JPH08157983A - Ornamental member made of hard gold alloy having high purity of gold - Google Patents

Abstract

PURPOSE: To obtain an ornamental member having the high-grade appearance of pure gold because of a high Au content, hard to scratch because of high hardness and hardly lowering the hardness with the lapse of time and at the time of heating. CONSTITUTION: This ornamental member is made of a hard Au alloy obtd. by incorporating 500-2,000ppm, in total, of one or more kinds of elements selected from among Gd, Y and Sm into Au of >=99.5wt.% purity or a hard Au alloy obtd. by incorporating 500-2,000ppm, in total, of one or more kinds of elements selected from among Gd, Y and Sm as primary elements and 0.1-15ppm Fe as a secondary element into Au of >=99.5wt.% purity.

Description

Detailed Description of the Invention

[0001]

The present invention has an Au content of 99.5.
Despite the weight% or more, the Vickers hardness (Hv) is around 100, which makes it hard to be scratched or scratched, and has little hardness deterioration with time and heating such as brazing. It relates to members.

[0002]

2. Description of the Related Art Generally, a member of a jewelry material made of a gold base material is made of Ag, Cu and N for the purpose of improving hardness and tensile strength.
Alloys such as K18 and K14 alloyed with i, Pd and Zn are well known.

[0003]

On the other hand, high-purity gold jewelery has a low hardness, and it is extremely difficult to maintain its aesthetic value in daily life for a long period of time, and the hardness decreases with time. In addition, since the hardness cannot be reduced even by heating such as brazing, its application as a decorative member is currently limited.

[0004]

From the above-mentioned viewpoint, as a result of research to develop an Au alloy decorative member having high hardness while maintaining the high-grade feeling of pure gold, the Au content was 9%.
9.5 wt% or more, Gd, Y, Sm as alloy components
A high-hardness decorative member can be obtained by including one or more kinds of the first element selected from the above elements in a cumulative amount of 500 ppm to 2,000 ppm and Fe of the second element of 0.1 ppm to 15 ppm. It came out. In addition, this decorative member has a small decrease in hardness even when the brazing is heated, and has a result that a high aesthetic value can be maintained for a long period of time.

The present invention has been made based on the above-mentioned research results, and has a first Au content of 99.5% by weight or more and an alloy component selected from the elements of Gd, Y, and Sm. Cumulative amount of one kind or plural kinds of elements 500
ppm to 2,000 ppm and Fe of the second element 0.1
It is characterized by a hard Au alloy decorative material containing from 15 to 15 ppm and having little decrease in hardness upon heating.

In the decorative member of the present invention, the Au content is set to 99.5% by weight or more. Below this, there is a tendency that a high content of Au is generally preferred, and high-grade pure gold is used. This is because the feeling is lost. Further, it is determined that one kind or plural kinds of the first element selected from the elements of Gd, Y, and Sm are contained in a cumulative amount of 500 ppm to 2,000 ppm and Fe of the second element is contained in the range of 0.1 ppm to 15 ppm. The respective components have the effects of increasing the hardness in the coexisting state and suppressing the deterioration of the hardness over time and the deterioration due to heating. Therefore, the total amount of one kind or plural kinds of the first element selected from the elements of Gd, Y and Sm is 50
It should be less than 0 ppm, or Fe of the second element should be 0.1 ppm.
If it is less than the desired value, the desired effect cannot be obtained. On the other hand, G
Even when the total amount of one kind or plural kinds of the first element selected from the elements of d, Y and Sm is 2,000 ppm or more, or when the Fe of the second element is 15 ppm or more,
This is because not only the further improvement effect cannot be obtained, but also it becomes difficult to maintain the Au content at 99.5% by weight or more.

[0007]

EXAMPLES The decorative member of the present invention will be specifically described by way of examples. In a vacuum melting furnace, an Au alloy having the composition shown in Table 1 and pure gold were melted, and 20 mm * 20
It is cast into an ingot having a size of mm * 150 mm. After collecting a test piece for hardness measurement from this end, wire drawing was performed to make a wire of 0.8 mm to produce the decorative members 1 to 20 of the present invention and a pure gold decorative member.

The decorative members 1 to 20 of the present invention obtained as a result
And, for pure gold decorative members, ingot state, immediately after processing, micro Vickers hardness after 6 months (load: 1
00g) is measured. Further, the micro-Vickers hardness (load: 100 g) was measured by holding under normal brazing conditions, for example, a temperature of 350 ° C. for 30 minutes, which is performed in an Au-20 wt% Sn alloy brazing material (melting point: 280 ° C.), and then cooling. . The results of these measurements are shown in Table 1.

[0009]

[Table 1]

[0010]

From the results shown in Table 1, it can be seen that the decorative member of the present invention has a higher hardness than the pure gold decorative member, and there is almost no decrease in hardness over time and hardness due to heating. From this, the decorative member of the present invention is A
Despite the u content of 99.5% by weight or more, the Vickers hardness (Hv) is around 100, scratches and scratches are less likely to occur, and hardness decreases with time and heating such as brazing. Since it is a hard Au alloy decorative member with few properties, it has industrially useful properties such as maintaining its aesthetic value for a long time when put into practical use as various decorative products.

Claims (2)

[Claims] 1. Au containing a purity of 99.5% by weight or more and G
A decorative member made of a hard Au alloy, which contains one kind or plural kinds selected from the elements of d, Y and Sm in a cumulative amount of 500 ppm to 2,000 ppm. 2. An Au having a purity of 99.5% by weight or more and G
The cumulative total amount of the first element selected from the elements of d, Y, and Sm is 500 ppm to 2,000 pp.
A hard Au alloy decorative member containing m and 0.1 ppm to 15 ppm of the second element Fe.