JPS6134152A - Silver material for accessory - Google Patents

Abstract

PURPOSE:To obtain an Ag material for accessories undergoing heat treatment without coarsening crystal grains and having no irregularity in color, fine luster, high hardness and superior brazability by dispersing uniformly and finely the specified amount of copper oxide and indium oxide in Ag. CONSTITUTION:The Ag material for accessories is manufactured by dispersing uniformly and finely 1-15wt% copper oxide and indium oxide in Ag by the powder metallurgical processing. The crystal grains of the Ag material are hardly coarsened by annealing, brazing or other heat treatment, and the material is hardly scratched because of the high hardness. The silver material for accessory which has fine luster with no irregularity in color and superior brazability is thus obtd.

Description

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

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, with this silver-copper (5 to 15 weight percent gold), the crystal grains of the alloy tend to become coarse due to heat treatments such as annealing and brazing that are repeated several times during the manufacturing stage of ornaments, and for this reason, the finishing process is difficult. The surface loses its luster, becomes too soft, and becomes easily scratched.Also, most heat treatments such as annealing and brazing are performed in the atmosphere, and the silver-copper alloy contains Since copper is easily oxidized, a copper oxide film 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 is made by uniformly and finely dispersing 1 to 15% by weight of copper oxide and indium oxide in silver.

In the silver material for ornaments of the present invention, the reason why copper oxide and indium oxide are dispersed in silver at 1 to 15% by weight is that 1% by weight
If it is less than 15% by weight, coarsening of crystal grains during heat treatment such as annealing and brazing cannot be suppressed, and the hardness is low.
This is because, if it exceeds 100%, the effect of grain refinement and hardness will be even better, but it will become difficult to plastically work, the material will crack, and it will become difficult to mold.

(Function) In the silver material for ornaments of the present invention having the above structure, copper and indium oxides uniformly and finely dispersed in silver act as crystal grain refining agents during heat treatments such as annealing and brazing. This prevents crystal grains from becoming coarse due to heat treatment and maintains hardness higher than that of silver-copper alloys, making it easier to produce a gloss in the final finish and resist scratches. In addition, since the oxides of copper and indium are already dispersed in the silver, an oxide film will not be formed during heat treatment in the atmosphere such as annealing and brazing, as is the case with silver-copper alloys. There is no need to remove the oxide film, and there is no uneven coloring of the product. 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 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. 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 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.

(Margin below) As is clear from the table above, the brooches made with the ornamental edge materials of Examples 1 to 4 have a higher finished surface than the brooches made with the ornamental silver 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. Therefore, it is possible to manufacture shiny and scratch-resistant decorative items.Furthermore, the material for decorative items of the present invention does not form an oxide film during heat treatment such as annealing and brazing. , there is no need to remove the oxide film, and it is possible to manufacture decorative items with no uneven color.Furthermore, the silver material for decorative items of the present invention does not oxidize during brazing, so brazing is easy. Brazing is easy, there are no defects in brazing, and brazing has excellent effects such as making it possible to manufacture decorative products with high strength.

Claims (1)

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