JPS616219A - Silver material for accessory - Google Patents

Abstract

PURPOSE:To obtain a lustrous accessory having improved hardness and taking hardly scratches by dispersing uniformly and finely a prescribed percentage of zinc oxide in silver so as to prevent the coarsening of the grains during heat treatment. CONSTITUTION:A mixture of silver powder with zinc oxide powder is subjected to powder metallurgical processing to obtain a silver material for an accessory contg. 1-15wt% zinc oxide dispersed uniformly and finely in silver. The grains of the silver material are not coarsened by heat treatment such as annealing or brazing, and a lustrous accessory having improved hardness and hardly scratched is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to rings, necklaces, brooches, tie pins (2) cufflinks, and watch frames (5) and watch bands.

This invention relates to the improvement of silver materials used in decorative items such as lighters, writing implements, eyeglass frames, and earrings.

(Prior art and problems) “Conventionally, the materials used for the above-mentioned ornaments were silver.
Copper (5-15% by weight) alloys are frequently used.

However, the crystal grains of this silver-copper (5 to 15% by weight) alloy tend to coarsen during heat treatments such as annealing and brazing, which are repeated several times during the manufacturing process of decorative items, resulting in poor surface finish. The gloss is difficult to produce, and it becomes too soft, making it easy to get scratched. In addition, most heat treatments such as annealing and brazing are performed in the atmosphere, and since the copper in the string-copper alloy is easily oxidized, a film of copper oxide is formed on the surface of the material through heat treatment. .

Since this oxide film is strong, it must be removed mechanically or by chemical treatment such as pickling.

Furthermore, since the oxide film is difficult to remove uniformly, it ultimately causes uneven coloring of the product. Further, during brazing work, there are problems such as oxidation of the brazing parts, making it difficult to braze due to copper oxide, and easily causing defects in the brazing.

(Object of the Invention) The present invention was made to solve the problems of the above-mentioned silver material for decorative items made of a silver-copper alloy. The object of the present invention is to provide a silver material for decorative items that does not cause corrosion, has high hardness, does not form an oxide film, and does not cause defects during brazing.

(Means for Solving the Problems) The silver material for ornaments of the present invention has 1 to 15% by weight of zinc oxide uniformly and finely dispersed in the chain.

In the silver material for ornaments of the present invention, zinc oxide 1 to 1 to 1 in the chain
The reason for dispersing 15% by weight is that if it is less than 1% by weight, coarsening of crystal grains during heat treatment such as annealing and brazing cannot be suppressed, and the hardness is low, and if it exceeds 15% by weight, crystal grains become fine. This is because although the effect of increasing grain size and hardness is improved, it becomes difficult to plastically work, causing the material to crack and becoming difficult to mold.

(Function) In the silver material for ornaments of the present invention having the above structure, the zinc oxide uniformly and finely dispersed in the chain is annealed.

Brazing acts as a crystal grain refining agent during heat treatment, preventing coarsening of crystal grains due to heat treatment, and maintains hardness higher than that of silver-copper alloys, making it easier to create a gloss in the final finish and prevent scratches. Hateful. In addition, since zinc oxide is already dispersed in the chain, an oxide film does not form during heat treatment in the atmosphere such as annealing and brazing, so oxidation does not occur as in the case of silver-copper alloys. There is no need to remove the film, and there is no uneven coloring of the product. Furthermore, brazing does not oxidize the parts, so
Brazing is easy to work with, and defects are less likely to occur with brazing.

(Examples and Conventional Examples) Examples 1 to 3 of the silver materials for ornaments of the present invention were produced by powder metallurgy and had the component compositions shown in the left column of the table below, and had the same composition as these silver materials for ornaments. Brooches were manufactured using silver materials for decorative items of Conventional Examples 1 to 3 having the component compositions shown in the left column of the table below. At this time, annealing was performed 3 times, brazing was performed once, and heat treatment was performed 4 times.

The finished surface of the broach produced in this way was inspected, and the strength and hardness of the brazing were measured, and the results shown in the table below on the right were obtained.

(Margins below) As is clear from the table above, the brooches made with the decorative silver materials of Examples 1 to 3 have a better finished surface than the brooches made with the ornamental string materials of Conventional Examples 1 to 3. It is clear that the surface is glossy and has no color unevenness, and that the brazing is strong and hard, making it difficult to scratch.

(Effects of the Invention) As can be seen from the above explanation, the silver material for ornaments of the present invention can prevent coarsening of crystal grains during heat treatments such as annealing and brazing, and can increase hardness. This makes it possible to produce shiny, scratch-resistant decorative items. In addition, the material for decorative items of the present invention does not form an oxide film during heat treatment such as annealing or brazing, so there is no need to remove the oxide film, and it is possible to manufacture decorative items with no uneven color. can. Furthermore, since the silver material for decorative items of the present invention does not oxidize during brazing, it is easy to work, there is no defect in brazing, and it is possible to manufacture decorative items with high strength. It has excellent effects such as being able to.

Claims (1)

[Claims] A silver material for ornaments made of 1 to 15% by weight of zinc oxide uniformly and finely dispersed in silver.