DE19807551C2 - jewelry alloy - Google Patents

Description

The invention relates to a jewelry alloy and on the use of an alloy for jewelry. In the Production of costume jewelery has long been a copper alloy used as base material, predominantly copper and zinc. These alloys are becoming education of the jewelry item poured into a mold and then Metallic gold-plated and rhodium-plated. The thickness of the Gold layer is depending on the required strength and quality of the jewelry at 0.1 to 15 microns.

Prolonged wearing this gold layer is rubbed, especially for mechanically stressed jewelry pieces, such as B. finger rings. The predominantly copper contained base material then shimmers coppery, so that the piece of jewelry looks at its wear. In some cases, even, especially in conjunction with body perspiration, start the material black or green become spanish.

The known copper alloys form while casting The shape very accurate, but have a relatively high Porosity and the tendency to cavitation. The Surface of the jewelry produced from this has a certain roughness, which causes the surface looks relatively dull and not shiny. Finally, go tet the known alloy with regard to considerable problems the resistance to body sweat.  

From JP 3-72045 A is a high-strength copper alloy with good electrical conductivity known from 0.1 10.0% manganese and also from a total of 0.01 to 10% of at least one element of the Group: P, Be, Al, As, Sb, Si, Ti, Cr, Mg, Fe, Co, Ni, Zr, Mo, Ag, Cd, Pb, In, Hf and / or Sn and copper as the remainder consists.

The object of the invention is an improved Schmucklegie tion, in particular an improved sweat has durability, is golden, good casting and Abformei properties and low surface roughness has the casting.

This object is achieved by a jewelery alloy according to claim 1 or 2 and by the use of the alloy according to An claim 4 solved.

The antimony content in the amount of 0.01-3.0 weight percent has the effect of preventing a fire while casting d. H. a reaction of the metal with the material of the mold (eg plaster).

The zirconium content in the amount of 0.05-0.5 weight percent also has a positive effect on the properties of Alloy because zirconium is high in oxygen, water has substance, nitrogen and sulfur affinity and therefore deoxidizing, hydrogen bonding, denitrating and blowing off it seems to be twinkling. The hydrogen binding property prevents a solution of hydrogen in the melt, causing water material and / or steam gas porosities are avoided. In addition, the zirconium grain refining and improves the ductility of the alloy.

According to a development of the invention, the alloy additionally added 0.02-0.2 percent by weight of phosphorus, which improves the deoxidation properties.  

The resulting alloy is in the cured state white-yellow to gold-colored and therefore ideal for the production of gold-plated costume jewelery, since an Abnut tion of the thin gold plating layer is barely visible.

The alloy has a fine-dendritic microstructure. It forms when casting very little slag and benö does not require any additional deoxidation or covering agent. Vergußtemperaturschwankungen have only a very small influence on strength and Oberflächengü te. The alloy has a very good flowability. This can also wall thicknesses below 0.5 mm in the casting can be achieved and the sprue cross sections can significantly be smaller than in known jewelry alloys on copper basis, which results in very good casting results.

For specimens were no leaks, porosities or gas bubbles detected and neither at very dickwan even at transitions from thick to thin wall parts.

Due to the fine-grained structure of the structure, the alloy is when casting extremely accurate. Also can be Achieve surface roughnesses of 1-5 microns. additionally is a casting of this alloy well polishable.

Finally, the alloy is compared to the state of Technique very good sweat resistant, such. B. in artificial Welding solution with a 12-14 carat (500-700 thousandths Gold content) gold alloy is comparable.

The jewelry pieces made with the above alloy have the following mechanical properties:

0.2 Limits: 140-290 N / mm ² Tensile strenght: 260-400 N / mm ² Elongation at break A5: 12-32% Brinell Hardness HB 10: 70-140

The following examples further illustrate the invention:

Composition:

Example I tin 14.5 to 15% silicon 0.3-0.5% manganese 0.1-1.0% antimony 0.05-1.0% zirconium 0.05-0.5% copper rest

This alloy has the following properties:

Strength: 0.2 Limits: about 200 N / mm ² Tensile strenght: about 360 N / mm ² Elongation at break A5: 12-22% Brinell Hardness HB 10: 90-120 liquidus: about 930 ° C solidus: about 820 ° C

The remaining properties weldability, pourability, Structure education, etc. are described with the above Alloy substantially the same.

Composition:

Example II tin 8-10% silicon 0.1-1.0% manganese 0.05 to 1.3% antimony 0.01-1.5% zirconium 0.05-0.5% copper rest

Strength: 0.2 Limits: about 140 N / mm ² Tensile strenght: about 260 N / mm ² Elongation at break A5: about 30% Brinell Hardness HB 10: 70-90 liquidus: about 1000 ° C solidus: about 870 ° C

Again, the other properties described above were those of the above-described alloy substantially equal.

Composition:

Example III tin 19-20% silicon 0.1-1.0% manganese 0.05 to 1.3% antimony 0.05-1.0% zirconium 0.05-0.5% copper rest

Strength: 0.2 Limits: about 290 N / mm ² Tensile strenght: about 400 N / mm ² Elongation at break A5: about 12% Brinell Hardness HB 10: 130-160 liquidus: about 900 ° C solidus: about 800 ° C

Again, the other properties were those of the above Alloys substantially the same.

Claims (8)

1. Jewelery alloy consisting of the following components in weight percent:
tin 14.5 to 15% silicon 0.3 to 0.5% manganese 0.1 to 1.0% antimony 0.05 to 1.0% zirconium 0.05 to 0.5% copper rest 2. Jewelery alloy consisting of the following components in weight percent:
tin 19 to 20% silicon 0.1 to 1.0% manganese 0.05 to 1.3% antimony 0.05 to 1.0% zirconium 0.05 to 0.5% copper rest 3. Alloy according to claim 1 or 2, characterized, that they additionally 0.02 to 0.2 weight percent Phos contains phor. 4. Use of an alloy consisting of the following components in percent by weight:
tin 8.0 to 20.0% silicon 0.1 to 1.0% manganese 0.05 to 4.0% antimony 0.01 to 3.0% zirconium 0.05 to 0.5% copper Rest,  for the production of jewelry. 5. Use of an alloy according to claim 4 consisting of the following components in percent by weight:
tin 8 to 10% silicon 0.1 to 1.0% manganese 0.05 to 1.3% antimony 0.01 to 1.5% zirconium 0.05 to 0.5% copper Rest,  for the purpose of claim 4. 6. Use of an alloy according to claim 4 or 5 with an additional 0.02 to 0.2% phosphorus for the purpose according to claim 4.