JP2004169168A - White alloy for ornament - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a white alloy for ornament consisting mainly of Pd, and causing no metal allergy and discoloration. <P>SOLUTION: The white alloy contains, by weight, 3 to 20% Cu and 2 to 10% Ag, and the balance Pd. Alternatively, the white alloy contains 3 to 20% Cu and 2 to 10% Ag, and one or two kinds of metals selected from 0.5 to 3% AuO and 0.5 to 3% PtO, and the balance Pd. As the white alloy for ornament, the color tone of the stock itself can be made white and bright without applying Rh plating, and also, the alloy is excellent in castability, workability and sulfurization resistance. Further, the alloy has relatively low density, so that the volume per product can be made large, and the product also having satisfactory strength can be produced. <P>COPYRIGHT: (C)2004,JPO

Description

【００１１】
【表２】

各比較は、色調、鋳造性、加工性、耐硫化性の変色について行った。
なお、従来のＡｕ系のホワイトゴールドについては、Ｎｉ系ホワイトゴールドがアレルギーの問題があり、あまり使用されていないことからＰｄ系ホワイトゴールドのみとした。
【００１２】
この中で、色調と鋳造性については、高周波吸引式精密鋳造機を用いてロストワックス鋳造し、研磨仕上げしたサンプルを用い、色調については目視により、鋳造性については外観および断面を観察し、鋳造欠陥の有無で判断した。
加工性については、高周波溶解で行い、サンプル５００ｇを厚さ１０ｍｍ、幅５０ｍｍ、長さＬの板状の鋳造体とし、表面切削後、圧延加工を行い加工性を判定した。
【００１３】
耐硫化性の変色テストは、各キャスト製品を用い、０．１％の硫化ナトリウム水溶液を用い、デシケータ内で４０°Ｃで１０時間の暴気テストを行い、変色度を比較した。
また、密度に関しては、理化年表２００２国立天文台編、株式会社丸善出版に記載されている密度をもとに計算による算出によった。
【００１４】
【発明の効果】
以上詳細に説明した本発明によると、Ｐｄを主成分とした装飾用白色合金として、Ｒｈめっきを施すことなく。素材そのものを白く明るい色調とすることができ、しかも鋳造性、加工性、耐硫化性に優れた白色合金とすることができた。
また、密度も比較的小さく、一製品当たりのボリュウムを大きくすることができ、強度的にも満足する製品となった。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a decorative white alloy that can be used as a processed material such as a ring, necklace, brooch, tie-stop, earring, piercing, eyeglasses, or other decorative metal material such as a plate material, a wire material, or a cast material.
[0002]
[Prior art]
Conventionally used decorative white metals include Pt or its alloys, Au-based alloy white gold, Ag or its alloys, and the like.
[0003]
[Problems to be solved by the invention]
Among such noble metals, Pt or its alloy has a high unit price of metal and a high density (heavy). For this reason, for example, the diameter of a strand becomes thinner per product, for example, for a chain, and thinner and smaller for cast products such as rings and earrings, which causes a problem in strength.
[0004]
Next, there are Ni-based and Pd-based Au-based alloy white gold. Ni-based materials have a problem of metal allergies, and are materials to be avoided as decorative materials that directly touch the skin. The Pd type has a problem that it is necessary to apply Rh plating because the color tone is blackish or yellowish.
Next, Ag or its alloy has good color tone itself, but there is discoloration due to sulfurization. To prevent this, it is necessary to apply Rh plating similarly to white gold.
[0005]
[Means for Solving the Problems]
Therefore, the present invention is an alloy containing Pd as a main component, and an alloy containing Pd by 3 to 20% by weight and Ag by 2 to 10% by weight.
An alloy containing Pd as a main component is added to Pd by one or two of Cu 3 to 20%, Ag 2 to 10% by weight, and Au 0.5 to 3% and Pt 0.5 to 3% by weight. It was added to form an alloy.
[0006]
According to such a configuration, the basic element of the Pd-Cu-Ag alloy exhibits a white and bright color tone, and also has a small increase in hardness as compared with Ni-based white gold with respect to workability. Processing is easy.
Further, by adding one or two of Au and Pt to the basic element, the strength of the material can be improved without changing the color tone, and the casting surface during casting can be improved.
[0007]
Here, the reason why Cu is set to 3 to 20% is that if it is less than 3%, there is no effect in improving the hardness, and if it exceeds 20%, the hardness increases and the fluidity at the time of casting is impaired. .
The reason why the content of Ag is set to 2 to 10% is that if it is less than 2%, there is no effect in improving the fluidity during casting, and if it exceeds 10%, no improvement in hardness can be obtained.
[0008]
Further, the reason why Au is 0.5-3% and Pt is 0.5-3% is that in any case, if it is less than 0.5, there is no effect on improvement of hardness and improvement of casting surface at the time of casting. If the content is more than 3%, the price and the density increase.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in a table.
Table 1 shows an embodiment, and Table 2 shows a conventional example as a comparative example.
[0010]
[Table 1]

[0011]
[Table 2]

Each comparison was made on the discoloration of the color tone, castability, workability, and sulfidation resistance.
In addition, as for the conventional Au-based white gold, Ni-based white gold has an allergic problem and is not used much, so only Pd-based white gold was used.
[0012]
Among these, the color tone and castability were measured by using a sample that was lost wax cast using a high frequency suction type precision casting machine and polished and finished.The color tone was visually observed, and the castability was observed by observing the appearance and cross section. Judgment was made based on the presence or absence of defects.
The workability was determined by high-frequency melting. A 500 g sample was formed into a plate-like cast having a thickness of 10 mm, a width of 50 mm, and a length L. After surface cutting, rolling was performed to determine the workability.
[0013]
For the discoloration test of sulfur resistance, each cast product was subjected to a violence test at 40 ° C. for 10 hours in a desiccator using a 0.1% sodium sulfide aqueous solution, and the degree of discoloration was compared.
The density was calculated by calculation based on the density described in Marikazen Shuppan Co., Ltd., edited by National Astronomical Observatory of Japan 2002.
[0014]
【The invention's effect】
According to the present invention described in detail above, a decorative white alloy mainly containing Pd is not subjected to Rh plating. The material itself could have a white and bright color tone, and could be a white alloy excellent in castability, workability, and sulfidation resistance.
In addition, the density was relatively low, the volume per product could be increased, and the product was satisfactory in terms of strength.

Claims (2)

A white alloy for decoration, characterized in that the weight ratio is 3 to 20% Cu, and 2 to 10% Ag is Pd. A decorative white color characterized by adding one or two of 0.5 to 3% of Au and 0.5 to 3% of Pt to 3 to 20% of Cu and 2 to 10% of Ag in weight ratio, and leaving Pd as the rest. alloy.