JPH05329012A - Manufacture of precious metal product - Google Patents

Abstract

PURPOSE:To prevent deformation of a product, discoloration of a brazed part, and discoloration due to the change with the lapse of time by placing two or more members composed mainly of Au or Pt in a butt state in an atmosphere of non-oxidative atmosphere gas having a lowered dew point and strong reducing property, and heating the same at a temperature below a solidus line to be welded. CONSTITUTION:A hollow product 21 is housed in a recessed hole 3 on a base of a jig, and the end area of a piercing pin 22 held on a pin holder 4 is butted to the outer surface thereof. The butted members are placed on a belt conveyer 12. Plural heaters 13 are disposed above the members and a gas introduction system 14 for supplying a non-oxidative atmosphere gas is provided on a transport path 11. The respective heaters 13 are divided in preheat zones N1-Nn' and soaking zones Nn'-Nn to precisely control the temperature, and as non- oxidative atmosphere gas, gas having strong reducing property such as H gas or the like, the dew point of which is lowered, is used. The respective welded members are heated at a temperature below a solidus line in the soaking zones Nn'-Nn under joining conditions to be diffusion-welded under the pressure conditions where the dead load acts.

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 noble metal product which can be suitably used, for example, as an accessory.

[0002]

2. Description of the Related Art As a method for producing a product such as a round ball of precious metal or a product in which multicolored members are laminated or connected, which is applied to a conventional accessory, etc. The members for were joined together by brazing and brazing, and then the joined portions were polished.

[0003]

However, in the above conventional example, the product is distorted at the time of joining, or the discoloration of the brazed part or the discoloration due to aging may cause
There was a drawback that the appearance was impaired.

The present invention provides a method for producing a noble metal product in which the product after bonding does not deform and discoloration of the brazed portion or discoloration due to aging does not occur.

[0005]

That is, the method for producing a noble metal product of the present invention produces a product in which two or more members are welded with an alloy containing Au as a main component or an alloy containing Pt as a main component. In this case, the above-mentioned two or more members are abutted with each other and placed in an atmosphere of a non-oxidizing atmosphere gas having a low dew point and a strong reducing property, and this is heated at a temperature below the solidus line. is there.

[0006]

Since the method for producing a noble metal product of the present invention is configured as described above, a noble metal product obtained by welding two or more members can be efficiently produced at low cost, and a noble metal product obtained by welding is It is possible to provide a method for producing a precious metal product which is excellent in quality.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for producing a noble metal product of the present invention will be described below with reference to the drawings. 1 and 2 show an opening jig for transportation used in the present invention. This jig is composed of a base 1 for mounting a product, which is made of a heat-resistant material, and an accommodating portion 2 formed on the base 1.

The accommodating portion 2 on the base 1 is provided with a concave hole 3 for accommodating a hollow product 21 made of a noble metal on the upper surface thereof, and is provided with a V groove 5 provided at a predetermined distance from the concave hole 3. The pin holder 4 is attached. The concave hole 3 is formed to have a predetermined depth, and when the end of the piercing pin 22 held by the V groove 5 is abutted against the outer surface of the hollow product 21, the hollow product 21 made of noble metal is moved. It just needs to be blocked.

FIGS. 3 and 4 show another example of an opening jig for carrying. The jig in this example also has a base 1 for mounting a product and a base 1 each formed of a heat-resistant material.
It is composed of the accommodation portion 2 formed above.

The accommodating portion 2 on the base 1 has a concave groove 6 for accommodating the sheet member 23 made of a noble metal along the lengthwise direction of the upper surface thereof. The sheet member 2 having various motifs formed on the sheet member 23 housed in the groove 6 is formed.
A precious metal sheet 24 having a different color from that of No. 3 is mounted, and it can be pressed in advance or pressed after welding if necessary. Of course, the pressing means can be appropriately adopted from a rolling roller or another pressing device.

Further, FIGS. 5 to 7 show another example of an opening jig for carrying. This jig is also composed of a base 1 for mounting a product, which is made of a heat-resistant material, and an accommodating portion 2 formed on the base 1.

The housing 2 on the base 1 has a plurality of recessed holes 3 formed in the upper surface thereof for housing the half members 25 and 25 'constituting a noble metal round ball. The concave hole 3 has a first
Second half-split member 25 ′ when the opening end of the second half-split member 25 ′ is abutted against the open end of the first half-split member 25. The open end of the can be held.

The opening jig to which each welding member is attached is diffusion-welded by being placed in a belt conveyor type atmosphere furnace 8 shown in FIG. 8 and heated.

The belt conveyor type atmosphere furnace 8 has a jig conveying path 11, an endless belt conveyor 12 that advances through the conveying path 11 to convey the jig, and a conveying path 1.
1, a plurality of heaters 13 installed on the upper part of 1, and a gas introduction system 14 for supplying a non-oxidizing atmosphere gas to the transfer path 11. The temperature of each heater 13 from N1 to Nn can be controlled for each zone. The heaters 13 have preheating zones N1 to Nn 'and soaking zones Nn' to Nn.
It is desirable to accurately control the temperature by dividing into

As the non-oxidizing atmosphere gas, a gas having a low dew point and a strong reducing property can be used.
Gas is particularly preferred.

Each welding member in the jig under a non-oxidizing atmosphere gas is heated below the solidus line in the soaking zones Nn 'to Nn and at a temperature condition at which welding is possible, and under the pressure condition of its own weight. Can be diffusion welded easily and at low cost.
The solidus line refers to a reference line at which an alloy changes from a solid to a liquid, and varies depending on the composition of the alloy as shown in FIG. Therefore, it is necessary to adjust the temperature conditions according to the composition of the noble metal that constitutes the product.

As described above, the noble metal product obtained by the method for producing a noble metal product of the present invention was of excellent quality without being oxidized and discolored, and having no deformation or pinhole.

Next, the noble metal products obtained by the present invention can be used for various accessories such as earrings, pendants, rings, broaches, etc., which greatly contribute to weight reduction and cost reduction of the products. Is.

Unlike the above embodiment, it is possible to manufacture the noble metal products in a batch process. That is, the product halved member is housed together with the jig in a vacuum device having a heating mechanism, for example, and the housing is housed in the above-mentioned hermetically sealable jig by abutting the openings under an atmosphere of non-oxidizing atmosphere gas,
Thereafter, by heating in a vacuum apparatus under an atmosphere of non-oxidizing atmosphere gas, a product joined by diffusion welding can be obtained as in the above-mentioned embodiment.

[0020]

Since the method for producing a precious metal product of the present invention is configured as described above, a precious metal product obtained by welding two or more members can be efficiently produced at a low cost, and a precious metal product obtained by welding is obtained. It is possible to provide a method for producing a precious metal product that is extremely excellent in quality.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a jig.

FIG. 2 is a plan view thereof.

FIG. 3 is a cross-sectional view showing an example of another jig.

FIG. 4 is a plan view thereof.

FIG. 5 is a vertical sectional view showing an example of still another jig.

FIG. 6 is a transverse sectional view thereof.

FIG. 7 is a plan view thereof.

FIG. 8 is a schematic view of an atmosphere furnace.

FIG. 9 is a graph showing an outline of a solidus line.

[Explanation of symbols]

 1 Base 2 Storage Section 3 Recessed Hole 4 Pin Holder 5 V Groove 6 Recessed Groove 8 Atmosphere Furnace 11 Conveyance Path 12 Belt Conveyor 13 Heater 14 Gas Introducing System 21 Hollow Product 22 Piercing Pin 23 Precious Metal Sheet Base Material 24 Precious Metal Sheet 25, 25 'Half-divided member

Claims (1)

[Claims] 1. When manufacturing a product in which two or more members are welded with an alloy containing Au as a main component or an alloy containing Pt as a main component, the two or more members are abutted with each other.
A method for producing a noble metal product, which comprises placing in a highly reducing non-oxidizing atmosphere gas atmosphere having a low dew point, and heating this at a temperature below the solidus line.