JPS60148664A - Diffusion brazing method - Google Patents

Abstract

PURPOSE:To obtain brazed parts having excellent corrosion resistance without oxidation discoloration by subjecting external parts of Ti, etc. plated with Au on the activated surface and parts consisting of an Au alloy to diffusion brazing via a Ge layer under prescribed conditions. CONSTITUTION:The surface of external parts to be brazed consisting of a material such as a stainless steel, Ti sintered hard alloy or the like is thoroughly activated. The surface is then coated thereon with a plating layer of Au.Pt- Ni.Ni, etc. having >=0.5mu thickness and thereafter the external parts coated with the above-described plating layer and the brazing parts consisting of an Au alloy are laminated via a Ge layer having 2mu-50mu thickness and are subjected to diffusion brazing at 600-800 deg.C in a non-oxidizing or reducing atmosphere. The brazed parts having excellent corrosion resistance without oxidation discoloration are thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of brazing a part made of an Au alloy to a part of an exterior part.

[Conventional technology and problems]

Conventionally, exterior parts made of materials such as stainless steel, Ti, cemented carbide, etc. have been made by adhering parts made of Au alloy to a part of the exterior part to increase the decorative value and diversify the design. is being carried out. However, since adhesion has the problem of deterioration of adhesive strength due to changes in the adhesive over time, brazing has recently been attempted as a method of joining the exterior parts and parts made of Au alloy. In the brazing method, it is preferable to braze the parts without causing oxidative discoloration, and the conditions are that the brazing is performed in a non-oxidizing or reducing atmosphere, and the temperature of the brazing is as follows: It is necessary that the temperature does not exceed 800°C.

Therefore, Ag is used as a brazing material for the brazing described above.
Wax and Au wax are considered, but Ag wax is prone to oxidation blackening and has problems in corrosion resistance, and Au wax has a high melting point because it requires a gold phase of 12 or more to satisfy corrosion resistance. Become.

It is difficult to braze at temperatures below 800°C. Therefore, with the conventional brazing method, there is a problem in that it is not possible to braze a part of the exterior part made of an Au alloy with a brazing material having excellent corrosion resistance without causing oxidation and discoloration.

[Object of the present invention]

The present invention solves the above-mentioned drawbacks and provides a method for brazing parts made of Au alloy to some exterior parts made of stainless steel, Ti, cemented carbide, etc. without causing oxidation discoloration and with excellent corrosion resistance. The purpose is to provide Au
-Using the eutectic reaction of Ge (356°C), brazing is done by using Au alloy on a part of the exterior part.
The present invention provides a method for performing diffusion waxing through a layer at a low temperature of 800° C. or less.

[Structure of the invention]

The structure of the present invention is to sufficiently activate the surface of the exterior part to be brazed made of materials such as stainless steel, Ti, and cemented carbide,
Next, Au*Pd-Ni with a thickness of 0.5μ or more
- For brazing, the parts are coated with a nail plating layer such as Ni and then coated with the plating layer to be brazed, and the Au alloy is laminated with a Ge layer interposed therebetween, and the parts are laminated at 600° in a non-oxidizing or reducing atmosphere. Method (3) is diffusion brazing at a temperature of 800°C to 800°C. To explain the contents in more detail, first, the plating layer that covers the surface of the exterior component to be brazed is formed by strong oxidation on the surface of stainless steel, Ti, cemented carbide, etc., which is the exterior component to be brazed. Since brazing the membrane will deteriorate its properties,
The brazing process activates the material surface of the part, further protects the active surface from oxidation, and the brazing plate is formed to improve properties. As the type of the plating layer, Au-Pd-Nl-N1 plating is suitable in consideration of corrosion resistance and wax flowability. Further, the thickness of the plating layer is required to be 0.5μ or more in order to protect the active surface of the exterior component surface during brazing.

Next, regarding the Ge layer, which is a feature of the present invention, the A, O alloy brazing material laminated on the Ge layer is made of Au, which is the main component of the component.
At a temperature of 356℃ or higher, a diffusion eutectic reaction occurs and
An e-eutectic alloy layer is formed, and when the A u -G e eutectic alloy layer is brazed with an exterior component, it acts as a brazing material by causing a reaction. The thickness of the Ge layer is 2μ to 50μ, and the reason for this limitation is that if the Ge layer is less than 2μ, it will not work as a brazing material, and if it exceeds 50μ, the Ge layer will be completely dissolved in the Au alloy. If some parts are left unbrazed, the strength will be weakened. Also, as a method for forming the Ge layer,
By vapor deposition, printing, and coating. Next, the temperature for brazing is as follows:
The upper limit for brazing parts and Au alloy brazing is set at 800°C to suppress oxidative discoloration of parts, and below 600°C,
Diffusion brazing has a lower limit of 600℃ because the reaction is not sufficient.
shall be.

[Embodiments of the invention]

Embodiments of the present invention will be described using the drawings.

FIG. 1 is an exploded perspective view of the embodiment before brazing, and FIG. 2 is a sectional view taken along the line AA in FIG. 1 in the direction of the arrow after brazing is completed. First, the watch side 1 made of 5US304 stainless steel was molded and polished, and in order to braze the decorative plate 6 made of 18KAu alloy, the entire surface of the watch side except for the part 2 to be brazed was masked.

Next, it was thoroughly degreased and cleaned, further activated by electrolytic cleaning, and then a 2μ thick Ni plating layer 4 was formed by electroplating, and then the masking was peeled off.

Next, 150 mesh under Ge powder was rough-ined and applied to a thickness of 20 μm on the plating layer 4.
A layer 5 is formed, and a decorative plate 6 is further placed on top of the Ge layer 5 at 18. After that, 800°C in a vacuum of 1O-4torr
Diffusion brazing was performed under the conditions of ℃ x 3 omin.

As a result, as shown in the perspective view of FIG.
The decorative plate 6 was completely brazed, and no oxidation discoloration was observed, and the soldering retained its original appearance. In addition, the strength of the soldered plate 6 on the rear clock side 1 and 18 was examined by a peel test, and the strength was 5 kg/-, indicating sufficient bonding strength.

Furthermore, when the watch side was subjected to a 24-hour test using the salt spray test method of JIS Z2371, no rust was observed from the brazed parts, indicating good corrosion resistance.

Although a detailed explanation will be omitted, various experiments were conducted under conditions other than those described above, and satisfactory results were obtained within the range of numerical limitations described above.

[Effects of the Invention] As is clear from the above examples, the diffusion brazing method of the present invention can apply Au alloy to some exterior parts made of stainless steel, TI, cemented carbide, etc., which was previously impossible. Brazing is a method of brazing parts that do not cause oxidative discoloration and has excellent corrosion resistance, and has many effects.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention, FIG. 1 is an exploded perspective view before soldering, and FIG. 2 is an exploded perspective view of part A-A in FIG. 1 after brazing is completed. A sectional view taken in the direction of arrows, and FIG. 3 is a perspective view after soldering. 1...Clock side, 2...Brazing part, 6
...Au alloy plaque, 4...plated layer, 5...Ge layer. 1st Circle 2nd Entrance 34th 29i-

Claims (1)

[Claims] For brazing materials made of materials such as stainless steel, TI, and cemented carbide, the surface of the exterior part is sufficiently activated, then coated with a plating layer of AusPd-NigNi or the like having a thickness of 0.5μ or more, and then the plating The outer parts for brazed parts covered with a layer and the parts for brazed parts made of Au alloy are 2μ to 50%
A diffusion brazing method characterized in that the layers are laminated via a Ge layer having a thickness of μ and brazed at a temperature of 600° C. to 800° C. in a non-oxidizing or reducing atmosphere.