JPH05123856A - Production of noble metal ornaments - Google Patents

Abstract

PURPOSE:To integrate a sintered body and a casting by mounting materials for sintering to a wax patterns to form the cavity of a casting mold and casting the materials by a lost wax method. CONSTITUTION:The materials for sintering essentially consisting of the noble metals are mounted at >=1 points of the wax pattern and are sintered at the m.p. of the material for sintering or below and are then cast by the lost wax method at the time of producing the noble metal ornaments. The resulted ornaments are eventually integrated with the sintered body and the casting. The casting having the surface constituting a smooth specular surface and the sintered body having a satin surface are thus combined, by which the ornaments having the extremely aesthetic value are obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a precious metal jewelry product in which a sintered body and a cast body are integrated.

[0002]

2. Description of the Related Art Conventionally, the lost wax casting method has been the main processing method in the production of precious metal jewelry. Features (advantages) of the lost wax casting method described above
Has a high degree of freedom in design and is capable of reproducing complex shapes with high reliability, and has become established in the industry as a mature technology.

On the other hand, recently, jewelry made of precious metal (pure metal, alloy) using fine particles having an average particle diameter of 10 μm or less has been disclosed, and the material has been put on the market.
The above jewelry is made by adding an organic binder to fine particles of noble metal, making it clay-like, and heating the one produced by hand processing to sublimate the organic material and hold it for a long time at a temperature below the melting point of the metal. And then sintered. This method
Conventionally, it has been used as a sintering method by powder metallurgy of base metals in all industrial fields, and iron-based materials are mixed with organic materials to form clay, which is an application of technology provided as ceramics. is there. The above-mentioned method using fine particles of noble metal (hereinafter referred to as fine particle sintering method) has the following advantages and disadvantages over the above-mentioned lost wax method. (Advantage) Since the hand-processed clay is molded and sintered, the process is extremely simplified. (Disadvantage) Since it is hand-processed, it is not suitable for forming a fine and complicated shape. It is extremely difficult to mass-produce to some extent, and to process a plurality of products of the same shape with a uniform weight. Since it is sintered (particles are bonded together), a smooth mirror surface cannot be obtained even if the surface is polished. Of the mechanical properties, post-processing is difficult because of poor ductility and bending strength. It is difficult to use brazing.

[0004]

Generally, the elements that a jewelery must have are required to have mechanical strength, specular gloss of the surface, highly reproducible shape reproducibility, mass productivity, color balance, and the like. The Lost Wax method has a long history of stable growth that fully meets this demand. On the other hand, the fine particle sintering method has various drawbacks as described above, but the present inventor has made earnest studies in order to utilize the advantages. And, the rough surface of the sintered body described as the above-mentioned drawback is considered to have aesthetic value only in the contrast with the smooth mirror surface of the cast body obtained by, for example, the lost wax method, and the sintered body and the cast body are The present invention has been achieved in which the lost wax method and the fine particle sintering method are effectively combined with each other for the purpose of producing an integrated jewelry.

[0005]

The present invention has been proposed in view of the above, and a sintering material containing a precious metal powder as a main component is attached to one or more places of a wax pattern, and the melting point of the sintering material is set. The present invention relates to a method for producing a precious metal jewelery, which is characterized in that after being sintered, it is cast by the lost wax method to obtain an integrated product.

The manufacturing method of the present invention effectively fuses the lost wax method and the fine particle sintering method as described above, and the apparatus used in the present invention is used for the lost wax method. Diverted as it is, also the raw materials,
Raw materials used in the lost wax method and raw materials (commercially available) used in the fine particle sintering method are diverted as they are.

Further, the manufacturing process of the present invention can be carried out almost in the same manner as the manufacturing process in the lost wax method.
That is, in the present invention, a sintering material containing a noble metal powder as a main component is used together when a wax prototype is prepared. However, since this sintering material is clay-like, it does not require particularly troublesome labor. Further, when a mold cavity is molded from the wax master manufactured as described above, the temperature is raised to a temperature higher than that of the usual lost wax method, but this is caused by the disappearance of the wax and is contained in the sintering material. This is to eliminate the organic matter and sinter the sintering material. In this way, even in the molding of the mold cavity, it is sufficient to raise the holding temperature, so that no trouble is added. As described above, the manufacturing method of the present invention is carried out by substantially the same steps as those of the conventional lost wax method, so that no troublesome steps and troubles are added.

The precious metal jewelry obtained by the present invention comprises a cast body and a sintered body which are integrated with each other, and has a satin-finished surface with respect to the cast body having a smooth mirror surface. It becomes a combination of the sintered bodies that have,
The contrast becomes extremely high in aesthetic value.
The obtained jewelry may be subjected to finishing treatment such as magnetic polishing, if necessary. At that time, since the sintered body does not become a mirror surface even if it is polished, even if it is integrally polished, the contrast between the mirror surface and the matte surface is not impaired.

However, in order to integrate the cast body and the sintered body, for example, there is a method of manufacturing the cast body and the sintered body separately and welding them (hereinafter referred to as a welding integrated method). However, the present invention has the following advantages over this welding integration method. First, as described above in the present invention, it is based on the lost wax method, which has extremely few steps and does not require welding work. On the other hand, the welding integration method requires three steps, for example, a step of manufacturing a cast body using the lost wax method, a step of manufacturing a sintered body from a sintering material, and a step of welding these. The number of processes is extremely large.

Further, the precious metal jewelry obtained by the present invention is extremely firmly joined because the cast body and the sintered body are fused and integrated with each other. On the other hand, in the product obtained by the welding integration method, the welding strength becomes the joining strength, and therefore extremely accurate welding work is required.

Further, according to the present invention, since a clay-like sintering material is used together when producing a wax prototype, it is possible to produce a jewelery in which a sintered body and a cast body are intricately entangled with each other. It is possible, and the degree of freedom in design is extremely high. On the other hand, in the welding integration method,
Since the sintered body and the cast body are welded to each other, there is a large geometrical limitation and the degree of freedom in design is narrowed.

On the other hand, the present invention is characterized in that casting is performed by the lost wax method, and the obtained casting is fitted with a sintering material containing a precious metal powder as a main component and sintered. It also proposes a method for manufacturing jewelry.

Mounting parts such as grooves and other recesses may be formed in the cast body produced in advance. For example, even if the mounting portion is formed into a groove shape such that the inlet is narrow and expands toward the inside, the sintering material can be easily filled because it is clay-like as described above. And, in the obtained jewelry, the cast body and the sintered body are fitted to each other, so that they are in a stable joined state. Further, a jewelery product in which a sintered body and a cast body are intricately intertwined with each other can be manufactured in the same manner as in the above-described manufacturing method, and the degree of freedom in design becomes extremely high.

[0014]

EXAMPLES Examples of the present invention are shown below.

Example 1 [Integral molding by combining dark red gold alloy and organic clay containing pure gold fine powder] Organic material containing pure metal powder in the groove of a round (semicircular ring) wax pattern Filled with clay (sintering material). This wax pattern is molded with a silica-based mold material, the wax or organic matter disappears at 150 to 250 ° C., then the temperature is raised to 1000 ° C. in the furnace and the powder is held for 2 to 3 hours to obtain gold powder. Was sintered. Next, the temperature of the mold was lowered, and a gold alloy of Au ⁷⁵ —Cu and other ²⁵ (melting point 830 ° C.) was cast at about 700 ° C. to obtain a jewelry product in which the sintered body and the cast body were integrally molded.

Example 2 [Integral molding by combining cast body of platinum alloy and organic clay containing fine gold fine powder] First, a cast body of platinum alloy and a lost wax method were used for production. Organic clay containing pure gold fine powder in the recesses formed in the cast body by polishing this (sintering material)
To obtain a jewelery product that was integrally molded in the same process as above.

Example 3 [Integral molding in which yellow gold alloy and organic clay containing pure platinum powder are combined] Platinum powder organic clay (sintering material) is filled in a groove having a round wax pattern. Then, after the wax and organic substances have disappeared, the temperature is raised to 1700 ° C and 2
Hold for 4 hours and sinter. Subsequently, the mold temperature is 700 ° C.
Was obtained jewelery is cast gold alloy Au ⁷⁵ -Ag ¹⁵ -Cu ¹⁰ lowered to.

Example 4 [Integral molding of a combination of dark red gold alloy and organic clay containing pure silver powder] Pure silver powder organic clay (sintering material) was filled into the groove of the round wax pattern. The mold was made by holding the siliceous mold material. After the wax and the organic matter disappeared in the previous step, sintering was performed at 850 ° C. for 2-3 hours. Subsequently, the mold temperature was lowered to 650 ° C., and Au ⁷⁵ —Cu and other ⁷⁵ (800 ° C.) gold alloys were cast into jewelery products.

Example 5 [Integral molding by combining platinum alloy cast body and organic clay containing pure gold powder] A platinum alloy was made into a cast body by the lost wax method. The spherical wax was wrapped around an organic clay containing pure gold powder, and was set in combination with a part of the cast body. A mold was made by holding a mold material using silica as a material. 100 ℃ after the wax organic matter disappears from the previous process
It was held for 2 to 4 hours and sintered. This made it jewelry.

When an alloy of a noble metal and a base metal (eg Cu, Ni) is used as the noble metal fine particles used in the sintering material, the sintering is performed in a high vacuum (10 ⁻³ mmH).
g) above or in an atmosphere of inert gas,
A powder having an extremely large specific surface area becomes an oxide layer.

[0021]

As described above, according to the present invention in which a sintering material is attached to a wax pattern to form a mold cavity and casting is performed by the lost wax method, the conventional lost wax method is used for fine particle burning. This is an effective fusion of the binding methods, and it is extremely easy to manufacture a jewelery product in which a cast body and a sintered body are integrated. Then, when the wax pattern is molded, the sintering material is also attached,
Since sintering of the sintering material is performed at the same time as the molding of the mold cavity, the steps are performed in substantially the same manner as the conventional lost wax method, and there is no need for troublesome steps and troubles. Therefore, the present invention possesses the advantages of the lost wax method,
For example, it is excellent in mass productivity and post-processability. Moreover, the advantages of the fine particle sintering method are also utilized. That is, the jewelry obtained by the present invention is a combination of a cast body having a smooth mirror surface and a sintered body having a matte surface,
The contrast becomes extremely high in aesthetic value.
Further, according to the present invention, as compared with, for example, a method in which a cast body and a sintered body which are separately manufactured are welded and integrated, the number of steps is one (one step), the fusion strength is high because of fusion bonding, and the freedom in design is provided. Since the degree is extremely high, even complicated intertwined designs are possible.

On the other hand, also in the manufacturing method of the present invention in which a sintering material is attached to the casting and sintered, the casting and the sintered body are integrated to obtain a jewelery whose contrast is extremely high in aesthetic value. However, in this case, although it is a two-step process, the degree of freedom in design is extremely high and the bonding strength is also high, as in the manufacturing method described above.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B22D 19/00 F 9266-4E

Claims (2)

[Claims] 1. A sintering material containing a precious metal powder as a main component is mounted on one or more places of a wax pattern, and after sintering at a melting point of the sintering material or less, casting is performed by a lost wax method. A method for producing a precious metal jewelery characterized by the above. 2. Casting is performed by the lost wax method,
A method for producing a precious metal jewelery, characterized in that a sintering material containing a precious metal powder as a main component is attached to the obtained cast body and sintered.