JPS59190340A - Gold alloy for vapor phase plating - Google Patents

Abstract

PURPOSE:To obtain a gold alloy for vapor phase plating giving a freely controllable reddish gold to golden yellow color tone by adding one or more among Cr, Fe, Co, Ni, Pd and Cu to Au. CONSTITUTION:A gold alloy for vapor phase plating having reddish gold to golden yellow color is obtd. by adding one or more among 1-10% each of Cr, Fe, Co, Ni and Pd and 0.5-20% Cu to Au as a principal component. By changing the composition of the alloy, a reddish gold to golden yellow color tone can be freely reproduced without requiring a skilled worker. For example, an alloy consisting of 95wt% Au and 5wt% Pd gives a pinkish golden yellow color tone, and an alloy consisting of, by weight, 75% Au, 3% Co, 5% Ni, 15% Cu and 2% Cr gives a golden yellow color tone. Such a gold alloy for vapor phase plating can be effectively used in the plating of a decorative article.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reddish-gold to golden-colored Au alloy used in metal alloys.

In recent years, the method of decorative plating has gradually shifted from the conventional wet plating method to the dry vapor phase plating method, which has come to be used more and more industrially.The greatest feature of vapor phase plating is This makes it possible to cover materials that could not be covered using conventional wet plating methods.

Recently, vapor phase plating has replaced the conventional wet chemical plating method and has been widely used for wristwatch exterior parts, eyeglass frames, jewelry, etc., especially for materials that are difficult to plate using conventional plating methods, such as Svenless steel and titanium. For this purpose, vapor phase plating is becoming very important.

The above-mentioned wristwatches, glasses, etc. are required to have a high level of corrosion resistance against sweat and dirt. For this reason, it is necessary that the plating coating layer satisfies not only its appearance but also its performance.

The present invention was developed as a result of extensive research into these requirements.
It has been discovered that alloys containing AuKCr, Fe, Co, Ni, Pd, and Cu added singly or in combination have excellent performance as alloys for red to golden color vapor phase plating. The characteristics of an Au alloy suitable for vapor phase plating are: (1) The evaporation of the alloy from the evaporation source has almost the same composition until the end of plating.

■ The color tone can be freely controlled from golden to red-gold.

■It must have a melting point of 1000°C to 1200°C.

■Do not react with the tungsten boat that is the evaporation source.

Or less reaction.

■ The plated film has excellent corrosion resistance.

■ Excellent overall corrosion resistance including materials.

■ Be a low-income rat as much as possible.

■ Can be processed into plates, wire rods, etc. etc., and it is important to fully satisfy these characteristics.

Traditionally, the gold dyes used in vapor phase plating are TiN, T
The main materials are ac, Tic, TiN, pure gold, etc., and there are many deficiencies in terms of color tone and cost.

Recently, as described in Japanese Patent Application No. 54-2942, a method of forming a 2-3 layer film by evaporating Au or Ti on a TiN film has been used, but it is very difficult to control the color tone and reduces the yield. There were problems and improvements were desired.

In particular, for wristwatch exterior parts and eyeglass frames, color tones ranging from pale gold to deep red gold are required, even within the same gold color system, in order to provide high decorative value and meet the diverse demands of users.
・The conventional methods described above were insufficient.

The alloy of the present invention is very effective for improving these drawbacks, and the composition of the alloy of the present invention is prepared in advance by adjusting and melting it, processing it into a thin plate shape, setting it in an evaporation source, and evaporating it.

By using this method, it is possible to control the color tone by varying the alloy composition. For example, depending on the amount of Pd added, the color changes from gold to light pink, Co and N1 change the color from gold to pale gold, and Cr changes from deep red gold to light spring gold, and various colors can be controlled by varying the alloy composition. I found out what was possible.

It has also been found that a color tone that cannot be obtained at all with the bulk state of the alloy can be obtained by vapor phase plating, and it is very effective for decorative items where appearance is important.

Next, the reasons for limiting the alloy composition of the present invention will be described.

The selection of elements such as Cr, Fe, C'o, Ni, Pd, and Cu is based on the alloy composition that becomes the base when they are alloyed, set in an evaporation source, and evaporated at a certain degree of vacuum. The precipitated alloy coating layer having the closest composition was selected first.

For example, Ag, which is generally added in large amounts to Au alloys, has a high evaporation rate and is therefore unsuitable as an alloy for vapor phase plating. This means that it is desirable that the added element evaporates to some extent at the same level as Au at a certain degree of vacuum and evaporation temperature.

As alloying elements that do not satisfy these conditions, Cr, Fc, C
They selected O, Ni, Pd, and Cu.

Next, regarding the amount of each element added, CO dissolves in Au at approximately 84% solid solution at high temperatures and hardly dissolves in solid solution at room temperature, but when more than 1% is added, the color becomes slightly reddish than pure gold. If it exceeds 10%, the color tone of the evaporated film becomes almost pale from golden yellow and becomes whiteish, so it was set to 10% or less. Moreover, if CO is added in an amount exceeding 10%, the corrosion resistance of the coating layer will be significantly deteriorated.

Ni is dissolved in solid solution at a ratio of AI-IK, but N1 has a strong tendency to whiten, and addition of more than 10% results in a platinum color, which is not suitable for the purpose of the present invention. The addition of N1 increases the A u − of the bulk alloy.
It exhibits a color tone similar to that of the three elements A g -Cu, and exhibits excellent color development when added in an amount of 1% or more.

Pd has almost the same whitening tendency as Ni, and is completely dissolved in Au. However, the difference with N1 is that, as mentioned above, the addition of N gives a golden color, but when Pd is added in an amount of 1% or more, it shows a reddish-gold color, and if it exceeds 10%, it becomes pale white, which is not the desired gold color. It was set to 10% or less.

Cr is dissolved in solid solution in about 7% A Ll, and the color tone of the film is different from the bulk state of the alloy, showing a reddish-gold color tone.
The color is different from the color of Pd addition (・, the color appears at 1%, and if it exceeds 10%, Cr tends to evaporate and becomes white, and the color tends to vary. did.

Fe is a large amount (solid solution) in A and u at high temperatures, and adding 1% or more produces almost the same effect, but Fe itself has poor corrosion resistance. If it exceeds 10%, the color tone of the film tends to vary. In addition, since the corrosion resistance would be significantly deteriorated, the content was set at 10% or less.

The effect of adding Cu alone is relatively small, but 0
At 5% or more, the color tone becomes reddish-gold, creating a very aesthetically pleasing color.

However, if the Cu content is further increased by more than 20%, only Cu evaporates first, becoming Cu-colored, and the corrosion resistance is significantly deteriorated. In addition, other elements, Co, Ni, not exceeding 20%
When added in combination with , Cr, Fe, and Pd, the aesthetic effect is remarkable, and there is an effect of reducing the number of gold particles and thereby lowering the cost, as well as subtly changing the color tone.

In particular, those made by alloying and adjusting Ni, Cr, and Cu at the same time have poor corrosion resistance and color even if they contain up to 20% Cu.]8
It is the same as I<alloy and has excellent effects.

Examples of the present invention will be described below.

Example 1 Inventive alloys having various compositions shown in Table 1 were prepared, and their color tone and corrosion resistance were investigated.

Corrosion resistance tests were conducted using artificial sweat made for the purpose of investigating the corrosion resistance of precious metal alloys.

Artificial sweat composition NaCl 9.9g/11 Sodium sulfide 0.8g/l Urea
1.7&/1 lactic acid
1.7 ml/l (Drop ammonia water into the above solution to adjust the pH to 36) Temperature: 40°C A high-frequency melting furnace was used for the X961-1 alloy, and zirconia was prepared in the crucible. It was dissolved in an argon gas stream. After that, it was repeatedly cast, annealed and rolled to a thickness of Q, 5 mm.
A test piece with a width of 20 mm and a length of 25 mm was prepared and subjected to the test.

The color tone was compared with a conventional pure gold color and visually inspected. Table 1
As can be seen from the above, it was found that characteristic color tones were exhibited depending on the added elements, and clear differences in color tone were created depending on the different added elements.

From this example, those to which 10% or more of elements other than Cu were added were excluded from the test because their white color was significant.

The alloy of the present invention is further processed in an ion blating device.
Vapor phase plating was performed and the color tone and film characteristics were investigated.

S [Made of J S 316, thickness 1 sq. x width 20% x length 3
0% test pieces were puff-polished to a mirror surface, washed with an organic solvent, and then placed in the cathode section of an ion blating device.

On the other hand, the alloy plate of the present invention rolled to a thickness of 0.5% was cut to an appropriate size with scissors, and set on a tungsten board for resistance heating at about 5.9 r.

After that, the entire ion blating device was
After vacuuming to 5 Torr, argon gas was added to the
5US31 installed and installed up to 10' Torr
6 test piece was bombarded by applying a voltage of I KV,
The surface of the test piece was cleaned. After this, an electric current was passed through the tungsten boat to melt and vaporize the alloy of the present invention. Then, a 5US316 plate placed on the cathode side was plated.

The voltage and current at this time were 30 V and 250 A, respectively, and the speed from melting to evaporation varied depending on the way the current was passed, and it was found that even with the same composition, the color tone could be delicately controlled. - For example, in the A 11-P d system, if the evaporation rate is fast,
It turned into a red-gold color, and if it was slow, it turned into a peach-red-gold color. This example was carried out under certain conditions. The thickness of the film at that time is approximately 1
~2μ, and the color and corrosion resistance of the coating, as well as the 5LI
The adhesion of this coating onto S316 specimens was investigated.

The results are shown in Table 2.

Adhesion was determined by bending a test piece 5US316 plate 90' and observing the peeling of the vapor phase plating at the bent portion. Corrosion resistance is artificial sweat, 961-1 immersion.

As shown in this embodiment of the present invention, more diverse color tones can be produced than when conventional single elements are evaporated. Furthermore, by keeping the resistance heating conditions of the tungsten boat constant, a wide variety of fixed color tones can be reproduced by changing the alloy composition without requiring any skill in the work.

Furthermore, by reducing the karat, it is possible to produce an alloy coating layer with a composition that could not be achieved by conventional general wet plating methods, which is highly effective in reducing costs and is very advantageous industrially.

As described above, the present invention has Au as the main component, Cr, F.
e, Co, Ni, Pd at 1-10%, Cu at 0.5%. ~2
It contains one or more types of 0%, and the watch side,
It has become possible to create products such as eyeglass frames that fully satisfy the diverse needs of users depending on their daily life situations.

We are confident that it is also effective for products that are highly fashionable and require decoration.

Note that after vapor phase plating the alloy of the present invention, the temperature is 1.00°C to 300°C.
By heating in the temperature range of °C, it is possible to further improve the color tone control, the adhesion of the plating film, and the corrosion resistance, and it is also effective in improving the hardness.

Table 1

Claims (1)

[Claims] Au is the main component, Cr, Fe, Co, Ni, Pd are 1
-10% Cu and 05-20% Cu, a red to golden gold alloy for vapor phase plating.