JPH09209059A - Gold alloy and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high grade gold alloy harder than pure gold and having high grade impression and color tone equal to those of pure gold. SOLUTION: This hard gold alloy has a composition which consists of, by weight, >=0.06% Ni, >=0.03% Ge, and the balance essentially Au and in which total content of Ni and Ge is regulated to <=1%. Further, this gold alloy can be produced by subjecting an alloy, having a composition which consists of, by weight, >=0.06% Ni, >=0.03% Ge, and the balance essentially Au and in which total content of Ni and Ge is regulated to <=1%, to solution heat treatment at 700-800 deg.C if necessary and then applying aging treatment to this alloy at 200-500 deg.C for 10-60min to harden it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ornaments such as rings, necklaces and watches, nibs, dental materials, medical instruments, and the like.
Regarding hardened gold alloys for use in electronic devices, measuring instruments, etc., and its manufacturing method, in detail, the addition of a small amount of components does not lose the luster, metallic color, beauty, weight and high-class feeling peculiar to pure gold. The present invention relates to a high-quality gold alloy with increased hardness and a method for manufacturing the same.

[0002]

2. Description of the Related Art Since high-grade gold alloys are soft, high-grade gold ornaments are easily scratched during processing and use, and it is difficult to maintain the original sense of quality. For example, the pure gold ingot has a micro Vickers hardness Hv of about 30. Therefore, so-called 18K or 14K, which is obtained by adding 25 to 40% by weight of silver (Ag), copper (Cu) or the like to gold and curing the gold, has been used for gold ornaments such as rings and necklaces.

[0003]

However, the so-called 18
Compared to pure gold, K, 14K, etc. have a gloss, metallic color,
It was inferior in beauty, weight and luxury.

[0004] Therefore, an object of the present invention is to obtain a high-grade gold alloy which is harder than pure gold and has the same high-grade appearance and color tone as pure gold.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that nickel (Ni) is added to 0.0
6 wt% or more, germanium (Ge) 0.03 wt%
And the total content of Ni and Ge is 1
It has been found that a high-grade gold alloy that is hard and has the same high-grade appearance and color tone as a pure gold decorative material can be obtained by using an alloy whose balance is substantially equal to or less than weight% and whose balance is substantially made of gold.

That is, in the gold alloy of the present invention, Ni is less than 0.
06 wt% or more, Ge 0.03 wt% or more, N
The total content of i and Ge is 1% by weight or less, and the balance is substantially Au.

Further, the method for producing a gold alloy of the present invention is based on Ni
Is 0.06 wt% or more, Ge is 0.03 wt% or more, the total content of Ni and Ge is 1 wt% or less, and the balance is substantially Au.
It is characterized by being subjected to aging treatment at a temperature of 10 ° C. for 10 to 60 minutes to harden.

[0008] Another method for producing a gold alloy of the present invention is as follows.
An alloy containing Ni of 0.06 wt% or more, Ge of 0.03 wt% or more, a total content of Ni and Ge of 1 wt% or less, and a balance of substantially Au is 700 to 80.
After solution treatment at a temperature of 0 ° C., aging treatment is performed at a temperature of 200 to 500 ° C. to harden.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Ni and G in the gold alloy of the present invention
e is added to harden soft pure gold, and the gold alloy is hardened as a synergistic effect of the addition of these two components.
The Ni content needs to be 0.06% by weight or more, and the Ge content needs to be 0.03% by weight or more. This is because if Ni is less than 0.06% by weight or Ge is less than 0.03% by weight, a sufficient curing effect cannot be obtained. Also, Ni and G
The total content of e must be 1% by weight or less. This is because if the total content of Ni and Ge exceeds 1% by weight, the quality of gold deteriorates although it is cured.

[0010] The gold alloy of the present invention is further hardened by aging treatment. It is considered that the aging treatment becomes harder at a lower temperature, but it takes a long time to obtain a certain hardness as the aging treatment at a low temperature, which is not industrially preferable. Therefore, the temperature of the aging treatment is preferably 200 ° C. or higher. Further, when the aging treatment is performed at a temperature higher than 500 ° C., the age hardening does not occur so much.

The aging time varies depending on the composition and the aging temperature, but generally less than 10 minutes is less effective.
Since 0 minutes is sufficient, it may be appropriately selected in the range of 10 to 60 minutes.

Further, in cast products such as large cast products in which segregation of solute elements is often observed, age hardening may not be sufficiently obtained. Therefore, a solution treatment is performed before aging treatment to eliminate solute element segregation. By doing so, age hardening can be sufficiently exhibited. The solution treatment is performed at a temperature at which the solute element is solid-dissolved in gold, but it is preferable to perform the solution treatment at a higher temperature in terms of production since the solution can be formed in a short time. Therefore, the optimum temperature varies depending on the composition, but generally the solution temperature is 700-8.
The temperature may be set to 00 ° C.

[0013]

The present invention will be described below in more detail with reference to examples. First, Au-Ni-based and Au-Ge-based mother alloys containing 1% by weight of each element of Ni or Ge were produced in a high-frequency vacuum melting furnace. And these mother alloys and pure gold (purity 9
9.99%) as raw materials, and blended so as to have a predetermined composition, and melt-cast in a high-frequency vacuum melting furnace to produce gold alloys having compositions shown in Tables 1 and 2.

Table 1 shows Examples 1 to 6 and Comparative Examples 1 to 1.
Hardness (HV _0.2 : micro Vickers hardness, load) before aging and at each aging time (10 to 60 minutes) of an alloy ingot of each composition described in Comparative Example 4 subjected to aging treatment at each temperature described in the table = 200 gf).

Further, Table 2 shows that alloy ingots having compositions shown in Tables 7 to 9 in Examples 7 to 9 were subjected to solution heat treatment at each temperature shown in the table and further subjected to aging treatment at each temperature shown in the table. The hardness (HV _0.2 ) before solution treatment and at each aging time (10 to 60 minutes) is shown.

The hardness (HV _0.2 ) of pure gold having a purity of 99.99% by weight is 27.6.

[0017]

[Table 1]

[0018]

[Table 2]

From Tables 1 and 2, after the aging treatment, the gold alloys of the present invention were pure gold (purity 99.99% by weight) and Comparative Examples 1 to 1.
It can be seen that as compared with No. 4, it is significantly hardened.

The gold alloy of the present invention has a gloss, metallic color,
The aesthetics, weight, and luxury feel are no different from pure gold.

[0021]

EFFECTS OF THE INVENTION The gold material for ornaments of the present invention is harder than pure gold and has a small amount of alloy components, so that it is hard to be scratched, and has the characteristics that pure gold does not impair the high-class feeling and color tone. . In addition, since a hard high-grade gold alloy can be manufactured by heat treatment after casting without processing such as cutting, the degree of freedom in design is increased, and it is possible to manufacture gold ornaments having complicated shapes.

Claims (7)

[Claims] 1. A Ni content of 0.06% by weight or more and a Ge content of 0.
A gold alloy containing at least 03% by weight, a total content of Ni and Ge of at most 1% by weight, and the balance being substantially Au. 2. Ni of 0.06% by weight or more and Ge of 0.
An age-hardened gold alloy containing 03% by weight or more, a total content of Ni and Ge of 1% by weight or less, and the balance being substantially Au. 3. Ni of 0.06% by weight or more and Ge of 0.
The content of Ni and Ge is 1 wt% or less, and the balance is substantially Au.
A gold alloy hardened by aging treatment for 10 to 60 minutes at a temperature of 0 to 800 ° C. 4. Ni of 0.06% by weight or more and Ge of 0.
The content of Ni and Ge is 1 wt% or less and the balance is substantially Au.
After solution treatment at a temperature of 0 to 800 ° C, 200 to 5
A hardened gold alloy that has been subjected to aging treatment at a temperature of 00C for 10 to 60 minutes. 5. A Ni content of 0.06% by weight or more and a Ge content of 0.
An alloy containing 03 wt% or more, a total content of Ni and Ge of 1 wt% or less, and a balance of substantially Au is subjected to an aging treatment for 10 to 60 minutes at a temperature of 200 to 500 ° C. A method for producing a gold alloy, characterized by hardening. 6. Ni of 0.06% by weight or more and Ge of 0.
An alloy containing 03% by weight or more, a total content of Ni and Ge of 1% by weight or less, and a balance of substantially Au is subjected to solution treatment at a temperature of 700 to 800 ° C., and then 20
A method for producing a gold alloy, characterized in that it is hardened by aging treatment at a temperature of 0 to 500 ° C. 7. The gold alloy according to claim 1, which has a micro Vickers hardness Hv of 60 or more.