramic component according to claim 13 or 14, wherein, before or after the step (E3) of depositing at least one added element or compound, the method comprises the step of adding a coloring pigment or a phosphorescent pigment, in particular a coloring compound other than the coloring pigment, to the bonded ceramic powder or to the ceramic powder without binder.

16. The method for manufacturing a ceramic component according to any of claims 13 to 15, wherein the method comprises the steps of:

-providing a ceramic powder with a binder comprising a colour pigment or more typically at least one added compound and/or further compound, whereby a ceramic component having a first colour or more typically a first property can be obtained by manufacturing the ceramic component from the ceramic powder with the binder;

-depositing at least one added element or compound (E3) on the ceramic powder with binder by Physical Vapor Deposition (PVD) and/or by Chemical Vapor Deposition (CVD) and/or by Atomic Layer Deposition (ALD);

-completing the manufacturing of the ceramic component from the ceramic powder with binder comprising the deposited added elements or compounds to obtain the ceramic component, the color of which is a second color different from said first color, or more generally the ceramic component has a second property different from the first property.

17. Method for manufacturing a ceramic component according to the preceding claim, wherein the method comprises repeating the step of depositing at least one additional element or compound on the ceramic powder with a plurality of different deposits of at least one additional compound by varying the content and/or the added compound until the ceramic component has a second color or second property sufficiently close to the desired one after completion of the manufacturing of the ceramic component.

18. The method for manufacturing a ceramic component according to claim 16 or 17, wherein said step comprises the step of selecting a ceramic powder with a binder containing at least one compound, so as to be able to obtain a first property close to a desired second property.

19. The method for manufacturing a ceramic component according to any one of claims 13 to 18, wherein said method enables the manufacture of a bezel, a dial, an indicator, a winding crown, a push button or any other timepiece case element or any timepiece movement element.

20. Ceramic powder with a binder, in particular obtained by a method according to any one of claims 1 to 12, wherein the ceramic powder with a binder comprises less than or equal to 5 wt.%, or less than or equal to 3 wt.%, or less than or equal to 1 wt.%, or less than or equal to 0.05 wt.%, less than or equal to 0.01 wt.%, of an added element or compound selected from metals, metal alloys, oxides, nitrides or carbides, based on the total amount, measured in the absence of an organic compound.

21. Component for a timepiece or jewelry part, in particular a ceramic component based on zirconia and/or alumina and/or strontium aluminate, wherein the ceramic component comprises, in total, less than or equal to 5% by weight, less than or equal to 3% by weight, or less than or equal to 1% by weight, or less than or equal to 0.05% by weight, less than or equal to 0.01% by weight of an added element or compound selected from the group consisting of metals, metal alloys, oxides, nitrides or carbides.

22. A timepiece or jewelry part comprising a ceramic assembly according to the preceding claim.

Technical Field

The present invention relates to a method for manufacturing ceramic powder and a ceramic component. Such ceramic powders and ceramic components are used in watchmaking and jewelry industries. In particular, such a component can be used in a timepiece, in particular a decorative component such as a bezel or a functional component such as a movement.

Background

In the field of watchmaking, as in jewelry, it is known to use ceramic components, in particular decorative components. However, one limiting factor in the use of these ceramic components is due to the fact that: it is difficult or even impossible to obtain certain colors, in particular certain grey shades, and it is difficult to obtain uniform, predictable and reproducible colors. Furthermore, obtaining a particular shade requires the production of a whole batch of material from the initial assembly and proves to be time consuming and complex.

Another limiting factor also comes from the fact that: it is difficult to test the effect of adding certain elements that can be used in combination with the composition of known ceramics, in particular in order to obtain certain specific mechanical properties of the ceramic component. Here too, each test is complicated and requires the production of a whole batch of material from the starting components.

Conventional processes for manufacturing ceramic components comprise a first stage consisting in preparing raw materials, i.e. ceramic powders, for example based on zirconia and/or alumina. In this first stage, the raw material is generally prepared in the form of a ceramic powder, to which for example other oxides may be added to reinforce the ceramic composition, or pigments to obtain a coloured material. The pigments are generally of the metal oxide type or rare earth oxide type and are added to and mixed with the base ceramic powder by a liquid route, thus using a carrier liquid to introduce the pigments.

The second stage of the method for manufacturing a ceramic component consists in incorporating a binder into the ceramic powder obtained in the first stage. Such binders are typically composed of one or more organic compounds. The nature and proportions of the binder depend on the intended method in the third stage and at the end of this stage usually ceramic powders with binder are involved.

The third stage includes the shaping of the ceramic assembly. To this end, the first route comprises a step of pressing the agglomerates of particles together with the binder obtained at the end of the second stage: in this method, a second stage prepares the ceramic powder with the binder in the form of spray-dried compacted granules. The second route consists of injection molding. In this case, the formulation resulting from the second stage is a ceramic powder with a binder, which is referred to as "feed". The third route consists of casting in a mould (commonly known as slip casting). In this case, the formulation resulting from the second stage is a ceramic powder with suspended binder, also known as slip or "slurry". At the end of the third stage, the ceramic component has a shape close to its final shape and contains ceramic powder and a binder. Other molding techniques may be used, for example, gel casting, freeze casting, or coagulation casting techniques.

The fourth stage may grind the ceramic assembly. This fourth stage comprises a first step consisting in degreasing the assembly, i.e. removing the binder, for example by heat treatment or using a solvent. The second step is to compact the assembly, thereby removing the holes created by the removal of the adhesive. The second step usually consists of a sintering heat treatment (high temperature firing). The final colour of the ceramic component and its final mechanical properties appear only at the end of the fourth phase and result from the reactions between the various constituents of the component and the atmosphere present in the furnace (which plays a role during the heat treatment). These reactions are complex and sometimes unpredictable.

It is observed that the above mentioned conventional methods for manufacturing ceramic components have several drawbacks. In particular, the colour and final properties obtained depend on many parameters, such as the microstructure of the powder formed in the first stage, in particular the size of the ceramic grains, the size of the pigments, their reactivity with the ceramic and sintering environment, etc. The properties also depend on all other factors related to the other manufacturing stages, such as the size and number of pores in the final assembly, the composition of the grain boundaries, the density, the percentage of pigments and their distribution within the matrix, their possible bonding to each other during sintering or to the constituents of the ceramic raw material or atmosphere, the chemical purity of the initial compounds, and possible internal and external contaminants. The parameters to be considered are so numerous that it is difficult to predict and reproduce a certain color that is desired to be manufactured. This observation is more true if the content of the coloring pigment is small: therefore, to alleviate this disadvantage, all of the prior art methods must use large amounts of pigment. Furthermore, some methods attempt to improve the results by adding steps based on complex chemistry, which naturally has the disadvantage of further complicating the manufacturing process.

More importantly, in practice, the difficulty in managing the color of the ceramic components results in the need to perform a large number of tests, including from ceramic powder preparation to final molding to generate a large number of complete samples, while varying some of the above parameters for each sample to determine the best method. Furthermore, when it is desired to change the color even slightly, it is necessary to restart the entire process, including preparing numerous samples again. In practice, therefore, finding a controllable ceramic component color, which is often necessary for its use as a decorative element, requires complex and laborious development steps.

Finally, despite numerous tests, it has so far been observed that it does not seem possible to obtain ceramic components having certain colours, in particular certain grays, such as those defined by CIE L a b colour coordinates (83; 0; 0.6) and CIE L a b colour coordinates (47; 0.2; -0.2). In general, it is not possible to obtain colors, defined for example by a and b parameters close to 0 and L parameters less than 96, in particular strictly grey.

the general object of the present invention is therefore to propose a solution for manufacturing ceramic components, in particular for a timepiece, which does not have the drawbacks of the prior art.

More precisely, a first object of the present invention is to propose a solution for manufacturing ceramic powders and ceramic components, making it possible to obtain ceramics with improved properties, in particular with controllable colours and/or in particular with novel or optimised properties (such as mechanical, thermal, electrical and tribological properties).

A second object of the invention is to propose a solution for simplifying the manufacture of coloured ceramic components.

A third object of the invention is to propose a grey ceramic.

a fourth object of the invention is to propose a simple method of modifying a ceramic powder which may already be coloured in order to modify the resulting colour of the final ceramic component.

Disclosure of Invention

To this end, the invention is based on a method for producing a ceramic powder or a ceramic component with a binder, in particular a ceramic powder or a ceramic component with a binder for a timepiece or jewelry part, in particular a ceramic powder or a ceramic component with a binder based on zirconium oxide and/or aluminum oxide and/or strontium aluminate, wherein the method comprises the step of depositing at least one added element or compound on the ceramic powder with a binder by Physical Vapor Deposition (PVD) and/or by Chemical Vapor Deposition (CVD) and/or by Atomic Layer Deposition (ALD).

The invention is more particularly defined by the claims.

Drawings

These objects, features and advantages of the present invention will be disclosed in detail in the following non-limiting description of specific embodiments with reference to the accompanying drawings, in which:

Fig. 1 schematically shows a flow chart of the steps of a method for manufacturing a coloured ceramic component for a timepiece according to an embodiment of the invention.

Fig. 2 shows a ceramic component obtained according to a first example of embodiment of the invention.

fig. 3 shows a ceramic component obtained according to a second example of embodiment of the invention.

fig. 4 shows a ceramic component obtained according to a third example of embodiment of the invention.

Fig. 5 shows a ceramic component obtained according to a fourth example of embodiment of the invention.

FIG. 6 is a table of results for ceramic assemblies obtained according to seven exemplary implementations of embodiments of the present invention.

fig. 7 shows the luminance of the ceramic components of examples 4 to 7 obtained by the embodiment of the present invention as a function of the platinum content.

Fig. 8 shows the variation of the chromaticity parameter a as a function of the platinum content of the ceramic components of examples 4 to 7 obtained by an embodiment of the present invention.

Fig. 9 shows the variation of the chromaticity parameter b as a function of the platinum content of the ceramic components of examples 4 to 7 obtained by an embodiment of the present invention.

FIG. 10 is a table of results for ceramic components obtained in accordance with an exemplary implementation of an embodiment of the present invention.

FIG. 11 is a table of results for ceramic assemblies obtained according to three exemplary implementations of embodiments of the present invention.

FIG. 12 is a table of results for ceramic components obtained in accordance with an exemplary implementation of an embodiment of the present invention.

Fig. 13 shows a ceramic component obtained according to a first example of embodiment of the invention.

Fig. 14 shows a ceramic component obtained according to a second example of embodiment of the present invention.

FIG. 15 is a table of results for ceramic components obtained from two previous example implementations of embodiments of the present invention.

Detailed Description

In the following, ceramic component or powder denotes a component or powder obtained from a polycrystalline compact material comprising mainly at least one ceramic, in particular based on zirconia and/or alumina and/or strontium aluminate, for example zirconia stabilized with yttria and/or ceria and/or magnesia and/or calcia. Ceramic powder means a powder in the form of a finely divided solid consisting of fine particles of a ceramic, in particular a ceramic based on zirconia and/or alumina and/or strontium aluminate. For the sake of simplicity of description, the same term "ceramic powder" will be used with the intention of reserving in a general manner for powders that contain predominantly fine particles of the ceramic but also other additive elements such as one or more pigments or oxides for reinforcing the ceramic, such as yttrium oxide. Similarly, a ceramic component means a component obtained by, for example, sintering such a ceramic powder. Thus, in all cases, the ceramic powder or component mainly comprises a component of ceramic type, i.e. at least 50 wt.%, or even at least 75 wt.%, or even at least 90 wt.%. For example, the ceramic powder or component comprises at least 50 wt% zirconia.

In all cases, the ceramic powder is free of organic compounds. The generic term "ceramic powder with binder" denotes a composite material consisting of a ceramic powder and a binder, usually consisting of one or more organic compounds in variable proportions, and used for shaping parts by pressing, by injection molding, by casting or by other techniques.

by (pressed) particles is meant agglomerates of ceramic powder with a binder to be formed by a pressing method, such as cold or hot uniaxial pressing or cold or hot isostatic pressing. The particles typically comprise 1 to 4% by weight of the organic compound.

The term "injectable ceramic powder", also commonly referred to as "charge", denotes a ceramic powder with a binder to be shaped by a high or low pressure injection molding process. Injectable ceramic powders typically comprise 12 to 25% by weight of organic compounds.

The term "slurry" means a ceramic powder with a binder to be formed by slip casting or gel casting. The slurry typically comprises 1 to 25 wt% of organic compounds.

A method for manufacturing a ceramic component according to an embodiment of the invention comprises the stages and steps schematically represented by the flow chart of fig. 1.

Thus, the manufacturing method comprises the respective conventional stages P1 to P4, i.e. preparing the ceramic powder (P1), adding the binder (P2), shaping the assembly (P3) and degreasing sintering heat treatment (P4). Since the conventional parts of these stages are known in the art, they will not be described in detail at this stage. Therefore, those skilled in the art will know how to implement them, including according to any existing variants or equivalents.

Embodiments of the present invention differ from conventional methods, inter alia, by the addition of step E3, i.e., the deposition of at least one added element or compound, such as a coloring element, on a ceramic powder with a binder via a vacuum drying route.

According to a first embodiment variant, the deposition step E3 consists of physical vapor deposition (abbreviated to PVD) and/or by chemical vapor deposition (abbreviated to CVD).

According to a second embodiment variant, the deposition step E3 consists of atomic layer deposition (abbreviated ALD).

thus, after the second stage P2 of the manufacturing method, the deposition step E3 is carried out on the ceramic powder with the binder. Thus, it can be carried out on ceramic powders comprising organic compounds, for example on granules or on injection-moulding feedstock. It is carried out before the third stage P3 of the process. For the sake of simplicity of description, the ceramic powder with a binder obtained by carrying out the deposition step E3 of the present invention, comprising one or more added elements or compounds, will continue to be referred to as ceramic powder with a binder.

The elements or compounds added, in particular metals and/or oxides and/or nitrides and/or carbides, can vary greatly. Metal is understood to mean a pure metal or alloy. Thus, it may advantageously be a metal-based compound. For simplicity, the terms added element or added compound will be used in the remainder of the text without distinction between individual elements and compounds or alloys.

The invention also makes it possible, in a novel way, to use metals that cannot be used with existing solutions, such as noble metals with a high melting point higher than or equal to 1200 ℃, or even higher than or equal to 1500 ℃. The invention thus makes it possible to use platinum and/or rhodium and/or osmium and/or palladium and/or ruthenium and/or iridium as additional element. As a variant, other metals may be used, and the aforementioned list may be supplemented with gold, aluminum, silver, rhenium, titanium, tantalum or niobium. Furthermore, according to the following list, transition metals (iron, chromium, vanadium, manganese, cobalt, nickel and copper) characterized by an incomplete d-shell are able to obtain particularly unprecedented advantageous results due to their addition according to the specific deposition step E3 of the present invention. Likewise, the lanthanides (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) enable the ceramic powder with the binder to be doped during step E3 and enable advantageous colors and/or properties to be obtained. As mentioned above, the added compound may thus be an alloy comprising or consisting of one or more of the metals listed above and the lanthanide.

Thus, the added compound may be a metal compound or alloy obtained by depositing a metal alloy directly on the ceramic powder with the binder or by a combination of depositing a plurality of elements of the metal alloy sequentially or simultaneously on the ceramic powder with the binder.

Similarly, the compound added may be an oxide, carbide or nitride of one or more metals obtained by direct deposition of the oxide, carbide or nitride on a ceramic powder with a binder or by reacting the metal deposit with a reactive atmosphere, in particular in a deposition chamber or after deposition, for example during the step of sintering the ceramic compound.

Naturally, a plurality of different added elements or compounds can be used and deposited simultaneously or successively on the same ceramic powder with binder by one or more deposition steps E3 as described above. This increase in available additional compounds naturally enables an increase in the possible colour of the ceramic and in other possible properties, in particular mechanical or tribological properties.

It should be noted that the person skilled in the art is used to add colour pigments to ceramics by liquid route. They are not used to proceed by the dry route or to deposit directly on ceramic powders with binders. During such dry deposition, the following parameters should be considered:

-the uniformity of the deposition on the powder,

-uniformity of shape and size of the particles,

-the temperature of the process,

The risk of degassing,

Electrostatic properties of the (insulated) moving finely divided solid matter,

-the finish and properties of the device material; in particular, the pairing between the nature of the deposit and the nature of the binder of the granules must be chosen correctly to prevent the powder from adhering to the equipment.

For example, during PVD deposition, it is advantageous to deposit on ceramic powders with a binder, for example on pressed particles (average size of the order of a few tens of microns) or on injectable ceramic powders in the form of pellets of larger size (average size of the order of a few millimeters). Therefore, this approach combines a mixed matrix comprising ceramic powder and organic compound, which has poor temperature performance with a maximum temperature of 45 ℃.

Furthermore, it was observed that the method of the invention enables very satisfactory results to be achieved in terms of novel or improved properties of the ceramic component, even with the addition of very small amounts of added compounds to the ceramic. Thus, not only is the color of the ceramic component improved as it is homogeneous and/or may allow new hues, but the result of such an improvement may be obtained by adding very small amounts of added coloring elements or compounds, especially in amounts much lower than the content of coloring pigments used in conventional processes, compared to existing solutions.

For example, in the case of using a PVD deposition method, the weight content of the added elements or compounds is less than or equal to 5%, or even less than or equal to 3%, or even less than or equal to 2%. Advantageously, this content is greater than or equal to 0.01%. Advantageously, the content is between 0.01% and 5% (inclusive) or even between 0.01% and 3% (inclusive). It should be noted that all weight contents are measured on the final (after performing the fourth stage of the manufacturing method) ceramic component or on the degreased ceramic powder, i.e. without taking into account the weight of the binder. The ALD deposition process is even used to obtain lower weight contents, possibly less than or equal to 5%, but in particular less than or equal to 3% or 2%, or even less than or equal to 1%, or even less than or equal to 0.05%, or even less than or equal to 0.01%. Advantageously, these contents are greater than or equal to 1 ppm. Advantageously, these levels are from 1ppm to 0.01%, or even from 1ppm to 0.05%, or even from 1ppm to 5%. Therefore, the invention has the following advantages: very advantageous results are obtained with small amounts of added compound material or even very small amounts of material, without having to prepare a complete batch each time, and in addition the base batch can be iteratively modified.

Furthermore, it is important to emphasize that the process of the invention enables to obtain a homogeneous distribution or a good dispersion of the added compounds and thus finally to obtain ceramic components with homogeneous properties (e.g. colour). It should be noted that since the added elements are deposited after the second stage P2 of the method, for example directly on the particles, the added compounds are distributed on the surface of the particles by the deposition method used and thus uniformly on the ceramic powder with the binder. The uniformity of deposition enables the coating to be distributed over the powder and, in the case of metallic coatings, the powder becomes less electrostatic. It aggregates less. The added compound will be particularly evenly distributed in the final sintered ceramic component.

Furthermore, the fact of coating on the powder with binder, and not on the ceramic powder without binder, has the following advantages: processing on readily available materials and larger sized particles makes them easier to recycle in deposition equipment.

In all the preceding cases, the analysis of the object obtained at the end of the fourth phase shows that a uniform distribution of the added compound remains in the final ceramic component. If PVD deposition is performed directly on the pressed particles, the microstructure of the ceramic component will show an ordered distribution of the other compound particles according to a superstructure reflecting the microstructure of the pressed particles (see fig. 2 and 3, for later review). As a variant, by adding an abrasion step after deposition, it is possible to make the distribution of the small particles of the added compound perfectly homogeneous (see fig. 4 and 5). In the case of deposition onto the injection molding material, in particular in the step of plasticizing the molten mixture by means of the injection molding screw, the distribution of the particles of the added compound in the material is homogenized. Thus, in all cases, the ceramic component comprises an added element that is uniformly distributed in its volume, which gives it the properties provided by the uniform distribution of the added element in the ceramic component.

finally, the deposition step E3 of the embodiment of the invention has the following main advantages:

The addition of added elements or compounds can be obtained in a fully controllable composition and content and in very small amounts, so that a micro-metering of the added compounds can be achieved.

It is possible to finally obtain a homogeneous distribution of the added compound in the ceramic component;

The possibility of adding a plurality of other compounds, increasing the number of possible other compounds compared to existing solutions, increasing the possibility of providing ceramic components with certain properties;

it enables reliable, repeatable and clean deposition of other compounds.

The present invention is exemplified below by examples which enable the production of gray ceramic components having a hue which cannot be produced by conventional techniques. In all these examples, the added compound was platinum, which was deposited on the pressed powder by PVD deposition. All the results obtained, in particular in terms of colour, are summarized in the table of figure 6.

The first example is based on the use of a ceramic powder with a binder in the form of granules containing 3 mol% yttria-stabilized zirconia (TZ3Y) and comprising 0.25 wt% alumina and 3 wt% of an organic binder (REF 1). 50g of these particles were placed in a vibrating bowl of a PVD chamber containing a platinum cathode. The PVD chamber was evacuated and then sputtered with an argon plasma for platinum. Inductively Coupled Plasma (ICP) analysis enables the determination of the platinum content of these previously degreased particles. The samples obtained from this example generally contained a platinum content of 2.26 wt.%. The obtained coated granules are then pressed into a cylindrical mould on a uniaxial press. The resulting pellets were degreased in air at 600 ℃ for 18 hours. Finally, it was sintered in air at 1450 ℃ for 2 hours. After sintering, the surface of the ceramic pellet is ground and then polished. The ceramic component obtained is grey in colour. Fig. 2 is an image of the resulting ceramic pellet obtained by a scanning electron microscope, which shows the distribution of platinum particles (bright spots). The figure can highlight the ordered distribution of platinum particles around the old pressed particles in the microscopic superstructure. The distribution of the particles is uniform on the scale of the assembly.

A second example was made from a bonded pressed powder in particulate form containing 3 mol% yttria-stabilized zirconia (TZ3Y) and comprising 0.25 wt% alumina and 3 wt% organic binder (REF 1). 50g of these particles were placed in a vibrating bowl of a PVD chamber containing a platinum cathode. The PVD chamber was evacuated and then sputtered with an argon plasma for platinum. Inductively Coupled Plasma (ICP) analysis enables the determination of the platinum content of these previously degreased particles. The samples obtained from this example generally contained a platinum content of 0.11 wt.%. The obtained coated granules are then pressed in a cylindrical mould on a uniaxial press. The resulting pellets were degreased in air at 600 ℃ for 18 hours. Finally, it was sintered in air at 1450 ℃ for 2 hours. After sintering, the surface of the pellets was ground and then polished. The ceramic component obtained is grey in colour. Fig. 3 is an image of the resulting ceramic pellet obtained by a scanning electron microscope, which shows the distribution of platinum particles (bright spots) at the grain boundary. This distribution is uniform on the scale of the assembly. These platinum particles are less pronounced due to the very low platinum content.

In a third example, a portion of the powder obtained in example 1 was taken out. Next, a degreasing step is added, followed by grinding (mixing, wet grinding) and a binding treatment. In this treatment, 0.47g of PVA, 0.71g of PEG20000 and 170ml of DI (deionized) water were added to 39.4g of the defatted powder of example 1. The suspension thus obtained was placed in the zirconia bowl of a mill with 1kg of zirconia beads and milled for 1 hour at a speed of 400 rpm. The suspension is then recovered for drying and granulation by spray drying using a "spray dryer". The granules thus obtained are then pressed into a cylindrical mould on a uniaxial press. The resulting pellets were degreased in air at 600 ℃ for 18 hours. Finally, it was sintered in air at 1450 ℃ for 2 hours. The sample from this example still contained, overall, 2.26 wt.% platinum at the same level as in example 1. After sintering, the surface of the pellets was ground and then polished. The ceramic component obtained is grey in colour. Fig. 4 is an image of the obtained ceramic pellet obtained by a scanning electron microscope, which shows a microscopically uniform distribution of platinum particles (bright spots) within the zirconia grains. The color difference between the polished ceramics from example 1 and example 3 was visually imperceptible (Δ Ε <1) and within the measurement error given by the apparatus; thus, the distribution of platinum particles in both samples is considered equivalent for the human eye in terms of the resulting color.

In the fourth embodiment, a part of the powder obtained when the second embodiment is performed is taken out. Next, a degreasing step is added, and then grinding and bonding treatment are performed. In this treatment, 0.46g of PVA, 0.69g of PEG20000 and 166ml of DI (deionized) water were added to 38.5g of the defatted powder of example 2. The suspension thus obtained was placed in the zirconia bowl of a mill with 1kg of zirconia beads and milled for 1 hour at a speed of 400 rpm. The suspension is then recovered for drying and granulation by spray drying using a "spray dryer". The obtained granules were then pressed into a cylindrical mould on a uniaxial press. The resulting pellets were degreased in air at 600 ℃ for 18 hours. Finally, it was sintered in air at 1450 ℃ for 2 hours. The sample from this example still contained 0.11 wt.% platinum overall at the same level as in example 2. After sintering, the surface of the pellets was ground and then polished. The ceramic component obtained is grey in colour. Fig. 5 is an image of the resulting ceramic pellet obtained by scanning electron microscopy, showing a microscopically uniform distribution of platinum particles (bright spots) within the zirconia grains. These platinum particles are less visible at this scale due to the very low platinum content. The color difference between the polished ceramics from example 2 and example 4 was visually imperceptible (Δ Ε <1) and within the measurement error given by the apparatus; thus, it is believed that the distribution of platinum particles in both samples is equivalent for the human eye with respect to the resulting color.

In a fifth example, 3.32g of the powder obtained when the third example was carried out was taken out and degreased so as to be mixed with 96.68g of a commercially available powder (3 mol% yttria-stabilized zirconia, degreased) before being subjected to a grinding treatment. Then 1.2g of PVA, 1.8g of PEG20000 and 200ml of DI (deionized) water were added to 100g of the obtained powder. The suspension thus obtained was placed in the zirconia bowl of a mill with 1kg of zirconia beads and milled for 70 minutes at a speed of 400 rpm. The suspension is then recovered for drying and granulation by spray drying using a "spray dryer". The obtained granules were then pressed into a cylindrical mould on a uniaxial press. The resulting pellets were degreased in air at 600 ℃ for 18 hours. Finally, it was sintered in air at 1450 ℃ for 2 hours. The sample of this example contained 0.075 wt.% platinum. After sintering, the surface of the pellets was ground and then polished. The ceramic component obtained is grey in colour.

In a sixth example, 2.21g of the powder obtained when the third example was carried out was taken out and degreased so as to be mixed with 97.79g of a commercially available powder (3 mol% yttria-stabilized zirconia, degreased) before being subjected to a grinding treatment. Then 1.2g of PVA, 1.8g of PEG20000 and 200ml of DI (deionized) water were added to 100g of the obtained powder. The suspension thus obtained was placed in the zirconia bowl of a mill with 1kg of zirconia beads and milled for 70 minutes at a speed of 400 rpm. The suspension is then recovered for drying and granulation by spray drying using a "spray dryer". The obtained granules were then pressed into a cylindrical mould on a uniaxial press. The resulting pellets were degreased in air at 600 ℃ for 18 hours. Finally, it was sintered in air at 1450 ℃ for 2 hours. The sample of this example contained 0.05 wt.% platinum. After sintering, the surface of the pellets was ground and then polished. The ceramic component obtained is grey in colour.

In a seventh example, 0.77g of the powder obtained when the third example was carried out was taken out and degreased so as to be mixed with 99.23g of a commercially available powder (3 mol% yttria-stabilized zirconia, degreased) before being subjected to the grinding treatment. Then 1.2g of PVA, 1.8g of PEG20000 and 200ml of DI (deionized) water were added to 100g of the obtained powder. The suspension thus obtained was placed in the zirconia bowl of a mill with 1kg of zirconia beads and milled for 70 minutes at a speed of 400 rpm. The suspension is then recovered for drying and granulation by spray drying using a "spray dryer". The obtained granules were then pressed into a cylindrical mould on a uniaxial press. The resulting pellets were degreased in air at 600 ℃ for 18 hours. Finally, it was sintered in air at 1450 ℃ for 2 hours. The sample of this example contained 0.02 wt.% platinum. After sintering, the surface of the pellets was ground and then polished. The ceramic component obtained is grey in colour.

Figure 6 shows the results of the previous seven embodiments. It is noted that all these embodiments enable grey ceramics to be obtained. In general, therefore, one embodiment of the invention advantageously enables the manufacture of grey ceramics, characterized by two parameters a and b ranging from-1 to 1 (inclusive). Further, it is noticeable that the color tone varies with the platinum content, as shown in fig. 7 to 9.

as a variant, one embodiment of the invention enables the manufacture of grey ceramic components, characterized in that the two parameters a and b are-3 to 3 inclusive, or even-2 to 2 inclusive, or even-0.5 to 0.5 inclusive.

It should be noted that the wear after the addition of platinum enables a better dispersion of the platinum in the material (see fig. 2 to 5) and does not significantly change the colour of the ceramic obtained in these examples. A very slight increase in the density of the sample associated with abrasion was also observed. However, this wear is still optional.

Naturally, the invention is not limited to the manufacture of ceramic components comprising platinum as the added compound. The grey colour can be obtained with other compounds than platinum, for example with rhodium, palladium or any other grey precious metal that does not react with other components of the ceramic or the sintering atmosphere. Furthermore, the invention is not limited to the manufacture of grey ceramic components. In fact, multiple colors can be obtained by varying the compounds added. Thus, the table of fig. 10 gives several examples of ceramic components obtained with various added compounds by the method according to an embodiment of the invention. More specifically, deposition tests on various added compounds by PVD deposition were performed directly on ceramic injection molding feedstock based on 3 mol% yttria stabilized zirconia (with or without the addition of alumina). It was observed that the addition of iron Fe produced a very yellowish ceramic. The addition of chromium Cr to the pure stabilized zirconia also produces a yellow ceramic with a slight red tendency. Chromium deposited on zirconia to which 2 wt% alumina has been added will result in a lighter but redder material. The addition of vanadium V makes the ceramic yellow, while the addition of aluminum Al has little effect on the primary color.

Alternatively, the manufacturing method may comprise the previous step E1 of adding another compound to the ceramic powder without a binder, for example, adding a coloring pigment or any other compound according to the above-mentioned conventional method or according to other techniques known to the person skilled in the art (e.g. by salt precipitation). Indeed, the present invention remains compatible with all other existing methods and can be complementary thereto, for example for enriching them. This step E1 may be performed at any suitable time during the manufacturing process.

As a variant and optionally, the manufacturing method may comprise the previous step E1 of adding another added element or compound to the ceramic powder with binder, in particular by atomic layer deposition ALD. In particular, the ALD deposition step can make the surface of the ceramic powder electrically conductive, for example by adding added metal compounds. This has the advantage of limiting the risk of agglomeration of the ceramic powder with the binder (particularly in the PVD chamber later on), since the particles of such ceramic powder with binder have electrostatic properties which tend to agglomerate them together and form agglomerates naturally, which is disadvantageous for a uniform coating with the added compound. It should be noted that the first conductive element need not cover the entire surface of the powder particles to be effective. It was observed that during the deposition step E3, the deposition of the additional compound by PVD deposition on the powder with binder was facilitated by the first thin layer formed by ALD deposition, forming a conductive sublayer limiting the agglomeration of the particles. It should be noted that the compound deposited by ALD deposition may be the same as the compound deposited by PVD deposition. As a variant, the two compounds deposited by ALD and by PVD are different in order to combine their properties.

As a variant, it is therefore possible to carry out the elements or compounds added by ALD deposition via the previous step E1 on the ceramic powder without binder before carrying out the second stage P2 of the process. The ceramic powder thus enriched may be subjected to successive dispersion/wet milling steps during the second stage P2 to combine it with organic compounds and then spray-dried to prepare particles therefrom at the end of the second stage P2 of the process. Thus, this second stage P2 enables a homogeneous distribution of the added elements or compounds.

As mentioned above, prior art solutions for colouring ceramic components are complex and not always satisfactory. Furthermore, when it is desired to change (even slightly) the hue by using ceramic components pre-coloured with pigments according to the prior art, it seems difficult to do with conventional techniques, in particular because the pigments tend to react with each other during sintering. Thus, according to the prior art, changing the intensity (brightness) and/or the hue of the color of a colored ceramic is lengthy and laborious: in fact, each attempt requires the creation of a new batch of ceramic powder with new chemical composition, followed by the production of injection molding raw material, up to the final (sintered and polished) ceramic component.

With the method of the present invention, it becomes much easier to make such a change in color or intensity. More generally, any other modification of the properties of the ceramic component is easy.

One embodiment of the invention is therefore based on a method for manufacturing a ceramic powder or a ceramic component (in particular based on zirconia and/or alumina and/or strontium aluminate), comprising the following steps:

-providing a ceramic powder with a binder comprising a colour pigment or more usually at least one added or added compound, whereby a ceramic component having a first colour or more usually a first property can be obtained by manufacturing a ceramic component from such a ceramic powder with a binder;

-depositing at least one coloured or added element or compound E3 on the ceramic powder with binder by physical vapour deposition PVD and/or by chemical vapour deposition CVD and/or by atomic layer deposition ALD;

-completing the manufacturing of the ceramic component from the ceramic powder with binder comprising the deposited added compound to obtain the ceramic component, the color of which is a second color different from said first color, or more generally the ceramic component has a second property different from the first property.

By this method, the first property obtained from a commercially available ceramic powder with a binder can be easily changed to the second property by adding the added compound according to an embodiment of the present invention. Since this embodiment of the invention uses step E3, which is easy to implement, control and reproduce, it is easy to perform several tests to obtain the desired final properties of the ceramic component by trial and error, without the need for laborious interventions at the ceramic powder preparation stage.

Thus, the method for manufacturing a ceramic component may repeat the following steps: depositing at least one additional compound on the ceramic powder with binder, varying the content of the additional compound or even of the additional compound itself, and completing the manufacture of the ceramic component until sufficiently close to the desired result.

In practice, the following steps can thus be implemented: the ceramic powder with binder containing the colouring pigment is selected so that a first colour close to the desired second colour can be obtained, and then the colour is changed by adding further colouring compounds until it has been close enough to the desired colour. As previously mentioned, the same method can be implemented to change any property other than color.

Advantageously, the at least one added compound is chosen so as not to react with the added compound (for example a colouring pigment) already present in the ceramic powder with binder.

The pigment present in the ceramic powder with the binder may comprise one or more elements selected from metal oxides, rare earth oxides, cobalt aluminate and/or phosphorescent pigments.

In the case of ceramic components comprising cobalt aluminate (blue pigment), the following three examples (numbered examples 8 to 10) illustrate this principle. The results are shown in the table of fig. 11.

In the eighth example, a ceramic component was first colored using a commercially available ceramic powder of 3 mol% yttria-stabilized zirconia (TZ3Y) containing 0.25 wt% alumina, to which 3 wt% organic binder and 1 wt% CoAl obtained by a conventional wet process (REF2) were added₂O₄A pigment. The resulting suspension was dried and granulated by spray drying. The granules were then pressed to obtain a sample. The sample was degreased and sintered to obtain a blue ceramic component characterized by the following CIEL a b parameters (50.5; -0.7; -19.4).

According to an embodiment of the present invention, the ceramic powder (REF2) having the binder is first degreased; 99g of the solution was taken out. The powder obtained in the first example was also subjected to degreasing; 1g of the resulting solution was taken out. The two removed samples were combined. Then 1.2g of PVA, 1.8g of PEG20000 and 200ml of DI water were added to 100g of this modified ceramic powder. The suspension thus obtained was placed in the zirconia bowl of a mill with 1kg of zirconia beads and milled for 70 minutes at a speed of 400 rpm. The suspension is then recovered for drying and granulation by spray drying using a "spray dryer". The obtained granules were then pressed into a cylindrical mould on a uniaxial press. The resulting pellets were degreased in air at 600 ℃ for 18 hours. Finally, it was sintered in air at 1450 ℃ for two hours according to a cycle known to the skilled person. The sample from this eighth example contains 0.02 wt.% platinum. After sintering, the surface of the pellets was ground and then polished. The modified color is then recorded (see fig. 11).

Ninth example first consider the manufacture of a 3 mol% yttria-stabilized zirconia (TZ3Y) powder comprising 3 wt% organic binder and 0.5 wt% CoAl doped by a conventional wet process (REF3)₂O₄a pigment. The resulting suspension was dried and granulated by spray drying. The granules were then pressed to obtain a sample.The sample was degreased and sintered. The ceramic obtained was blue in color, having the parameters CIE L a b (52.0; -1.9; -15.5).

Next, the particles (REF3) used to manufacture the zirconia-based ceramic component were degreased. 1g of the degreased powder from the first example was added to 99g of the degreased ceramic powder. Subsequently, 1.2g of PVA, 1.8g of PEG20000 and 200ml of deionized water were added to the 100g of mixed powder. The resulting suspension was placed in the zirconia bowl of a mill with 1kg of zirconia beads and milled for 70 minutes at a speed of 400 rpm. The suspension is then recovered for drying and granulation by spray drying using a "spray dryer". The obtained granules were then pressed into a cylindrical mould on a uniaxial press. The resulting pellets were degreased in air at 600 ℃ for 18 hours. Finally, it was sintered in air at 1450 ℃ for 2 hours. The sample from this ninth example contained 0.02 wt.% platinum. After sintering, the surface of the pellets was ground and then polished. The ceramic component thus has a modified color (see parameters shown in fig. 11).

In a tenth embodiment, the ceramic component was formed from a commercial powder of 3 mol% yttria-stabilized zirconia (TZ3Y) containing 0.25 wt% alumina, 3 wt% organic binder, and 0.5 wt% CoAl added by a conventional wet process (REF3)₂O₄A pigment. The resulting suspension was dried and granulated by spray drying. The granules were then pressed to obtain a sample. The sample was degreased and sintered. The ceramic obtained was blue in color, having the parameters CIE L a b (52.0; -1.9; -15.5).

According to an embodiment, the particles (REF3) used to manufacture the aforementioned ceramic components are first degreased. Next, 1.8g of the degreased ceramic powder from example 1 was added to 98.2g of the degreased ceramic powder. Then 1.2g of PVA, 1.8g of PEG20000 and 200ml of deionized water were added to 100g of the modified ceramic powder. The suspension thus obtained was placed in the zirconia bowl of a mill with 1kg of zirconia beads and milled for 70 minutes at a speed of 400 rpm. The suspension is then recovered for drying and granulation by spray drying using a "spray dryer". The obtained granules were then pressed into a cylindrical mould on a uniaxial press. The resulting pellets were degreased in air at 600 ℃ for 18 hours. Finally, it was sintered in air at 1450 ℃ for 2 hours. Thus, the sample from the tenth example contained 0.036 wt.% of platinum. After sintering, the surface of the pellets was ground and then polished. The ceramic component thus has a modified color (see parameters shown in fig. 11).

The three previous examples are based on the application of embodiments of the invention to easily obtain the desired colour starting from a coloured ceramic powder, the colour of which is finally changed.

More generally, embodiments of the present invention are readily compatible with all other techniques for adding at least one compound to ceramic powders having a binder. Thus, the present invention can be combined with any other technique, in particular with conventional methods, to obtain any type of ceramic with novel properties.

For example, the eleventh example considers a ceramic powder of 3 mol% yttria-stabilized zirconia to which 30 wt% of a luminescent pigment Sr was added by a conventional wet process (REF4)₄Al₁₄O₂₅Dy and 3% of organic adhesive. The resulting suspension was dried and granulated by spray drying. The granules were pressed, degreased in air and sintered at 1450 ℃ for 2 hours under a specific atmosphere. The conventional process enables to obtain ceramics having a color defined by the CIE L a b parameter (94.0; -4.7; 6.7).

As a modification of the embodiment of the present invention, the particles (REF4) of the composite ceramic powder used above are degreased. 1g of the defatted powder from the first example was added to 99g of the powder. Subsequently, 1.2g of PVA, 1.8g of PEG20000 and 200ml of deionized water were added to 100g of the obtained powder. The resulting suspension was placed in the zirconia bowl of a mill with 1kg of zirconia beads and milled for 70 minutes at a speed of 400 rpm. The suspension is then recovered for drying and granulation by spray drying using a "spray dryer". The obtained granules were then pressed into a cylindrical mould on a uniaxial press. The resulting pellets were degreased in air at 600 ℃ for 18 hours. Finally, it was sintered for 2 hours at 1450 ℃ in a specific atmosphere. The sample from this eleventh example contains 0.02 wt.% platinum. After sintering, the surface of the pellets was ground and then polished. Thus, by combining the present invention with conventional methods, this results in a colored and luminescent ceramic component, the precise properties of which are summarized in the table of fig. 12. As a variant, further colors can be imparted to such phosphorescent or luminescent ceramic components by adding further added elements or compounds.

The preceding examples are based on the use of added compounds to obtain colored ceramic components, since such examples have the advantage of illustrating the invention in a very meaningful way for visualization.

The following examples enable the production of grey ceramic components on powders without binders with a colour tone not producible by conventional techniques through the specific use of the ALD method. All the results obtained, in particular in terms of colour, are summarized in the table of figure 15.

The first example is based on the use of a ceramic powder with binder removal consisting of 3 mol% yttria-stabilized zirconia (TZ3 YS). 10g of this powder was placed in the vibrating bowl of the ALD chamber and evacuated to initiate the deposition of platinum by the ALD process. 50 deposition cycles were performed.

The ceramic powder thus coated is then subjected to grinding (mixing, wet grinding) and binding processes. In this treatment, 0.6g of PVA, 0.9g of PEG20000 and 116ml of deionized water were added to 50.4g of the platinum coated ceramic powder. The suspension thus obtained was placed in the zirconia bowl of a mill with 1kg of zirconia beads and milled/milled at a speed of 400rpm for 2 hours. The suspension is then recovered for drying and granulation by spray drying using a "spray dryer". The granules thus obtained are then pressed into a cylindrical mould on a uniaxial press. The resulting pellets were degreased in air at 600 ℃ for 18 hours. Finally, it was sintered in air at 1450 ℃ for 2 hours. After sintering, the surface of the ceramic pellet is ground and then polished. The ceramic component obtained is grey in colour. Fig. 13 is an image of the sintered ceramic pellet obtained by a Scanning Electron Microscope (SEM), which shows the distribution of platinum particles (bright spots). The figure can demonstrate a uniform distribution of platinum particles. In particular, the distribution of these particles is considered uniform over the size of the assembly. The color produced appears uniform to the naked eye. The color and composition are given in the table of fig. 15 with the number 1ALD 50.

The second example is based on the use of a ceramic powder freed of binder, consisting of 3 mol% of yttria-stabilized zirconia (TZ3 YS). 10g of this powder was placed in the vibrating bowl of the ALD chamber and evacuated to initiate the deposition of platinum by the ALD process. 200 deposition cycles were performed. The ceramic powder thus coated is then subjected to grinding (mixing, wet grinding) and binding processes. In this treatment, 0.6g of PVA, 0.9g of PEG20000 and 120ml of deionized water were added to 50.4g of the platinum coated ceramic powder. The suspension thus obtained was placed in the zirconia bowl of a mill with 1kg of zirconia beads and milled/milled at a speed of 400rpm for 2 hours.

The suspension is then recovered for drying and granulation by spray drying using a "spray dryer". The granules thus obtained are then pressed into a cylindrical mould on a uniaxial press. The resulting pellets were degreased in air at 600 ℃ for 18 hours. Finally, it was sintered in air at 1450 ℃ for 2 hours. After sintering, the surface of the ceramic pellet is ground and then polished. The ceramic component obtained is grey in colour. Fig. 14 is an image of the sintered ceramic pellet obtained by a Scanning Electron Microscope (SEM), which shows the distribution of platinum particles (bright spots). The figure can demonstrate a uniform distribution of platinum particles. In particular, the distribution of these particles is considered uniform over the size of the assembly. The color produced appears uniform to the naked eye. The color and composition are given in the table of fig. 15 as number 2ALD 200.

The results of the previous two examples are shown in the table of fig. 15. It is noted that all these embodiments enable grey ceramics to be obtained. In general, therefore, one embodiment of the invention advantageously enables the manufacture of grey ceramics, characterized by two parameters a and b ranging from-1 to 1 (inclusive).

as a variant, one embodiment of the invention enables the manufacture of grey ceramic components, characterized in that the two parameters a and b are-3 to 3 inclusive, or even-2 to 2 inclusive, or even-0.5 to 0.5 inclusive.

Furthermore, the colour of the ceramic component is particularly important for a timepiece or jewelry part, since it allows to achieve the desired aesthetic effect. The invention is therefore particularly advantageous for the manufacture of timepiece or jewelry parts. The timepiece component may be, in particular, a bezel, a dial, an indicator, a winding crown, a push button or any other timepiece housing element or timepiece movement element. The invention also relates to a timepiece, in particular a wristwatch, including such a timepiece assembly.

Naturally, the invention is not limited to a specific color, nor to a given performance of the ceramic component. In fact, the concept of the invention is to increase and simplify the possible enrichment of ceramic components, and the invention finally enables the manufacture of a variety of novel ceramic components.

In particular, the ceramic component obtained by the embodiments of the present invention comprises at least one specific property obtained by a very small amount of added compound distributed in the ceramic component. This very small amount is less than or equal to 5 wt%, or less than or equal to 3 wt%, or less than or equal to 1 wt%, or less than or equal to 0.05 wt%, or less than or equal to 0.01 wt%, relative to the total weight of the final ceramic compound. Moreover, this content will advantageously be greater than or equal to 1ppm, or greater than or equal to 10 ppm.

The invention further relates to a device for producing a ceramic component, wherein the device uses a method for producing a ceramic component. To this end, the manufacturing apparatus includes a chamber for performing Physical Vapor Deposition (PVD) or Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD).