Cermet decorative items

Abstract

The present invention provides decorative items made of cermet material that do not contain allergy-inducing metal binders such as nickel or cobalt, and a method for manufacturing the same. [Solution] The cermet material comprises 70 to 97% by weight of a ceramic phase and 3 to 30% by weight of a metallic binder phase. The metallic binder comprises at least one element or an alloy thereof selected from the list consisting of ruthenium, rhodium, palladium, osmium, iridium, platinum, gold, and silver. The ceramic phase comprises a nitride phase and optionally an oxide phase and / or an oxynitride phase. The nitride phase is present in a proportion of 70 to 97% by weight of the total weight of the cermet material, and the oxide phase and / or oxynitride phase is present in a proportion of 0 to 15% by weight.

Description

[Technical Field]

[0001] The present invention relates to decorative items made of cermet-type material, and more specifically to timekeeping devices. Regarding external components. Cermet-type materials consist of a ceramic phase comprising nitrides and precious It consists of a metallic phase containing metal. [Background technology]

[0002] Nitride-based colored cermets contain allergenic metals such as nickel or cobalt. Contains a compound. Manufactured of parts that may come into contact with the skin, such as watch cases or jewelry. To manufacture it, it is essential to develop a composition that does not use binders containing these elements. be.

[0003] Furthermore, cermets used for specific applications such as watch cases have extremely high durability. It must be scratch-resistant, meaning it must have a hardness exceeding 1,000 HV. This includes gold. It is necessary to reduce the amount of metal binder while controlling the wettability between the metal binder and the ceramic phase. Yes. Low wettability leads to a decrease in the density of the final product, and therefore a decrease in hardness. It does not contain nickel or cobalt and has excellent final properties, including yellow titanium nitride (Ti It is difficult to manufacture N-type colored cermets by powder metallurgy and conventional liquid-phase sintering. This is mainly because titanium nitride has a very high melting point of 2,930°C, and the metal in liquid phase sintering... This is due to poor wetting with the binder. As a result, the porosity of the cermet at the end of sintering The temperature increases, and the hardness decreases.

[0004] In addition to hardness, different phases are used to ensure that high toughness and the desired color tone are obtained in the final product. The proportions also need to be adjusted. [Overview of the project]

[0005] The objective of the present invention is to propose a cermet having an optimal composition that satisfies the following criteria, as described above. It's about overcoming shortcomings. - Do not use allergy-inducing elements such as nickel or cobalt. - Densification is possible through liquid-phase sintering under low pressure (conventional sintering). - For applications requiring very high scratch resistance, 2.8 MPa.m is preferred. 1 / 2 Below K above iC It possesses sufficient toughness, with a minimum hardness of 500HV30, preferably the minimum hardness of 500HV30. Having a low hardness of 550 HV30, and more preferably a minimum hardness of 1,000 HV30. -Having a color tone ranging from white to yellow, and having a high metallic luster (65 <L*≦80)。

[0006] Therefore, the present invention proposes decorative items made of cermet material. The material comprises 70 to 97% by weight of a ceramic phase and 3 to 30% by weight of a metal binder phase. The metal binders are ruthenium, rhodium, palladium, osmium, iridium, and platinum. It comprises at least one element or an alloy thereof selected from the list consisting of gold, silver, and na. The ceramic phase comprises a nitride phase and optionally an oxide phase and / or an oxynitride phase. The nitride phase makes up 70 to 97% by weight of the total weight of the cermet material, and oxidation The material phase and / or oxynitride material phase are present in a proportion of 0 to 15% by weight.

[0007] Specifically, titanium nitride (TiN) based yellow cermets are produced using powder metallurgy and conventional liquid phase calcination. To manufacture by knotting, oxides and / or oxynitrides are added to create a dense structure. It is proposed to promote the transformation and increase the hardness.

[0008] The cermet material thus developed has a metallic luster exceeding that of cermets using nickel or cobalt as a metal binder after polishing, and has a metallic luster comparable to that of stainless steel (L* = 75 - 80). These precious cermets have a hardness that can reach 1,250 HV30 and have sufficient toughness for manufacturing external parts. Furthermore, these cermets can be formed by conventional powder metallurgy such as compression or injection to obtain "near-net shape" 3D parts close to the finished product.

[0009] Other features and advantages of the present invention will become apparent from the following description of the preferred embodiments, which are described by way of non-limiting examples with reference to the accompanying drawings.

Brief Description of the Drawings

[0010] [Figure 1] A timepiece comprising a body made of a cermet-type material according to the present invention is shown. [Figure 2] An optical microscope image of a cermet-type material according to the present invention having a composition of 92 wt% TiN and 8 wt% Pd is shown. [Figure 3] An optical microscope image of a cermet-type material according to the present invention having a composition of 84.6 wt% TiN, 9.4 wt% zirconium oxide (ZrO2), and 6 wt% Pd is shown.

Mode for Carrying Out the Invention

[0011] The present invention relates to a decorative item made of a cermet-type material. The cermet-type material comprises 70 to 97 wt% of a ceramic phase and 3 to 30 wt% of a metal binder phase. ​Comprising (consisting of). Preferably, the cemented carbide comprises 75 to 97% by weight of a ceramic phase and 3 to 25% by weight of a metal binder phase. More preferably, the cemented carbide comprises 78 to 96% by weight of a ceramic phase and 4 to 22% by weight of a metal binder phase. The metal binder is selected from the list of elements comprising ruthenium, rhodium, palladium, osmium, iridium, platinum, gold and silver. The metal binder may also relate to, for example, combinations of these elements such as Au-3N, Au-5N, etc., or combinations of alloys of one of these elements. The ceramic phase comprises a nitride phase and optionally an oxide phase and / or an oxynitride phase. In other words, the ceramic phase consists of a nitride phase and optionally an oxide phase and / or an oxynitride phase. The purpose of the oxide phase and / or the oxynitride phase is to increase the mechanical properties. When the oxide phase and / or the oxynitride phase is present, the oxide phase and / or the oxynitride phase is less than the nitride phase. More specifically, based on the total weight of the cemented carbide, the nitride phase is present in a proportion of 70 to 97% by weight, and the oxide phase and the oxynitride phase are present in a proportion of 0 to 15% by weight. The nitride is selected from the non-exclusive list comprising Al, Ti, Si, Mn, Zr, Hf, Ta, Nb, V, Cr, Mo, W, B nitrides, and combinations of nitrides of these elements. The oxide and the oxynitride are each selected from the non-exclusive list comprising Al, Ti, Si, Mn, Zr, Hf, Ta, Nb, V, Cr, Mo, W, B oxides and oxynitrides, and combinations of oxides and oxynitrides of these elements. The decorative item may be a component such as a wristwatch, a part of a jewel, a bracelet, etc.

[0012] ​ In the field of watch manufacturing, decorative items include the case, case back, bezel, crown, and bracelet. External components such as rings, dials, hands, and dial indices may also be included. Figure 1 shows the body portion 1 made of the cermet-type material according to the present invention.

[0013] Cermet items are manufactured by sintering, starting with a mixture of ceramic and metal powders. The manufacturing method includes the following steps. a) Steps to produce a mixture of various powders in a humid environment if possible. The diameter (d50) is preferably less than 10 μm, and more preferably 2 to 5 μm. The mixture may be prepared in a grinder if possible, after milling. The d50 powder particles are reduced to a size of about a micron, or even smaller. The mixture is made up of 70 to 97% by weight, preferably 75 to 97% by weight, more preferably It contains 78 to 96% by weight of ceramic powder, and 3 to 30% by weight, preferably 3 to The ceramic powder contains 25% by weight, more preferably 4 to 22% by weight of metal powder. The substance and optionally oxides and / or oxynitrides. More specifically, relative to the total weight of the powder. The nitride is then 70 to 97% by weight, preferably 75 to 97% by weight, more preferably 7 They are present in proportions of 8 to 96% by weight, and oxides and / or oxynitrides are present in proportions of 0 to 15% by weight. They exist in proportions. Nitrides include Al, Ti, Si, Mn, Zr, Hf, Ta, Nb, V, and C. A non-exclusive list including r, Mo, W, B nitrides and combinations of nitrides of these elements. Selected from: Advantageously, nitrides include Ti, Ta, Nb, Zr nitrides and their elements. The selection is made from combinations of basic nitrides. Oxides and oxynitrides are Al, T, etc. i, Si, Mn, Zr, Hf, Ta, Nb, V, Cr, Mo, W, B oxides and oxynitridations From a non-exclusive list including substances and combinations of oxides and oxynitrides of these elements Selected. Advantageously, oxides and oxynitrides are Zr or Nb oxides and oxynitrides. Selected from: Metal powders include ruthenium, rhodium, palladium, osmium, iridium Metallic elements including platinum, gold, and silver, combinations of these elements and these A selection is made from a list of alloys of one element. Therefore, preferably, gold is Cu, It is an alloy with at least one element selected from Ag, Pd, C, and N. Advantageously, gold The powders mainly consist of palladium, platinum, silver, or gold alloyed with copper and / or silver. The metal powder, apart from impurities, is platinum, palladium, silver, or copper and / or silver. It may consist entirely of alloyed gold. For example, the powder mixture may have the following weight distributions You may include one of them. -78 to 96% by weight of TiN and 5 to 20% by weight of Pd or Pt, -80 to 90 wt% TiN and 10 to 20 wt% Ag, -75 to 85 wt% TiN and 15 to 25 wt% Au alloy, -80 to 90 wt% niobium nitride (NbN) and 10 to 20 wt% Au alloy, -85 to 95% by weight NbN or tantalum nitride (TaN) and 5 to 15% by weight Pd or Pt, -80 to 90 wt% TiN, 5 to 15 wt% ZrO2, and 3 to 10 wt% % Pd or Au alloy, -75 to 85 wt% TiN, 5 to 15 wt% zirconium nitride (ZrN), and 5 to 15% by weight of Au alloy, -70 to 80 wt% NbN, 5 to 20 wt% niobium pentoxide (Nb2O5), and 5 to 15% by weight of Pt. b) Optionally comprising the aforementioned mixture and an organic binder system (paraffin, polyethylene, etc.) A second step in which a mixture can be created. c) For example, by injection (ceramic injection molding) or compression, the mixture is as desired. This step involves shaping the item and forming a blank. d) Under an inert atmosphere, nitrogen, or vacuum, to 1,100 to 2,100°C At a temperature, preferably between 1,400 and 1,750°C, for 30 minutes to 20 hours. The next step is to sinter the blank, preferably for 30 minutes to 2 hours. The mixture is an organic binder. If a system is included, decouple it at a temperature range of 200 to 800°C before this step. You may take the first step.

[0014] The blank obtained in this way is cooled and polished. The blank may be machined before polishing.

[0015] The item obtained by this manufacturing method has a ceramic phase and a metallic phase. This is close to the weight percentage of the starting powder. However, due to contamination or alteration during sintering, for example, There is a possibility of slight variations in composition and proportion between the raw material powder and the material obtained from sintering. This cannot be denied. For example, if the starting powder contains both nitrides and oxides of the same element, acid Nitrides can sometimes form in situ. The metallic and ceramic phases are present in the cermet material. It is distributed uniformly.

[0016] The item is (International Commission on Illumination (CIE) Standard No. 15, ISO7724 / 1, Germany) According to industrial standards (DIN) 5033 Teil 7 and ASTM E-1164, the light of the material The brightness L* component, which indicates the reflectance, is at least 60, preferably at least 65, and more preferably at least It has a CIELAB color space where the value is 75. The range of color variation is from white, which corresponds to steel color, From a slightly yellowish hue to a distinct yellow. More specifically, white. For this item, the a* component is between -3 and +3, and the b* component is between -3 and +3. For colors between white and yellow, the a* component is between 0 and +3, and the b* component is between 0 and +1. It is between 0. In yellow, the a* component is between 0 and +5, and the b* component is between +20 and +3. It is between 0.

[0017] The ceramic material was measured under a 30kg (HV30) load to determine the type and proportion of constituent materials. This results in a Vickers hardness of 500 to 1,300, preferably 550 to 1,250. It has advantages. For external parts where very high scratch resistance is required, ceramic material is advantageous. It has a hardness higher than 1,000 Vickers. Ceramic materials have a minimum hardness of 2 MPa.m 1 / 2 Preferably a minimum of 2.8 MPa.m 1 / 2 Toughness K iC It has the following toughness: The hardness is determined according to the formula, based on the measurement of the length of the crack at the four ends of the diagonal of the indentation. It is determined.

[0018]

number

[0019] In the formula, P is the applied load (N), a is half the diagonal (m), and l is the measured length. This is the length of the crack (m).

[0020] Table 1 below includes various examples of cermets according to the present invention. Italicized and bold values ​​are: Hardness exceeding 1,000 Vickers, 2.8 MPa.m 1 / 2 Superior toughness, deep yellow It must meet the criteria for an L* index of over 75 or a b* index of over 25.

[0021] Thirteen mixtures of powders with different compositions were prepared using a pulverizer in the presence of a solvent. The mixtures were organic It was manufactured without the addition of a binder. After drying, the mixture was formed by uniaxial pressure and baked in a vacuum. The mixture is bonded, or heated under a dynamic partial pressure of argon or nitrogen at 60 mbar, depending on the temperature of the powder composition. It was sintered at [temperature]. After sintering, the sample was flattened to accurately measure its mechanical properties and color index. It was polished.

[0022] The hardness was determined by performing HV30 hardness measurements on the surface of the sample, based on the aforementioned hardness measurements.

[0023] The Lab colorimetric values ​​of the polished sample were measured using a KONICA MINOLTA CM-5 spectrophotometer. Using this, SCI (including specular reflection) and SCE (excluding specular reflection) measurements were performed, with a tilt of 8°. Measurements were taken under the conditions of an 8mm diameter MAV measurement zone.

[0024] These tests show that hardness exceeding 1,000 Vickers can be achieved with the following composition. This is clear. TiN 84.6%, ZrO 29.4%, Pd 6% (test number 3), Nb N89.5%, Pd10.5% (Test No. 4), TaN89.5%, Pd10.5% (Test No. 4) Test No. 5), TiN 85%, Pt 15% (Test No. 6), NbN 75%, Nb2O 515 %, Pt 10% (Test No. 8), TiN 84.6%, ZrO2 9.4%, Au3N 6%( (Test No. 9), NbN 86%, Au 10.5%, Cu 3.5% (Test No. 12). These same compositions have toughness exceeding 3.3 MPa·m 1 / 2 and have toughness exceeding 3.3 MPa·m

[0025] Specifically, when comparing Test No. 2 (TiN 92%, Pd 8%) and Test No. 3 (TiN 84.6% , ZrO2 9.4%, Pd 6%), it can be seen that when adding an oxide in the case of ZrO2, the Vickers hardness clearly increases from 590 to 1,050. Densification can be improved by the oxide, and the oxide functions as a reinforcing agent for enhancing mechanical properties. In FIG. 3, when adding an oxide to Sample No. 3, a decrease in porosity (black dots) is observed compared to Sample No. 2 in FIG. 2. Thus, without significantly affecting toughness, the hardness almost doubles. Similarly, when comparing Test No. 7 and Test No. 8 , an increase in hardness and toughness is observed by adding Nb2O5.

[0026] Furthermore, by combining NbN and a gold alloy (Test No. 12), a hardness value exceeding 1,000 Vickers

[0027] and toughness exceeding 4.5 MPa·m 1 / 2 and a lightness L* value close to 80, that is, it becomes possible to combine the same lightness as polished stainless steel.

[0028] When using platinum of Sample No. 6 as a binder instead of palladium of Sample No. 1, it can be seen that the hardness increases to reach a maximum value of 1,192 Vickers hardness due to this difference including 85% TiN. <​​​ *Au-3N: Au 75%, Ag 12.5%, Cu 12.5%, added as per Table 1

Claims

1. A decorative item made of cermet material, wherein the cermet material is 70 to 97 The material comprises a ceramic phase in weight percent and a metal binder phase in weight percent of 3 to 25 percent, wherein the metal binder is Ruthenium, rhodium, palladium, osmium, iridium, platinum, gold, and silver The set comprises at least one element or an alloy thereof selected from the list consisting of the following: The lamic phase comprises a nitride phase and optionally an oxide phase and / or an oxynitride phase, and the - The nitride phase is present in a proportion of 70 to 97% by weight relative to the total weight of the metal material, The oxide phase and / or oxynitride phase are present in a proportion of 0 to 15% by weight, decorative item Hmm.

2. The item according to claim 1, wherein the metal binder phase is present in a proportion of 4 to 22% by weight. The ceramic phase is present in a proportion of 78 to 96% by weight, and the total of the cermet material The nitride phase is present in a proportion of 78 to 96% by weight, and the oxide phase and The item is characterized by the presence of a nitride / or oxynitride phase in a proportion of 0 to 15% by weight. Hmm.

3. An item according to claim 1 or claim 2, wherein the nitride phase is Al, Ti, S Select from the list of nitrides i, Mn, Zr, Hf, Ta, Nb, V, Cr, Mo, W, B An item characterized by containing one or more nitrides.

4. The item according to claim 3, wherein the nitride is Al, Si, Ti, Ta, Nb, An item characterized by being selected from Zr nitrides.

5. An item according to any one of claims 1 to 4, wherein the oxide and acid Nitrides are Al, Ti, Si, Mn, Zr, Hf, Ta, Nb, V, Cr, and M, respectively. O, W, B oxides and oxynitrides, and combinations of oxides and oxynitrides of these elements An item characterized by being selected from a list that includes the following.

6. The item according to claim 5, wherein the oxide and oxynitride are Al, Si, Ti An item characterized by being selected from Ta, Nb, Zr oxides and oxynitrides.

7. The item according to claim 6, wherein the ceramic phase is a Ti nitride phase and a Zr acid An item characterized by being composed of a chromoid phase.

8. The item according to claim 6, wherein the ceramic phase is an Nb nitride phase and an Nb acid An item characterized by being composed of a chromoid phase.

9. An item according to any one of claims 1 to 8, wherein the metal binder phase is It is characterized by being composed of palladium, platinum, silver, or a gold alloy, apart from impurities. ,item.

10. An item according to any one of claims 1 to 9, wherein the metal binder phase is The material contains a gold alloy, wherein the gold alloy is selected from one or more of copper, silver, palladium, and nitrogen. An item characterized by possessing a number of elements.

11. An item according to any one of claims 1 to 10, wherein 500 to 1,3 00, preferably characterized by having a Vickers hardness HV30 of 550 to 1,250. An item to do.

12. An item according to any one of claims 1 to 11, - The ceramic phase comprises Ti nitride and Zr oxide, and the metal binder phase comprises Pd Or when it contains an Au alloy, - If the ceramic phase contains Ta or Nb nitride and the metal binder phase contains Pd tree, - When the ceramic phase contains Ti nitride and the metal binder phase contains Pt, - The ceramic phase comprises Nb nitride and Nb oxide, and the metal binder phase comprises Pt. At that time, - When the ceramic phase contains Nb nitride and the metal binder phase contains Au alloy, An item characterized by having a Vickers hardness of over 1,000, HV30.

13. An item according to any one of claims 1 to 12, wherein the pressure is 2.8 MPa. m １／２ The above toughness K ｉＣ An item characterized by having the following features.

14. An item according to any one of claims 1 to 13, wherein the color is CIELAB. In between, the L* component has a minimum of 60, preferably a minimum of 65, and more preferably a minimum of 75. An item characterized by [something].

15. An item according to any one of claims 1 to 14, which is yellow and CI In the ELAB color space, the a* component is between 0 and +5, and the b* component is between +20 and +3. An item characterized by being between zero.

16. An item according to any one of claims 1 to 14, wherein it is white and CI In the ELAB color space, the a* component is between -3 and +3, and the b* component is between -3 and +3. An item characterized by being between [something].

17. An item according to any one of claims 1 to 14, wherein the color is between white and yellow. It has a color, and in the CIELAB color space, the a* component is between 0 and +3, and the b* component is An item characterized by being between 0 and +10.

18. An item according to any one of claims 1 to 17, comprising a body, a case back, and a bezel. It features a crown, bracelet links, dial, hands, and dial indices. An item characterized by relating to a component of an external timekeeping device selected from a list.

19. A method for manufacturing decorative items, a) A step of producing a mixture of ceramic powder and metal binder powder, wherein the Lamic powder comprises nitrides and optionally oxides and / or oxynitrides, and a metal binder. The powder contains ruthenium, rhodium, palladium, osmium, iridium, platinum, gold, A step comprising at least one element selected from a list of elements consisting of silver or an alloy thereof. and, b) The step of forming a blank in which the mixture is shaped into the item, c) At a temperature between 1,100 and 2,100°C, preferably between 1,400 and 1,750°C At a temperature up to ℃, for a period of 30 minutes to 20 hours, preferably for a period of 30 minutes to 2 hours, the bra The steps of sintering the ink, A method comprising a series of steps, In the above method, the ceramic powder is 70 to 97% by weight, preferably 75 to 9 The metal binder powder is present in an amount of 7% by weight, more preferably 78 to 96% by weight, and the metal binder powder is present in an amount of 3 to 25% by weight. A method characterized by the presence of %, more preferably 4 to 22% by weight.

20. The method according to claim 19, wherein the mixture in step a) is -78 to 96 wt% TiN and 4 to 22 wt% Pd or Pt, -80 to 90% by weight of TiN and 10 to 20% by weight of Ag, - 75 to 85 wt% TiN and 15 to 25 wt% Au alloy, -80 to 90 wt% NbN and 10 to 20 wt% Au alloy, -85 to 95% by weight of NbN or TaN, and 5 to 15% by weight of Pd or Pt, -80 to 90 wt% TiN and 5 to 15 wt% ZrO ２ and 3 to 10% by weight Pd or Au alloy, -75 to 85 wt% TiN, 5 to 15 wt% ZrN, and 5 to 15 wt% Au alloy, -70 to 80% by weight of NbN and 5 to 20% by weight of Nb ２ O ５ And, 5 to 15 weight % of points A method characterized by including one of the following formulations.

21. A method according to claim 19 or claim 20, wherein step b) compression or injection A method characterized by being carried out accordingly.

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