JPH05185279A - White au brazing alloy for jewellery - Google Patents

Abstract

PURPOSE:To prevent the contamination in a furnace in vacuum brazing or in-furnace brazing of a nonoxidative atmosphere by incorporating specific ratios of Au, Cu, Ni, Ag, In and Sn into the above alloy. CONSTITUTION:The white Au brazing alloy for jewellery is produced by incorporating, by weight%, 58 to 75 Au, 10 to 25 Cu, 8 to 15 Ni, 1 to 10 Ag, 0.5 to 3 In and 0.5 to 5 Sn therein. The Cu has an effect of lowering a m. p. and is incorporated at 10 to 25 into the alloy in consideration for color tones as well. The Ni has a high effect of making the color tone white but increases the m. p. and, therefore, the content thereof is confined to 8 to 15. The Ag improves a flow property and the content thereof is confined to 1 to 10 for sulfiding resistance. The In and the Sn lower the m. p. and improve the flow property but are not effective at <0.5. The In and the Sn degrades workability at the time of production and degrade the strength when the content of the former exceeds 3 and the latter 5. Since the high-vapor pressure components are not included, the brazing is executable by vacuum brazing, etc., without contaminating the inside of the furnace.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a white Au brazing alloy used for brazing white jewelry and watch exterior parts.

[0002]

2. Description of the Related Art Conventionally, as a brazing filler metal used for jewelry such as white platinum alloy or white gold, watch parts, etc., an Au brazing alloy containing Ag as a main component and a small amount of Au,
A Pd solder containing Ag as a main component and Pd is used.

[0003]

However, since both of the brazing materials are mainly composed of Ag, they are apt to form sulfides and discolor, which makes them unsuitable for brazing jewelry and watch parts. there were. In Pd wax, P
The alloy containing a large amount of d was improved in terms of sulfide formation but increased in brazing temperature, and was not suitable for brazing of white gold having a relatively low melting point.

There are brazing materials to which Cd or Zn is added for the purpose of lowering the melting point, but in recent years, quality improvement in automation, mass production and quality control has been enhanced, and vacuum brazing is performed in a furnace in a non-oxidizing atmosphere. Brazing is often used, and at that time, there is a problem that high vapor pressure components Cd and Zn contaminate the inside of the furnace. It is an object of the present invention to solve these drawbacks and provide an Au brazing alloy which is white, has a relatively low melting point, and is corrosion resistant.

[0005]

The present invention provides Au58-7.
5w%, Cu10-25w%, Ni8-15w%, Ag
1-10w%, In0.5-3w%, Sn0.5-5w
Is a white Au brazing alloy for jewelry. In the above structure, Au is indispensable for Au brazing alloy,
In order to provide an Au brazing alloy of K14 to K18 in terms of corrosion resistance, the range is 58 to 75% by weight. Cu has an effect of lowering the melting point of Au brazing alloy within a certain range, but it is set to 10 to 25 w% in consideration of the color tone.

Ni is an element that has the greatest effect of making the Au brazing alloy white in terms of color tone, but since the melting point of the Au brazing alloy increases as the amount of addition increases, it is 8 to 15 w%.
And Ag is for improving the fluidity of the Au brazing alloy, and is 1 to 10 w% in terms of sulfuration resistance.

Both In and Sn are for lowering the melting point of the Au brazing alloy and for having an appropriate fluidity. If both are less than 0.5% by weight, the effect is not obtained, and In is 3w.
%, Sn exceeds 5% by weight, the workability for the production of the Au brazing alloy deteriorates and the brazing strength using the Au brazing alloy deteriorates.

[0008]

EXAMPLES Examples of the present invention are shown in Table 1 below.

[0009]

[Table 1]

500 g of each of the Au brazing alloys of Examples 1 to 5 shown in Table 1 was melted in a Tanman furnace, the surface of the ingot was cut, and rolling and annealing were repeated to manufacture a plate having a thickness of 0.2 mm. . Then, it was judged whether the workability was good or not during the working, and the melting point of the remaining sample was measured and the corrosion resistance was observed by the artificial sweat penetration test.

[0011]

As described above, the Au of the present invention is 58 to 75% by weight, C
u10-25w%, Ni8-15w%, Ag1-10w
%, In 0.5 to 3 w%, Sn 0.5 to 5 w% white Au brazing alloy for jewelery does not contain a high vapor pressure component as compared with conventional Au brazing alloys containing Cd and Zn, and therefore has a high vacuum. Even when brazing or brazing in a furnace in a non-oxidizing atmosphere, there is an effect that brazing can be performed without contaminating the inside of the furnace.

Moreover, the addition of Ni produces a white color, and the addition of In and Sn in the brazed portion also provides a suitable spreadability, which has the effect of preventing the protrusion of the braze and providing a beautifully finished appearance. It is an extremely effective brazing material for brazing of watch parts and watch parts.

Claims (1)

[Claims] 1. Au 58 to 75 w%, Cu 10 to 25 w
%, Ni8-15w%, Ag1-10w%, In0.5
~ 3w%, Sn0.5 ~ 5w%, white Au brazing alloy for jewelry.