JPH06306408A - Production of metallic product - Google Patents

Abstract

PURPOSE:To easily and rapidly produce a metallic product of a high technical value such as a noble-metal ornament, artistic handicraft, interior ornament and tableware in absolute minimum thickness. CONSTITUTION:A slurry obtained by mixing a metal powder and an org. binder soln. is deposited on a part or the whole of the surface of an optionally shaped combustible material or a natural combustible material, the solvent is vaporized, and then the material is heated to a sintering temp. to produce a metallic product. The sintered compact has an absolute minimum thickness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, precious metal jewelry,
The present invention relates to a method of manufacturing a metal product having a large craft factor such as arts and crafts, interior decoration, and table decoration.

[0002]

[Prior Art] Conventionally, precious metal jewelry, arts and crafts,
Alternatively, in the case of an interior for construction or the like, if the shape is simple, press molding is used, but generally, the casting method is most often used. Among them, the lost wax casting method is a mainstream method although it is handled as a high-grade product because it has a great degree of freedom in design and can reproduce a complicated shape with high reliability.

However, the above-mentioned lost wax casting method requires a large amount of capital investment and requires a great deal of time to become skilled. This lost wax casting method has extremely many steps,
Moreover, it takes a long time (usually 7 days). In particular, the fixed cost is extremely high, such as shell molding, pollution problem of dewaxing firing, trouble of removing mold, pollution elimination equipment of acid treatment, etc., but no casting method superior to this is found today.

On the other hand, there are mainly four sintering methods, namely, a pressure method, an injection molding method, a slurry method, and a clay hand-working method, but the clay-like sintered material used in the clay hand-working method has already been used. Developed and marketed. This material has a particle size of 2 to 20 μm
20% by weight of various binders such as methyl cellulose and ethyl cellulose, and water are added to the metal fine particles to make a clay-like material, and the clay-like material has a thickness of 0.5 to 1
In recent years, there has been proposed a method of forming a flat plate having a size of mm, bending it, assembling it into a three-dimensional shape, and then sintering it.

[0005]

However, in the above-mentioned method, since the thickness of the clay-like material cannot be further reduced in order to maintain the shape of the molded material, the weight becomes large, and it is generated in the molding work. Due to excess (cutting off, scraping off) etc., expensive metal powder is wasted, resulting in high cost.

Further, the clay-like material easily dries and becomes brittle when dried, so that the moldability was extremely poor. That is, since it is necessary to pay sufficient attention to humidity and mold in a short time, the creativity is remarkably limited. Moreover, since the clay-like material has a large thickness and a low strength, it is practically impossible to form a complicated shape such as a paper crane. Further, for example, a basket-shaped product having a hollow portion can be manufactured without using a mold material (attaching to the inner surface of a split mold material) or without welding or brazing. It was also impossible.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been proposed in view of the above, and a part of or the entire surface of a combustible material formed into an arbitrary shape or a combustible natural material,
The present invention relates to a method for producing a metal product, which comprises mixing a metal powder and an organic binder solution, depositing a sludge, adsorbing a solvent, evaporating the solvent, and then raising the temperature to a sintering temperature.

The first step of the present invention is to form a flammable material into an arbitrary shape or to prepare a flammable natural material. As the combustible material, any material having a property of burning at a temperature lower than the sintering temperature of the metal powder can be used. For example, if a thin-walled substrate such as Japanese paper, paper, or film is selected as a flammable material, it may be origami processed or bent, or if necessary, a flammable adhesive such as glue may be used in combination. It may be formed into a shape. In addition, since the wet strength of ordinary paper is low, it is impossible to absorb the water and maintain the shape when the liquid that has been slurried in the third step to be described later is applied. Water repellency is imparted by impregnating a low melting point wax such as paraffin wax dissolved therein or by coating a solution in which this low melting point wax is dissolved. Furthermore, for example, when agar (aqueous solution), thermoplastic resin, or the like is selected as the combustible material, the lumps may be ground into an arbitrary shape, or a mold material may be used to form an arbitrary shape. In addition, a natural material such as a leaf of a plant which originally has a design element can be used as it is without being subjected to a molding process.

Next, precious metals such as Pt, Au, Ag, and C
Particle size 3 to 100 μm selected from one or more of pure metal powder or alloy powder of base metals such as u, Zn, In, Ni, Sn
The metal powder is mixed according to the composition so as to have an average particle size of 10 to 20 μm, and an organic binder solution (solvent: lower alcohol / water) such as methyl cellulose or ethyl cellulose is mixed with the powder. The second step is to produce a liquid (slurry) that has been solidified. If necessary, an antifoaming agent or a surfactant may be added to improve the wettability.

Then, the slurred liquid (slurry) obtained in the second step is adhered to the surface of the combustible material molded body or the combustible natural material obtained in the first step. This is the third step. As this attachment method, for example, a method of dipping and attaching to the surface may be used,
A method of applying by a spray gun or a brush coating and attaching it may be used. For example, a liquid (slurry) obtained by mixing 3 to 8% of an aqueous solution of an organic binder with 30 to 50% (weight ratio) with respect to the weight of metal powder is mixed with a molded body of a flammable material or a flammable material. When the natural material is dipped and pulled up, the slurry adheres to the surface with a uniform thickness of about 0.1 to 0.15 mm. This is naturally dried or air-dried at 40 to 80 ° C., and the same operation is repeated again, and if this number is repeated three times or more, an adhesion layer having a uniform thickness of about 0.3 to 0.6 mm can be obtained. In the third step, the concentration of the slurried liquid (slurry), the number of impregnations, and the like are not limited, so that the adhesion thickness can be set arbitrarily. It should be noted that, although not limited, the adhesion method by dipping is suitable for adhering the slurry to the entire surface of the molded body of combustible material or combustible natural material, and the adhesion method by spray gun or brush coating is slurry. Is suitable when it is attached only to a part of the surface.

In the third step, for example, after the slurry is attached to the surface of the flammable material or the flammable natural material with a uniform thickness and dried, letters or pictures are applied by brushing or the like on the slurry. Or, if a pattern is drawn, the artistic interest will increase. The slurry used at this time should have a higher concentration than that used in the third step.

[0012] After that, it is dried until the solvent is lost, and in an oxidizing or reducing heating furnace kept at a temperature (about 250 ° C) or higher at which the organic binder (binder) in the slurry sublimes (vapors). In the fourth step, the temperature is increased by placing the temperature in the chamber, and the temperature is held at the sintering temperature which is 10% lower than the melting point of the used metal powder for an arbitrary time. In the middle of this fourth step, organic binder (sublimation) and combustible material (combustion)
Disappears, and as a result, a metal product that is a sintered body can be obtained. When agar (aqueous solution) or thermoplastic resin is used as the combustible material, it is better to fluidize it with heat and discharge it from the system rather than burning it.

As described above, according to the present invention, the thickness of the sintered body to be a product can be set at any value by changing the concentration of the slurry, the number of times of immersion, etc. in the second and third steps. And, for example, desktop crafts can be relatively thin, accessories can be relatively thick, and in any case it can be set to the minimum required thickness, so that expensive metal powder can be used without wasting it. The amount can be suppressed to the required minimum amount.

In the first step, the basic shape of the product is substantially set, and a thin-walled base material such as Japanese paper, western paper, film or the like is used by a well-known origami processing technique, such as a paper crane. It is extremely easy to form into a balloon having a hollow portion, and it is also possible to use a natural material such as a plant leaf which originally has a design element originally. . Moreover, since there is no particular limitation on the molding in this first step, the creator can freely design (creat). Therefore,
INDUSTRIAL APPLICATION This invention can obtain a metal product with high industrial value.

Further, in the third step, the slurry may be attached to the entire surface of the combustible material molded body or the combustible natural material obtained in the first step, but it is attached only to a part of the surface. Since this may be done, the width of the design can be further expanded by appropriately selecting this attachment point.

Further, in the present invention, after the slurry is adhered to the surface of the combustible material compact or the combustible natural material in the third step, the first step and the third step are further repeated once or a plurality of times. It may be repeated. For example, after selecting plant leaves as the flammable material (first step), depositing the slurry obtained in the second step on the entire surface and drying (third step), the surrounding area is flammable such as an agar aqueous solution. When covered with a material and solidified into, for example, a hexahedron (first step), the slurry is attached to the periphery of the solidified agar aqueous solution in a grid pattern (third step), and thereafter sintered (fourth step), a grid is formed. It is possible to obtain a metal product in which a leaf-shaped plant-shaped sintered body exists inside a sintered body that is a cage. It goes without saying that a metal product having a complicated shape can be obtained by increasing the number of repetitions of the first step and the third step.

[0017]

EXAMPLES Examples of the present invention will be shown below.

Example 1; thickness is 0.1 mm and one side is 60 m
After the Japanese paper of m is shaped into a paper crane, it is immersed in a molten paraffin liquid to impregnate the Japanese paper with wax (first step). On the other hand, silver powder having a particle size of 5 to 30 μm (99.9
7%) Cellulose water-soluble binder 8% liquid 2 to 50 g
0 g is mixed, and 20 g of water is further added to form a slurry (second step). The slurry is applied to the entire surface of the paper crane with a brush so as to have a uniform thickness and dried. This operation is repeated 3 times to form an adhesion layer having a thickness of about 0.5 to 0.7 mm (third step). Then, this is air-dried at about 50 ° C. for 30 to 60 minutes and placed in a heating furnace (oxidizing electric furnace) kept at 500 ° C. Then, the temperature is rapidly raised to 850 ° C., the temperature is held at 850 ± 10 ° C. for 20 minutes, and then taken out from the heating furnace (fourth step). Thus, about 5 g of origami crane, which is a silver sintered body, was obtained.

Example 2; Thickness is 0.1 mm and one side is 60 m
After the Japanese paper of m is shaped into a balloon (substantially hexahedral shape), it is immersed in a molten paraffin liquid to impregnate the Japanese paper with wax (first step). On the other hand, 20 g of 8% liquid cellulosic binder is mixed with 50 g of silver powder (99.97%) having a particle size of 5 to 30 μm, and 20 g of water is further added to form a slurry (second step). The slurry is attached to each side and diagonal of the balloon with a brush so as to have a thickness of 0.5 mm and a width of 2 mm and dried (third step). Then, the fourth step was carried out according to the above-mentioned Example 1 to sinter, and a cage having a hollow portion of about 5 g, which was a silver sintered body, was obtained.

Example 3; thickness of 0.1 mm and one side of 50 m
The first step and the second step were carried out in accordance with Example 2 except that m paper was used, and the slurry obtained in the second step was used for the entire surface of the balloon (substantially hexahedral shape) obtained in the first step. Apply with a brush so that the coating thickness is uniform, and dry. This operation is repeated 3 times to form an adhesion layer having a thickness of about 0.5 to 0.7 mm. Further, a pattern is drawn on the surface of the adhesion layer with slurry and dried (third step). After that, the fourth step was performed according to the above-mentioned Example 1 to sinter, and a substantially hexahedron having a hollow portion of about 10 g, which was a silver sintered body, was obtained.

The present invention has been described above based on the embodiments, but the present invention is not limited to the above-mentioned embodiments, and can be carried out in any manner as long as the configuration described in the claims is not changed. You can

[0022]

As described above, in the method for producing a metal product of the present invention, the concentration of the liquid (slurry) obtained by mixing the metal powder and the organic binder solution and the method of adhering the same are appropriately adjusted. By selecting, the thickness of the sintered body can be set to the minimum required thickness. Therefore, unlike the conventional method of molding and sintering a clay-like material, expensive metal powder is not wasted, and only the necessary minimum amount is used, so that the cost can be kept low.

The basic shape of the metal product of the present invention is
By designing the flammable material, the selected flammable material originally has a design element or setting. Therefore, for example, plant leaves can be used as they are as a flammable material, or if a thin base material such as Japanese paper, western paper, or a film is selected as a flammable material, a well-known origami processing technique is used. It is also extremely easy to form a folded paper crane having a complicated shape, a balloon having a hollow portion, or the like, which is substantially impossible by the conventional method. In addition, in that case, multiple flammable materials may be used, and an adhesive may be used, so a metal product with a shape of high craft value that gives the creator's free creativity (design) is provided. Can be made.

Further, since the slurry may be adhered only to a part of the surface of the combustible material molded body, for example, the adhered portion may be adhered to the surface of the combustible material molded body formed into a substantially hexahedral balloon. You may make it adhere | attach slurry so that it may become substantially lattice shape. In this case, when sintered, it is possible to obtain a sintered body which is a hollow and substantially lattice-shaped basket. In this way, since the selection of the location where the slurry adheres can be incorporated as one element of the design, the width of the design will be further expanded, and the conventional method cannot be manufactured without applying welding or brazing. Shaped ones can be manufactured very easily and quickly.

Further, the present invention does not require a mold material or the like at all, and each step in the present invention, that is, the step of forming a combustible material, the step of preparing a slurry, the step of adhering a slurry, and the step of sintering. Can be easily and quickly performed, so that a product can be obtained in an extremely short time from the planning of a design.

In addition, in the present invention, after the slurry is adhered to the surface of a molded body of combustible material or a combustible natural material, the step of covering the periphery of this with the combustible material and the surface of the combustible material. You may make it sinter after performing the process of making a slurry adhere once or several times. In this case, it is possible to obtain a product having a complicated structure in which another sintered body exists inside the sintered body.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeji Uesaka 675-3 Kizu, Takaoka City, Toyama Prefecture (72) Haruhiko Shimoo Inventor Haruhiko Shiga 9-3, Asahigaoka, Takaoka City, Toyama Prefecture

Claims (1)

[Claims] 1. A liquid obtained by mixing a metal powder and an organic binder solution on a part or the whole of the surface of a flammable material or a flammable natural material molded into a sludge. A method for producing a metal product, comprising depositing, evaporating a solvent, and then raising the temperature to a sintering temperature.