JPS605831A - Age hardening au alloy for white ornament - Google Patents

Abstract

PURPOSE:To obtain a hard Au alloy for white ornament with superior scratch resistance and workability by adding specified percentages of Pd, Cu, Zn, Ni and Co to Au. CONSTITUTION:An Au alloy consisting of, by weight, 3-10% Pd, 15-25% Cu, 3-10% Zn, 3-10% Ni, 1-5% Co and the balance Au is prepd., rolled to a prescribed thickness, and aged. An Au alloy having value as metal and comparable to a conventional Au alloy in corrosion resistance is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a white Au alloy used for decoration of watches, necklaces, rings, etc.

In general, watches, necklaces, rings, etc., have scratches, etc. (and their decorative value is inferior, so hard and scratchy materials are required. Since complex processing is performed as a material, one of the requirements is that it has excellent workability.

By the way, K18. is a decorative material that has metal value (that is, contains precious metals). K16. Although ΔU alloy materials such as K14 are known, these alloy side slopes cannot fully satisfy the above-mentioned requirements.

The present invention has been made in view of the above-mentioned circumstances, and provides a white decorative Au material that is hard, scratch-resistant, and has excellent workability. The purpose is to provide alloys.

The following describes the Au alloy of the present invention: Pd 3-10% by weight, Cu 15-25% by weight,
Zn3-10% by weight 1N13-10% by weight, G.

It is characterized by being composed of 1 to 5% by weight, the balance being Au, and subjected to an age hardening treatment.

However, as mentioned above, the reason for including each metal and limiting the composition range is that Pd is used to create a white color tone, increase workability, and improve corrosion resistance. If the content is less than 3% by weight, corrosion resistance cannot be particularly improved, and if it exceeds 10% by weight, uniform fraction Ii & precipitation of 00 particles may occur during hardening treatment.
(11) and the effect of the hardening treatment is weakened.Next, C
As for u, it is intended to improve workability and to cause precipitation hardening by forming an Ag-Cu alloy, and 1
If the width is less than 5 m%, the effect of precipitation hardening is small;
This is because, if the color tone exceeds , the color tone will no longer be white.

Zn is used to increase the white color tone and improve processability; if the content is less than 3% by weight, the effect of creating a white color is weak (and if it exceeds 10% by weight, the material Ni is added to increase whiteness and hardness, but if it is less than 3% by weight, whiteness and hardness cannot be increased; If it exceeds, it becomes too hard and difficult to process.
This is because it becomes Regarding Co, Co particles are precipitated in the Au matrix during age hardening treatment to harden the material by precipitation hardening action, but 1
When the weight% is not &Mi, the amount of Co particles precipitated in the A, IJ matrix is small and the effect of precipitation hardening is weak, and if it exceeds 5% by weight, it inhibits the workability of the material and reduces the corrosion resistance. It is.

Next, in order to further clarify the white Au alloy of the present invention, specific examples and conventional examples thereof will be described.

[Example 1] Pd5.1% by weight, Cu2O,5i amount%, Zn4ffi
f? t%, Ni5.9% by weight, Co, 5% most, balance A
After rolling an alloy material made of u to a thickness of 1 mm, it was heated at 800°C for 1 hr in a N2 atmosphere to undergo solution treatment. After this, it was further heated to 400°C in a N2 atmosphere.
Age hardening treatment was performed by heating for 3 hours.

(Example 2) Pd6.5% by weight, Cu2O heavy weight%, Zn6 heavy weight%.

An alloy material consisting of 6% by weight of Ni, 2.5% by weight of Co, and the balance being Au was rolled to a thickness of 1 mm, and then subjected to solution treatment and age hardening treatment under the same conditions as in Example 1.

[Conventional example]

Cu 24.8% by weight, Zn 6.3ffli%,
An alloy material consisting of 10.4% by weight of Ni and the remainder U was rolled to the size of 1 tuna, and then rolled to 80% by weight in an N2 atmosphere.
Solution treatment was performed by heating at 0° C. for 1 hr. Furthermore, it was then heated at 400°C in an N2 atmosphere to perform age hardening treatment. Corrosion resistance tests were conducted on the hardness of each material thus obtained before and after the age hardening treatment, and on artificial sweat shown in Table 1, and the results shown in Table 2 were obtained.

Table 1: Artificial sweat composition and test conditions Table 2: Measurement/test results As is clear from Table 2, the Au alloy of the example has a slightly higher strength after solution treatment than the conventional Au alloy. Although it is hard, after the age hardening treatment, the hardness becomes more than twice that of the conventional Au alloy. Also, in the corrosion resistance test, it was comparable to the conventional example.

Furthermore, regarding its workability, its hardness is 1 after solution treatment.
It was around 90HV, and it was possible to easily perform multiple 11ffl processing.

As explained in detail above, the Au alloy according to the present invention is
It has a white color and its hardness is around 190 HV after solution treatment, which is not very high, so it can be easily processed into multiple pieces as ornaments such as watches, rings, necklaces, etc., and it is age hardened. After treatment, it has a resistance of 350 HV or more, which is extremely hard compared to conventional Au alloys, and even when used as a decorative item, it is scratched and hard.

Furthermore, it has corrosion resistance that is approximately equal to that of conventional Au alloys.

Claims (1)

[Claims] Pd 3-10ffi amount%, Cu 15-25% by weight,
Zn3-10% by weight, Ni3-10% by weight, C01-5
71. White decorative age-hardening material characterized by weight percent and balance being Au. u alloy.