JP2006002248A - Hardened platinum ornament - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hardened high purity platinum ornament which retains a high grade corresponding to the grade test standards on the Mint Bureau in the Ministry of Finance and has high hardness, thus is free from cracks, deformation or the like, can obtain mirror-finishing properties, and is less liable to be scratched when being worn regarding Pt1000, and to provide a hardened platinum alloy ornament which has hardness equal or above that of the conventional Pt 900, has mirror-finishing properties and is hard to be scratched at an extremely low cost. <P>SOLUTION: An ornament of pure platinum or a platinum alloy is subjected to heat treatment simultaneously with one or more kinds of ceramics at 500 to 1,700°C for 2 min to 40 hr by an electric furnace or an induction heating furnace in a carbon (C) atmosphere obtained by burning carbon (C) in an inert gas atmosphere, and the optional one or more kinds of ceramic constituting elements are cemented therein, thus the ornament in which only the surface layer is hardened, and which has high hardness and high deformation strength can be obtained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a decorative article in which elements effective for hardening platinum are diffused and penetrated on the surface of pure platinum and a platinum alloy, and a hardened layer is formed on the surface of platinum to make it difficult to cause wrinkles.

  Conventionally, platinum materials for decoration include platinum alloys of Pt850, Pt900, and Pt950 composed of an alloy in which a metal element such as palladium or copper is added to 99.95% or more of platinum. The present situation is that the Pt1000 decoration has a higher consumer preference than the platinum alloy.

  Decorative products with high hardness, such as the platinum alloy, such as rings that are less likely to be wrinkled when worn, are more marketable, but Pt1000 is particularly soft (hardness is Hv = 60) and the surface is damaged. There was a problem that was easy to receive.

  As an example of Pt1000 improvement measures, a Pt-B alloy in which element B is added to 99.95% by weight of Pt in advance is prepared, and then the Pt-B alloy is dissolved using a crucible composed of Si oxide. By doing so, a high-purity platinum alloy for jewelry that conforms to the Pt1000 hole mark certification standard produced by reducing a part B of the Si oxide and adding Si to the Pt-B alloy is obtained. There is a method to obtain (for example, refer to Patent Document 1).

  However, when a ring is manufactured by lost wax casting using the above-described method, there is a problem that as the hardness becomes high, the ring is easily cracked and the rework cost increases.

  In addition, as a conventional technique for increasing the hardness of a platinum alloy, in the method of manufacturing a watch exterior part, the composition of the platinum alloy is platinum, copper or platinum, palladium, platinum alloy exterior parts made of platinum alone or boron and silicon in advance. There is a method of diffusing, penetrating and curing in a composite (see, for example, Patent Document 2).

  In addition, a patent is made on a technique that hardens metal elements such as aluminum, zirconium, chromium, and titanium by diffusion (chemical vapor deposition) in platinum jewelry containing at least 85% by weight of platinum, and forms an intermetallic compound on the surface layer. There is a description of a European patent document in the prior art listing of No. 3048833 (see, for example, Patent Document 3).

Japanese Patent No. 3100804 Japanese Patent Application Laid-Open No. 09-026485 European Patent Application No. 0274239

  In view of the prior art as described above, the present invention has a problem to be solved. Pure platinum Pt1000 maintains a high quality that conforms to the Ministry of Finance Mint Quality Standards and has a high hardness. There is no deformation or the like, mirror surface properties are obtained, and provision of a hardened high-purity platinum decorative article that is hard to be wrinkled at the time of wearing. The object is to provide a hardened platinum alloy decorative article that is specular and difficult to wrinkle at a very low cost.

  In order to achieve the above object, the invention of claim 1 includes pure platinum (containing 99.95% by weight of platinum) and a platinum alloy (containing no less than 85% by weight of platinum and excluding up to 15% by weight of platinum and Cu). , Including one or more metals selected from the group of In, Co) at 500 ° C. to 1700 ° C. using an electric furnace or induction heating furnace in a carbon (C) or nitriding (N) atmosphere. Heat treatment is performed for 2 minutes to 40 hours, and carbon (C) or nitrogen (N) is diffused and infiltrated into pure platinum and a platinum alloy surface layer portion, thereby having a high hardness and a high deformation strength obtained by hardening only the surface layer. .

The invention of claim 2 is selected from the group of pure platinum (containing 99.95% by weight of platinum) and a platinum alloy (containing no less than 85% by weight of platinum and excluding platinum up to 15% by weight) and Cu, In and Co. (Including one or more types of metals) of Al ₂ O ₃ , Fe ₂ O ₃ , MgO, ZrO ₂ , SiO ₂ , TiO ₂ , SnO ₂ , Cr ₂ O ₃ , CaO, BeO or ThO ₂ . 500 ° C. in a carbon (C) atmosphere obtained by burning carbon (C) in an inert gas in an electric furnace or induction heating furnace simultaneously with one or more ceramics selected from the inside By heat-treating at ~ 1700 ° C for 2 minutes to 40 hours, any one or more elements of ceramics decomposed by the reducing action of carbon (C) are diffused and penetrated into the surface layer of pure platinum and the platinum alloy. It is characterized by having a high hardness and a high deformation strength in which only the surface layer is cured.

  As described above, the pure platinum and platinum alloy ornament of claim 1 is heated to 500 ° C. using an electric furnace or induction heating furnace in a carbon (C) or nitriding (N) atmosphere, which is an element effective for curing. The cured pure platinum decorative article obtained by heat treatment at ˜1700 ° C. for 2 minutes to 40 hours and diffusing and infiltrating carbon (C) or nitrogen (N) into the surface layer of pure platinum and platinum alloy, High quality that meets the Mint Quality Test Criteria was maintained, no cracking occurred due to punching, etc., and sufficient strength to withstand deformation was secured. Moreover, the mirror surface property was acquired by having high hardness, and the objective that it was hard to be wrinkled at the time of wear was achieved. In addition, with regard to hardened platinum alloy ornaments, it is possible to provide products with good results that exceed the above-mentioned hardened high-purity platinum ornaments in terms of the occurrence of cracks, deformation, etc. due to punching, etc. It was.

Pure platinum and platinum alloy ornaments according to claim 2 in Al ₂ O ₃ , Fe ₂ O ₃ , MgO, ZrO ₂ , SiO ₂ , TiO ₂ , SnO ₂ , Cr ₂ O ₃ , CaO, BeO or ThO ₂ . 500 ° C. or higher in a carbon (C) atmosphere obtained by burning carbon (C) in an inert gas atmosphere in an electric furnace or induction heating furnace simultaneously with one or more ceramics selected from A cured pure platinum decorative article obtained by heat treating at 1700 ° C. for 2 minutes to 40 hours and curing only the surface layer by diffusing and penetrating any one or more ceramic constituent elements decomposed by carbon (C), Maintains high quality that meets the standards of the Ministry of Finance Mint Quality Test, and has high hardness, so that it can be mirror-finished and not easily wrinkled when worn. Raw is none, to achieve the purpose of securing the strength to withstand the deformation. Also, there was no cracking due to punching etc. for hardened platinum alloy ornaments, and better results were obtained than platinum alloy ornaments before heat treatment in terms of hardness, deformation, etc., specularity, and wrinkles .

  In the following, embodiments of the present invention will be described by way of examples. In practice, the hardness was measured using an AKASI Vickers hardness tester MVK-E, and the compression test (deformation strength) was a SHIMADZU tensile tester AGS-500ND. In addition, 10 samples were used each, and the curing treatment was performed 5 to 10 times each at different temperatures and times, and the embodiment in which the surface hardness Hv = 200 or more was obtained as the following examples. The average value of was described.

  Using a Pt1000 ring manufactured by lost wax casting as a sample, diffusion penetration treatment was performed by heating at 1200 ° C. for 20 hours in a carbon (C) atmosphere in an induction heating furnace. After the treatment, the Pt1000 ring was taken out, rough-finished by magnetic polishing, and then mirror-polished with a buff. The polished Pt1000 ring sample was cut in the thickness direction and the cross section was polished, and then the Vickers hardness of the cross section was measured with an AKASI Vickers hardness meter MVK-E. The surface hardness showed Hv = 237, and the hardness decreased as it went inside, and Hv = 60 equivalent to the pre-penetration hardness was shown at a position where the inside entered up to about 250 μm. In addition, when a compression test (deformation strength) was performed with a tensile tester AGS-500ND made by SHIMADZU, the same shape without diffusion penetration treatment showed a deformation strength of 4 kgf, whereas diffusion penetration treatment was performed. What was performed showed a deformation strength of about 2.5 times that of 11 kgf, and a ring of Pt1000 having a surface hardness and a deformation strength much higher than before diffusion diffusion treatment and satisfying the standards of the Ministry of Finance Mint Quality Test was obtained. Table 1 below shows the results of Example 1 in which the change in hardness (Hv) from the sample surface to the inside when the carbon (C) diffusion and penetration treatment was performed was measured with a micro Vickers hardness meter.

  A buffed mirror-finished Pt950 ring sample was heated in a carbon (C) atmosphere at 1500 ° C. for 0.5 hour in an electric furnace to perform diffusion penetration treatment. After the infiltration treatment, a buffed Pt950 ring sample that had been mirror-polished to the product level was cut in the thickness direction, the cross-section was polished, and the hardness of the cross-section was measured to show Hv = 237 on the sample surface and go inside. Therefore, the hardness decreased, and Hv = 105 equivalent to the hardness before heat treatment was shown at a position of about 250 μm from the sample surface. Further, when the deformation strength was measured, the deformation strength was about twice as high as that of the same shape not subjected to diffusion permeation treatment with 12 kgf. Table 2 below shows the results of Example 2 in which the change in hardness (Hv) from the sample surface to the inside when the carbon (C) diffusion and penetration treatment was performed was measured with a micro Vickers hardness meter.

  A buffed Pt900 ring sample was mirror-finished by heating in a carbon (C) atmosphere at 1400 ° C. for 15 hours in an induction heating furnace. After the treatment, it was mirror polished to a product level with a buff. After the mirror-polished Pt900 ring sample was cut in the thickness direction and the cross-section was polished, the hardness of the cross-section was measured. The sample surface showed Hv = 247, and the hardness decreased as the sample surface moved inward. Furthermore, Hv = 115 equivalent to the hardness before heat treatment was shown at a position of about 250 μm. Further, when the deformation strength was measured, the deformation strength was about 3 times that of the same shape not subjected to diffusion permeation treatment with 15 kgf. Table 3 below shows the results of Example 3 in which the change in hardness (Hv) from the sample surface to the inside when the carbon (C) diffusion permeation treatment was performed was measured with a micro Vickers hardness meter.

A Pt1000 pendant sample mirror-finished by buffing was heated in an induction heating furnace in a nitriding (N) atmosphere at 1400 ° C. for 25 hours to perform diffusion penetration treatment. After the treatment, it was mirror polished to a product level with a buff. After the mirror-polished Pt1000 pendant sample was cut in the thickness direction and the cross section was polished, the hardness of the cross section was measured. The sample surface showed Hv = 228, and the hardness decreased from the sample surface toward the inside. Hv = 60 equivalent to that before the heat treatment was shown at a position of about 200 μm from the sample surface. In addition, when the Ministry of Finance Mint Quality Test was performed, the standards were met.

A Pt950 ring sample mirror-finished by buffing was heated in an electric furnace at 1100 ° C. for 40 hours in a nitriding (N) atmosphere to carry out diffusion penetration treatment. After the treatment, it was mirror polished to a product level with a buff. After the mirror-polished Pt950 ring sample was cut in the thickness direction and the cross-section was polished, the hardness of the cross-section was measured. The sample surface showed Hv = 262, and the hardness decreased from the sample surface toward the inside. Hv = 116 equivalent to the hardness before heat treatment was shown at a position of about 200 μm from the surface. When the deformation strength was measured, the deformation strength was about 2.5 times as high as that of 13 kgf and the same shape not subjected to diffusion permeation treatment.

  A Pt900 pendant sample mirror-finished by buffing was heated in a nitriding (N) atmosphere at 1300 ° C. for 30 hours in an electric furnace to carry out diffusion penetration treatment. After the treatment, it was mirror polished to a product level with a buff. After the mirror-polished Pt900 pendant sample was cut in the thickness direction and the cross section was polished, the hardness of the cross section was measured. The sample surface showed Hv = 257, and the hardness decreased from the sample surface toward the inside. Hv = 109 equivalent to the hardness before heat treatment was shown at a position of about 200 μm from the surface.

  A ring of Pt1000 mirror-finished by buffing and MgO are simultaneously heated at 1500 ° C. for 10 hours in a carbon (C) atmosphere obtained by burning carbon (C) in an inert gas atmosphere in an induction heating furnace. Then, diffusion and permeation treatment was performed. After the treatment, the Pt1000 ring was taken out, rough-finished by magnetic polishing, and then mirror-polished with a buff. The polished Pt1000 ring sample was cut in the thickness direction and the cross section was polished, and then the Vickers hardness of the cross section was measured. The surface hardness showed Hv = 237, and the hardness decreased as it went inside, and Hv = 63 equivalent to the pre-penetration hardness was shown at the position where the inside entered up to about 250 μm. In addition, when the deformation strength was measured, it showed a deformation strength of about 2.5 times that of 13 kgf and the same shape not subjected to the diffusion permeation treatment. The surface hardness and deformation strength were much higher than before the diffusion permeation treatment. And a Pt 1000 ring that meets the standards for the quality test of the Ministry of Finance Mint.

  The Pt900 ring and MgO rough-finished by barrel polishing were simultaneously heated at 1400 ° C. for 10 hours in a carbon (C) atmosphere obtained by burning carbon (C) in an inert gas atmosphere in an induction heating furnace. Then, diffusion and permeation treatment was performed. After the treatment, the Pt900 ring was mirror-polished to a product level with a buff. After the polished Pt900 ring sample was cut in the thickness direction and the cross section was polished, the hardness of the cross section was measured to show Hv = 245 as the surface hardness. Hv = 107 equivalent to the hardness before infiltration treatment was shown at the position where it entered. Further, when the deformation strength was measured, the deformation strength was about twice as high as that of 14 kgf and the same shape not subjected to diffusion permeation treatment.

A ring sample of Pt1000 mirror-finished by buffing is heated at 1500 ° C. in a carbon (C) atmosphere obtained by burning carbon (C) in an inert gas atmosphere in an electric furnace simultaneously with Al ₂ O _3. Diffusion treatment was performed by heating for a period of time. After the treatment, it was mirror polished to a product level with a buff. After the polished Pt1000 ring sample was cut in the thickness direction and the cross section was polished, the hardness of the cross section was measured. As a result, the surface hardness showed Hv = 223, and the hardness decreased toward the inside, up to about 250 μm. Hv = 65, which is equivalent to the hardness before the infiltration treatment, was shown at the position inside. Further, when the deformation strength was measured, the deformation strength was about twice as much as 11 kgf than that of the same shape not subjected to the diffusion permeation treatment.

A ring of Pt950 rough-finished by barrel polishing is simultaneously heated at 1300 ° C. in a carbon (C) atmosphere obtained by burning carbon (C) in an inert gas atmosphere in an electric furnace simultaneously with Al ₂ O _3. Diffusion permeation treatment was performed by heating. After the treatment, it was mirror polished to a product level with a buff. After the polished Pt950 ring sample was cut in the thickness direction and the cross section was polished, the hardness of the cross section was measured. The surface hardness showed Hv = 216, and the hardness decreased toward the inside, up to about 250 μm. Hv = 115 equivalent to the hardness before the infiltration treatment was shown at the position inside. Further, when the deformation strength was measured, the deformation strength was about twice as much as 11 kgf than that of the same shape not subjected to the diffusion permeation treatment.

A sample of Pt1000 ring mirror-finished by buffing is heated at 1500 ° C. for 1 hour in a carbon (C) atmosphere obtained by burning carbon (C) in an inert gas atmosphere in an electric furnace simultaneously with ZrO ₂ and CaO. Then, diffusion penetration treatment was performed. After the treatment, the Pt1000 ring sample was mirror-polished with a buff to the product level. After the polished Pt1000 ring sample was cut in the thickness direction and the cross section was polished, the hardness of the cross section was measured. As a result, the surface hardness showed Hv = 212, and the hardness decreased toward the inside and decreased from the sample surface. Hv = 58 equivalent to the hardness before heat treatment was shown at a position of 250 μm. Moreover, when the deformation strength was measured, it showed a deformation strength about 12 times that of 12 kgf and the same shape not subjected to the diffusion permeation treatment, and had much higher surface hardness and deformation strength than before the diffusion permeation treatment. A ring of Pt1000 that meets the quality assessment standards of the Ministry of Finance Mint was obtained.

A Pt900 pendant sample mirror-finished by buffing is heated at 1100 ° C. for 10 hours in a carbon (C) atmosphere obtained by burning carbon (C) in an inert gas atmosphere in an electric furnace simultaneously with ZrO ₂ and CaO. Then, diffusion penetration treatment was performed. After the treatment, the Pt900 pendant sample was mirror-polished to the product level with a buff. After the polished Pt900 pendant sample was cut in the thickness direction and the cross section was polished, the hardness of the cross section was measured. As a result, the surface hardness showed Hv = 203, and the hardness decreased toward the inside. Hv = 102 equivalent to the hardness before heat treatment was shown at a position of 250 μm.

  Table 4 shows the results of the curing treatment performed in Examples 1 to 12 for obtaining the cured platinum decorative article of the present invention. As a result, as shown in the table, the surface hardness is higher than the internal hardness. ing.

_Further, in the method and conditions shown in _{Fe 2 O 3, SiO 2,} TiO 2, SnO 2, Cr 2 O 3, BeO or ThO also Example 7-12 in ₂ ceramics, the same effect was obtained.

Claims (2)

  Pure platinum and platinum alloy decorations are heat-treated at 500 ° C. to 1700 ° C. for 2 minutes to 40 hours using an electric furnace or an induction heating furnace in a carbon (C) or nitriding (N) atmosphere to obtain carbon (C). Alternatively, a cured platinum decorative article characterized by having a high hardness and a high deformation strength in which only the surface layer is cured by diffusing and penetrating nitrogen (N) into the surface layer of pure platinum and the platinum alloy. Pure platinum and platinum alloy ornaments are selected from Al ₂ O ₃ , Fe ₂ O ₃ , MgO, ZrO ₂ , SiO ₂ , TiO ₂ , SnO ₂ , Cr ₂ O ₃ , CaO, BeO or ThO _2. Simultaneously with one or two or more ceramics, in a carbon (C) atmosphere obtained by burning carbon (C) in an inert gas in an electric furnace or induction heating furnace, the temperature is 500 ° C. to 1700 ° C. The surface layer is formed by diffusing and penetrating any one or more elements of ceramics decomposed by the reducing action of carbon (C) into the surface layer of pure platinum and the platinum alloy by heat treatment for 2 minutes to 40 hours. Cured platinum ornaments characterized by high hardness and high deformation strength that are only cured.