JPS5852017B2 - How to get started - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a white alloy for decorative articles having excellent corrosion resistance, brazeability and machinability.

Conventionally, white alloys such as 14 white gold or rhodium-plated nickel silver have been used for eyeglass frame materials, wristwatch sides, band materials, and the like.

However, 14 white gold has excellent brazing and cutting properties, but as it is used, it gradually loses its luster and changes color from white to grayish white, and the same is true for rhodium-plated nickel silver. Although it has excellent brazing and cutting properties, it has drawbacks such as peeling off of the plating and discoloration of the nickel silver due to pinholes and cracks during use, making it unsatisfactory in terms of corrosion resistance. It was something.

For these reasons, there has been a strong demand for a white alloy that has good brazing properties, good machinability, and particularly excellent corrosion resistance, and is suitable for use in decorative products.

In order to meet these demands, the inventors of the present invention conducted intensive research and found that the present inventors have developed a material that has particularly excellent brazing and cutting properties comparable to conventionally used 14 white gold or rhodium-plated nickel silver. We have discovered a nickel-chromium-copper-manganese white alloy for ornaments that has excellent corrosion resistance.

The white alloy for ornaments of the present invention is the above-mentioned nickel-chromium alloy.
An alloy based on a copper-manganese alloy, to which two or less elements selected from platinum group elements and gold are added, and an alloy in which carbon is further added, and these alloys can be used for decorative items. The present invention aims to provide a suitable white alloy.

One of the alloys of the invention contains chromium 15-25 w/o
, copper 1 to 23w101, manganese 0.5 to 10w10, platinum group elements, and gold, each of which is within the range of 0.01 to 3w10, and the balance is nickel. It is.

Furthermore, another alloy of the present invention is an alloy described in claim 2, which is obtained by adding 0.01 to 0.2w10 of carbon to the alloy described in claim 1.

In terms of alloy components, the most significant feature obtained by co-adding chromium, copper, and manganese to nickel is that corrosion resistance, brazeability, and machinability can be obtained at the same time.

Alloys containing only nickel and chromium have poor brazing and machinability, and alloys containing only nickel and copper have poor corrosion resistance.
Both are inferior to the conventionally used 14 white gold and rhodium-plated nickel silver as white alloys for decorative items.

That is, by co-adding chromium, copper, and manganese to nickel, it is possible to exhibit excellent effects as a white alloy for ornaments.

Furthermore, among these effects, corrosion resistance is further improved by adding platinum group elements and gold, and machinability is further improved by adding carbon.

Next, the reason for limiting the components and composition range of the alloy of the present invention as described above will be explained as follows.

The composition of the alloy according to claim 1 is chromium 15-25w10. Copper 1-23 wlo.

0.5 to 10 w/o of manganese and 0.5 to 10 w/o of each of platinum group elements and gold. Within the O1-3 w/o range, there are 2 types or less and the balance is nickel, and it was known that adding chromium to nickel has an effect on corrosion resistance.
In the alloy of the present invention, below 15 w/o of chromium,
This is because the anticorrosion effect is weak due to the presence of copper and manganese, and chromium of 25 w/o or more deteriorates the color tone as a white alloy for decorative items.

Addition of copper to this alloy improves brazing properties due to good solder wettability.

If copper is less than 1w10, brazing properties will be poor, and if copper is more than 23w10, corrosion resistance will be poor.

Therefore, a suitable value for copper is 1w10 to 23 VV/O.

Further, manganese has the effect of improving corrosion resistance against sulfur and machinability, but if it is less than 0.5 w/o, the effect of contributing to sulfidation resistance and machinability is small, and if it is more than 10 w/o, it worsens the corrosion resistance.

Therefore, the appropriate amount of manganese is 0.5 to 10w10.

Next, when two or more of the platinum group elements, ie, ruthenium, rhodium, palladium, osmium, iridium, platinum, and gold are further added to the nickel-chromium-copper-manganese alloy, the platinum group elements and gold eventually become monickel, chromium, and gold. copper,
Since it is a more electrochemically sensitive metal than manganese, its corrosion resistance is further improved.

However, none of the platinum group elements and gold added are present.
．． If it is less than 01w10, the corrosion resistance of the nickel-chromium-copper-manganese alloy cannot be improved;
If it is more than o, the ratio of improvement in corrosion resistance to price begins to decrease, which is inappropriate.

In addition, the reason why we limited the addition of platinum group elements and gold to two or less is that even if three or more of these metals are added, platinum group elements and gold are expensive, so it is more difficult to manage materials and scrap. This is because it only adds to the effort and cost of the collection work.

Therefore, corrosion resistance is further improved by adding at most two types of platinum group elements and gold, each in a limited amount within the range of 0.01 to 3w10.

Further, the alloy according to claim 2 is an alloy according to claim 1 which contains 0.01 to 0.2 w/carbon in the alloy according to claim 1.
The addition of carbon creates metal and metal carbide, and this metal carbide further improves machinability.

If the carbon content is less than 0.01 w/o, sufficient metal carbide cannot be obtained to further improve machinability;
This is because if it is more than /o, the machinability is further improved, but the corrosion resistance of the alloy described in claim 1 is extremely deteriorated.

Therefore, the addition of carbon is limited to a range of 0.01 to 0.2w10.

The above components and composition ranges have been determined for the above reasons, and the alloy of the present invention having such a composition has no problems with corrosion resistance, machinability, and brazing properties as a white alloy for ornaments, and has not been used conventionally. 14 white gold and
It can replace rhodium-plated nickel silver.

Next, in order to further clarify the characteristics of the white alloy for ornaments of the present invention, specific examples will be given and explained in comparison with conventional products.

First, examples having the alloy compositions of each of the inventions described in claims 1 to 2 for the alloy of the present invention will be described.
161 to /162, and the samples of these examples were melted and cast using a normal method, and then rolled to a size of 0.5 m.
It was formed into a plate with a thickness of m and then cut into pieces of 30 mm x 30 mm.

Next, two types of conventional product samples were used: A63 (K14 white gold) and /%4 (nickel silver plated with rhodium).

Comparative tests were conducted on both the samples of the alloy of the present invention as described above and the conventional product using the test strip shown below, and the following results were obtained.

a. Corrosion resistance test conditions Liquid composition NH4OH: 0.2 fl/l, NaC1:
9.9g/It, Na2s: 0.3g/I
t, urea = 1.7 g/ / lactic acid: 1.7fi/l
j Liquid temperature 40±2℃ b, Brazing test conditions Brazing metal: JISBAg-3 Spreading test based on JIS Z3191 C0 cutting test conditions 0.5φ drill 3000 R, P, M.

Test for the number of holes that can be drilled per drill As is clear from the above-mentioned corrosion-resistant test coat, Example layers 1 to 2 of the alloy of the present invention were 43. Compared to A4 white alloy,
It can be seen that the corrosion resistance is extremely long and the corrosion resistance is extremely excellent.

Next, although conventional products are excellent in terms of brazing and cutting properties, the spread area of brazing in tests ranges from /161 to /
All of 164 are over 200m1L, and the number of holes that can be drilled per drill in cutting tests is /161~/I
64 fell more than 700 times, and in terms of brazing properties and machinability, the examples of the alloys of the present invention had excellent performance that was no different from conventional products.

As detailed above, the alloy of the present invention not only has excellent brazing properties and machinability equivalent to conventional 14 white gold or rhodium-plated nickel silver, but also has far superior corrosion resistance than the conventional products mentioned above. This has enabled us to provide an epoch-making white alloy for ornaments that is far superior to the previous one.

Therefore, the alloy of the present invention, which has the characteristics and effects of particularly excellent corrosion resistance, brazing properties, and machinability, can be widely used as a white alloy for decorative items in place of the conventional products mentioned above, and can also be used to take advantage of the characteristics of the alloy. The range of applications is extremely wide.

Claims (1)

[Claims] 1 Chromium 15-25W 10% Copper 1-23 w/o
s manganese 0,5-10 w/o and platinum group elements,
A white alloy for ornaments consisting of two or less types of gold within the range of o, oi to 3w10, and the balance being nickel. 2 Chromium 15-25 Manganese 0.5-10w 101 Carbon 0.01-0.2w
10 and platinum group elements, 0.01 to 3w each from gold
A white alloy for decorative items having a composition of two types or less within the range of 10 and the balance being nickel.