JPS62130240A - Silver material for ornament - Google Patents

Abstract

PURPOSE:To improve a silver material for an ornament by dispersing uniformly and finely a specified amount of indium oxide and manganese oxide in silver so as to produce the silver material. CONSTITUTION:The composition of this silver material for an ornament consists of 85-99.5wt% silver and 0.5-15wt% indium oxide and manganese oxide. The silver material is produced by powder metallurgical processing and the oxides of indium and manganese dispersed uniformly and finely in silver are converted into a grain refiner by heat treatment such as annealing or brazing. An oxide film is not formed by the heat treatment. Since the hardness of the silver material can be increased, a lustrous ornament hard to scratch can be produced. The resulting ornament has no irregularity in color and causes no defective brazing.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is used for ornaments such as rings, necklaces, brooches, tie clips, cufflinks, watch frames, watch bands, lighters, writing instruments, eyeglass frames, earrings, etc. This invention relates to improvements in silver materials.

(Prior art and problems) Conventionally, the materials used for the above-mentioned ornaments were
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. 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 indium oxide and manganese oxide in an amount of 0.5 to 15% by weight in the eye.

In the silver material for ornaments of the present invention, indium oxide and manganese oxide are dispersed in the eye in an amount of 0.5 to 15% by weight. It is not possible to suppress crystal grain coarsening, and the hardness is low. This is because it becomes difficult to mold.

(Function) °゛The silver material for ornaments of the present invention having the above structure has indium and manganese oxides uniformly and finely dispersed in the eye as a crystal grain refining agent during heat treatment 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 create a gloss in the final finish.
Not easily scratched. In addition, since the oxides of indium and manganese are already dispersed in the eye, an oxide film will not be formed during heat treatment in the atmosphere such as annealing and brazing, so unlike in the case of 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 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.

(Leaving space below) □ As is clear from the table above, the brooches made with the decorative silver materials of Examples 1 to 4 have a higher finish than the brooches made with the decorative silver materials of Conventional Examples 1 to 3. It can be seen that the surface is glossy and has no color unevenness, and 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 produce decorative items that are glossy and resistant to scratches.Also, the silver material for decorative items of the present invention does not produce an oxide film during heat treatment such as annealing and brazing. Since there is no oxidation film, 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 it is possible to manufacture decorative items without oxidation. Attaching is easy to work, brazing is free from defects, and brazing has excellent effects such as being able to manufacture decorative items with high strength.

Claims (1)

[Claims] A silver material for ornaments comprising 0.5-15% by weight of indium oxide and manganese oxide uniformly and finely dispersed in 85-99.5% by weight of silver.