DE202008017584U1 - Platinum jewelery alloy - Google Patents

Abstract

The invention relates to a platinum alloy for jewelry, comprising or consisting preferably of the following components: - 94.0 wt.-% to 96.5 wt.-% platinum, - 2.5 wt.-% to 4.5 wt.-% tungsten, - 0.5 wt.-% to 3.0 wt.-% copper, and - 0.02 wt.-% to 2.0 wt.-% of at least one element from the group ruthenium, rhodium and iridium.

Description

The The invention relates to new platinum jewelry alloys and with the help semi-finished products made of these alloys.

platinum has been around for a long time due to its characteristic gray-white color Entrance into jewelry production and thus also in the jewelry industry found. However, like all precious metals, platinum is elemental Condition comparatively soft, so that it is easy to work can be, however, for everyday use does not have the necessary strength and durability having. That is why platinum is also used in the jewelry industry Usually alloyed with other metals to increase its strength. Such Platinum alloys have therefore always been in recent years greater importance attained in the jewelry area.

Accordingly A variety of platinum alloys are known and will already commercially used.

So For example, there are binary systems of platinum and ruthenium or platinum and tungsten, where usually the platinum in each case in a weight fraction of 95% by weight (950 ‰) and the ruthenium or Tungsten in a proportion by weight of 5 wt .-% (50 ‰) is present. such Although alloys are hard and therefore resistant to Abrasion, but hard cold formable and only with high tool wear machined editable.

Binary systems platinum and copper are also known, for example Pt960 / Cu40. Although such alloys are easily machined and also slightly cold formable, but they are comparatively soft and for Jewelry not for every product suitable.

Other Platinum alloys for Ornamental purposes are based on the addition of iridium to platinum, for example, systems such as Pt800 / Ir200 and Pt950 / Ir50 are known. Also such systems are comparatively hard and accordingly comparatively difficult without cutting and machining editable.

Finally, should here are the binary systems platinum / palladium or platinum / gold mentioned Here, too, systems such as Pt900 / Pd100 and Pt900 / Au100 and Pt950 / Pd50 or Pt950 / Au50 are known. There are However, the palladium alloys comparatively soft with the already mentioned Disadvantages of such a soft material. In addition, the original gray-white color of the platinum shifted by the addition of palladium in the direction of gray, What jewelry often not wanted is.

A undesirable Color shift may also be due to the gold addition in the platinum-gold alloys occur. Furthermore At least for now, the high gold price speaks against the use of Gold as alloying additive.

As from the previous versions Accordingly, there is a need to have a platinum alloy, especially for Ornamental purposes, available which optimizes in terms of their processing properties is. So shall the desired Alloy on the one hand the highest possible hardness and thus a high resistance against abrasion. Also a good polishability with mechanical Aids is desired. On the other hand, the alloy should be well workable despite its hardness, d. H. have a good cold workability and also easily machined, for example by turning, milling and the like editable. This should result in less tool wear. Ideally, the desired Alloy can be diamond coated, d. H. Mechanically machinable with the help of natural diamonds.

These Tasks are at least partially solved by the platinum jewelry alloys the claims 1 and 2. Preferred embodiments These alloys are described in the dependent claims 3 to 8 described. Further included the invention the semifinished product for jewelry production according to claim 9 and its preferred embodiment according to claim 10. The wording of all claims is hereby incorporated by reference into the content of this specification.

• – 94,0 Gew.-% bis 96,5 Gew.-% Platin (Pt),
• – 2,5 Gew.-% bis 4,5 Gew.-% Wolfram (W),
• – 0,5 Gew.-% bis 3,0 Gew.-% Kupfer (Cu), und
• – 0,02 Gew.-% bis 2,0 Gew.-% mindestens eines Elements aus der Gruppe Ruthenium (Ru), Rhodium (Rh) und Iridium (Ir).

According to the invention, the platinum jewelery alloy according to the invention comprises the following constituents and preferably consists according to the invention of the folenden components, namely

• 94.0% by weight to 96.5% by weight of platinum (Pt),
• 2.5 wt.% To 4.5 wt.% Tungsten (W),
• - 0.5 wt .-% to 3.0 wt .-% copper (Cu), and
• - 0.02 wt .-% to 2.0 wt .-% of at least one element from the group ruthenium (Ru), rhodium (Rh) and iridium (Ir).

• – 940 bis 965 Platin,
• – 25 bis 45 Wolfram,
• – 5 bis 30 Kupfer, und
• – 0,2 bis 20 Ruthenium, Rhodium und/oder Iridium.

If one refers to the mentioned weight proportions, as usual in the jewelry sector, to the total weight of 1,000 (‰, in English: ppt = parts per thousand), the abovementioned proportions of weight are written as follows:

• - 940-965 platinum,
• - 25 to 45 tungsten,
• - 5 to 30 copper, and
• - 0.2 to 20 ruthenium, rhodium and / or iridium.

In further education, the platinum content is at the alloys according to the invention at least 95 wt .-% and is preferably between 95.1 wt .-% and 95.5 wt .-%.

at Further preferred embodiments is the tungsten content in the alloys of the invention preferably between 3.5% by weight and 4.0% by weight, in particular between 3.6% by weight and 3.9% by weight. Within the last mentioned range In turn, tungsten contents are between 3.7% by weight and 3.8% by weight. more preferred.

at also preferred embodiments the alloys of the invention the copper content is preferably between 0.5% by weight and 2% by weight, in particular between 0.7% by weight and 1.3% by weight. Here are inside of the latter range, copper contents between 0.9% by weight and 1.1 wt .-% of particular advantage.

Regarding the Content of the elements from the group ruthenium, rhodium and iridium here are total contents of at least one of these elements between 0.02 wt .-% and 0.5 wt .-% to emphasize. Within this area the corresponding contents are preferably between 0.03% by weight and 0.1% by weight, especially between 0.04% by weight and 0.07% by weight.

In Training is in the alloys of the invention as an element from the group ruthenium, rhodium and iridium, preferably ruthenium used.

at the explanations the invention, in which in addition to the elements of platinum, tungsten, copper and Ruthenium, rhodium and / or iridium still other elements, preferably Metals, may be included it is preferred if the alloy is gold free, i. H. no Added to gold.

Finally, the invention includes a semi-finished product for Jewelry purposes, at least partially, but preferably completely, from the described alloys according to the invention is made. As is known, these semi-finished products are prefabricated geometrical shapes of the corresponding alloy material, the subsequently handcrafted or further processed industrially to the respective jewelery end products become. In the jewelry sector are such semi-finished products usually for example pipes, rods, rings, sheets, strips, wires and like. It is according to the invention preferred if it is tubular or ring-like semi-finished products act.

The described and other features of the invention will become apparent the following example in conjunction with the subclaims. The can individual characteristics for be realized alone or in combination with each other.

example

• – 952 Platin (Pt),
• – 37,7 Wolfram (W),
• – 9,8 Kupfer (Cu), und
• – 0,5 Ruthenium (Ru).

For the production of a platinum alloy according to the invention, based on the total weight of 1,000 (in ‰), the following metals are provided in the form of their pure fine metals:

• - 952 platinum (Pt),
• - 37.7 tungsten (W),
• - 9.8 copper (Cu), and
• - 0.5 ruthenium (Ru).

• – 95,2 Gew.-% Platin,
• – 3,77 Gew.-% Wolfram,
• – 0,98 Gew.-% Kupfer, und
• – 0,05 Gew.-% Ruthenium.

The mixture thus obtained is melted together at a temperature of about 1800 ° C. to give an alloy which accordingly has the following composition:

• 95.2% by weight of platinum,
• - 3.77 wt.% Tungsten,
• 0.98% by weight of copper, and
• - 0.05 wt .-% ruthenium.

The obtained alloy melt is cold worked by drawing into a tube, where a fine-grained structure established. The color of the resulting alloy corresponds to the desired one Platinum color, namely gray-white.

The obtained tubular semi-finished products can be artisanal in the usual way or industrially in usual Jewelry products are further processed, the material a sufficient hardness has good cold workability. The material can be synonymous very good machinability and is easy to polish. Any kind from version for Gemstones can be made from the material of the invention or be incorporated into this by means of suitable tools. The Material is also diamond able.

Claims (10)

Platinum jewelry alloy, comprising - 94.0% by weight up to 96.5% by weight of platinum, - 2.5 Wt% to 4.5 wt% tungsten, From 0.5% to 3.0% by weight Copper, and - 0.02 Wt .-% to 2.0 wt .-% of at least one element from the group ruthenium, Rhodium and iridium. Platinum jewelry alloy, consisting of - 94.0% by weight up to 96.5% by weight of platinum, - 2.5 Wt% to 4.5 wt% tungsten, From 0.5% to 3.0% by weight Copper, and - 0.02 Wt .-% to 2.0 wt .-% of at least one element from the group ruthenium, Rhodium and iridium. Platinum jewelery alloy according to claim 1 or claim 2, characterized in that the platinum content> 95 wt .-%, preferably between 95.1 wt .-% and 95.5 wt .-% is. Platinum jewelry alloy after one of the previous ones Claims, characterized in that the Tungsten content between 3.5 wt .-% and 4.0 wt .-%, preferably between 3.6 wt .-% and 3.9 wt .-%, in particular between 3.7 wt .-% and 3.8% by weight. Platinum jewelry alloy after one of the previous ones Claims, characterized in that the Copper content between 0.5 wt .-% and 2.0 wt .-%, preferably between 0.7 wt .-% and 1.3 wt .-%, in particular between 0.9 wt .-% and 1.1 wt .-%, is. Platinum jewelry alloy after one of the previous ones Claims, characterized in that the Content of the elements from the group ruthenium, rhodium and iridium between 0.02 wt.% and 0.5 wt.%, preferably between 0.03 Wt .-% and 0.1 wt .-%, in particular between 0.04 wt .-% and 0.07 Wt .-%, is. Platinum jewelry alloy after one of the previous ones Claims, characterized in that it is in the element of the group ruthenium, rhodium and iridium Ruthenium acts. Platinum jewelery alloy according to one of claims 1 or 3 to 7, characterized in that the alloy is gold-free. Semi-finished product for the manufacture of jewelery, characterized in that it is at least partially, preferably completely, made of an alloy according to one of the preceding claims is. Semifinished product according to claim 9, characterized that it is a tubular or ring-like semi-finished.