JPS616222A - Silver material for accessory - Google Patents

Abstract

PURPOSE:To obtain a silver material for an accessory not coarsening the grains during heat treatment such as annealing or brazing, capable of increasing the hardness, and forming no oxide film by dispersing uniformly and finely a prescribed percentage of cadmium oxide in silver. CONSTITUTION:A silver material for an accessory is obtd. by dispersing uniformly and finely 1-15wt% cadmium oxide in silver. The silver material prevents the coarsening of the grains during heat treatment such as annealing or brazing, and the hardness can be increased, so a lustrous accessory, hardly scratched can be manufactured. Since no oxide film is formed on the silver material by said heat treatment, an accessory with no irregular color can be manufactured without requiring work for removing an oxide film.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to rings, necklaces, brooches, tie pins, cufflinks, and watch bands with one hour hand frame.

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. It becomes less glossy and too soft, making it more susceptible to scratches. Furthermore, 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. .

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. Furthermore, during the brazing operation, there are problems such as the brazing part becomes oxidized, copper oxide makes it difficult to braze, and the brazing tends to be 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 decorative string material of the present invention contains 1 to 1 cadmium oxide in silver.
It is made by uniformly finely dispersing 15% by weight.

In the silver material for ornaments of the present invention, the reason why 1 to 15% by weight of cadmium oxide is dispersed in the silver is that if it is less than 1% by weight, crystal grains may become coarse during heat treatment such as annealing and brazing. However, if it exceeds 15% by weight, the effect of grain refinement and hardness will be even better.
This is because it becomes difficult to plastically process, 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, cadmium oxide uniformly and finely dispersed in silver acts as a crystal grain refining agent during heat treatments such as annealing and brazing. This prevents crystal grains from becoming coarse due to heat treatment, and the hardness is maintained higher than that of silver-copper alloys, making it easier to produce a gloss in the final finish and resist scratches.Also, cadmium oxides are already dispersed in the silver Because of this, no oxide film is formed during heat treatment in the atmosphere during annealing, brazing, etc., so there is no need to remove the oxide film as in the case of lN-11i1 alloy, and there is no uneven color of the product. It doesn't happen. Furthermore, since brazing parts do not oxidize, brazing is easy to work with, and brazing is less likely to cause defects.

(Examples and Conventional Examples) Examples 1 to 3 of silver materials for ornaments of the present invention were manufactured by powder metallurgy and had the compositions shown in the left column of the table below, and had the same composition as these ornamental string materials. 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 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 way 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 3 have a higher 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 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 without uneven color. can. Furthermore, since the silver material for ornaments of the present invention does not oxidize during brazing, the brazing process is easy, the brazing process is free from defects, and the brazing process allows the manufacture of highly strong decorative items. It has excellent effects such as being able to.

Claims (1)

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