JPH0717974B2 - Gold alloy with shiny grey-black and black coloring and its coloring method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a brilliant gray-black and black-colored gold alloy and a method for coloring the same, which are related to the production of precious metal ornaments.

(Prior Art) In the field of precious metal ornaments, gold products are stipulated by the carat method, and in Japan, 90% or more of the 18 carat processed products with a gold content of 75% by weight are in circulation. There is. This is considered to be established because 18-karat gold has the most stable mechanical, physical and chemical properties, has good workability, and is easily applied to hue changes. And the concept that 18-karat gold color is golden has long been fixed, but in recent years the needs of consumers for precious metal ornaments made of gold alloys have diversified, and it is devised to make use of designs by making them multicolored. It's starting to happen.

Currently, the hues used in gold alloy products are light green yellow of Au-Ag alloy, yellow of Au-Ag-Cu alloy, red of Au-Cu alloy, and light yellow-white of Au-Cu-Ni alloy. , By combining these colors, it was a colorful processed product.
In addition, very recently, it became possible to change the color by adding purple of Au-Al alloy and yellow-green of Au-Cd alloy.

(Problems to be Solved by the Invention) However, as described above, the five colors of white, yellow, red, purple, and yellow-green have a limit in achieving a multicolor design as an ornamental product. Under the present circumstances, there is a demand for the development of an alloy, especially a gray-black and blackened gold alloy which has an extremely high contrast with respect to a golden color which consumes a large amount.

(Means for Solving the Problems) The present invention has been proposed in view of the above, in which pure platinum (Au) is a platinum group element (Pt, Pd, Rh, Ir, Ru, O) as a gold grade adjusting element.
s), silver (Ag) or nickel (Ni), and one or more of them are added, and the content of gold (Au) is 38% by weight.
3-40% by weight of copper (Cu), 3-40% by weight of iron (Fe), 3-40% by weight of cobalt (Co), 1-
Within 10% by weight of titanium (Ti) black coloring element, one or more kinds within the range of this addition amount, 0.2 as a blackening degree adjusting element
~ 10 wt% vanadium (V), 0.2-10 wt% manganese (Mn), 1-10 wt% chromium (Cr), 0.2-5 wt% tungsten (W), 0.2-5 wt% molybdenum (Mo), 0.2-5 wt% niobium (Nb), 0.2-15 wt% hafnium (Hf), 0.2-15 wt% tantalum (T
a), 0.2-15 wt% zirconium (Zr), 0.2-15 wt% yttrium (Y), 0.2-15 wt% rhenium (Re), 0.2-15 wt% germanium (Ge), 0.2-10
Wt% rare earth metal (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, H
o, Er, Tm, Yb, Lu) within the range of this addition amount,
A gold alloy of three or more elements in which 0.5 to 10% by weight of tin (Sn) and 0.5 to 10% by weight of zinc (Zn) are added as the fluidity and cleaning elements of the alloy within the range of this addition amount. After air-cooling, water-cooling, or oil-cooling after heat treatment in the atmosphere or in an oxidizing atmosphere whose oxygen partial pressure is higher or lower than the oxygen partial pressure of the atmosphere at a temperature below the melting point of the gold alloy in which the total amount of elements other than gold is 65 wt% or less. The present invention also relates to a gold alloy for coloring the whole or a part of the surface layer portion of a semi-processed product or a completely processed product of gold alloy in bright grey-black and black and a coloring method thereof.

Gold alloys composed of the various elements described above are obtained by melting each composition described above in a vacuum or in an inert gas atmosphere in an arc melting furnace or a high-frequency melting furnace equipped with a water-cooled copper crucible. To be

In addition, the amount of one dissolution is usually about 50 to 100 g.

The ingot of each alloy produced as described above is melted in a vacuum or an atmosphere of an inert gas such as argon gas, and cast into a mold made of magnesia, zircon, alumina, mullite, silica or the like. In this case, it is desirable to improve the filling property into the cavity in the mold by utilizing the pressure or centrifugal force of the inert gas during casting.

Gold alloy products obtained by casting as described above, after sanding, scraping, grinding stone polishing, puff polishing, in the atmosphere or in an oxidizing atmosphere higher or lower than the oxygen partial pressure of the atmosphere, Usually, after heating at 850 to 950 ° C for about 20 to 30 minutes, air cooling, oil cooling or water cooling is performed.

The above-described heating step of the gold alloy may be performed in the atmosphere, and the heating temperature can be arbitrarily changed as long as it is a temperature equal to or lower than the melting point of each alloy and the heating time can be arbitrarily changed.

In addition, at the time when the above-described gray-black color and the blackening treatment are completed,
If the grey-black color and black gloss formed on the surface are insufficient, lightly puff polish again, and then apply a gas burner flame such as city gas or propane gas to the surface of the product for a short time to puff polish. With gloss, sufficient gloss can be generated.

By the way, the grey-black and black color-developing treatment by heating according to the present invention can be set in a considerably wide range, though it depends on the size of the processed product, and the heating temperature is under an atmospheric atmosphere.
At about 800-1000 ° C, the blackening layer becomes thicker as the heating time becomes longer, so the degree of blackening increases, but it takes about 15-20 minutes for small items such as rings and brooches, and 30-40 minutes for slightly larger items. It is enough.

Incidentally, in the gold alloy of the present invention and the coloring method thereof, it is important to adjust each additive element and each addition amount in the range shown in the constitution of the present invention, and when it is out of the range of the constitution, , It is difficult to achieve the intended purpose.

(Example) Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to the examples.

(A) Cu, Fe, Co, Ti as a black coloring element on gold (Au) 1
Or more, V, Mn, Cr, W, Mo, Nb, Hf, T as blackening degree adjusting element
In the case of a gold alloy and its product containing at least one of a, Zr, Y, Re, Ge and rare earth metals, and at least one of Sn and Zn as fluidity and cleaning elements Example 1 Au alloy composition Au 75g Electrolysis Fe 10g Pure Sn 10g Pure Ge 3g Pure Y 1g Pure Nb 1g Coloring of Au alloy product The above composition was melted by arc melting in an argon gas atmosphere. Using a mold made of this alloy by the lost wax method under vacuum, the cast product (ring) obtained by centrifugal casting was sanded, polished, and the surface was finished. After soaking for 1 minute for color development, the mixture was cooled with water. Then, when the product was subjected to puff polishing again, a beautiful and bright black product was obtained. The blackened layer had a thickness of 3 to 4 μm and was beautiful.

Example 2 Formulation of Au alloy Au 75g Electrolytic Fe 10g Oxygen-free Cu 5g Pure Sn 5g Pure Cr 2g Pure V 2g Pure W 0.5g Pure Zr 0.5g Coloring of Au alloy product Melting, casting and heating as in Example 1. Color development processing was performed. The blackened layer had a thickness of 3 to 4 μm and was beautiful.

Example 3 Formulation of Au alloy Au 75g Electrolytic Co 15g Pure Cr 3g Pure Mo 2g Pure Zr 2g Pure Y 1g Pure Zn 2g Coloring of Au alloy product The same melting, casting and coloring treatment as in Example 1 was performed. . The blackened layer had a thickness of 3 to 4 μm and was beautiful.

Example 4 Formulation of Au alloy Au 75g Electrolytic Fe 12g Pure Sn 7g Electrolytic Mn 4.5g Pure Hf 0.2g Pure Re 0.3g Pure Sm 0.5g Pure Er 0.3g Pure Nb 0.2g Coloring of Au alloy product Same as Example 1. Color processing was performed by melting, casting, and heating. The blackened layer had a thickness of 3 to 4 μm and was beautiful.

Example 5 Formulation of Au alloy Au 75g Electrolytic Co 10g Oxygen-free Cu 5g Pure Sn 4g Pure V 3g Pure Mo 1.5g Pure W 1g Pure Ta 0.3g Pure Pr 0.2g Coloring of Au alloy product Melting as in Example 1 Then, color development processing was performed by casting, heating. The blackened layer had a thickness of 3 to 4 μm and was beautiful.

(B) Platinum group element (P
t, Pd, Rh, Ir, Ru, Os), silver (Ag) or nickel (Ni)
One or two or more of these are added to gold alloys containing 38% by weight or more of gold (Au), and Cu, F as black coloring elements
One or more of e, Co, Ti, V, Mn, Cr, and
In the case of gold alloys and their products containing one or more of W, Mo, Nb, Hf, Ta, Zr, Y, Re, Ge and rare earth metals, and one or more of Sn and Zn as fluidity and cleaning elements. Example 6 Au alloy formulation Au 75g Pure Ag 6g Pure Pd 5g Electrolytic Co 8g Pure Cr 3g Pure V 2g Pure W 0.5g Pure Zr 0.2g Pure Mo 0.3g Au alloy product coloring Melting and casting similar to Example 1 Then, color development processing by heating was performed. The blackened layer had a thickness of 3 to 4 μm and was beautiful.

Example 7 Formulation of Au alloy Au 75g Electrolytic Ni 12g Electrolytic Fe 7g Pure Cr 3g Pure V 3g Pure Zr 0.3g Pure Y 0.2g Pure Ta 0.5g Pure Zn 1g Coloring of Au alloy product Melting as in Example 1, Color development processing was performed by casting and heating. The blackened layer had a thickness of 3 to 4 μm and was beautiful.

Example 8 Formulation of Au alloy Au 75g Electrolytic Co 8g Pure Pt 5g Pure Ni 5g Oxygen-free Cu 5g Pure Mo 1g Pure Zr 0.2g Pure Ta 0.3g Pure Mn 0.3g Pure Pr 0.2g Coloring of Au alloy product Example 1 and The same smelting, casting, and coloring treatment by heating were performed. The blackened layer had a thickness of 3 to 4 μm and was beautiful.

Example 9 Formulation of Au alloy Au 75g Electrolytic Fe 8g Pure Pd 3g Pure Rh 2g Pure Ag 7g Pure Ge 2.5g Pure Y 0.5g Pure Hf 0.5g Pure Nb 0.2g Pure Re 0.3g Pure Zn 1g Coloring Au alloy products The same melting, casting, and color development treatments as in Example 1 were performed. The blackened layer had a thickness of 3 to 4 μm and was beautiful.

Example 10 Formulation of Au alloy Au 75g Pure Pt 5g Electrolytic Co 7g Pure Ag 5g Pure Sn 5g Pure Ti 1g Pure V 1.3g Pure Mo 0.3g Pure Zr 0.2g Pure Pr 0.2g Au alloy product coloring Same as Example 1 Was melted, cast, and colored by heating. The blackened layer had a thickness of 3 to 4 μm and was beautiful.

The examples of the 18K (carat, Au = 75% by weight) Au alloy have been described above. However, the composition of the Au alloy may be adjusted by appropriately adjusting each additive element and each additive amount within the range shown in the constitution of the present invention. When it was carried out in the same manner, it was possible to obtain a product which was similarly gray-black or blackened. Also, for example, 20 above 18K
K, 22K, etc., and also in 18K or less Au alloy, the noble metal product of the Au alloy whose additive element and the amount of addition are adjusted in the range shown in the above-mentioned constitution of the present invention is grayish black and gray by subjecting it to heat treatment. It was possible to obtain a blackened product.

(Effects of the Invention) As described above, the gold alloy of the present invention is
It makes it possible to add gray black and black to the Au alloy which was five colors of yellow, yellow green, white and purple, which enables more diverse designs as precious metal ornaments, This will lead to higher added value for ornaments.

In addition, the method for producing a bright gold-black and black-colored gold alloy of the present invention does not require special raw materials and processing equipment, and is therefore highly practical.

Claims (4)

[Claims] 1. Pure gold (Au), as a black color-developing element, 3 to 40% by weight of copper (Cu), 3 to 40% by weight of iron (Fe), 3 to 40% by weight of cobalt (Co), 1 to 10 Within the range of this addition amount, one or more kinds of titanium (Ti) in weight%, vanadium (V) in an amount of 0.2 to 10% by weight as a blackening degree adjusting element, manganese (Mn) in an amount of 0.2 to 10% by weight, 1 ~ 10 wt% chromium (Cr), 0.
2-5 wt% tungsten (W), 0.2-5 wt% molybdenum (Mo), 0.2-5 wt% niobium (Nb), 0.2-
15 wt% hafnium (Hf), 0.2-15 wt% tantalum (Ta), 0.2-15 wt% zirconium (Zr), 0.2-
15 wt% yttrium (Y), 0.2-15 wt% rhenium (Re), 0.2-15 wt% germanium (Ge), 0.2
~ 10wt% rare earth metal (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, T
b, Dy, Ho, Er, Tm, Yb, Lu) within the range of this addition amount, 0.5 to 15% by weight of tin (Sn), 0.5 to 15% as a fluidity and cleaning element of the alloy and a cleaning element. A ternary or higher gold alloy in which 1% or more by weight of zinc (Zn) is added within the above range. 2. A semi-finished product or a completely processed product of the gold alloy according to claim 1 is heated in the atmosphere at a temperature below the melting point of the gold alloy or in an oxidizing atmosphere higher or lower than the oxygen partial pressure of the atmosphere. A method in which the whole or a part of the surface layer of a gold alloy processed product is colored into a glossy gray black or black by subjecting it to air cooling, water cooling or oil cooling after heat treatment. 3. One or more of platinum group elements (Pt, Pd, Rh, Ir, Ru, Os), silver (Ag) or nickel (Ni) as a gold grade adjusting element in pure gold (Au). Is added to a gold alloy having a gold (Au) content of 38% by weight or more as a black coloring element, 3 to 40% by weight of copper (Cu), 3 to 40% by weight of iron (Fe), and 3 to 40% by weight. Wt% cobalt (Co), 1-10 wt%
Of titanium (Ti) within the range of the addition amount, 0.2 to 10% by weight of vanadium (V), 0.2 to 10% by weight of manganese (Mn), and Ten
Wt% chromium (Cr), 0.2-5 wt% tungsten (W), 0.2-5 wt% molybdenum (Mo), 0.2-5 wt% niobium (Nb), 0.2-15 wt% hafnium (H
f), 0.2-15 wt% tantalum (Ta), 0.2-15 wt%
Zirconium (Zr), 0.2-15 wt% yttrium (Y), 0.2-15 wt% rhenium (Re), 0.2-15 wt% germanium (Ge), 0.2-10 wt% rare earth metal (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu)
Within the range of this addition amount, 0.5 to 15% by weight of tin (Sn) and 0.5 to 10% by weight of zinc (Zn) as the fluidity and cleaning elements of the alloy within the range of the addition amount. A ternary or higher gold alloy with one or more added in. 4. A semi-finished product or a complete processed product of the gold alloy according to claim 3 is heated in the atmosphere at a temperature not higher than the melting point of the gold alloy or in an oxidizing atmosphere higher or lower than the oxygen partial pressure of the atmosphere. After the treatment, it is cooled with air, water or oil to color the whole or part of the surface layer of the gold alloy processed product to a glossy blackish black or black.