• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a method for manufacturing a decorative article, in particular a clock component, of brown color, comprising the successive steps of: making a first mixture with a powder of Si 3 N 4, a powder of Y 2 O 3, an Al 2 O 3 powder and a TiO 2 powder, said first mixture comprising, by weight, between 79 and 91% Si 3 N 4, between 3 and 7% Y 2 O 3, between 3 and 7% Al 2 O 3, between 3 and 7% of TiO 2, make a second mixture comprising the first mixture and a binder, form a blank giving this second mixture the desired shape of the article, dissolve the the blank, sinter the debonded blank at a temperature between 1650 and 1850 ° C under a pressure between 20 and 80 bar nitrogen for a period of between 30 minutes and 3 hours.
    公开号:CH714796A2
    申请号:CH00342/18
    申请日:2018-03-16
    公开日:2019-09-30
    发明作者:Cartier Damien；Le Colleter Alexandre；Tkocz Valentin；Dumain Jonathan
    申请人:Comadur Sa；
    IPC主号:
    专利说明:

    Description
    TECHNICAL FIELD The present invention relates to a method for manufacturing a decorative article, in particular a watch component, of brown color based on silicon nitride. It also relates to the decorative article.
    PRIOR ART In the watchmaking field, it is known to produce covering components such as ceramic watch cases based on zirconium oxide, otherwise called zirconia, with a color which can be adjusted according to the composition of the ceramic. Thus, documents EP 3 012 239 and CH 708 030 disclose zirconia ceramics based on gray color and on orange color respectively.
    Another ceramic which is silicon nitride is also used in watch components. This ceramic has the advantage of being less dense than zirconia, which makes it possible to manufacture components which are light while being hard. For example, the document CH 699 793 discloses a ceramic material based on silicon nitride used as a substrate for watch case middle pieces or bracelet links.
    [0004] The silicon nitride is gray in color. For aesthetic reasons, other colors may be desired.
    SUMMARY OF THE INVENTION The object of the present invention is therefore to propose a method for manufacturing a sintered article based on silicon nitride which is colored in its mass and, in particular, which is brown in color.
    To this end, the composition of the ceramic powder based on silicon nitride (Si 3 N 4 ) is suitable. It contains oxides of titanium (TiO 2 ), yttrium (Y 2 O 3 ) and aluminum (AI 2 O 3 ). Titanium oxide gives the product brown color. The yttrium and aluminum oxides form a liquid phase during sintering which acts as a binder for the grains of Si 3 N 4 while allowing the brown color of the final product to be nuanced. The different oxides are thus present in percentages chosen to obtain a very specific brown color which qualitatively can be described as chocolate brown. The percentage by weight of TiO 2 is maintained in a range between 3 and 7%, preferably between 4 and 6% and more preferably between 4.5 and 5.5%. The percentages by weight of Y 2 O 3 and of AI 2 O are maintained between 3 and 7% and, preferably, between 4 and 6%.
    Other features and advantages of the present invention will appear in the following description of a preferred embodiment, presented by way of non-limiting example with reference to the accompanying drawing.
    BRIEF DESCRIPTION OF THE FIGURE [0008] FIG. 1 shows a watch case made with the ceramic material based on silicon nitride according to the invention.
    DETAILED DESCRIPTION The present invention relates to an article of brown color made of a ceramic material based on silicon nitride and to its manufacturing process. This article can be a component of watches, jewelry, bracelets, brooches, necklaces, handbags, etc. In the watchmaking field, this article can be a middle part, a back, a bezel, a push-piece, a bracelet link, a dial, a hand, a dial index, etc. By way of illustration, a watch case 1 produced with the ceramic material according to the invention is shown in FIG. 1.
    The article is manufactured by sintering with the process consisting in:
    - Make a first mixture with a powder of Si 3 N 4 , a powder of Y 2 O 3 , a powder of AI 2 O 3 and a powder of TiO 2 . The mixture comprises by weight between 3 and 7%, preferably between 4 and 6%, of Y 2 O 3 , between 3 and 7%, preferably between 4 and 6% of AI 2 O 3 , between 3 and 7 %, preferably between 4 and 6%, and more preferably between 4.5 and 5.5% of TiO 2 , the complement being the powder of Si 3 N 4 . In a particularly preferred manner, the mixture comprises by weight 85% of Si 3 N 4 , 5% of Y 2 O 3 , 5% of AI 2 O 3 and 5% of TiO 2 .
    - Grind the first mixture to obtain a particle diameter d100 less than or equal to 5 μm if the first mixture has a diameter d100 greater than this value. Preferably, the diameter d100 of the particles is less than or equal to 3 μm to finally obtain a very dense sintered product with a very fine microstructure. The grinding time can be of the order of an hour with, for example, a time of 2 hours.
    - Make a second mixture comprising the first mixture and an organic binder system (paraffin, polyethylene, etc.).
    - Form a blank by giving this second mixture the shape of the desired article, for example, by injection or pressing.
    - Unbind the blank, for example with a solvent.
    CH 714 796 A2
    - Sinter the debonded blank at a temperature between 1650 and 1850 ° C, preferably between 1700 and 1800 ° C, under a pressure between 20 and 80, preferably between 50 and 70, bars of nitrogen for a period included between 30 minutes and 3 hours and, preferably, between 1 and 2 hours.
    The article from the process has a brown color imparted by titanium oxide. More specifically, it has a chocolate brown color when the starting powder contains 85% of Si 3 N 4 , 5% of Y 2 O 3 , 5% of AI 2 O 3 and 5% of TiO 2 . The shade of brown can be modulated by adjusting the TiO 2 content as well as the Y 2 O 3 content which tends to change the intensity of the color and the AI 2 O 3 content which tends to provide shades of green. The yttrium and aluminum oxides act as a binder for the grains of silicon nitride and form a glassy phase in the final product.
    For example, the method according to the invention was implemented to manufacture a watch case back from a powder comprising by weight 85% of Si 3 N 4 (UBE SNE10), 5% Y 2 O 3 (Starck Grade C), 5% AI 2 O 3 (Sumitomo AKP 50) and 5% TiO 2 (US Research Nanomaterials 300 nm), the powder mixture having passed through an attritor for 1 hour in order to obtain a d100 of less than 3 μm. Hardness (HV30), toughness (Kic), colorimetry (CIELab compliant with CIE n ° 15, ISO 7724/1, DIN 5033 Teil 7, ASTM E-1164) measurements were carried out.
    Table 1 below shows the results of the hardness and toughness measurements. The hardness measurements were carried out on a transverse section of the bottom with respectively three measurements below the surface and three measurements at the heart of the sample. The toughness was determined on the basis of the measurements of the lengths of the cracks at the four ends of the diagonals of the hardness imprint according to the formula:
    0.0319
    P
    FF 5 with P which is the applied load (N), a which is the half-diagonal (m) and / which is the length of the crack measured (m).
    The hardness is greater than 1500 Vickers and the toughness is greater than 4 MPa vm.
    Watch case back Hardness (HV30) Kic (MPa Vm) Position Average Standard deviation Average Standard deviation Area 1514 9.2 5.3 0.1 Heart 1509 8 4.8 0.2
    Table 1 Lab color values were measured with a KONICA MINOLTA CM-5 spectrophotometer under the following conditions: SCI measurements (specular reflection included) and SCE (specular reflection excluded), 8 ° tilt, MAV measurement area of 8 mm in diameter. The L * a * b * values are 43.320.42 and 2.42 respectively.
    claims
    权利要求:
    Claims (10)
    [1]
    1. Method for manufacturing a decorative article, in particular a watch component, of brown color, comprising the successive steps consisting in:
    - Make a first mixture with a powder of Si 3 N 4 , a powder of Y 2 O 3 , a powder of AI 2 O 3 and a powder of TiO 2 , said first mixture comprising by weight between 79 and 91% of If 3 N 4 , between 3 and 7% of Y 2 O 3 , between 3 and 7% of AI 2 O 3 and between 3 and 7% of TiO 2 ,
    - Make a second mixture comprising the first mixture and a binder,
    - Form a blank by giving this second mixture the desired shape of the article,
    - Unbinding the draft,
    - Sinter the debonded blank at a temperature between 1650 and 1850 ° C under a pressure between 20 and 80 bars of nitrogen for a period between 30 minutes and 3 hours.
    [2]
    2. Method according to claim 1, characterized in that the first mixture comprises by weight between 82 and 88% of Si 3 N 4 , between 4 and 6% of Y 2 O 3 , between 4 and 6% of AI 2 O 3 and between 4 and 6%, preferably between 4.5 and 5.5% of TiO 2 .
    [3]
    3. Method according to claim 2, characterized in that the first mixture comprises by weight 85% of Si 3 N 4 , 5% of Y 2 O 3 , 5% of AI 2 O 3 and 5% of TiO 2 .
    [4]
    4. Method according to any one of the preceding claims, characterized in that it comprises, before the step consisting in producing the second mixture, a step consisting in grinding the first mixture to obtain a diameter d100 of the particles less than or equal to 5 μm and preferably less than or equal to 3 μm.
    CH 714 796 A2
    [5]
    5. Method according to any one of the preceding claims, characterized in that the step consisting in sintering the debonded blank is carried out at a temperature between 1700 and 1800 ° C under a pressure between 50 and 70 bars of nitrogen for a period between 1 and 2 hours.
    [6]
    6. Decorative article, in particular a watch component, of brown color, produced in a sintered material from a base powder comprising a silicon nitride Si 3 N 4 , an oxide of yttrium Y 2 O 3 , an oxide of aluminum AI 2 O 3 and a titanium oxide “TiO 2 with by weight a percentage of Si 3 N 4 between 79 and 91%, a percentage of Y 2 O 3 between 3 and 7%, a percentage of AI 2 O 3 between 3 and 7% and a percentage of TiO 2 between 3 and 7%.
    [7]
    7. Article according to claim 6, characterized in that the base powder comprises by weight between 82 and 88% of Si 3 N 4 , between 4 and 6% of Y 2 O 3 , between 4 and 6% of AI 2 O 3 and between 4 and 6%, preferably between 4.5 and 5.5% of TiO 2 .
    [8]
    8. Article according to claim 7, characterized in that the base powder comprises 85% of Si 3 N 4 , 5% of Y 2 O 3 , 5% of AI 2 O 3 and 5% of TiO 2 .
    [9]
    9. Article according to claim 8, characterized in that it has a L * a * b * colorimetry of 43.320.42 and 2.42.
    [10]
    10. Article according to any one of claims 6 to 9, characterized in that the timepiece component is chosen from the list comprising a middle part, a case back, a bezel, a push button, a bracelet link, a dial, a hand and a dial index.
    类似技术:
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    同族专利:
    公开号 | 公开日
    CH714796B1|2021-05-14|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    CH00342/18A|CH714796B1|2018-03-16|2018-03-16|Brown-colored article and its manufacturing process.|CH00342/18A| CH714796B1|2018-03-16|2018-03-16|Brown-colored article and its manufacturing process.|
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