JP2009029669A - Ceramics for ornamental component, ornamental component for guide of fishing wire using the same and ornamental component for watch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that no ceramics for an ornamental component has been provided which has a tone of reddish silver, highly valuable as an ornamental means, and high abrasion resistance even though each person has his own taste for the color of an ornamental part for the guide of fishing wire and for a watch. <P>SOLUTION: The ceramics for ornamental part is composed of a sintered product of titanium carbonitride and has on its surface nickel, chromium, and their silicides and silicon nitride. The ceramics has excellent abrasion resistance and a balanced color of a color tone of blackish brown with metallic luster of titanium carbonitride, a silver tone of chrome, nickel and their silicides and a black tone of nitrogen silicide; wherein the lightness index L* is in the range of 60-71, while chromaticness index a* is 4-9 and b* is 7-10 in color specification system of CIE1976L*a*b*, and whereby the color of reddish silver, highly valuable for ornamental purpose, can be achieved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to ceramics for decorative parts used for fishing line guides, watches and the like, and more particularly to ceramics for decorative parts that are excellent in wear resistance and produce a reddish silver color with an extremely high decorative value. .

  Conventionally, metal parts are used for decorative parts used for fishing line guides, watches, etc., but scratch resistance and corrosion resistance are inferior, and the surface of decorative parts tends to be damaged, and the decorative characteristics are gradually impaired. There was a problem.

  In addition, a base layer is formed on the surface of the substrate, and a DLC (Diamond Like Carbon) film is formed on the substrate by CVD (Chemical Vapor Deposition) using plasma discharge to create complex colors and tones. However, some coating layers are easily peeled off or damaged, and some are not suitable for decorative parts.

  Therefore, recently, in order to solve such problems, ceramics having various colors are being used. For example, Patent Document 1 selects from Group 4a and Group 5a metal elements of the periodic table. There has been proposed a fishing tackle component that is made of a sintered body having a volume ratio of at least one kind of carbide, nitride, or carbonitride and having a porosity of 5% or less. According to this fishing tackle component, it has excellent strength and wear resistance, in particular, good sliding properties with the fishing line, no occurrence of thread breakage, etc., and a glossy golden color on the mirror surface. Can be maintained for a long time.

Moreover, in patent document 2, the hard phase represented by following Formula (A) is 70 to 98 weight%,
(Tia, Mb) (Nw, Cx, Oy) Z (A)
However, one or more of M: Zr, Hf, V, Nb, Ta, Cr a + b = 1, 1 ≧ a ≧ 0.4, 0.6 ≧ b ≧ 0
W + X + Y = 1, X + Y> 0, 1> W ≧ 0.4
0.19 ≧ X ≧ 0, 0.6 ≧ Y ≧ 0, 0.93 ≧ Z ≧ 0.6
A decorative sintered alloy is proposed in which one or more binder phases selected from Fe, Ni, Co, Cr, Mo, and W are composed of 2 to 30% by weight and inevitable impurities. According to this decorative sintered alloy, the color tone of the golden color system is maintained by the hard phase mainly composed of TiNz, but as the value of Z becomes smaller than the stoichiometric composition, the golden color system becomes light golden color. This color change is further enhanced by adding TiO, ZrN, HfN, VN, NbN, TaN, CrN, Cr ₂ N, TaC, and NbC, which exhibit a golden color, from a deep light golden color. Color control up to golden color becomes easier.

Patent Document 3 discloses a hard silver ceramic containing titanium carbide as a main component, chromium carbide in an amount of 0.1 to 40% by weight, and Y ₂ O ₃ or one or more rare earth oxides in an amount of 0.05 to 15% by weight. Has been proposed. According to this hard silver ceramic, the corrosion resistance and high strength are remarkably improved as compared with conventional silver ceramics, and it is used as a decorative member free from corrosion or scratches over a long period of time.
JP-A-4-271739 JP 58-204149 A JP-A-3-69561

  However, the preference of the color tone of decorative parts used for fishing line guides, watches, etc. is ten colors, the fishing tackle parts disclosed in Patent Document 1, the decorative sintered alloy disclosed in Patent Document 2, Although the hard silver ceramic disclosed in Patent Document 3 is excellent in strength and wear resistance, it has a hue of only gold or silver and exhibits a monotonous color tone. For this reason, there is a demand for practical use of ceramics for decorative parts having a color tone with a higher decorative value.

  The present invention has been devised to solve the above-described problems, and provides a ceramic for decorative parts that has a high decorative value such as being reddish in silver and has excellent wear resistance. Objective. It is another object of the present invention to provide a fishing line guiding decorative part and a watch decorative part using the ceramic for decorative parts of the present invention.

  The ceramic for decorative parts of the present invention is made of a titanium carbonitride sintered body and includes nickel, chromium, silicides thereof, and silicon nitride on the surface.

  Moreover, the ceramic for decorative parts of the present invention is characterized in that, in the above configuration, silicon nitride is β-type silicon nitride.

Moreover, the ceramic for decorative parts of the present invention is characterized in that, in any of the above-described configurations, the fracture toughness is 3.5 MPa · m ^1/2 or more and the Vickers hardness is 11 GPa or more.

  Further, the decorative component for fishing line guide according to the present invention is made of the ceramic for decorative component according to any one of the above-described configurations.

  Moreover, the decorative part for timepieces of the present invention is characterized by comprising the ceramics for decorative parts of the present invention having any of the above-described configurations.

  According to the ceramic for decorative parts of the present invention, it is made of a titanium carbonitride sintered body, and the surface contains nickel, chromium, silicides thereof, and silicon nitride. The CIE 1976 L * a * b * table is a balance between the brown color tone having a metallic luster exhibited by Ni, the silver color tone exhibited by nickel, chromium, and silicides thereof, and the black color tone exhibited by silicon nitride. In the color system, the color index L * is 60 to 71, the chromaticness index a * is 4 to 9, and the b * is 7 to 10. Can be created. In addition, while exhibiting a color with such a decorative value, it is extremely excellent in hardness and wear resistance.

  Further, according to the ceramic for decorative parts of the present invention, when silicon nitride is β-type silicon nitride, the starting α-type silicon nitride undergoes phase transition to β-type silicon nitride during sintering, and columnar silicon nitride. Since the grains are formed at the grain boundaries, the columnar silicon nitride particles become wedges even if grain boundary slippage occurs due to deformation caused by crystals moving between the grain boundaries. Since progress of grain boundary sliding can be suppressed, toughness can be improved.

Further, according to the ceramic for decorative parts of the present invention, when the fracture toughness is 3.5 MPa · m ^1/2 or more and the Vickers hardness is 11 GPa or more, the surface is scratched because of excellent wear resistance. It is difficult to maintain a color with a high decorative value such as reddish silver.

  Moreover, according to the decorative component for fishing line guide of the present invention, since it is made of the ceramic for decorative component of the present invention, it is excellent in wear resistance even when it is rubbed against fine sand adhered to the fishing line when guiding the fishing line. Therefore, it is possible to withstand long-term use as a fishing line guide component while maintaining a color tone having a high decorative value of being reddish in silver and not easily scratched on the surface.

  Further, according to the decorative part for a watch of the present invention, since it is made of the ceramic for decorative parts of the present invention, it is possible to bring out a color with a high decorative value of being reddish in silver and to suppress scratches over a long period of time. Therefore, it is possible to configure a decorative part for a watch as an attractive product full of luxury.

  Examples of embodiments of ceramics for decorative parts of the present invention, decorative parts for fishing line guides using the ceramics, and decorative parts for watches will be described below.

  First, the ceramic for decorative parts of the present invention is made of a titanium carbonitride sintered body, and includes nickel, chromium, silicides thereof, and silicon nitride on the surface. In addition, the surface in the ceramic for decorative parts of this invention refers to the surface where the decorative value of a decorative component is requested | required, and does not indicate all the surfaces.

In the present invention, the titanium carbonitride sintered body is a sintered body containing titanium carbonitride (TiCN) as a main component, and the main component referred to here is 100 masses of all components constituting the ceramic for decorative parts. % Is a component occupying 50% by mass or more. Next, nickel and nickel silicide, such as NiSi, NiSi ₂ , Ni ₂ Si, Ni ₃ Si, and Ni ₃ Si ₂ , function as a binder phase that bonds titanium carbonitride crystal grains. Further, chromium and chromium silicides, such as CrSi, Cr ₃ Si, CrSi ₃ and Cr ₅ Si ₃ , suppress corrosion of nickel and nickel silicide and improve corrosion resistance. And since silicon nitride has high toughness, it improves wear resistance.

  In addition, the titanium carbonitride sintered body may contain, for example, Mn, Fe, Co, Zn, Nb, Mo, W and a compound of these metal elements as a trace component.

  As described above, the ceramic for decorative parts of the present invention is made of a titanium carbonitride sintered body, and it is important that the surface contains nickel, chromium, and these silicides and silicon nitride. However, there is a balance between the brown color tone with metallic luster exhibited by titanium carbonitride, the silver color tone exhibited by nickel, chromium and these silicides, and the black color tone exhibited by silicon nitride. It is possible to produce ceramics for decorative parts that have a high decorative value that is not just a monochromatic color such as gold or silver, which is reddish, and that have excellent wear resistance.

  And this ceramic for decorative parts of this invention uses the preparation raw material which made nickel 7 to 16 mass%, chromium 2 to 6 mass%, silicon nitride 5 to 14 mass%, and the remainder comprised titanium carbonitride. Can be obtained.

  Here, the reason why the nickel content is 7 to 16% by mass is that if the nickel content is within this range, the nickel increases the bonding of the titanium carbonitride crystal particles, so that the hardness (for example, Vickers hardness) is increased while having as high fracture toughness as possible. Because it can. The reason why the chromium content is 2 to 6% by mass is that good corrosion resistance can be obtained and a high-class feeling can be produced without suppressing the vividness of the color tone. Furthermore, the reason why the silicon nitride is 5 to 14% by mass is that the toughness is high and the wear resistance can be improved, and the influence of black, which is the color of the silicon nitride itself, can be suppressed. It is.

  And if nickel is less than 7 mass%, the crystal grains of titanium carbonitride cannot be satisfactorily bonded and the strength and fracture toughness will decrease, and if it exceeds 16 mass%, the Vickers hardness will decrease. It will be. On the other hand, if the chromium content is less than 2% by mass, the oxidation of nickel and nickel silicide cannot be suppressed and the corrosion resistance is lowered. If the chromium content exceeds 6% by mass, the chromaticness index a * and b * The vividness of the color tone is suppressed and the color tone is suppressed, making it impossible to obtain an attractive ceramic for decorative parts. Further, if silicon nitride is less than 5% by mass, fracture toughness decreases and wear resistance decreases, and if it exceeds 14% by mass, the blackness increases, and lightness index L * and chromaticness are increased. The indexes a * and b * are lowered, and it becomes impossible to bring out a color with a high decorative value of reddish silver.

  At this time, the surface of the ceramic for decorative parts of the present invention has a lightness index L * of 60 to 71, a chromaticness index a * of 4 to 9, and a b * of CIE1976L * a * b * color system. Is in the range of 7-10.

  Here, the lightness index L * is an index indicating the lightness and darkness of the color tone. When the value of the lightness index L * is large, the color tone is bright, and when the value of the lightness index L * is small, the color tone is dark. The chromaticness index a * is an index indicating the degree of color tone from red to green. When the value of the chromaticness index a * is large in the positive direction, the color tone becomes red. When the absolute value is small, the color tone is vivid. When the value of the chromaticness index a * is large in the negative direction, the color tone becomes green. Furthermore, the chromaticness index b * is an index indicating the degree of yellow to blue color tone. When the chromaticness index b * is large in the positive direction, the color tone becomes yellow, and when the absolute value is small, the color tone is vivid. When the value of the chromaticness index b * is large in the negative direction, the color tone becomes blue.

  In this CIE1976 L * a * b * color system, if the lightness index L * is 60 to 71, the chromaticness index a * is 4 to 9, and b * is 7 to 10, a moderate metallic luster is obtained. It has a high decorative color tone with a reddish silver color, and can be an attractive ceramic for decorative parts that is full of luxury.

  These components forming the ceramics for decorative parts can be identified by X-ray diffraction, and the ratio of these components can be determined by fluorescent X-ray analysis or ICP (Inductivity Coupled Plasma) emission analysis. Find it. The lightness index L * and chromaticness index a *, b * in the CIE 1976 L * a * b * color system are determined by measuring in accordance with JIS Z 8722-2000. For example, a spectrocolorimeter (such as CM-3700d manufactured by Konica Minolta Holdings) may be used, the light source may be CIE standard light source D65, the viewing angle may be set to 10 °, and the measurement range may be set to 5 mm × 7 mm.

  In addition, from the viewpoint of maintaining the decorative value, trace components such as Mn, Fe, Co, Zn, Nb, Mo, W, and compounds of these metal elements are each 100% by mass of the titanium carbonitride sintered body. It is suitable that it is 1 mass% or less, and the ratio of these trace components can be measured by fluorescent X-ray analysis.

  In the ceramic for decorative parts of the present invention, it is preferable that the silicon nitride is β-type silicon nitride. When the silicon nitride is β-type silicon nitride, the α-type silicon nitride as a starting material is phase-transformed into β-type silicon nitride as it is sintered, and columnar silicon nitride particles are formed at the grain boundaries. Therefore, even if a grain boundary slip occurs due to the movement of crystals between the grain boundaries, the columnar silicon nitride particles become wedges and can suppress the progress of the grain boundary slip. , Toughness can be improved. The crystal phase of silicon nitride can be identified using an X-ray diffraction method.

The ceramic for decorative parts of the present invention preferably has a fracture toughness of 3.5 MPa · m ^1/2 or more and a Vickers hardness of 11 GPa or more. This is because the wear resistance of the ceramics for decorative parts of the present invention is affected by the fracture toughness and hardness, and the higher the fracture toughness and hardness, the higher the wear resistance. This is because a ceramic for decorative parts exhibiting a value is excellent in wear resistance, so that the surface is hard to be scratched and the color tone with a high decorative value of being reddish in silver can be maintained for a long time.

At this time, it is the ratio of the nickel powder that affects the fracture toughness and hardness of the ceramic for decorative parts of the present invention. The higher the nickel powder ratio, the higher the fracture toughness, and the lower the ratio, the higher the hardness. From such a viewpoint, the nickel powder is preferably 9 to 11% by mass with respect to 100% by mass of the raw material for preparation, and the fracture toughness is 3.5 MPa · m ¹ by setting the ratio of the nickel powder within this range. ^A ceramic for decorative parts having a Vickers hardness of 11 GPa or more can be obtained. The fracture toughness and Vickers hardness can be measured in accordance with the indenter press-in method (IF method) and JIS R 1610-2003 specified in JIS R 1607-1995, respectively.

  Next, FIG. 1 is a perspective view of a fishing line guide ring showing an example of an embodiment of a fishing line guiding decorative part of the present invention comprising the ceramic for decorative part of the present invention.

  The fishing line guide ring 1 is an annular body, and is fixed to a jig (not shown) and attached to a fishing rod. The fishing line guide ring 1 is used to guide the fishing line on the inner peripheral side of the fishing line guide ring 1.

  This fishing line guide ring 1 is made of the ceramics for decorative parts of the present invention, so that it is excellent in wear resistance even when rubbed against fine sand adhered to the fishing line when guiding the fishing line on the inner peripheral side. Therefore, it is possible to maintain a color tone with a high decorative value that the surface is hard to be scratched and reddish silver. The abrasion resistance of such a fishing line guide ring 1 can be evaluated by producing and using an abrasion resistance evaluation apparatus having the following configuration.

  FIG. 2 is a schematic configuration diagram of an abrasion resistance evaluation apparatus used for evaluating the abrasion resistance of a fishing line guide ring which is a decorative component for fishing line guide according to the present invention. The wear resistance evaluation apparatus 10 includes a nylon thread 6, a pulley 5 that applies tension to the thread 6 at a predetermined position, a motor 3 that runs the thread 6, and a water tank 2 that adheres muddy water to the thread 6. A load corresponding to the mass of the weight 4 is applied to the toroidal fishing line guide ring 1 fixed at a predetermined position with a jig (not shown) or the like through the wire 7, and muddy water adheres through the water tank 2. The thread 6 is structured to slide on the inner peripheral surface of the fishing line guide ring 1, and the number of the nylon thread 6 may be, for example, 3.

  The conditions for evaluating the wear resistance of the fishing line guide ring 1 using this wear resistance evaluation apparatus 10 are, for example, that the weight 4 is 500 g in mass, and the thread 6 is the inner circumference of the fishing line guide ring 1. The speed of sliding on the side may be set to 60 m / min, and the traveling distance of the yarn 6 may be set to 3000 m or more.

  Next, FIG. 3 is a perspective view showing an example of a watch case which is a decorative part for watch of the present invention. FIG. 4 is a perspective view showing another example of a watch case which is a decorative part for watch of the present invention. FIG. 5 is a schematic view showing an example of the configuration of a watch band which is a decorative part for watch of the present invention. In these drawings, the same reference numerals are assigned to the same parts.

  A watch case 20A shown in FIG. 3 includes a recess 11 for housing a movement (drive mechanism) (not shown) and a foot 12 for fixing a watch band (not shown) for mounting the watch on an arm. The concave portion 11 includes a thin bottom portion 13 and a thick body portion 14.

  The watch case 20B shown in FIG. 4 has a hole 15 for receiving a movement (drive mechanism) (not shown) and a watch band (not shown) for attaching the watch to the arm formed on the body portion 14. And a foot 12 to be provided.

  Further, the band piece constituting the watch band 50 shown in FIG. 5 is arranged so as to sandwich the middle piece 25 having the through hole 21 into which the pin 40 is inserted and the middle piece 25, and the pins into which both ends of the pin 40 are inserted. An outer piece 30 having a hole 31, and a pin 40 is inserted into the through hole 21 of the middle piece 20, and both ends of the pin 40 inserted into the through hole 21 of the middle piece 20 are the outer pieces 30 on both sides. By inserting the pin into the pin hole 31, the middle piece 20 and the outer piece 30 are sequentially connected to form the watch band 50.

  Since the watch decorative parts of the present invention used as the band pieces constituting the watch cases 20A and 20B and the watch band 50 are made of the ceramics for decorative parts of the present invention, they are reddish silver. In addition to being able to bring out a color with a high decorative value, it has high hardness and extremely excellent wear resistance, so it can be made an attractive product that is highly reliable and full of luxury.

  Next, the manufacturing method of the ceramics for decorative parts of this invention is demonstrated.

In order to obtain the ceramic for decorative parts of the present invention, first, at least one of titanium nitride (TiN) and titanium carbonitride (TiCN), each of nickel (Ni), chromium (Cr), and silicon nitride (SiN) A predetermined amount of powder is weighed and mixed to obtain a blended raw material. More specifically, the nickel powder is 7 to 16% by mass, the chromium powder is 2 to 6% by mass, the silicon nitride powder is 5 to 14% by mass and the remaining powder is 100% by mass of the raw material. What is necessary is just to weigh and mix so that it may become at least any 1 type of a titanium nitride and a titanium carbonitride. At this time, if titanium nitride is used, the titanium nitride reacts with the carbon constituting the organic solvent and the binder to remain in the ceramic for decorative parts as titanium carbonitride. The titanium nitride powder may be TiN having a stoichiometric composition or TiN _1-x (0 <x <1) having a non-stoichiometric composition.

  Next, 2-propanol (isopropyl alcohol) or methanol, for example, is added to the prepared raw material as an organic solvent, and after pulverizing and mixing using a mill, a predetermined amount of paraffin wax is added as a binder, and a desired molding method, for example, A molded body is obtained by molding into a desired shape such as a disk, flat plate, or torus by a dry pressure molding method, a cold isostatic pressing method, an extrusion molding method, or the like. Then, the obtained molded body is degreased in a non-oxidizing atmosphere such as a nitrogen atmosphere or an inert gas atmosphere as necessary, and then in at least one gas atmosphere selected from nitrogen and an inert gas or in a vacuum By firing at a temperature of 1350 ° C. or higher and 1600 ° C. or lower, a dense sintered body having a relative density of 95% or higher, for example, can be obtained.

  In addition, when α-type silicon nitride is used as the silicon nitride powder, by firing at a temperature of 1400 ° C to 1600 ° C, α-type silicon nitride undergoes phase transition to β-type silicon nitride and columnar silicon nitride particles Even when grain boundary slipping, which is one type of fracture mode, occurs, the columnar silicon nitride particles serve as wedges and can suppress the progress of grain boundary slipping.

Note that silicon constituting silicon nitride is partly released from silicon nitride during firing and is combined with nickel or chromium to form nickel such as NiSi, NiSi ₂ , Ni ₂ Si, Ni ₃ Si, Ni ₃ Si _2, etc. A silicide is formed, or a chromium silicide such as CrSi, Cr ₃ Si, CrSi ₃ , Cr ₅ Si ₃ is formed.

  Then, after lapping using a lapping machine on the surface where the decorative value of the obtained sintered body is required, the surface of the sintered body is silver-reddish in color by barrel polishing. Thus, the decorative part ceramics of the present invention can be obtained. In addition, when there are pores appearing on such a surface, the maximum diameter is preferably 30 μm or less. By setting the maximum diameter of the pores within this range, the surface of the ceramic for decorative parts can be made into a beautiful mirror surface, and adhesion of germs, foreign matters, contaminants, etc. into the pores can be reduced.

  Also, if the product shape of ceramics for decorative parts is complex, close to the block shape or product shape by dry pressure molding method, cold isostatic pressing method, extrusion molding method, injection molding method, etc. After forming into a shape and sintering this, grinding may be performed to obtain a product shape, and then lapping and barrel polishing may be sequentially performed. Alternatively, a product shape may be formed by an injection molding method from the beginning, and after firing, lapping and barrel polishing may be sequentially performed.

  The ceramic for decorative parts of the present invention obtained as described above exhibits a color with a high decorative value that the surface is reddish in silver and has excellent wear resistance. In addition, if the ceramics for decorative parts of the present invention is used for decorative parts for fishing line guides, the surface is scratched because it is excellent in wear resistance even when rubbed against fine sand adhered to the fishing line when guiding the fishing line. It is hard to stick and can maintain a silvery reddish color for a long time. Furthermore, the ceramics for decorative parts of the present invention can produce attractive products with a high sense of quality, with a highly decorative color tone that makes the surface reddish in silver. Including decorative parts for watches such as band pieces, decorative parts for mobile phones such as dial buttons, decorative parts for accessories such as brooches, necklaces, earrings, rings, tie pins, tie tacks, medals, buttons, floors, walls, It can be suitably used as a decorative part for building materials such as tiles or door handles that decorate the ceiling, or a decorative part for kitchen parts such as spoons and forks.

  Examples of the present invention are shown below, but the present invention is not limited to the following examples.

  First, titanium carbonitride (TiCN) powder, titanium carbide (TiN) powder, nickel (Ni) powder, chromium (Cr) powder, and silicon nitride (SiN) powder are weighed and mixed in the ratios shown in Table 1 to prepare a raw material. It was. Further, as a comparative example, a prepared raw material in which titanium nitride (TiN) powder, nickel powder, chromium powder and zirconium oxide powder were weighed and mixed at the ratio shown in Table 1 was prepared.

Next, after adding methanol as an organic solvent to each of the above prepared raw materials and pulverizing and mixing for 72 hours using a vibration mill, a binder such as polyethylene glycol is added in an amount of 3% by mass with respect to the prepared raw material, and mixed. And then dried into granules. Then, the obtained granules were filled into a molding die and subjected to pressure molding at a pressure of 98 MPa to produce a plurality of annular and flat molded bodies one by one. These compacts were degreased at 600 ° C. in a nitrogen atmosphere and then held at the firing temperature shown in Table 1 for 2 hours in a nitrogen atmosphere to obtain sintered bodies. Thereafter, barrel polishing was performed using a rotating barrel polishing machine to obtain a ceramic for decorative parts having a surface with an arithmetic average height (Ra) defined by JIS B 0601-2001 of 0.05 to 0.23 μm.

  The composition of the ceramic for decorative parts was identified using an X-ray diffraction method. Ceramics for decorative parts using a spectrocolorimeter (CM-3700d manufactured by Konica Minolta Holdings) in accordance with JIS Z 8722-2000, a CIE standard light source D65 as the light source, and a viewing angle of 10 °. The color tone of the surface of was measured. Furthermore, 20 people were asked to monitor, and sample Nos. The ceramics for decorative parts 1 to 15 were evaluated as ◯ for the ceramics for decorative parts that gave a good impression, and Δ for the ceramics for decorative parts that did not give a good impression. Further, the fracture toughness was measured by indentation press-fitting method (IF method) defined in JIS R 1607-1995 by cutting a test piece from a flat ceramic for decorative parts. Further, the Vickers hardness was measured according to JIS R 1610-2003.

Furthermore, for the evaluation of wear resistance, sample No. 1 was used using the wear resistance evaluation apparatus shown in FIG. After fixing 1 to 15 ring-shaped ceramics for decorative parts at a predetermined position (position of fishing line guide ring 1) with a jig, 10 g of semi-porcelain soil is added to 0.001 m ^{3 of} water and mixed to aquarium 2 Muddy water was prepared inside. The thread 6 made of nylon (Toray's silver scale Σ3) to which the muddy water adhered was slid on the inner peripheral side of the ceramic for decorative parts of a torus. In this sliding, the mass of the weight 4 is set to 500 g, the speed at which the thread 6 slides on the inner peripheral side of the ceramic for decorative parts is set to 60 m / min, and the traveling distance of the thread 6 is set to 3000 m. The maximum depth of scratches caused by the wear of the ceramics for decorative parts was measured as the wear depth. For measurement of the wear depth, a surface shape measurement microscope (Keyence measurement unit VF-7510 / controller VF-7500) was used.

These identification, evaluation and measurement results are shown in Table 2.

  As can be seen from the results shown in Tables 1 and 2, Sample No. 2 is a comparative example made of a titanium nitride sintered body and has nickel, chromium and zirconium oxide on the surface. No. 15 was a gold color with a strong reddish color tone and was not preferred by the monitor, so it could not give a good impression.

  On the other hand, it consists of a titanium carbonitride sintered body, and the surface of nickel, chromium, and their silicides and silicon nitride is included in Sample No. 1 to 14 are reddish in the CIE1976 L * a * b * color system in which the lightness index L * is 60 to 71, the chromaticness index a * is 4 to 9, and the b * is 7 to 10. Since the color tone was preferred by the monitor, it was confirmed that it gave a good impression as a decorative part.

In particular, sample No. ¹ having a fracture toughness of 3.5 MPa · m ^1/2 or more and a Vickers hardness of 11 GPa or more. Samples Nos. 2 to 4, 7, 9 to 11 and 14 have sample Nos. With fracture toughness or Vickers hardness outside this range. From 1, 5, 6, 8, 12, and 13, the wear depth was 2.2 μm or less, which was confirmed to be suitable. Sample No. 3 and 7, sample no. 10 and 14 use the same type of powder in the same ratio, but are fired at 1350 ° C and the crystal phase of silicon nitride is α-type, resulting in poor fracture toughness, and firing at temperatures in the range of 1400-1600 ° C. It was confirmed that the toughness can be improved by using the β-type crystal phase.

  Then, grinding is performed to form the shape of a watch case using the above-described flat molded body, and the molded body subjected to the grinding process is degreased in a nitrogen atmosphere, and then fired and fired in a nitrogen atmosphere. A ligature was obtained. Thereafter, the decorative surface portion of the sintered body is mirror-polished to produce a watch case as shown in FIG. 4, and when incorporated into the watch body and visually evaluated, the decorative value of being reddish in silver It can be seen that it is possible to construct an attractive product full of high-class color and high-class feeling, and the ceramics for decorative parts of the present invention can be suitably used for decorative parts for watches as well as decorative parts for fishing line guides. Was confirmed.

It is a perspective view of a fishing line guide ring showing an example of an embodiment of a decorative component for fishing line guide of the present invention. It is a schematic block diagram of the abrasion resistance evaluation apparatus of the fishing line guide ring which is a decorative component for fishing line guide of this invention. It is a perspective view which shows an example of the case for timepieces which is the decorative component for timepieces of this invention. It is a perspective view which shows the other example of the case for timepieces which is the decorative component for timepieces of this invention. It is a schematic diagram which shows an example of a structure of the timepiece band which is the decorative component for timepieces of this invention.

Explanation of symbols

1: Guide ring for fishing line
20A, 20B: Watch case
50: Watch band

Claims (5)

A ceramic for decorative parts comprising a titanium carbonitride-based sintered body and containing nickel, chromium, silicides thereof and silicon nitride on the surface. The ceramic for decorative parts according to claim 1, wherein the silicon nitride is β-type silicon nitride. The ceramic for decorative parts according to claim 1 or 2, wherein the fracture toughness is 3.5 MPa · m ^1/2 or more and the Vickers hardness is 11 GPa or more. A decorative part for fishing line guide, comprising the ceramic for decorative part according to any one of claims 1 to 3. A decorative part for a watch comprising the ceramic for a decorative part according to any one of claims 1 to 3.

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