JP4291998B2 - Decorative white alloy - Google Patents

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]
BACKGROUND OF THE INVENTION
The present invention relates to a decorative white alloy that can be used as a processing material such as a plate material, a wire material, or a cast material, such as a ring, a necklace, a broach, a tie stopper, an earring, a pierced earring, or a spectacle.
[0002]
[Prior art]
Conventionally used white metal for decoration includes Pt or its alloy, Au-based alloy white gold, Ag or its alloy.
[0003]
[Problems to be solved by the invention]
Among such noble metals, Pt or its alloy has a high unit price and high density (heavy). For this reason, for example, the diameter of the strand of the product is thin in each product, and the cast product such as a ring or earring tends to be thinner and smaller, which causes a problem in strength.
[0004]
Next, Au-based alloy white gold includes Ni-based and Pd-based. Ni-based materials have a problem of metal allergy, and are a material that should be avoided as a decorative material that directly touches the skin. The Pd system 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 a good color tone but has a discoloration due to sulfuration. In order to prevent this, it is necessary to apply Rh plating like white gold.
[0005]
[Means for Solving the Problems]
Therefore, the present invention is an alloy containing Pd as a main component and containing 3 to 20% Cu and 2 to 10% Ag by mass in Pd.
In addition, an alloy containing Pd as a main component is added to Pd in a mass ratio of Cu 3 to 20%, Ag 2 to 10%, Au 0.3 to 3%, and Pt 0.3 to 3%. The alloy was added.
[0006]
According to such a configuration, the basic composition of the Pd-Cu-Ag alloy exhibits a white and bright color tone, and the workability is less increased than Ni-based white gold. Easy to process.
Further, by adding one or two of Au and Pt to the basic composition, the strength of the material can be improved and the casting surface at the time of casting can be improved without changing the color tone.
[0007]
Here, the reason why Cu is 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 is increased and the fluidity during casting is impaired. .
The reason why Ag is set to 2 to 10% is that if it is less than 2%, there is no effect in improving the fluidity at the time of casting, and if it exceeds 10%, the hardness cannot be improved.
[0008]
Furthermore, the reason for setting Au to 0.3 to 3% and Pt to 0.3 to 3% is that, in any case, if less than 0.3%, it is effective in improving hardness and casting surface during casting. This is because the price and density increase at 3% or more.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in the form of a table.
Table 1 shows an embodiment, and Table 2 shows an example according to the prior art as a comparative example.
[0010]
[Table 1]

[0011]
[Table 2]

Each comparison was made with respect to discoloration of color tone, castability, workability, and sulfidation resistance.
As for conventional Au-based white gold, only Ni-based white gold has a problem of allergies and is not used so much, so only Pd-based white gold is used.
[0012]
Among these, for color tone and castability, samples were subjected to lost wax casting using a high-frequency suction-type precision casting machine and polished, and the color tone was visually observed. Judged by the presence or absence of defects.
About workability, it carried out by high frequency melt | dissolution, the sample 500g was made into the plate-shaped casting body of thickness 10mm, width 50mm, and length L, and after surface cutting, it rolled and determined workability.
[0013]
In the sulfidation resistance discoloration test, each cast product was used, a 0.1% sodium sulfide aqueous solution was used, an aerial test was conducted at 40 ° C. for 10 hours in a desiccator, and the discoloration degree was compared.
The density was calculated by calculation based on the density described in the chronological chronology 2002 National Astronomical Observatory edition, Maruzen Publishing Co., Ltd.
[0014]
【The invention's effect】
According to the present invention described in detail above, the decorative white alloy mainly composed of Pd is not subjected to Rh plating. The material itself was able to have a white and bright color tone, and a white alloy excellent in castability, workability and sulfidation resistance could be obtained.
In addition, the density is relatively small, the volume per product can be increased, and the product is satisfactory in terms of strength.

Claims (2)

A platinum alloy for decoration, characterized in that Cu is 3 to 20% by mass and Ag is 2 to 10%, and the balance is Pd. A decoration characterized in that one or two of Au 0.3 to 3% and Pt 0.3 to 3% are added to Cu 3 to 20% and Ag 2 to 10% by mass ratio, and the rest is Pd. Platinum alloy.