JP2886818B2 - Method of manufacturing copper alloy for decoration - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative material made of metal, such as a watch, an eyeglass frame, pierced earrings, a necklace, a pendant, a ring and the like, which is in direct contact with the skin, and is free from metal allergy and is used for decoration It relates to a decorative copper alloy having mechanical properties as a material and does not use nickel.

[0002]

2. Description of the Related Art Conventionally, nickel-containing nickel silver, stainless steel, etc. have been used for forming watches, eyeglass frames, piercings, necklaces, pendants, rings and the like.
Nickel is contained as a main component of nickel silver and stainless steel, and its material is widely used for watches, eyeglass frames, piercings, necklaces, pendants, rings and the like.

[0003] Nickel contained in nickel silver and stainless steel has conventionally been an indispensable element in order to improve the strength, corrosion resistance, spring properties and other properties of the material. In addition, as a decorative copper alloy, nickel silver is excellent in strength, corrosion resistance, spring properties, etc., and has both the workability unique to copper alloy and the economical efficiency as a decorative material, and it is still used considerably. I have.

[0004]

However, in the case of decorative parts such as watches, eyeglass frames, pierced earrings, necklaces, pendants, rings, and the like, which are conventionally formed of nickel-white material, nickel contained in the material is applied to the skin of the human body. The problem is that contact can cause serious contact allergies.
Therefore, there is a demand for a decorative alloy which has the same or better characteristics as that of nickel silver without worrying about metal allergy.

[0005] In addition, Ti alloy is used as a material free from metal allergy. However, it is an expensive metal and has a problem in workability as a decorative material. Ti
Alloys are inferior to copper alloys particularly in machinability, bending workability, plastic workability and the like.

Accordingly, the present inventors have addressed the problem of not being able to develop a copper alloy which does not contain nickel and has mechanical properties equivalent to or higher than that of nickel silver as a decorative metal.

[0007] Regarding the target mechanical properties and corrosion resistance, the target characteristic values required for the decorative copper alloy are as follows.

[0008] Tensile strength 600 to 1,000 N / mm ² Hardness (Hv) 180 to 270 Young's modulus 12,000 to 13,000 kg / mm ² Corrosion resistance Casing test (JIS standard) Passed the Cass test method of JIS H8502 to be.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has been made to solve the above-mentioned problems.
7.0 to 20.0 wt%, Fe 0.5 to 2.5 wt%,
3.0-15.0 wt% Zn, 0.1-1.5 wt% Si
%, And the balance is made of a copper alloy made of copper excluding inevitable impurities.
It is characterized in that 0% to 60% is applied.

Another different invention is that Al2.0
6.0 wt%, Mn 7.0-20.0 wt%, Fe0.
5 to 2.5 wt%, Zn 3.0 to 15.0 wt%, Si
A copper alloy containing 0.1 to 1.5 wt%, the remainder of which is made of copper excluding inevitable impurities, is subjected to hot plastic working and further subjected to a cold plastic working rate of 10% to 60% to obtain a tensile strength. 600-1,000 N / mm ² , Young's modulus 12,000
0~13,000kgf / mm ^2, hardness Hv180~2
It is characterized by having 70 mechanical properties.

[0011]

The present inventors did not include nickel, which is a main cause of metal allergy, and used Al as an additive element instead of nickel as a method of producing mechanical properties comparable to that of nickel silver. For the purpose of forming a white alloy such as nickel silver as a decorative alloy, an attempt was made to add a large amount of Mn as a copper alloy. Further, Fe was added for the purpose of refining the structure and increasing the strength. Further, Zn was also added in order to obtain ductility as a wrought material.

Next, the composition and addition amount of the present alloy other than Cu will be described. Al can improve mechanical properties without increasing specific gravity and can maintain corrosion resistance, which is important as a metal for decoration. If the content exceeds 6.0% by weight, the material becomes brittle and the workability deteriorates, and when used as an eyeglass frame or the like, the brazeability of the brazing operation that occurs during the manufacturing process deteriorates. If the addition amount of Al is less than 2.0 wt%, mechanical strength and corrosion resistance deteriorate.

Further, Mn strengthens the base and improves mechanical strength, and also contributes to improvement of heat resistance. Further, it combines with other additional elements to improve the spring property. If the addition amount exceeds 20 wt%, the cold plastic workability is deteriorated, the elongation of the mechanical properties is lost, and the heat resistance is deteriorated. Conversely, if the amount of Mn is less than 7% by weight, the target mechanical properties cannot be satisfied. In addition, when Mn is contained as large as 15 to 20 wt%, the formed material becomes a white alloy, the decorative effect can be increased, and the commercial value can be increased.

Further, Fe has the effect of making the structure of the alloy finer and improving the mechanical properties. Also,
Fe can improve the adhesion of plating, which is important as a decorative alloy. On the other hand, if the added amount of Fe exceeds 2.5 wt%, the corrosion resistance deteriorates, and if it is less than 0.5 wt%, the effect of refining the structure of the alloy or improving the mechanical properties cannot be produced.

[0015] Zn can improve the mechanical strength and improve the hot and cold plastic workability. If added in excess of 15 wt%, the material becomes brittle and the cold workability deteriorates in relation to other added elements. If the amount is less than 3.0 wt%, the above effects cannot be obtained.

Further, Si improves the corrosion resistance of the material, forms a compound with other elements, improves the mechanical strength, and improves the spring property. If Si is added in excess of 1.5 wt%, elongation of the mechanical properties deteriorates. If the amount is less than 0.1 wt%, the above effects cannot be obtained.

A material obtained by forming an ingot with the above composition, applying hot plastic working and performing cold plastic working by 10% to 60% does not contain metal elements such as nickel and chromium which cause allergy. Therefore, it is possible to obtain a decorative copper alloy which is free from a metal allergy and has both the initial target mechanical properties and corrosion resistance.

[0018]

【Example】

Formulation of Examples and Comparative Examples of the present invention.

[0020]

[Table 1]

3 shows the results of tensile strength, hardness, Young's modulus, and Cass test in Examples and Comparative Examples of the present invention.

[0022]

[Table 2]

Examples 1 to 7 and Comparative Examples 8 to
After the test material prepared with each of the materials No. 19 was melted in a high-frequency induction furnace in a graphite crucible using a predetermined flux, the molten metal was subjected to die pressure casting to obtain φ80 × 200 mm.
An L sample was obtained.

Then, the sample was hot-worked to a diameter of 30 m.
m, after bar milling, solution treatment at 700-800 ° C, cold rolling (rolling reduction 15-50%) by a roll rolling mill (square groove roll), and gas-heating bogie furnace The heat treatment (550 to 800 ° C. for 1 to 3 hours) was repeated several times to obtain φ9.0 mm to obtain an intermediate processed material.

Here, this intermediate material is cold drawn at a draft of 35%, and is φ7.0 × height 7.0 by surface grinding.
A sample for examining 0 mm heat resistance (high-temperature hardness measurement) was obtained.

The sample for the measurement of Young's modulus and the cast test was prepared by subjecting the above-mentioned intermediate work material to cold drawing to φ4.5 mm and subjecting it to a heat treatment in a continuous bright annealing furnace at a reduction rate of 53%. A rectangular material having a thickness of 1.5 mm, a width of 5.0 mm and a length of 50 mm was obtained.

Further, in the sample for the cass test, the surface of the manufactured rectangular material was polished, and palladium plating was applied to 0.5 mm.
The one subjected to μm was used.

Further, the intermediate workpiece is cold drawn by a continuous wire drawing machine (reduction rate: 15 to 60%) and heat-treated by a continuous bright annealing furnace (550 to 800 ° C. for 10 to 30 minutes).
Was repeated to produce a wire having a diameter of 1.6 mm. This wire was evaluated for tensile strength and Vickers hardness.

Hereinafter, effects of the present invention will be described based on embodiments.

In Examples 1 to 7 of the present invention, as shown in Table 2, tensile strength (N / mm ² ), hardness (HVI), Young's modulus (k)
The mechanical properties of gf / mm ² ) satisfy all target ranges. The results of the Cass test (JIS H8502), which is a standard for decorative materials, are rating No. 9.0 or more.

In Comparative Example 8, the amount of Mn added was small, and in Comparative Example 9, the amount of Mn exceeded the allowable range of the present invention. As a result, Comparative Examples 8 and 9 were satisfactory in tensile strength and hardness as shown in Table 2, but did not satisfy the target values of Young's modulus and were materials having low spring properties. The Cass test was not performed because the target mechanical properties were not satisfied.

On the other hand, Comparative Examples 10 to 12 are examples in which Zn and Si were not added. As shown in Table 2, the hardness and Young's modulus of Comparative Example 10 in which the amount of Al added was low did not satisfy the target ranges. Comparative Example 1
No. 1 does not satisfy the target ranges in tensile strength, hardness, and Young's modulus, and the Cas test result is poor. Comparative Example 1
As in Comparative Example 11, Nos. 0 and 12 did not contain Zn and Si, and the same results as in Comparative Example 11 were expected.

Comparative Examples 13 to 15 are examples in which the amount of added Mn is low. Comparative Examples 13 to 15 are satisfactory in tensile strength and hardness (except for Comparative Example 14), but have low Young's modulus and low spring properties. In addition, the results of the Cass test were poor and the corrosion resistance was poor. As for the comparative example 15, the same result as that of the comparative examples 12 to 14 is expected, and thus the Cass test is not performed.

Comparative Examples 16 and 17 are examples in which the influence of the Zn content was investigated. The comparative examples 16 and 17
It contains n and does not contain Si, and satisfies mechanical properties. However, in the Cass test, very good results were not obtained. Particularly, in Comparative Example 16, the Zn content was as low as 2.0 wt%, the Young's modulus did not slightly reach the target value, and in the Cass test, the corrosion resistance was lower than that of Comparative Example 17 having a large Zn content. Was inferior.

Comparative Examples 18 and 19 are examples in which the influence of the contents of Si and Ti was investigated. This comparative example does not contain Zn but contains Si and Ti.
Although the mechanical properties were satisfied as in the cases of Nos. 6 and 17, good results were not obtained in the Cass test.

Comparative Examples 20 and 21 are commercially produced nickel silver. Although the mechanical properties and Cass test are not a problem, they contain a considerable amount of nickel, and thus are likely to cause metal allergy when used in decorative materials.

[0037]

According to the present invention, as described above, the main factors of metal allergy in a metal decorative material such as a watch, an eyeglass frame, pierced earrings, a necklace, a pendant, a ring and the like which come into direct contact with the skin. By not containing nickel or the like, it is possible to provide a decorative copper alloy free of metal allergy and safe. Further, the decorative copper alloy of the present invention can produce mechanical properties comparable to that of nickel silver, and can form a white alloy such as nickel silver which is preferable as a nickel alloy.

──────────────────────────────────────────────────の Continuation of front page (51) Int.Cl. ⁶ Identification code FI C22F 1/00 683 C22F 1/00 683 685 685Z 694 694A (72) Inventor Shigeru Kuramoto 508 Kamitomi, Miyoshi-cho, Iruma-gun, Saitama (56) References JP-A-54-132424 (JP, A) JP-A-56-47535 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C22C 9/00-9/10 C22F 1/08

Claims (2)

(57) [Claims] 1. Al 2.0 to 6.0 wt%, Mn 7.0
~ 20.0wt%, Fe0.5 ~ 2.5wt%, Zn
3.0-15.0 wt% , Si0 . A copper alloy containing 1 to 1.5 wt%, the remainder of which is made of copper excluding inevitable impurities, is subjected to hot plastic working and is further subjected to a cold plastic working rate of 10%.
A method for producing a decorative copper alloy, characterized in that the copper alloy is applied in an amount of about 60%. 2. Al 2.0 to 6.0 wt%, Mn 7.0
~ 20.0wt%, Fe0.5 ~ 2.5wt%, Zn
3.0-15.0 wt% , Si0 . A copper alloy containing 1 to 1.5 wt%, the remainder of which is made of copper excluding inevitable impurities, is subjected to hot plastic working and is further subjected to a cold plastic working rate of 10%.
~ 60%, tensile strength 600 ~ 1,000N
/ Mm ² , Young's modulus 12,000-13,000 kgf
/ Mm ² , a method for producing a decorative copper alloy having mechanical properties of hardness Hv 180 to 270.