JP2009030156A - Composite material and ornament - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite material and an ornament having excellent corrosion resistance and of pink color. <P>SOLUTION: Disclosed is a composite material comprising: a first phase essentially consisting of Pt; and a second phase at least comprising Cu and Au and further comprising Pd and Ag. Also disclosed is an ornament comprising the composite material at least in a part thereof. Regarding the compositions of Au, Pd and Ag in the second phase, provided that their mass ratios are defined as X mass%, Y mass% and Z mass%, respectively, and (X+Y+Z=100) is satisfied, they lie in the range surrounded by 6 points in a three-dimensional diagram (X, Y, Z)=(90, 10, 0), (80, 20, 0), (78, 16, 6), (78, 6, 16), (80, 0, 20), and (90, 0, 10) (excepting the values on a straight line connecting the point (X, Y, Z)=(90, 10, 0) and the point (X, Y, Z)=(80, 20, 0) and the values on a straight line connecting the point (X, Y, Z)=(80, 0, 20) and the point (X, Y, Z)=(90, 0, 10)). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a composite material containing Pt and Cu and a decorative article using at least a part of this composite material.

  Conventionally, as a Pt alloy, a Pt—Pd alloy, a Pt—Pd—Cu alloy, a Pt—Pd—Ru alloy, a Pt—Pd—Co alloy, a Pt—Ru alloy, a Pt—Co alloy, a Pt—Ir alloy, etc. is there. These Pt alloys exhibit a white color that matches well with gemstones. On the other hand, Pt shows a considerably lower reflectance than silver (Ag), its neat shine, its price is higher than gold (Au), and rareness is also recognized. Rarely used for jewelry.

Due to the diversification of tastes in recent years, there is a demand for multicolored Pt as well as gold ornaments and silver ornaments. For example, pink is attracting a lot of support from women, as can be seen in silver ornaments, and pink is expected to appear as an ornament for Pt. On the other hand, attempts have been made to develop various colors by adding Cu to the intermetallic compound PtAl ₂ of Pt and aluminum (Al) or melting Pt.Al.Cu together (for example, patents). Reference 1). More specifically, in Patent Document 1, a yellow compound is obtained by setting the addition amount of Cu to 1 to 8% by mass, and a brown compound is added by setting the addition amount of Cu to 8 to 15% by mass. It is described that a reddish brown color (pinkish-brown color) can be obtained by adding 20 to 30% by mass.

In addition, a decorative member is described that adjusts the color tone by uniformly forming aluminum oxide as a transparent hard film on the surface of the step formed on the substrate (see Patent Document 2).
JP-A-3-158430 JP-A-4-344300

However, since the metal material described in Patent Document 1 is formed by adding Cu to the intermetallic compound PtAl ₂ of Pt and Al, or by melting Pt · Al · Cu together, the whole is made. It is considered an intermetallic compound. Such an intermetallic compound does not have a desired color because the wavelength dependency of reflectance is a color in which a plurality of wavelengths are mixed.

  Further, in the decorative member described in Patent Document 2, since the materials of the base material and the transparent hard film are greatly different, the adhesion between the transparent hard film and the aluminum oxide is poor. Furthermore, since the film thickness distribution is locally different, local internal stress is generated and the film tends to peel off.

  An object of the present invention is to provide a pink composite material and a decorative article excellent in corrosion resistance.

  In view of the above, the present invention is characterized by having a first phase containing Pt as a main component and a second phase containing at least Cu and Au and further containing Pd and Ag.

  Furthermore, the composition of Au, Pd and Ag in the second phase is as follows in the ternary diagram when the mass ratios are X mass%, Y mass% and Z mass%, respectively, and (X + Y + Z = 100). 6 points (X, Y, Z) = (90, 10, 0), (80, 20, 0), (78, 16, 6), (78, 6, 16), (80, 0, 20), A range surrounded by (90, 0, 10) (however, a straight line connecting the point (X, Y, Z) = (90, 10, 0) and the point (X, Y, Z) = (80, 20, 0)) The above value and the value on the straight line connecting the point (X, Y, Z) = (80, 0, 20) and the point (X, Y, Z) = (90, 0, 10) are excluded) It is characterized by that.

  Furthermore, one of the first and second phases is arranged around the other phase.

  Further, the plurality of second phases are arranged in the first phase.

  Further, the plurality of first phases are arranged in the second phase.

  Furthermore, it has further the 3rd phase containing the intermetallic compound formed in contact with both phases between the said 1st phase and the said 2nd phase, and Pt and Cu, It is characterized by the above-mentioned.

  Further, the third phase is characterized by covering the first phase or the second phase.

  Furthermore, the total amount of Pt contained in the first phase is 25% by mass or more and 75% by mass or less of the total composition.

  Furthermore, the total amount of Cu contained in the second phase is 20% by mass or more and 80% by mass or less of the total composition of the second phase.

  Furthermore, it is a decorative product having a composite material region formed of the composite material.

  Furthermore, at least a part of the second phase and the third phase is exposed from the surface.

  Further, the exposed portion of the second phase is surrounded by the exposed portion of the third phase.

  Furthermore, the composite material region has a region defined by a circle having a diameter of at least 1 mm.

  Furthermore, the composite material region is formed at least to a region having a depth of 1 mm from the surface.

  Furthermore, a coating layer made of aluminum oxide is formed on the surface of the composite material region.

  Furthermore, the aluminum oxide is non-single crystal.

  Furthermore, the thickness of the coating layer is in the range of 5 to 50 nm.

  Furthermore, the average refractive index of the coating layer is in the range of 1.5 to 2.5.

  Furthermore, the refractive index of the coating layer is high on the surface side of the composite material region.

  Further, the atomic ratio of oxygen to aluminum in the aluminum oxide is 25 to 75%.

  Furthermore, the oxygen concentration of the coating layer is low on the surface side of the composite material region.

  The composite material according to the present invention has a first phase mainly composed of Pt and a second phase containing Cu and Au and further containing Ag and Pd. The composite material with good property can be provided. That is, in the second phase, since a predetermined amount of Au having a smaller ionization tendency than Cu and Pt is contained, the corrosion resistance of the composite material as a whole is improved. Moreover, in the second phase, by including Ag or Pd whose ionization tendency is between Cu and Pt, it is based on the battery effect based on the difference in ionization tendency between Pt and Cu, that is, based on the transfer of electrons from Cu to Pt. Cu ionization can be suppressed and deterioration of corrosion resistance can be suppressed.

  In the present invention, by setting the composition of Cu, Au, Ag and Pd in the second phase within a predetermined range, a composite material having a pink color with good corrosion resistance can be provided.

  If the composite material according to the present invention further has a third phase in contact with the first phase and the second phase, an intermetallic compound is interposed between the first phase and the second phase. Thereby, generation | occurrence | production of the battery effect based on the difference in the ionization tendency between Pt of 1st phase and Cu of 2nd phase can be suppressed by the intermetallic compound of 3rd phase. Therefore, since the composite material of the present invention has excellent corrosion resistance, the metallic luster can be maintained for a long time.

  In the present invention, if the Pt content is 25% by mass or more and 75% by mass or less, since the Pt ratio is relatively high, the Pt quality can be improved, so that the Pt original metallic luster is exhibited and the corrosion resistance is improved. It will be excellent.

  In the present invention, if the total amount of Cu contained in the second phase is, for example, 20% by mass or more and 80% by mass or less of the total composition (total composition of the second phase), a favorable pink color can be obtained. , Deterioration of corrosion resistance can be suppressed.

  The decorative article according to the present invention has a composite material region including the composite material according to the first aspect. In the decorative article of the present invention, at least part of the decorative article can be given a pink color having the original metallic luster of Pt, so that the aesthetics can be improved while maintaining the corrosion resistance.

  In the decorative article according to the present invention, if the composite material region further includes a third phase in contact with the first phase and the second phase, the corrosion resistance of the composite material region can be improved. The metallic luster can be maintained for a long time. In particular, in an ornament that touches human skin, such as an ornament such as a ring, corrosion is likely to proceed due to sweat or the like, and therefore, it is significant to improve the corrosion resistance.

  Moreover, according to the decorative article of the present invention, corrosion resistance and smoothness can be imparted.

  In addition, as a coating layer for protecting it, it is possible to form it with a low stress by using amorphous aluminum oxide in particular, so that the decorative article can be protected while reducing the peeling of the coating layer. Can do. Furthermore, since the aluminum of the coating layer is oxidized and becomes amorphous, corrosion due to the battery effect between the substrate and the coating layer can be prevented.

  Furthermore, by changing the refractive index and thickness of this coating layer, the hue, brightness, and saturation of the ornament can be appropriately changed, and a play-coloring effect can be expected. Can be provided.

  Hereinafter, the decorative article and the composite material according to the present invention will be described with reference to the drawings, taking a ring as an example. However, the decorative article to which the composite material according to the present invention is applied or the decorative article according to the present invention is not limited to the ring.

  The ring 1 shown in FIGS. 1 (a) and 1 (b) is one in which the entire ring-shaped portion is formed of the composite material 2. As shown in FIG. 2, in one embodiment of the present invention, the composite material 20 has a first phase 21, a second phase 22, and a third phase 23, and the composite material 20 has a first phase 21. Includes Pt as a main component, the second phase 22 includes Cu and Au, and further includes Pd and Ag.

  The first phase 21 is a base material of the composite material 2 and contains platinum (Pt) as a main component. The total amount of Pt contained in the first phase 21 is, for example, 25% by mass or more and 75% by mass or less of the total composition. If the total amount of Pt contained in the first phase 21 is 25% by mass or more and 75% by mass or less of the total composition, the corrosion resistance is high and pink color development is easy. That is, if the total amount of Pt is 25% by mass or more, the ratio of copper (Cu), which is a main component of the second phase 22 described later, can be kept small, so that corrosion resistance is achieved by the battery effect between Pt and Cu. Is not deteriorated, and the hue is not close to the color of copper. On the other hand, if the total amount of Pt is 75% by mass or less, the ratio of Cu does not decrease, so that the color can be pink.

  The Pt mass of the first phase 21 can be calculated by EDS (energy dispersive X-ray analysis) quantitative analysis. That is, it is possible to detect characteristic X-rays generated from a depth region of several μm from the surface, analyze each element, and calculate the composition from the peak intensity.

  The second phase 22 is dispersed in the first phase 21 and contains copper (Cu) and gold (Au), and further contains at least one of palladium (Pd) and silver (Ag). It is out. Due to the presence of the second phase 22, the composite material 2 contains Cu in addition to Pt, and a part of the second phase 22 is exposed on the surface, so that the composite material 2 becomes pink. Moreover, since the composite material 2 is obtained by dispersing the second phase 22 in the first phase 21, the entire composite material 2 is not an intermetallic compound. Therefore, the composite material 2 has lower toughness than the case where the whole is made of an intermetallic compound like a Pt—Cu material obtained by a casting method, and the workability is improved by the presence of the second phase 22. To do.

  The composition of Cu in the second phase 22 is 20% by mass or more and 80% by mass or less with respect to the total composition of the second phase. If the total amount of Cu is 80% by mass or less, the corrosion resistance is not deteriorated by the battery effect between Pt and Cu, and the hue does not approach the color of copper. Moreover, if the total amount of Cu is 20 mass% or more, it is enough to maintain a pink color.

 The composition of Au, Pd, and Ag in the second phase 22 is shown in FIG. 3 and FIG. 3 when their mass ratios are X mass%, Y mass%, and Z mass%, respectively, and (X + Y + Z = 100). 6 points (X, Y, Z) = A (90, 10, 0), B (80, 20, 0), C (78, 16, 6), D (78, 6) in the ternary diagram shown in FIG. , 16), E (80, 0, 20), F (90, 0, 10) surrounded by a range (however, the point (X, Y, Z) = (90, 10, 0) and the point (X, Y) , Z) = (80,20,0) on a straight line, and the point (X, Y, Z) = (80,0,20) and the point (X, Y, Z) = (90,0) , 10) is preferably excluded). 3 is a ternary diagram based on the mass ratio of Au, Pd, and Ag, and FIG. 4 is a ternary diagram in which the shaded portion in FIG. 3 is enlarged.

  Here, the amount of Au having the largest ionization tendency in the second phase 22 is smaller on the side where the amount of Au is smaller than that on the B-C-D-E line in FIG. 4 (below the B-C-D-E line). This is not preferable because corrosion cannot be appropriately suppressed. Therefore, in order to improve the corrosion resistance, it is preferable to have a composition on the side having a larger amount of Au than the B-C-D-E line (upper side of the B-C-D-E line).

  On the other hand, the side where there is more Au than the A-F line (the upper side of the A-F line), in the second phase 22, the amount of Au increases while the amount of Pd and Ag decreases, so the hue of the second phase 22 Will move away from the pink color, and it will not become the desired light pink color. Therefore, in order to make the color light pink, it is preferable to have a composition on the side with less Au than the A-F line (the lower side of the A-F line).

  Therefore, regarding the composition of the second phase 22, regarding Au, Pd and Ag, in order to obtain a desired light pink while making the corrosion resistance of the composite material good, in the ternary diagram shown in FIG. , B, C, D, E, and F are preferably set in a range (including the boundary line).

  The masses of Cu, Au, Pd, and Ag in the second phase 22 can be calculated by EDS semi-quantitative analysis in the same manner as when the mass of Pt in the first phase 21 is measured.

  As expected from FIG. 2, in the ring 1, a part of the second phase 22 is exposed on the surface, and the diameter (average value) of such an exposed portion is preferably 5 μm or more and 150 μm or less. . If the diameter of the exposed portion of the second phase 22 is 5 μm or more, the pink color of the composite material 2 is not thinned. If the diameter of the second phase 22 is 150 μm or less, the exposed area of the second phase 22 is increased. Since this can be suppressed, it is possible to reduce the possibility of the exposed portion being oxidized when used for a long period of time. If the first phase is also exposed here, it is preferable because it can give the luster of platinum and contribute to corrosion resistance.

  In addition, the diameter (average value) of the exposed portion in the second phase 22 can be calculated from a photograph (SEM photograph) obtained by a scanning electron microscope (SEM) with an arbitrary cross section. In the cross-sectional observation by SEM, it is preferable to observe the crystal phase by an electron reflection image without performing gold deposition on the cross-section. Then, since the distinction between the first phase 21 and the second phase 22 can be ensured, the diameter of the exposed portion in the second phase 22 can be calculated appropriately.

  The third phase 23 contributes to the improvement of the corrosion resistance of the composite material 2 and is formed of an intermetallic compound. The third phase 23 is in contact with both the first phase 21 and the second phase 22. The third phase 23 covers the second phase 22 inside the composite material 2, and the third phase 23 on the surface. Are arranged so as to surround the exposed portion of the second layer 22. That is, the third phase 23 is interposed between the first phase 21 and the second phase 22. In this way, the third phase 23, which is an intermetallic compound, is interposed between the first phase 21 and the second phase 22, whereby ionization between Pt of the first phase 21 and Cu of the second phase 22. The battery effect based on the difference in tendency can be suppressed. As a result, the composite material 2 is excellent in corrosion resistance.

The intermetallic compound of the third phase 23 is typically one in which Pt and Cu are present in an integer ratio, for example, PtCu or PtCu ₃ . In the third phase 23, an intermetallic compound of noble metal other than Pt and Cu, for example, PtAu ₃ may exist. The ratio of Pt to Cu and Pt to Au is preferably an integer ratio because it is chemically stable.

  The thickness of the third phase 23 is, for example, 20 μm or less, preferably 0.59 μm or less. If the thickness of the third phase is 0.59 μm or less, the third phase 23 made of an intermetallic compound having high toughness is different from other parts when the composite material 2 is trimmed to produce jewelry or the like. By making it harder to be polished, it is possible to reduce the tendency that relatively large irregularities are formed on the surface and it is difficult to give gloss.

  The thickness (width on the exposed surface) of the third phase 23 can be calculated from a cross-sectional SEM photograph obtained by photographing an arbitrary cross-section of the composite material 2 with a SEM at a magnification of 3500 times in a 20 × 20 μm range. More specifically, the thickness of the third phase 23 is determined by selecting five portions including tangent lines that intersect perpendicularly to the surfaces of both the first phase 21 and the second phase 22, The thickness in each of the three phases 23 can be measured and calculated as an average value thereof.

  The area ratio of the third phase 23 on the surface of the composite material 2 is preferably 1% or more and 10% or less in an arbitrary range of 100 μm × 100 μm, and the third phase 23 in the previous range determines the second phase 22 as the second phase 22. The surrounding ratio is preferably 85% or more with respect to the length of the outer periphery of the second phase 22.

  In the example shown in FIG. 2, a plurality of second phases 22 containing Cu are arranged in the first phase 21 containing Pt as a main component, but the composite material of the present invention is made of Cu. The second phase may be a base material, and a plurality of first phases mainly composed of Pt may be arranged in the second phase. In this case, the first phase is preferably covered with a third phase that is an intermetallic compound of Pt and Cu.

  Next, the manufacturing method of the composite material 2 of this invention is demonstrated taking the case where the ring-shaped part of the ring 1 is formed by a discharge plasma sintering method as an example.

  First, a powder having a desired mass ratio of Pt, Cu, Au, Pd, and Ag (one of Pd and Ag may be omitted) is mixed to obtain a raw material powder. Each element may be mixed as a powder of a single metal or may be mixed as an alloy powder.

  The mass ratio of Pt in the raw material powder is, for example, 25% by mass or more and 75% by mass or less. The mass ratio of Cu in the raw material powder is 5% by mass or more and 60% by mass or less. The total mass ratio of Au, Pd and Ag is, for example, 5% by mass or more and 60% by mass or less. The mass ratio of Au, Pd, and Ag is 6 points (X, Y, Z) in the ternary diagram, where X mass%, Y mass%, and Z mass% are (X + Y + Z = 100), respectively. A (90, 10, 0), B (80, 20, 0), C (78, 16, 6), D (78, 6, 16), E (80, 0, 20), F (90, 0) , 10) (however, a value on a straight line connecting the point (X, Y, Z) = (90, 10, 0) and the point (X, Y, Z) = (80, 20, 0)), The point (X, Y, Z) = (80, 0, 20) and the point (X, Y, Z) = (90, 0, 10) are excluded).

  Next, the mixed powder is filled into a sintered mold and molded into a ring shape, and then the molded body is subjected to a low firing temperature of, for example, 200 ° C. or more and 500 ° C. or less, 4V or more and 20V or less in a vacuum atmosphere Apply pulsed current with voltage. Thereby, discharge plasma is instantaneously generated in the gaps between the particles of the molded body, and the molded body is sintered.

  Here, the molding pressure when forming the molded body is, for example, 300 MPa or more and 500 MPa or less. When the molding pressure is less than 300 MPa, pores are easily generated in the composite material 2 and become brittle. When the molding pressure exceeds 500 MPa, stress concentration occurs due to filling of the raw material, leading to damage to the mold. There is. Setting the firing temperature to 200 ° C. or more and 500 ° C. or less can reduce poor sintering if the firing temperature is 200 ° C. or more, and can reduce excessive firing if the firing temperature is 500 ° C. or less. . On the other hand, if the applied pulse voltage is 4 V or more and 20 V or less, if the applied pulse voltage is 4 V or more, sufficient discharge occurs in the gap between the molded bodies, and the intended plasma state can be achieved, and the applied pulse voltage is 20 V. Since the possibility of abnormal discharge occurring can be reduced as long as it is below, the target tissue state can be easily obtained in any case.

  In such a discharge plasma sintering method, high energy density and Joule heat are widely applied, thereby enabling efficient sintering with less power consumption. Therefore, the sintering time including the temperature raising and holding time is approximately 5 to 20 minutes, and the entire material does not become an intermetallic compound as in the casting method. A plurality of second phases 22 containing Cu, Au, Pd, and Ag are dispersed in the first phase 21. The second phase 22 is a third intermetallic compound having an appropriate thickness. The phase 23 can be coated, or a plurality of first phases mainly composed of Pt are dispersed in a second phase containing Cu, Au, Pd and Ag, and the first phase is appropriately It can be coated with a third phase of a thick intermetallic compound.

  The ring 1 (ring-shaped part) thus obtained has a first phase 21 mainly composed of Pt and a second phase 22 containing Cu, Au, Pd and Ag, The composition of Au, Pd and Ag in the second phase 22 is 6 points in the ternary diagram when the mass ratio is X mass%, Y mass% and Z mass%, respectively, and (X + Y + Z = 100). (X, Y, Z) = A (90, 10, 0), B (80, 20, 0), C (78, 16, 6), D (78, 6, 16), E (80, 0, 20), F (90,0,10) (however, the point (X, Y, Z) = (90,10,0) and the point (X, Y, Z) = (80,20,0) ) On a straight line connecting points) and a point (X, Y, Z) = (80, 0, 20) and a point (X, Y, Z) = (90, 0, 0) the exception of value on the straight line) connecting the. That is, in the second phase, since a predetermined amount of Au having a smaller ionization tendency than Cu and Pt is contained, the corrosion resistance of the composite material as a whole is improved. In addition, by including both Pd and Ag whose ionization tendency is between Cu and Pt in the second phase, the battery effect based on the difference in ionization tendency between Pt and Cu, that is, the transfer of electrons from Cu to Pt. Cu ionization based on this can be suppressed, and deterioration of corrosion resistance can be suppressed.

  The ring 1 (ring-shaped portion) is also configured such that the second phase 22 is disposed in the first phase 21 or the first phase is disposed in the second phase and is in contact with the first phase 21 and the second phase 22. The composite material 2 further includes a three-phase 23. Therefore, the toughness does not become unnecessarily high as in the case of the composite material formed entirely by the intermetallic compound phase, and the workability is excellent. As a result, the ring 1 can be easily subjected to finishing surface processing and the like, and the surface can be easily mirror-finished, so that the pink color that maintains the neat brightness that is the original metallic luster of Pt. Can be.

  In the case where the composite material 2 further includes a third phase 23 in contact with the first phase 21 and the second phase 22, a third intermetallic compound is formed between the first phase 21 and the second phase 22. Phase 23 will intervene. Therefore, the generation of the battery effect based on the difference in ionization tendency between Pt of the first phase 21 and Cu of the second phase 22 can be suppressed by the third phase 23 that is an intermetallic compound. As a result, the ring 1 has higher corrosion resistance, so that the metallic luster of Pt can be maintained for a long time. In particular, in an ornament that touches human skin, such as an ornament such as the ring 1, since corrosion is likely to proceed due to sweat or the like, it is significant to improve the corrosion resistance.

  Next, an example in which a composite material layer is formed on a part of a decorative article will be described using the ring shown in FIG. 5 as an example.

  The ring 3 shown in FIG. 5 is obtained by covering the surface of the core material 30 with a composite material layer 31.

  The core material 30 mainly defines the shape of the ring 3 and is formed in a ring shape having an inner diameter of 13 to 22 mm, an outer diameter of 15 to 24 mm, and a thickness of 2 to 10 mm, for example. Such a core material 30 can be formed by, for example, a casting method or an extrusion molding method.

As a material for forming the core material 30, any of noble metals and base metals can be used. However, when it is necessary to consider material cost etc., you may use Ag, Fe, and an alloy containing them.

The composite material layer 31 is formed of the composite material 2 having the composition state shown in FIG. 2 similarly to the ring 1 described with reference to FIG. That is, in the composite material layer 31, a plurality of second phases 22 containing Cu are dispersed in the first phase 21 containing Pt as a main component, and the second phase 22 contains an intermetallic compound of Pt and Cu. The structure is covered with the third phase 23 (see FIG. 2). The thickness of the composite material layer 31 is, for example, 0.03 to 0.1 μm. Of course, in the composite material layer 31, the first phase containing Pt as the main component is dispersed in the second phase containing Cu, and this first phase is covered with the third phase containing the intermetallic compound of Pt and Cu. It may be an organized organization.

  This composite material layer 31 also contains Cu, Au, Pd, and Ag in the second phase 22, and the composition of Au, Pd, and Ag has a mass ratio of X mass%, Y mass%, and When Z mass% and (X + Y + Z = 100), 6 points (X, Y, Z) = A (90, 10, 0), B (80, 20, 0), C (78 in the ternary diagram) , 16, 6), D (78, 6, 16), E (80, 0, 20), F (90, 0, 10) surrounded by a range (however, the point (X, Y, Z) = (90 , 10, 0) and a value on a straight line connecting the point (X, Y, Z) = (80, 20, 0), and the point (X, Y, Z) = (80, 0, 20) and the point ( X, Y, Z) = (except values on a straight line connecting (90, 0, 10)).

  Such a ring 3 forms a molded body in which a core material 30 formed in advance is inserted with a mixed powder of Pt, Cu, Au, Pd, and Ag (Pd or Ag may be omitted). After that, the formed body can be formed by firing by a discharge plasma sintering method.

  Also in the ring 3 obtained in this way, the composite material layer 31 composed of the composite material 2 in the tissue state shown in FIG. 2 or the composite in which the first phase covered with the third phase is dispersed in the second phase. A material layer 31 is formed on the surface.

  Next, another example of the decorative article according to the present invention will be described with reference to FIGS.

  The necklace 4 shown in FIG. 6 includes a head 40 and a chain 41, and at least one of the head 40 and the chain 41 has at least the rings 1 and 3 described above (FIGS. 1 to 3). And a composite material layer having the same composition and structure as those of (see Fig. 1).

The head 40 or the chain 41 may be entirely formed of the composite material of the present invention, or the surface of the core material may be covered with the composite material of the present invention. When the composite material layer is formed on the surface of the core material in the head 40 or the chain 41, the thickness of the composite material layer is set to 0.03 to 0.1 μm, for example.

  In the necklace 4, the form of the head 40 and the chain 41 can be variously changed, and the head 40 may be omitted and the necklace 4 may be configured as a necklace.

  The bracelet 5 shown in FIG. 7 is formed by connecting a plurality of pieces 50 in a ring shape, and at least the surface layer of each piece 50 has the same composition as the rings 1 and 3 (see FIGS. 1 to 3) described above. And a composite material layer in a tissue state. The whole piece 50 may be formed of the composite material of the present invention, or the surface of the core material may be coated with the composite material of the present invention. When the composite material layer is formed on the surface of the core material in the piece 50, the thickness of the composite material layer is set to 0.03 to 0.1 μm, for example.

  The bracelet 5 can be variously changed with respect to the shape of the piece 50, and the bracelet of the present invention does not necessarily have to be composed of a plurality of pieces.

  In the timepiece 6 shown in FIG. 8, at least the surface layer of the belt 60 is a composite material layer having the same composition and structure as the rings 1 and 3 (see FIGS. 1 to 3) described above. The belt 60 may be entirely formed of the composite material of the present invention, or the surface of the core material may be coated with the composite material of the present invention. In the timepiece 6, the side edge 61 may be formed of the composite material of the present invention, and in this case, the side edge 61 may be entirely formed of the composite material of the present invention. The surface may be coated with the composite material of the present invention. When the composite material layer is formed on the surface of the core material at the belt 60 or the side edge 61, the thickness of the composite material layer is set to 0.03 to 0.1 μm, for example.

  The timepiece 6 can be variously changed in the shape of the belt 60, the side edge 61, and the like, and the present invention can be applied to a timepiece having a form other than that illustrated.

  The glasses 7 shown in FIG. 9 have a composite material layer (hereinafter referred to as a composite material) in which at least the surface layer of the frame 70 has the same composition and structure as the rings 1 and 3 (see FIGS. 1 to 3) described above. The region in which is formed is referred to as a composite material region). The frame 70 may be entirely formed of the composite material of the present invention, or the surface of the core material may be coated with the composite material of the present invention. When a composite material layer is formed on the surface of the core material in the frame 70, the thickness of the composite material layer is set to 0.03 to 0.1 μm, for example.

  The glasses 7 can be variously modified with respect to the shape of the frame 70 and the like, and the present invention can be applied to a timepiece having a form other than that illustrated.

  When the composite material region has a region defined by a circle having a diameter of at least 1 mm, it can be easily confirmed as colored by the naked eye.

  When the composite material region is formed at least to a region having a depth of 1 mm from the surface, it is possible to reduce the occurrence of color unevenness in the surface even if polishing is repeated.

  In the fountain pen 8 shown in FIG. 10, at least one surface layer of the nib 80 is a composite material layer having the same composition and structure as the rings 1 and 3 described above (see FIGS. 1 to 4). The pen tip 80 may be entirely formed of the composite material of the present invention, or may be one in which the surface of the core material is coated with the composite material of the present invention. When the composite material layer is formed on the surface of the core material at the pen tip 80, the thickness of the composite material layer is set to 0.03 to 0.1 μm, for example. In the fountain pen 8, in addition to the pen tip 80 or instead of the pen tip 80, at least the surface layer in other parts such as the clip 81 may be formed as a composite tissue layer.

  The shape of the fountain pen 8 can be variously changed with respect to the shape of the nib 80, the clip 81, and the like, and the present invention can be applied to a timepiece having a form other than the illustrated one.

  Further, the decorative material shown in FIGS. 6 to 10, that is, the composite material layer in the necklace 4, the bracelet 5, the watch 6, the glasses 7, and the fountain pen 8, has a second phase containing Cu as a main component. One phase may be disposed, and the first phase may be in a textured state surrounded by a third phase containing an intermetallic compound of Pt and Cu. A third phase containing an intermetallic compound of Pt and Cu may be used. It may be in a tissue state in which no phase is substantially present.

The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the third phase 23 of the composite material 2 (composite material layer 6) may be omitted as long as the corrosion resistance and strength according to the application can be ensured. By appropriately setting the conditions, it may be generated by a method other than the discharge plasma sintering method. For example, although some voids are generated, it can also be generated by gradually raising the temperature to 500 ° C. under vacuum conditions of 1.33 × 10 ⁻² Pa by vacuum firing and firing at this temperature for 30 minutes. it can.

  Furthermore, a coating layer made of aluminum oxide may be formed on the surface of the composite material region. This coating layer can be formed, for example, by reactive sputtering using oxygen as a target material and mixing oxygen gas in an argon gas atmosphere. At this time, the argon gas pressure is about 1 Pa, the oxygen gas flow rate is 10 sccm, and a suitable coating layer can be formed by managing the film formation rate while controlling the DC power at 100 to 500 W. That is, since transparent aluminum oxide with high hardness can be formed, it is possible to provide an always beautiful decorative product that is not easily scratched and has excellent weather resistance.

  When the aluminum oxide is non-single crystal, a more suitable coating layer can be obtained. Here, in order to make the aluminum oxide non-single crystal, the oxygen gas flow rate is kept lower than a predetermined amount or the DC power is increased so that the atomic ratio of oxygen to aluminum is lower than the constant ratio of aluminum oxide. Formation is possible. Thus, by forming the coating layer on non-single crystal aluminum oxide, peeling of the coating layer due to cracking can be prevented, and this effect makes the coating layer amorphous aluminum oxide without crystal grain boundaries. In particular, it is possible to provide a highly reliable decorative product.

  In addition, if the thickness of the coating layer is in the range of 5 to 50 nm, the thickness of the coating layer is too large and the warping amount of the coating layer is increased while ensuring a thickness that can prevent the surface of the decorative article from being damaged. It is possible to prevent peeling.

  In particular, compared with the prior art, since the coating layer of the present invention forms a uniform film, local stress does not occur. The stress is generated due to the heat when forming the coating layer or the density difference of the film itself, but in the present invention, DC reactive sputtering is used, and the DC power can be kept low to reduce heat generation. By gradually changing the oxygen flow rate, it is possible to avoid a sudden change in the film density, so that the occurrence of a stress difference can be reduced.

  Further, the present invention does not have a pure aluminum layer, and particularly uses a chemically stable amorphous aluminum oxide, so that corrosion does not proceed rapidly.

  The average refractive index of the coating layer is particularly preferably in the range of 1.5 to 2.5. This average refractive index can be measured and determined by irradiating a flat coating layer with a laser using a commercially available ellipsometer.

  An ellipsometer (ESM-1 type manufactured by ULVAC) is used for measurement of the average refractive index, but the measurement sample is a flat plate obtained by mirror-processing a target decorative article and having a coating layer of 100 nm. Alternatively, a coating layer may be formed on the main surface of the quartz glass substrate, and a black paint may be applied on the opposite surface side to the extent that measurement light does not pass through.

  Even when a thin coating layer such as 5 nm is formed, a measurement sample having a thickness of 100 nm is prepared and the average refractive index is evaluated in advance.

  When the oxygen concentration or DC power is changed with time, a measurement sample is formed according to the film formation conditions at the midpoint of the elapsed time.

  Here, since the average refractive index of the coating layer tends to decrease as the amount of oxygen in the aluminum oxide increases, it is easy to manage by controlling either the oxygen gas flow rate or the DC power during the formation of the coating layer. It is. If the average refractive index is particularly in the range of 1.5 to 2.5, the coating layer maintains a predetermined refractive index while maintaining a transparent state with high transmittance and low reflectance and absorption coefficient. Therefore, it is possible to enhance the brightness and saturation without changing the hue of the decorative product itself, thereby providing a beautiful and rich decorative product.

  The refractive index of the coating layer is preferably high on the surface side of the composite material region (or the oxygen concentration is low on the surface side of the composite material region). To do this, it is possible to reduce the oxygen gas flow rate at the start of film formation of the coating layer or increase the DC power. As a result, aluminum becomes rich at the interface on the surface side of the composite material region in the coating layer, so that the bond between the surface of the composite material region that is a metal and the aluminum-rich surface of the coating layer can be further strengthened. Yes, it is possible to prevent peeling due to improved adhesion. As a result, it is possible to provide a more reliable decorative article.

  In addition, by setting the atomic ratio of oxygen to aluminum in the coating layer to be 25 to 75%, the aluminum oxide coating with less non-single crystal grain boundaries prevents the coating layer from being peeled off from the composite material region. Can provide excellent decorations.

  Furthermore, by changing the refractive index and thickness of this coating layer, the hue, brightness, and saturation of the ornament can be appropriately changed, and a play-coloring effect can be expected. Can be provided.

  The present invention is not limited to the above-described rings, necklaces, bracelets, watches, and glasses, but can be applied as a part or all of other decorative items. Examples of other ornaments to which the present invention can be applied include tableware, figurines, golf clubs, mobile phones, buttons, and the like. Further, the composite material of the present invention is not limited to a decorative article, and can also be used as a target material in film formation by a PVD (physical vapor deposition) method.

  In this example, for a sample obtained from a composite material containing Pt, Cu, Au, Pd and Ag (Pd or Ag may not be included), color, corrosion resistance (sulfuration resistance), discoloration and production Sex was evaluated.

(Sample preparation)
The sample was formed by forming a mixed powder having the composition shown in Table 1 below into a tablet having a diameter of 10 mm in a sintered mold and then firing it by a discharge plasma sintering method. The mass ratio of the first phase (Pt) and the second phase (Cu, Au, Pd, Ag) was 50% by mass: 50% by mass.

Moreover, the mass ratio of Cu in the second phase (Cu, Au, Pd, Ag) and the total mass of other compositions (Au, Pd, Ag) was set to 50% by mass: 50% by mass.

The discharge plasma sintering was performed by raising the temperature to 500 ° C. at a rate of 40 ° C./min and firing for 10 minutes in a vacuum atmosphere of 1.33 × 10 ⁻² Pa.

(Color evaluation)
The evaluation of the color was performed by buffing the sample after the discharge plasma sintering and then visually comparing the color with a commercially available pink silver (PSV manufactured by Kyocera Corporation). The sample is buffed using a hub with aluminum oxide abrasive grains attached to the face cloth, and while supplying an organic solvent as a polishing liquid, the buff is rotated on the belt and pressed against the object to polish the surface. Was done. The arithmetic average surface roughness of the sample after buffing was set to be in the range of 0.04 to 0.07 μmRa. The color evaluation results are shown in Table 1 below and FIG. In Table 1 below, an O mark is given to those having a pink color development equal to or greater than that of pink silver, and an X mark is given to those having no pink color development. In FIG. 11, an O mark is given to those having a pink color development equal to or greater than that of pink silver, and a ● mark is given to those having no pink color development.

(Evaluation of corrosion resistance)
The corrosion resistance of the sample was determined by visually observing the degree of discoloration and the surface condition after half-immersing the buffed sample in artificial sweat and leaving it in an atmosphere of 40 ± 5 ° C. for 2 hours.

  For artificial sweat, 9.2 g / liter of sodium chloride, 0.8 g / liter of sodium sulfide, 1.7 g / liter of urea, 0.18 ml / liter of aqueous ammonia, 0.22 g / liter of sucrose, 1.1 ml / liter of lactic acid It was prepared with 1 liter of pure water.

  The evaluation results of the corrosion resistance are shown in Table 1 below and FIG. In Table 1 below, a mark ◯ is given to the case where there is no change in the color tone, and a mark X is given to the case where the color tone is changed or blackened. In FIG. 121, a circle mark is given to those that have no change in color tone, and a circle mark is given to those that have been discolored or blackened.

  As can be seen from Table 1, regarding the color, good pink coloration was confirmed for samples other than Sample No. 12. As can be seen from FIG. 11, the composition of Au, Pd, and Ag in the second phase that gives good results for the colors is the composition of sample numbers 1, 13, 14, 15, and 6 in the mass ratio (ternary diagram). It became the range (including the boundary line) surrounded by the points corresponding to.

  As can be seen from Table 1, regarding the corrosion resistance, good results were obtained for sample numbers 1 to 9 and 12. As can be seen from FIG. 12, the composition of Au, Pd, and Ag in the second phase that gives good results for color is the sample number 1, 2, 3, 4, 5, 6 in mass ratio (ternary diagram). , 12 (inclusive of the boundary line).

  Samples 1 to 9 gave good results for both color and corrosion resistance. As can be seen from Table 1, these samples 1 to 5 had no discoloration and were excellent in productivity.

  Here, FIG. 13 shows the results of both coloring and corrosion resistance simultaneously. In FIG. 13, those with good results for both color and corrosion resistance are marked with ○, and those with unfavorable results for either color and corrosion resistance are marked with ●. It is.

  As can be seen from FIG. 13, the composition of Au, Pd and Ag in the second phase substantially corresponds to the composition of sample number 1 in terms of mass ratio in order to obtain a pink composite material having excellent corrosion resistance. , Point B substantially corresponding to the composition of sample number 2, point C corresponding to the composition of sample number 3, point D corresponding to the composition of sample number 4, point E substantially corresponding to the composition of sample number 5, and sample number It is preferable to make the range (including the boundary line) surrounded by the point F substantially corresponding to the composition of No. 6. More specifically, the composition of Au, Pd and Ag in the second phase is three when their mass ratios are X mass%, Y mass% and Z mass%, respectively, and (X + Y + Z = 100). 6 points (X, Y, Z) in the original diagram = A (90, 10, 0), B (80, 20, 0), C (78, 16, 6), D (78, 6, 16), E A range surrounded by (80, 0, 20), F (90, 0, 10) (however, the point (X, Y, Z) = (90, 10, 0) and the point (X, Y, Z) = ( 80,20,0) and a value on a straight line connecting point (X, Y, Z) = (80,0,20) and point (X, Y, Z) = (90,0,10) The value on the straight line is preferably excluded).

  In this example, the color and corrosion resistance (sulfuration resistance) of the sample in which the composition ratio between the first phase and the second phase was changed were evaluated.

(Sample preparation)
The sample was formed by molding a mixed powder having the composition shown in Table 2 below into a tablet shape having a diameter of 10 mm in a molding die and then firing it by a discharge plasma sintering method. Each sample 16-20 shown in Table 2 differs in the mass ratio of a 1st phase and a 2nd phase, and the composition in a 2nd phase is constant.

The discharge plasma sintering was performed by raising the temperature to 500 ° C. at a rate of 40 ° C./min and firing for 10 minutes in a vacuum atmosphere of 1.33 × 10 ⁻² Pa.

  The color and corrosion resistance were evaluated in the same manner as in Example 1. The evaluation results of color and corrosion resistance are shown in Table 2 below. In Table 2 below, regarding the color, O mark is given to those having a pink color better than pink silver, and Δ mark is given to those having a pink color similar to pink silver. It is attached. On the other hand, in Table 2 below, with respect to corrosion resistance, a mark “◯” indicates that there is no change in color tone, and a mark “△” indicates that there is no problem in practical use although discoloration or blackening is slightly observed. Was attached.

  As can be seen from Table 2, regarding the color, good pink color development was confirmed for sample numbers 16 to 19. Sample No. 20 was comparable to commercially available pink silver although pink coloration was observed.

  On the other hand, regarding the corrosion resistance, good results were obtained for sample numbers 17 to 20. Sample No. 16 was slightly discolored although practically sufficient corrosion resistance was observed.

  From the above results, the mass ratio of the first phase in the composite material is 25 mass% or more and 75 mass% or less, which is the composition ratio of sample numbers 16 to 19 in order to obtain good pink color development and corrosion resistance. It can be seen that this is preferable.

  In this example, the color and corrosion resistance (sulfuration resistance) of the sample when the composition ratio between the first phase and the second phase was changed were evaluated.

(Sample preparation)
The sample was formed by forming a mixed powder having the composition shown in Table 3 below into a tablet having a diameter of 10 mm in a sintering mold and then firing it by a discharge plasma sintering method. The samples 21 to 25 shown in Table 3 have the same mass ratio of the first phase and the second phase, and the second phase has the same mass ratio of Au, Pd, and Ag while maintaining the second mass ratio. The mass ratio of Cu in the phase is changed.

The discharge plasma sintering was performed by raising the temperature to 500 ° C. at a rate of 40 ° C./min and firing for 10 minutes in a vacuum atmosphere of 1.33 × 10 ⁻² Pa.

  The color and corrosion resistance were evaluated in the same manner as in Example 1. The evaluation results of color and corrosion resistance are shown in Table 2 below. In Table 3 below, regarding the color, O mark is given to those having a pink color development better than pink silver, and Δ mark is given to those having a pink color development similar to pink silver. It is attached. On the other hand, in Table 3 below, with respect to corrosion resistance, the mark “◯” indicates that there is no change in the color tone, and the mark “△” indicates that there is no problem in practical use although discoloration or blackening is slightly observed. Was attached.

  As can be seen from Table 3, regarding the color, good pink color development was confirmed for sample numbers 22 to 25. Sample No. 21 was similar to commercially available pink silver although pink coloration was observed.

  On the other hand, regarding the corrosion resistance, good results were obtained for sample numbers 21 to 24. Sample No. 25 was slightly discolored although practically sufficient corrosion resistance was observed.

  From the above results, the mass ratio of Cu in the second phase of the composite material is 20 mass% or more and 80 weight% or less which is the composition ratio of sample numbers 22 to 24 in order to obtain good pink color development and corrosion resistance. It can be seen that it is preferable.

  Sample number 18 in Table 2 has the same composition as sample number 9 in Example 1.

  Sample number 23 in Table 3 has the same composition as sample number 9 in Example 1.

FIG. 1A is an overall perspective view of a ring which is an example of a decorative article according to the present invention, and FIG. 1B is a cross-sectional view taken along the line Ib-Ib in FIG. It is a schematic diagram which shows an example of the structure | tissue state of the composite material which concerns on this invention. It is a ternary diagram for demonstrating the composite material which concerns on this invention. FIG. 4 is a ternary diagram in which a part of the ternary diagram shown in FIG. 3 is enlarged. It is sectional drawing which shows the other example of the ring which is an example of the ornament which concerns on this invention. It is a front view which shows the necklace which is an example of the ornament which concerns on this invention. It is a front view which shows the bracelet which is an example of the ornament which concerns on this invention. It is a front view of a timepiece which is an example of a decorative article according to the present invention. It is a whole perspective view which shows the glasses which are an example of the ornament which concerns on this invention. It is a front view which shows the fountain pen which is an example of the ornament which concerns on this invention. It is a ternary diagram which shows the evaluation result of the color in an Example. It is a ternary diagram which shows the corrosion resistance evaluation result in an Example. It is a ternary diagram which shows the evaluation result of both the color and corrosion resistance in an Example.

Explanation of symbols

1, 3 Ring 2 Composite material 21, 21 'First phase 22, 22' Second phase 23, 23 'Third phase 31 Composite material layer (composite material region)
4 necklace 5 bracelet 6 watch 7 glasses 8 fountain pen

Claims (21)

A first phase mainly composed of Pt;
And a second phase containing at least Cu and Au and further containing Pd and Ag.   The composition of Au, Pd and Ag in the second phase is 6 points in the ternary diagram when the mass ratio is X mass%, Y mass% and Z mass%, respectively, and (X + Y + Z = 100). (X, Y, Z) = (90, 10, 0), (80, 20, 0), (78, 16, 6), (78, 6, 16), (80, 0, 20), (90 , 0, 10) on the straight line connecting the point (X, Y, Z) = (90, 10, 0) and the point (X, Y, Z) = (80, 20, 0) The value and the point (X, Y, Z) = (80,0,20) and the value on the straight line connecting the point (X, Y, Z) = (90,0,10) are excluded) Item 4. The composite material according to Item 1.   The composite material according to claim 1, wherein one phase of the first phase and the second phase is arranged around the other phase.   The composite material according to claim 3, wherein the plurality of second phases are disposed in the first phase.   The composite material according to claim 3, wherein the plurality of first phases are disposed in the second phase.   6. The method according to claim 1, further comprising a third phase in contact with both phases between the first phase and the second phase and including an intermetallic compound formed of Pt and Cu. The composite material described.   The composite material according to claim 6, wherein the third phase covers the first phase or the second phase.   The composite material according to any one of claims 1 to 7, wherein a total amount of Pt contained in the first phase is 25% by mass or more and 75% by mass or less of the total composition.   9. The composite material according to claim 1, wherein the total amount of Cu contained in the second phase is 20% by mass or more and 80% by mass or less of the total composition of the second phase. A decorative article having a composite material region formed of a composite material, wherein the composite material is one according to any one of claims 1 to 9.
Ornaments.   The ornament according to claim 10, wherein at least a part of the second phase and the third phase is exposed from a surface.   12. The decorative article according to claim 11, wherein the exposed portion of the second phase is surrounded by the exposed portion of the third phase.   The decorative article according to any one of claims 10 to 12, wherein the composite material area has an area defined by a circle having a diameter of at least 1 mm.   The decorative article according to claim 13, wherein the composite material region is formed at least to a region having a depth of 1 mm from the surface.   The decorative article according to any one of claims 10 to 14, wherein a coating layer made of aluminum oxide is formed on a surface of the composite material region.   The decorative article according to claim 15, wherein the aluminum oxide is non-single crystal.   The decorative article according to claim 15 or 16, wherein the thickness of the covering layer is in the range of 5 to 50 nm.   The decorative article according to any one of claims 15 to 17, wherein an average refractive index of the covering layer is in a range of 1.5 to 2.5.   The decorative article according to any one of claims 15 to 18, wherein a refractive index of the covering layer is high on a surface side of the composite material region.   The decorative article according to any one of claims 15 to 19, wherein an atomic ratio of oxygen to aluminum of the aluminum oxide is 25 to 75%.   The decorative article according to any one of claims 15 to 20, wherein an oxygen concentration of the covering layer is low on a surface side of the composite material region.

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