JPS6018318B2 - ornaments - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a decorative article made of a Ni-based alloy that is highly hard, non-magnetic, and has good gloss.

For example, rings, lighter cases, fountain pen cases, etc. are made of metal or alloy for decorative purposes, and are generally made of stainless steel (ordinary items) or precious metals (luxury items).

However, in the case of the stainless steel mentioned above, it is not only inferior in hardness and easily scratched, but also inferior in decorativeness even after mirror finishing, and in the case of precious metal, although it is good in terms of decoration, its hardness is low. It is easily damaged and its decorative properties deteriorate during the use process. The inventors of the present invention conducted studies in consideration of these points, and found that when a certain type of Cr-AI-Ni alloy is aged, its hardness improves to a Vickers hardness of Hv600 or higher, making it less susceptible to damage from external impacts. On the other hand, we have found that mirror finishing gives a good appearance and always has excellent decorative properties.

Accordingly, the present invention is based on the above-mentioned findings to provide a decorative article that is easy to manufacture and maintains and exhibits the required decorative properties over a long period of time.

The present invention will be described in detail below.
This decorative item is made of a Ni-based alloy containing 5% by weight of aluminum and 2.5-5% by weight of AI, and is mirror-finished and aged.

When the Cr-AI-Ni alloy forming the decorative article of the present invention is subjected to an aging treatment, Q phase, y phase, y' phase, etc. are precipitated in a composite manner, resulting in high hardness.

Therefore, in the above alloy, the Ni component contributes to improving rutting resistance and maintains corrosion resistance. Further, while the Cr component contributes to corrosion resistance like the Ni component, it also has the effect of promoting precipitation of the Q phase through grain boundary reactions. However, the concentration range in which a layered phase is precipitated due to the Cr component is generally 30 to 55%.
If the content exceeds 45% by weight, the ductility decreases significantly and becomes mechanically brittle, so the composition ratio is 3.
It is selected in the range of 0 to 45%. Furthermore, the AI component is y'-
It is an element that forms the Ni3AI phase and contributes to the promotion of composite precipitation such as the above-mentioned Q phase, and significantly improves age hardenability. This can be seen in the attached curve diagram showing the relationship between aging time and hardness Hv when a 40% Cr-4% Yamaichi Ni alloy is solution-treated at 120,000 for 1 hour and then aged at 700°C. It is clear from this. For comparison, the attached diagram also shows the case of a 40% Cr--Ni alloy that does not contain an N component. However, the composition ratio of the M component was selected to be 2.5 to 5% by weight because if it is less than 2.5%, sufficient composite precipitation will not occur even after aging treatment, and the necessary hardness cannot be obtained. This is because if it exceeds 100%, the Vickers hardness Hv will already be 300 or more after the solution treatment, and the machinability will deteriorate. Cr-AI-Ni according to the present invention
Although the above three components are essential for the alloy, for example, by containing Ti etc., age hardening due to the above composite precipitation is promoted, or by containing 2% by weight or less of Si to improve wear resistance, and furthermore, it is possible to improve the wear resistance. Therefore, Mn or the like may be added and contained as appropriate.

The decorative article of the present invention can be manufactured as follows.

That is, a desired decorative element body is first produced by casting a melt of a desired Cr--N--Ni alloy as a raw material. Thereafter, this ornamental element body is subjected to a heat treatment of 1,000 to 120,000 degrees Celsius, and a so-called solution treatment is carried out to form a solid solution of the alloying elements.
The solution treatment time is not particularly limited, but from the viewpoint of work efficiency, it is preferably selected to be 110,000 to 120,000 and several minutes to more than ten minutes. Next, the solution-treated ornamental body is subjected to cutting, plastic working, etc., if necessary, and then subjected to aging treatment. This aging treatment is to form a composite precipitated phase consisting of the above-mentioned y phase, y phase, and y' phase, thereby improving hardness, and the treatment temperature is 500 to 950 qo, preferably 5
This can be easily achieved by selecting a time of about 50 to 700 o'clock. After imparting the required hardness in this way, the desired decorative item can be obtained by polishing and mirror finishing. As described above, by successively performing the steps of casting, solution treatment, aging treatment, polishing, and mirror finishing, a highly hard, damage-resistant, non-magnetic, and aesthetically pleasing decorative article can be obtained.

Incidentally, the above aging treatment may be carried out by combining the cooling process after the solution treatment. Next, specific examples of the present invention will be described.

First, examples will be shown regarding the corrosion resistance, hardness (Vickers) before and after aging treatment, etc. of the Cr-AI-Ni alloy forming the decorative article according to the present invention.

That is, as shown in Table 1, fleas of alloy sample 1 (including comparative examples) were prepared in which Cr, AI, and Nj were selected at predetermined composition ratios (wt%). After that, each of these alloy samples was melted and cast, and then solution treated at 1200 oo for 1 hour.
A rod-shaped test piece with a diameter of IQ ribs and a height of IW ribs was prepared by aging with 70% O for 3 powders, followed by polishing and mirror finishing. These test pieces were treated with {1} 20% NaCI aqueous solution,'
2) 5% N-ratio OH aqueous solution, {3} 5% 2S04 aqueous solution, and {4) 5% lactic acid aqueous solution were soaked in each for 7 baits to examine their corrosion resistance. All of them exhibited a beautiful appearance without losing their metallic luster. It had corrosion resistance comparable to that of stainless steel (SUS304).

The * mark in the table also shows the results of measuring the Vickers hardness Hv when the aging treatment time was 10 hours and after the solution treatment and after the aging treatment as described above.

As is clear from the specific examples, after solution treatment, the hardness is low and it is easy to perform cutting, etc., but after aging treatment, the hardness increases significantly, making it easy to polish, etc., and it is difficult to be damaged by external impact. is recognized. Further, an alloy having the same composition as in Example 5 was melted, a ring for a ring was cast, and a size of 120,000×0. Insect time solution treatment. Thereafter, this solution-treated ring was subjected to expansion processing, and was able to be plastically worked to 50% by cold working. This plastic workability can be said to bring many advantages in manufacturing rings of a predetermined size. After plastic working in this way,
This ring is 700oo x 0. When subjected to aging treatment, it exhibited a Vickers hardness of Hv700, and by polishing and mirror finishing, a ring with excellent gloss and good appearance was obtained.

Furthermore, this ring was not only highly hard and scratch resistant, but also non-magnetic, making it suitable as an ornament.

[Brief explanation of the drawing]

The attached diagram shows Cr-AI as a material forming the decorative article of the present invention.
- It is a curve diagram which compares and shows an example of the relationship between aging treatment and hardness for Ni-based alloys. Curve A: Example, Curve B: Comparative example.

Claims (1)

[Claims] 1 60-45% by weight of Cr and 2.5-5% by weight of Al
1. An ornament characterized by being made of a Ni-based alloy containing Ni, having a mirror finish, and being subjected to an aging treatment.