JPS61143538A - Silver material for ornament - Google Patents

Abstract

PURPOSE:To obtain a lustrous silver material for an ornament having no irregularity in color and taking hardly scratches by dispersing uniformly and finely a specified percentage of copper oxide and cadmium oxide in silver. CONSTITUTION:A silver material for an ornament is manufactured by dispersing uniformly and finely 0.5-15wt.% copper oxide and cadmium oxide in silver. The grains of the silver material are not coarsened by heat treatment such as annealing or brazing, and the hardness can be increased. An oxide film is not produced, and defects are not caused by brazing.

Description

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

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, silver has been used as a material for decorative items such as those mentioned above.
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 copper in silver-copper alloys is easily oxidized, a film of copper oxide is formed on the surface of the material through heat treatment. .

This oxide film is strong and must be removed mechanically or through chemical treatment such as pickling.
Furthermore, since the oxide film is difficult to remove uniformly, it ultimately causes uneven coloring of the product. Furthermore, during the brazing process, there were problems such as the brazing parts becoming oxidized, copper oxide making it difficult to braze, and brazing easily becoming defective.

(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 is made by uniformly and finely dispersing 0.5 to 15% by weight of copper oxide and cadmium oxide in silver.

In the silver material for ornaments of the present invention, the reason why copper oxide and cadmium oxide are dispersed in silver in an amount of 0.5 to 15% by weight is as follows.
5! If the amount is less than i%, coarsening of crystal grains during heat treatments such as annealing and brazing cannot be suppressed, and the hardness is low.
If it exceeds 15% by weight, the effect of grain refinement and hardness will be better, but it will become difficult to plastically work, causing the material to crack or become difficult to mold.

(Function) In the silver material for ornaments of the present invention having the above structure, copper and cadmium oxides uniformly and finely dispersed in silver act as crystal granulation agents during heat treatments such as annealing and brazing. This prevents crystal grains from becoming coarse due to heat treatment, and the hardness remains higher than that of silver-steel alloys, making it easier to produce a gloss in the final finish and less likely to be scratched. Since it is dispersed, an oxide film does not form during heat treatment in the atmosphere such as annealing and brazing, so there is no need to remove the oxide film as in the case of silver-copper alloys, and the color of the product changes. There is no unevenness, and brazing parts do not oxidize, so brazing is easy to work with and defects are less likely to occur.

(Examples and Conventional Examples) Examples 1 to 4 of the silver materials for ornaments of the present invention were manufactured 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. This tightening and annealing was performed three times, brazing was performed once, and heat treatment was performed a total of four times.

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

(Margins below) As is clear from the table above, the brooches made with the silver materials for decorations of Examples 1 to 4 have a better finished surface than the brooches made with the silver materials for decorations 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 silver 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 decorative items without uneven color can be manufactured. Can be done. Furthermore, since the silver material for ornaments 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 highly strong ornaments. It has excellent effects such as:

Claims (1)

[Claims] A silver material for ornaments comprising 0.5 to 15% by weight of copper oxide and cadmium oxide uniformly and finely dispersed in silver.