JPS62130246A - Silver material for ornament - Google Patents

Abstract

PURPOSE:To improve silver material for an ornament by forming it by dispersing, finely and uniformly, specific amounts of zinc oxide and cadmium oxide in silver. CONSTITUTION:The silver material for an ornament has a composition consisting of 85-99.5wt% silver and 0.5-15wt% zinc oxide and cadmium oixde. This ornamental silver material is manufactured by powder metallurgy, in which oxides of zinc and cadmium finely and uniformly dispersed in silver become a grain refiner by heat treatment such as annealing, brazing, etc. More over, formation of oxidation films due to the above heat treatment is not ob served. This silver material is capable of improving hardness by the above method, so that ornaments which are lustrous, hardly scratched, and free from irregular color and inferior brazing can be manufactured.

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, 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. 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 zinc oxide and cadmium oxide in an amount of 0.5 to 15% by weight in the eye.

In the silver material for ornaments of the present invention, the reason why 0.5 to 15% by weight of zinc oxide and cadmium oxide are dispersed in the eye is as follows.
．． If it is less than 5% by weight, coarsening of crystal grains during heat treatment 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, and the material will crack or become difficult to mold.

(Function) The silver material for ornaments of the present invention having the above structure has zinc and cadmium oxides uniformly and finely dispersed in the eye.
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 the oxides of zinc and cadmium are already dispersed in the eye, an oxide film does not form during heat treatment in the atmosphere such as annealing and brazing, so unlike the case of 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 produced by powder metallurgy and had the component compositions shown in the left column of the table below, and were the same as these silver materials for ornaments. Brooches were manufactured using silver materials for decorative items of Conventional Examples 1 to 3 having the 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.

(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. I can do it. 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:

Claims (1)

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