JPH02225655A - Gold alloy that is colored shiny black and its coloring method - Google Patents

Abstract

PURPOSE:To color a gold alloy into bright black color and to produce a more colorful design as noble metal ornament by subjecting a gold alloy with a specific composition to prescribed heating treatment in the air, etc., and then to cooling. CONSTITUTION:A gold alloy having a composition in which 5-65wt.% of one element among Cu, Fe, Co, and Ti is incorporated to pure gold is refined, e.g. in a vacuum atmosphere by means of arc melting, etc., subsequently, centrifugal casting is applied to the above gold alloy under vacuum by using a mold prepared by a lost wax process, etc., and a worked part of the resulting casting, etc., is filed and polished to undergo surface finish. The above worked part is heated at a temp. of the melting point of the gold alloy or below in the air or in an oxidizing atmosphere in which pressure is regulated to a value higher or lower than the partial pressure of oxygen in the air to undergo coloring treatment, and is then subjected to air cooling, water cooling, or oil cooling, by which the whole or a part of the surface layer part of the above worked part can be colored into bright black color.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a gold alloy that is colored shiny black and a method for coloring the gold alloy, which is related to the production of precious metal ornaments.

(Conventional technology) In the field of precious metal accessories, gold products are defined by the Karabut Law, and in Japan, 18-strength processed products with a gold content of 75% by weight account for more than 90% of the products in circulation. This is because 18 karat gold has become popular because it has the most stable mechanical, physical, and chemical properties, is easy to process, and is easy to apply to changes in hue.

The concept that the hue of 18 karat gold is golden has long been fixed, but in recent years consumers' needs for precious metal ornaments made from gold alloys have diversified, and efforts have been made to utilize multi-colored designs. It's starting to look like this.

Currently, the hues used for gold alloy products are pale green-yellow for Au-heg alloy, yellow for Au-^g-Cu alloy, and yellow for Au-^g-Cu alloy.
-Cu alloy is red, and Au-Cu-Ni alloy is pale yellow-white, and by combining these colors, colorful processed products have been created. Furthermore, very recently, A.
It became possible to bring about a change in color by adding purple of the u-^1 gold alloy and yellow-green of the Au-Cd alloy.

(Problem to be solved by the invention) However, as mentioned above, using the three colors of white, yellow, red, purple, and yellow-green has a limit in creating a multicolor design as an ornament. Currently, there is a demand for the development of a black gold alloy that has an extremely good contrast with the gold color of Au alloys, which is consumed in large quantities.

Means for Solving the Problems> The present invention was proposed in view of the above, and includes pure gold (Au) and one of copper (Cu), iron (Fe), cobalt (CO), or titanium (Tit). Gold alloy containing 5 to 65% by weight, gold (Au)-silver (8g) alloy containing 38% by weight or more of gold (Au), or gold containing 38% by weight or more of gold (Au) (Aul-nickel (Ni) alloy, copper (C)
u) Contains 5 to 65% by weight of one of iron (Fe), cobalt (CO), or titanium (Ti),
Gold alloy, pure gold (Au), or gold (gold (Au)-silver (Ag1 alloy) in which the total content of elements other than gold does not exceed 65% by weight, or gold (Au) with a content of 38% or more by weight)
Gold (Au)-nickel (Ni) alloy with an ul content of 38% by weight or more, 55 to 40% by weight of III (Cu),
3-40% by weight iron (Fe), 3-40% by weight cobalt (Co).

1-10% by weight of titanium (TL) or 0.5-10
A gold alloy containing two or more types of zinc (Zn) with a total content of 5 to 65% by weight of all other elements is heated in the atmosphere or at the atmospheric oxygen partial pressure at a temperature below the melting point of the gold alloy. A gold alloy and its coloring method in which the whole or part of the surface layer of a processed gold alloy product is colored glossy black by heat treatment in a high or low oxidation atmosphere and then air-cooled, water-cooled, or oil-cooled. It is related to.

Gold alloys composed of the various elements described above are produced by melting each of the above-mentioned compositions in a water-cooled copper crucible in a vacuum or in an inert gas atmosphere using a built-in arc melting furnace or high-frequency melting furnace. can get.

Moreover, the amount of dissolution for - times is usually 50 to IQOg.

The ingots of each alloy produced as described above are melted in vacuum or in an inert gas atmosphere, 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 use pressurization with an inert gas or centrifugal force during casting to improve filling of the cavity in the mold.

The gold alloy product obtained by casting as described above is subjected to sanding, scraping, whetstone polishing, and puff polishing, and then is heated in the atmosphere or in an oxidizing atmosphere higher or lower than the oxygen partial pressure of the atmosphere. Usually, it is heated at 850 to 950°C for 2 to 3 minutes, and then cooled in air, oil, or water.

The heating process for the gold alloy described above may be carried out in the atmosphere, and the heating temperature can be arbitrarily changed for two heating times as long as it is below the melting point of each alloy.

If the black gloss formed on the surface is insufficient after the above-mentioned blackening process is completed, perform light (puff polishing) again, and then burn the flame of a gas burner using city gas, propane gas, etc. A sufficient gloss can be generated by applying the product to the surface of the product for a short time and polishing it with a puff polish.

By the way, the black coloring process by heating 1 of the present invention varies depending on the size of the processed product, but it can be applied over a fairly wide range, and the heating temperature can be 800 - 800℃ in an atmospheric environment.
The longer the heating time, the thicker the blackening layer and therefore the degree of blackening. It seems so.

<Example> An example carried out using an alloy of 18 carats (Au = 75% by weight), which is the most common Au grade, is shown below.

(A) Pure gold with one of Cu, Fe, Co, and Ti
For alloy systems with added seeds.

Example 1 〇 Alloy blend pure^u 75 g Electrolytic Fe 25 g The above-mentioned alloy was melted by arc melting in an argon gas atmosphere, using a mold made by the lost wax method under vacuum. The surface of the cast product (finger tiled) obtained by centrifugal casting was finished by filing and polishing, and then soaked in the air at 900° C. for 2 minutes to develop a color, and then cooled with water. After that, the product was puff-polished again, and a beautiful, shiny black product was obtained.
The thickness of the blackening layer formed by coloring treatment is 3 to 4 μm.
At m, the composition forming the blackening layer is Fe containing Au.
It was an oxide of 5O4.

Example 2 Au alloy composition Pure Au 75 g Pure Ti 25 g The cast product (transportation) obtained by melting and casting in the same manner as in Example 1 was soaked in the atmosphere at 850°C for 2 minutes. After that, the product was air cooled to blacken the entire surface layer of the product. The black layer is 2
~3 μm, the composition of the blackening layer is T + containing Au
, Oz was a lower oxide.

Example 3 Blend of Au alloy Pure Au 75 g Electrolytic Co 25 g The cast product (ring) obtained by melting and casting in the same manner as in Example 1 was soaked at 950°C for 3 minutes in the air. After that, the product was air cooled to blacken the entire shallow layer of the product. The black layer is 3
~4 μm, and the composition of the black layer was CoO containing Au.

Example 4 Mixture of Au alloy Pure^u 75g Oxygen-free Cu 25g The cast product (ring) obtained by melting and casting in the same manner as in Example 1 was soaked in the atmosphere at 800°C for 2 minutes. After that, the product was air cooled to blacken the entire shallow layer of the product. The black layer is 3
The thickness was ~4 μm, and the composition of the black layer was CuO containing Au.

(B), Au-Ag alloy (Au content 38% by weight or more)
Or Au-Ni alloy (Au content 38% by weight or more)
In the case of an alloy system in which one of Cu, Fe, Go, and Ti is added.

Example 5 Au alloy composition Pure Au 75 g Pure AI! 10 g Electrolytic Fe l 5 g The cast product (ring) obtained by melting and casting in the same manner as in Example 1 was soaked in the air at soo Celsius for 2 minutes, then air cooled, and the product was shallowly heated. The entire layer was blackened. The black layer is 3
~4 μm, and the composition of the black layer was Fe5Oa containing Au and Ag, but Ag!

contained a small amount.

Example 6 Au alloy composition Pure Au 75 g Pure Ag l Og Electrolytic Go 15 g A cast product (ring) obtained by melting and casting in the same manner as in Example 1 was heated at 1150'c in the atmosphere. After soaking for 3 minutes, the product was air cooled to blacken the entire shallow layer of the product. The black layer has a thickness of 2 to 3 μm, and most of the composition of the black layer is Au,
Although Coo contained Ag, it contained a small amount of 8g and o.

Example 7 Combination of Au alloy Pure Au 75 g Pure Ag 17 g Pure Ti 8 g The cast product (ring) obtained by melting and casting in the same manner as in Example 1 was equalized in the air at 850°C for 3 minutes. After heating, the product was air cooled to blacken the entire shallow layer of the product. The black layer is 2
The thickness was ~3 μm, and the composition of the black layer was a low-order oxide of TiOx containing Au and Ag.

Example 8 Blend of Au alloy Pure Au 75 g Electrolytic Ni 10 g FII-free Cu 15 g A cast product (ring) obtained by melting and casting in the same manner as in Example 1 was heated at 800°C in the atmosphere. After soaking for 2 minutes, the product was air cooled to blacken the entire shallow layer of the product. The black layer is 3
~4 μm, and the composition of the black layer was CuO containing Au and NiO.

Example 9 Mixture of Au alloy Purity^u 75g Electrolytic Ni 15g Electrolytic Fs 10g A cast product (ring) obtained by melting and casting in the same manner as in Example 1 was heated at 850°C for 2 minutes in the atmosphere. After soaking, the product was air cooled to blacken the entire shallow layer of the product. The black layer is 3
~ 4 μm, and most of the composition of the black layer is Au, Ni
It was Fe50* containing.

(C), pure gold or ^U-8g gold (Au content 3
8% by weight or more) or Au-Ni alloy (Au content 38% by weight or more) with Cu, Fe, Go, Ti, Z
In the case of an alloy system in which two or more types of n are added.

Example 10 Mixture of Au alloy Purity^u 75g Electrolytic Go 18g Electrolytic Fe 7g A cast product (ring) obtained by melting and casting in the same manner as Example 1 was heated at 900°C for 2 minutes in the atmosphere. After soaking, the product was air cooled to blacken the entire surface layer of the product. The black layer is 3
~4μm, the composition of the black layer is Fflt containing Au
It was a composite oxide of On and CoO.

Example 11 Mixture of Au alloy Pure Au 75 g Electrolytic Co 20 g Pure Ti 5 g The cast product (ring) obtained by melting and casting in the same manner as in Example 1 was heated at 900°C for 3 minutes in the atmosphere. After soaking, the product was air-cooled to turn the entire surface of the product black. The black layer is 2
The thickness was ~3 μm, and the composition of the black layer was a composite oxide of Coo containing Au and a lower oxide of Ti0m.

Example 12 Blend of Au alloy Pure Au 75 g Electrolytic Co 20 g Oxygen-free Cu 5 g A cast product (ring) obtained by melting and casting in the same manner as in Example 1 was heated at 800°C in the atmosphere for 2 hours. After soaking for a minute, the product was air cooled to blacken the entire surface layer of the product. The black layer is 3
The thickness was ~4 μm, and the composition of the black layer was a composite oxide of CoO and CuO containing Au.

Example 13 Mixture of Au alloy Pure^u 75g Electrolytic Fe 24g Pure Zn 1g A cast product (ring) obtained by melting and casting in the same manner as Example 1 was heated at 800°C for 2 minutes in the atmosphere. After soaking, the product was air cooled to blacken the entire surface layer of the product. The black layer is 3
~4 μm, the composition of the black layer is Fe5O containing ^U
4 contained a very small amount of ZnO.

Example 14 Mixture of Au alloy Pure^u 75 g Electrolytic Fe 10 g Oxygen-free Cu 15 g A cast product (ring) was produced and cast in the same manner as in Example 1 at 850°C in the atmosphere. After soaking for 2 minutes, the product was air cooled to blacken the entire surface layer of the product. The black layer is 3
~4 μm, and the composition of the black layer is Fe5O containing Au.
It was a composite oxide of a and CuO.

Example 15 Combination of Au alloy Pure Au 75 g Electrolytic Co 10 g Electrolytic Fe 3 g Pure 11 2 g Au-Go-Fe-T was prepared by the same melting method as in Example 1.
i alloy was obtained. Thereafter, a cast product (ring) obtained by performing centrifugal casting using this alloy was preheated in the atmosphere at 900° C. for 3 minutes to develop a black color, and then cooled in water. The thickness of the blackened layer was 3 to 4 Im and was beautiful.

Example 16 Mixture of Au alloy Pure^u 75g Pure Heg log Electrolytic Co 5g Electrolytic Fe 9g Pure Tt 1g The same coloring treatment as in Example 1 was performed by melting, casting, and heating. The thickness of the blackening layer was 3 to 4 μm, and the blackening layer was a composite oxide of Ag, Co, Fe, and Ti containing Au.

Example 17 Mixture of Au alloy Pure^u 75g Pureheg 10 [Oxygen-free Cu 5g Electrolytic Co 10g The same coloring treatment as in Example 1 was performed by melting, casting, and heating, and the blackening layer was 3 to 4 μm thick. And it was beautiful.

Example 18 Composition of Au alloy Pure Au 75 g Pure Au 10 g Oxygen-free Cu 5 g Electrolytic Fe 10 g The same coloring treatment as in Example 1 was performed by melting, casting, and heating. The blackened layer had a thickness of 3 to 4 μm and was beautiful.

Example 19 Mixture of Au alloy Pure^u 75g Pure Ag 10g Oxygen-free Cu 10g Pure Ti 5g The same coloring treatment as in Example 1 was performed by melting, casting, and heating, and the blackening layer was 3 to 4 μm thick. Yes, it was beautiful.

Example 20 Combination of Au alloy Pure Au 75 g Pure Ag 10 g Oxygen-free Cu 5 g Electrolytic Co 5 g Electrolytic Fe 5 g The same coloring treatment as in Example 1 was performed by melting, casting, and heating, and the blackening layer was 3 to 4 μm thick. And it was beautiful.

Example 21 Mixture of Au alloy Pure Au 75 g Pure Au 10 g Oxygen-free Cu 5 g Electrolytic Go 8 g Pure Ti 2 g The same coloring treatment as in Example 1 was carried out by melting, casting, and heating, and the blackening layer was 3~ It was 4 μm and beautiful.

Example 22 Mixture of Au alloy Purity^u 75g Pure Ag log Oxygen-free Cu 5g Electrolytic Fe 8g Pure Ti 2g The same coloring treatment as in Example 1 was performed by melting, casting, and heating, and the blackening layer was 3 to 4 μm thick. And it was beautiful.

Example 23 Composition of Au alloy Pure Au 75 g Oxygen-free Cu 5 g Electrolytic Go 10 g Electrolytic Fe 10 g The same coloring treatment as in Example 1 was carried out by melting, casting, and heating, and the blackening layer was 3 to 4 μm thick. Yes, it was beautiful.

Example 24 Combination of Au alloy Pure Au 75 g Oxygen-free Cu 3 g Electrolytic Co 20 g Pure Ti 2 g The same coloring treatment as in Example 1 was carried out by melting, casting, and heating, and the blackening layer was 3 to 4 μm thick. , it was beautiful.

Example 25 Mixture of Au alloy Pure^u 75g Oxygen-free Cu 2g Electrolytic Go 15g Electrolytic Fe 7g Pure Ti lg The blackening layer was subjected to the same coloring treatment as in Example 1 by melting, ul-forming, and heating. It was 3 to 4 μm and beautiful.

Example 26 Composition of Au alloy Pure Au 75 g Pure Ag 10 g Electrolytic Ni 5 g Electrolytic Go 10 g The same coloring treatment as in Example 1 was performed by melting, casting, and heating. The blackened layer had a thickness of 3 to 4 μm and was beautiful.

Example 27 Mixture of Au alloy Pure^u 75 to pure g Log Electrolytic Ni 5g Electrolytic Fe 9g Pure Ti 1g The same coloring treatment as in Example 1 was performed by melting, casting, and heating. The blackened layer had a thickness of 3 to 4 μm and was beautiful.

Example 28 Mixture of Au alloy Pure^u 75g Pure Ag 15g Electrolytic Ml 5g Pure Ti 5g The same coloring treatment as in Example 1 was performed by melting, casting, and heating, and the blackening layer was 3 to 4 μm thick. It was beautiful.

Example 29 Mixture of Au alloy Pure Au 75 g Pure heg log Electrolytic Nl 2 g Electrolytic Co 6 g Electrolytic Fe 6 g Pure Zn 1 g Blackened layer subjected to coloring treatment by melting, casting, and heating in the same manner as in Example 1 It was 3 to 4 μm and beautiful.

Example 30 Mixture of Au alloy Pure ^, 75 g Pure Heg 10 g Electrolytic Ni 3 g Electrolytic Co 10 g Pure Ti l g Pure Zn 1 g Black color obtained by coloring treatment by melting, casting, and heating in the same manner as in Example 1 The layer was 3 to 4 μm thick and beautiful.

Example 31 ^1 Gold alloy blend Pure Au Pure Ag Electrolytic Ni Electrolytic Fe Electrolytic CO Pure Ti Pure Zn 5g 5g 3g 3g 3g 3g 3g Blackened by coloring treatment by melting, casting, and heating similar to Example 1 The layer was 3-4 μm thick and beautiful.

Above, examples have been described for Au alloys of 18K (carats), but in Au alloys of IgK or higher, such as 20K, 22, etc., and L8 or less, additive elements can be added within the range shown in the constitution of the present invention described above. A blackened product can be obtained by heat-treating a precious metal product made of an Au alloy with an adjusted amount of addition.

(Effects of the Invention) As explained above, the gold alloy of the present invention adds black to the conventional Au alloy, which has five colors of red, yellow, yellow-green, white, and purple, and can be used for precious metal ornaments. This not only makes it possible to create a wider variety of designs, but also leads to higher added value for decorative items.

In addition, the method for producing a gold alloy that is colored shiny black according to the present invention does not require special raw materials or processing equipment.
The applicability is extremely high.

Procedural amendment (part 1) April 27, 1990

Claims (6)

[Claims] (1) One of copper (Cu), iron (Fe), cobalt (Co), or titanium (Ti) is added to pure gold (Au) from 5 to 50%.
A gold alloy containing 65% by weight is heat treated in the atmosphere or in an oxidizing atmosphere higher or lower than the oxygen partial pressure of the atmosphere at a temperature below the melting point of the gold alloy, and then air-cooled, water-cooled, or oil-cooled to form a gold alloy. A gold alloy that colors the entire or part of the surface layer of processed alloy products a glossy black color. (2) One of copper (Cu), iron (Fe), cobalt (Co), or titanium (Ti) is added to pure gold (Au) from 5 to 50%.
A gold alloy containing 65% by weight is heat treated in the atmosphere or in an oxidizing atmosphere higher or lower than the oxygen partial pressure of the atmosphere at a temperature below the melting point of the gold alloy, and then air-cooled, water-cooled, or oil-cooled to produce gold. A gold alloy coloring method that colors all or part of the surface layer of a processed alloy product a glossy black color. (3) Gold (Au) with a gold (Au) content of 38% by weight or more
) - Silver (Ag) alloy or gold (Au) content of 3
8% by weight or more of gold (Au)-nickel (Ni) alloy,
A gold alloy containing 5 to 65% by weight of one of copper (Cu), iron (Fe), cobalt (Co), or titanium (Ti), and in which the total amount of elements other than gold does not exceed 65% by weight, is After heat treatment in the atmosphere or in an oxidizing atmosphere higher or lower than the atmospheric oxygen partial pressure at a temperature below the melting point of the alloy, the entire surface layer of the gold alloy processed product or A gold alloy that is partially colored a glossy black color. (4) Gold (Au) with a gold (Au) content of 38% by weight or more
) - Silver (Ag) alloy or gold (Au) content of 3
8% by weight or more of gold (Au)-nickel (Ni) alloy,
A gold alloy containing 5 to 65% by weight of one of copper (Cu), iron (Fe), cobalt (Co), or titanium (Ti), and in which the total amount of elements other than gold does not exceed 65% by weight, is After heat treatment in the atmosphere or in an oxidizing atmosphere higher or lower than the oxygen partial pressure of the atmosphere at a temperature below the melting point of the alloy, the whole or surface layer of the gold alloy processed product is cooled by air, water or oil cooling. A method of coloring gold alloys that partially colors them a glossy black color. (5) Pure gold (Au) or gold (Au) content of 3
A gold (Au)-silver (Ag) alloy containing 8% by weight or more, or a gold (Au)-nickel (Ni) alloy containing 38% by weight or more of gold (Au), and 5 to 40% by weight copper ( Cu),
Two or more of 3-40% by weight of iron (Fe), 3-40% by weight of cobalt (Co), 1-10% by weight of titanium (Ti), or 0.5-10% by weight of zinc (Zn) A gold alloy containing 5 to 65% by weight of elements other than gold is heat-treated in the atmosphere or in an oxidizing atmosphere higher or lower than the oxygen partial pressure of the atmosphere at a temperature below the melting point of the gold alloy. After that, the gold alloy is air-cooled, water-cooled, or oil-cooled to color the whole or part of the surface layer of the gold alloy processed product a glossy black color. (6) Pure gold (Au) or gold (Au) content of 3
A gold (Au)-silver (Ag) alloy containing 8% by weight or more, or a gold (Au)-nickel (Ni) alloy containing 38% by weight or more of gold (Au), and 5 to 40% by weight copper ( Cu),
Two or more of 3-40% by weight of iron (Fe), 3-40% by weight of cobalt (Co), 1-10% by weight of titanium (Ti), or 0.5-10% by weight of zinc (Zn) A gold alloy containing 5 to 65% by weight of elements other than gold is heat-treated in the atmosphere or in an oxidizing atmosphere higher or lower than the oxygen partial pressure of the atmosphere at a temperature below the melting point of the gold alloy. A gold alloy coloring method in which the gold alloy is then air-cooled, water-cooled, or oil-cooled to color all or part of the surface layer of the processed gold alloy product a glossy black color.