JP3578830B2

JP3578830B2 - Gold alloy for jewelry

Info

Publication number: JP3578830B2
Application number: JP12027395A
Authority: JP
Inventors: 治渡辺; 昌樹栗田
Original assignee: Tokuriki Honten Co Ltd
Current assignee: Tokuriki Honten Co Ltd
Priority date: 1995-05-18
Filing date: 1995-05-18
Publication date: 2004-10-20
Anticipated expiration: 2019-10-20
Also published as: JPH08311579A

Description

【０００１】
【産業上の利用分野】
本発明は、純Ａｕに微量の元素を含有させて硬さを高くした宝飾用金合金に関する。
【０００２】
【従来の技術】
Ａｕは、耐蝕性、展延性に優れ、その色彩の優雅さから宝飾用品などに広く使用されている。
【０００３】
【発明が解決しようとする課題】
ところが、純Ａｕは非常に柔軟であり、硬さや機械的強度が低いために表面に傷が付き易く、変形し易いという問題があった。
【０００４】
【課題を解決するための手段】
そこで本発明は、Ｐを５〜１０００ｐｐｍ含有し、残部が９９．５重量％以上のＡｕおよび不純物元素からなることを特徴とし、さらには、Ｐを５〜１０００ｐｐｍ、Ｓｂ、Ｃｕ、Ｚｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｇａ、Ａｇ、Ｇｅの中の一種以上を副添加元素とし、これら副添加元素を合計で１０ｐｐｍ以上で、これら副添加元素と不純物元素の合計が５０００ｐｐｍ以下を含有し、残部が９９．５重量％以上のＡｕからなることを特徴とする。
【０００５】
Ｐを添加元素とした理由は、鋳造後及び加工後における硬さを向上させるためである。
副添加元素であるＳｂ，Ｃｕ，Ｚｎ，Ｆｅ，Ｃｏ，Ｎｉ，Ｇａ，Ａｇ，Ｇｅは、鋳造時の流動性に効果があり、また、結晶を微細化し硬さの向上に効果がある。
添加元素Ｐの添加量を５〜１０００ｐｐｍとしたのは、５ｐｐｍ未満では硬さの向上に効果がなく、１０００ｐｐｍを超えると硬くなり過ぎて脆さがでてしまうためである。
【０００６】
また、副添加元素の添加量が１０ｐｐｍ未満では上記効果が得られないためであり、上記副添加元素および不純物元素の合計が５０００ｐｐｍを超えると金の品位の低下をきたし、色調においてもいわゆる純Ａｕのもつ黄金色を失うからである。
【０００７】
【作用】
以上の本発明によると、添加元素の作用によって純Ａｕに比べて鋳造後の硬さが向上し、また、板材、線材の加工等の塑性加工においては加工硬化により硬さの上昇が大きくなる。
【０００８】
【実施例】
以下に本発明の実施例を表１に示し、従来例として純Ａｕを合わせて示す。
【０００９】
【表１】

【００１０】
表１に示す各試料は、まず、実施例に示す添加元素であるＰを主元素とした合金をアーク溶解にて鋳造して母合金とした。
つぎに、純Ａｕに実施例に示す組成で上記母合金を配合し、上記同様アーク溶解を行い、厚さ１０ｍｍ，幅３０ｍｍ，長さ５０ｍｍのケーキ状の鋳造体とし、この鋳造体を、熱間鍛造で線用、板用に成形し、所定の形状まで加工を行って試料とした。
【００１１】
その結果、表より明らかな如く、各実施例は純Ａｕに比べて硬さが高い。
【００１２】
【発明の効果】
以上詳細に説明した本発明によると、Ａｕと称呼できる程の微量の添加元素組成でも、純Ａｕに比べてほぼ同等の耐蝕性や純Ａｕ特有の光沢をもち、しかも硬さや機械的強度が高く、また添加量の多い場合は飛躍的に機械的特性の上昇となる効果を有し、宝飾用ばかりでなく、電子部品、医療分野等広い範囲で有用な金材料となる。[0001]
[Industrial applications]
The present invention relates to a gold alloy for jewelry in which a hardness is increased by adding a trace element to pure Au.
[0002]
[Prior art]
Au has excellent corrosion resistance and spreadability, and is widely used in jewelry and the like because of its elegant color.
[0003]
[Problems to be solved by the invention]
However, pure Au has a problem that it is very flexible and has low hardness and low mechanical strength, so that the surface is easily scratched and easily deformed.
[0004]
[Means for Solving the Problems]
Therefore, the present invention is characterized in that P is contained in an amount of 5 to 1000 ppm, and the balance is made up of 99.5% by weight or more of Au and an impurity element . Further, P is contained in an amount of 5 to 1000 ppm, and Sb, Cu, Zn, Fe, At least one of Co, Ni, Ga, Ag, and Ge is used as a sub-addition element, and the total of these sub-addition elements is 10 ppm or more, and the total of these sub-addition elements and impurity elements is 5000 ppm or less, with the balance being 99 ppm or less. It is characterized by being composed of not less than 0.5% by weight of Au .
[0005]
The reason for using P 2 as an additive element is to improve the hardness after casting and after processing.
Sb, Cu, Zn, Fe, Co, Ni, Ga, Ag, and Ge, which are sub-additional elements, have an effect on fluidity during casting, and have an effect on making crystals finer and improving hardness.
The addition amount of the additional element P is set to 5 to 1000 ppm because if it is less than 5 ppm, there is no effect on the improvement of hardness, and if it exceeds 1000 ppm, it becomes too hard and becomes brittle.
[0006]
If the amount of the sub-additive element is less than 10 ppm, the above effect cannot be obtained. If the total amount of the sub-additive element and the impurity element exceeds 5000 ppm, the quality of gold is deteriorated, and the so-called pure Au is also used in the color tone. For it loses its golden color.
[0007]
[Action]
According to the present invention described above, the hardness after casting is improved as compared with pure Au due to the action of the additional element, and the increase in hardness due to work hardening in plastic working such as processing of a plate or wire is increased.
[0008]
【Example】
Examples of the present invention are shown in Table 1 below, and pure Au is also shown as a conventional example.
[0009]
[Table 1]

[0010]
First, each sample shown in Table 1 was formed into a mother alloy by casting an alloy containing P 2 as a main element, which is an additive element shown in Examples, by arc melting.
Next, the above-described mother alloy was mixed with pure Au with the composition shown in the example, and arc melting was performed in the same manner as described above to obtain a cake-like casting having a thickness of 10 mm, a width of 30 mm, and a length of 50 mm. It was formed into a wire or plate by cold forging and processed to a predetermined shape to obtain a sample.
[0011]
As a result, as is clear from the table, each example has a higher hardness than pure Au.
[0012]
【The invention's effect】
According to the present invention described in detail above, even with a trace amount of additive element composition that can be referred to as Au, it has almost the same corrosion resistance and luster unique to pure Au as compared to pure Au, and has high hardness and mechanical strength. Also, when the addition amount is large, it has the effect of dramatically increasing the mechanical properties, and is a gold material useful not only for jewelry but also for a wide range of fields such as electronic parts and medical fields.

Claims

A jewelry gold alloy containing 5 to 1000 ppm of P, with the balance being 99.5% by weight or more of Au and an impurity element .

P is 5 to 1000 ppm, and one or more of Sb, Cu, Zn, Fe, Co, Ni, Ga, Ag, and Ge are used as subadditive elements, and the total of these subadditive elements is 10 ppm or more. A jewelry gold alloy containing Au in a total content of impurity elements of 5000 ppm or less and a balance of 99.5% by weight or more .