KR100507793B1 - Nickel-free white copper alloy, and method of producing nickel-free white copper alloy - Google Patents

Abstract

Formula Cu _a Zn _b Ti _c or Cu _a Zn _b Ti _c X _d (wherein X is at least one element selected from the group consisting of Al, Sn, Ag and Mn, b, c and d in mass%, A nickel-free white copper alloy of 0.5 ≦ b ≦ 30, 1 ≦ c <7 and 0.1 <d <4, a being the remainder and possibly containing other unavoidable elements), and also a material alloy for the copper alloy To manufacture; The alloy is heated to 700 to 885 ° C .; A method for producing the same comprising the step of cooling the alloy. Nickel-free white copper alloy has excellent workability, corrosion resistance and whiteness in addition to the strength, excellent hardness and ductility comparable to those of nickel silver, and since it does not contain nickel, there is no Ni allergy problem and the malfunction of the needle detector It is not easy to cause.

Description

NICKEL-FREE WHITE COPPER ALLOY, AND METHOD OF PRODUCING NICKEL-FREE WHITE COPPER ALLOY}

Background of the Invention

1. Field of Invention

The present invention is suitable, for example, for use in elements such as slide fasteners, sliders, stops, or for accessories such as metal buttons, garment fasteners, etc., and is excellent in strength, hardness, workability and corrosion resistance, and does not cause nickel allergy. The present invention relates to a nickel-free white copper alloy which does not cause a malfunction of a needle detector, and a method of manufacturing such a nickel-free white copper alloy.

2. Description of Prior Art

Until now, copper-nickel-zinc alloys such as nickel silver with a white alloy tint, copper-zinc alloys represented by red brass and brass, and the like have been used as the copper alloy for slide fasteners, for example, as described above. However, nickel silver contains nickel as an alloying element and thus has excellent corrosion resistance, but when used for slide fasteners or the like, the fasteners will often come into contact with the skin, which may cause problems of nickel allergy. Moreover, copper-zinc alloys represented by red brass and brass do not contain nickel so that the problem of nickel allergy does not occur, but its color tone is yellowish, and thus a white alloy cannot be obtained.

Therefore, the present inventor has developed a nickel-free white copper alloy as disclosed in Japanese Patent Application Publication No. 11-124644, Japanese Patent Application Publication No. 2000-303129, Japanese Patent Application Publication No. 2000-303130, and Japanese Patent Application Publication No. 2001-3125. Patent application. The nickel-free white copper alloys disclosed in Japanese Patent Application Publication No. 11-124644, Japanese Patent Application Publication No. 2000-303129, Japanese Patent Application Publication No. 2000-303130, and Japanese Patent Application Publication No. 2001-3125 have excellent strength, hardness, processability and It is corrosion resistant, does not contain nickel, and therefore does not cause the problem of nickel allergy, and furthermore, these alloys have a high decorative value and maintain an attractive whiteness.

However, since the manganese contained in the alloy is magnetic, the alloy has magnetic properties, and thus they cause a malfunction in the needle detector when irradiation is performed using the needle detector to find pins in a garment such as clothing. As a result, the pin cannot be identified. In the case of a Cu-Mn copper alloy in which a small amount of Mn is added, the magnetization is low and therefore the alloy is not easy to cause a malfunction of the needle detector, but the color tone of the alloy tends not to be white, thus high- There is a problem that it is not easy to give a quality impression.

As a needle detector countermeasure for the alloy, it is conceivable to perform surface treatment by plating or the like so that the needle detector does not cause malfunction; The plated film or the like formed on the surface of the alloy may be peeled off due to changes over time, contact with other members, etc. In this case, the needle detector functions if the plated substrate alloy contains the magnetic element as described above. This will cause a problem and thus the problem of not being able to identify the pin as described above. Furthermore, although there are also copper alloys that do not cause the malfunction of the needle detector, for example the tint of the alloy is not white or the alloy contains nickel which causes nickel allergy problems; There was no alloy that met all of the above requirements.

Accordingly, the object of the present invention is to have excellent workability, corrosion resistance and whiteness, together with strength and excellent hardness, and ductility comparable to those of nickel silver, and because there is no nickel, there is no concern of nickel allergy problem, and furthermore, in finished products It is to provide a nickel-free white copper alloy which does not tend to cause a malfunction of the needle detector when performing irradiation using the needle detector to identify the pin. Another object of the present invention is to provide a method for producing such nickel-free copper alloy.

The present invention consists of the following.

(1) with the formula Cu _a Zn _b Ti _c (where b and c are by mass, 0.5 ≦ b ≦ 30 and 1 ≦ c <7, a is the remainder and possibly contains other unavoidable elements) Nickel-free white copper alloy shown.

(2) Formula Cu _a Zn _b Ti _c X _d (where X is at least one element selected from the group consisting of Al, Sn, Ag and Mn, b, c and d in mass%, 0.5 ≦ b ≦ A nickel-free white copper alloy represented by 30, 1 ≦ c <7 and 0.1 <d <4, a being the remainder and possibly containing other unavoidable elements).

(3) The nickel-free white copper alloy according to (1) or (2), which consists of a single α-phase at room temperature.

(4) The nickel-free white copper alloy according to the above (1) to (3), which has a magnetization of 80 memu / g or less in a magnetic field of 18 kOe.

(5) The nickel-free white copper alloy according to the above (1) to (4), having a conductivity of 20% or less of the International Annealed Copper Standard (IACS).

(6) The nickel-free white copper alloy according to the above (1) to (5), wherein b and c are% by mass and 2 ≦ b ≦ 13 and 3 ≦ c ≦ 6.

(7) with the formula Cu _a Zn _b Ti _c (where b and c are by mass, 0.5 ≦ b ≦ 30 and 1 ≦ c <7, a is the remainder and possibly contains other unavoidable elements) Preparing the alloys indicated; The alloy is heated to 700 to 885 ° C .; A method for producing a nickel-free white copper alloy, comprising the step of cooling the alloy.

(8) Formula Cu _a Zn _b Ti _c X _d (where X is at least one element selected from the group consisting of Al, Sn, Ag and Mn, b, c and d in mass%, 0.5 ≦ b ≦ 30, 1 ≦ c <7 and 0.1 <d <4, a being the remainder and possibly containing other unavoidable elements); The alloy is heated to 700 to 885 ° C .; A method for producing a nickel-free white copper alloy, comprising the step of cooling the alloy.

(9) The method for producing a nickel-free white copper alloy according to the above (7) or (8), wherein the nickel-free white copper alloy consists of a single α-phase at room temperature.

(10) The method for producing a nickel-free copper alloy according to (7) to (9), wherein the nickel-free copper alloy has a magnetization of 80 memu / g or less in a magnetic field of 18 kOe.

(11) A method for producing a nickel-free white copper alloy according to (7) to (10), wherein the nickel-free white copper alloy has a conductivity of 20% IACS or less.

Detailed Description of the Preferred Embodiments

The composition of the nickel-free copper alloy of the present invention is described below.

The object of the present invention can be achieved by the composition defined above.

Zn has an effect of improving the mechanical properties of the alloy through its solid solution strengthening effect, removing oxygen from the melt during melting, and reducing the alloy price. If the Zn content is less than the above 0.5 mass%, the reduction of the alloy price will be insufficient, and the strengthening and oxygen removing action in the melt will be insufficient. In addition, if the Zn content is greater than 30 mass%, the seasonal cracking resistance will be lowered.

Ti has the effect of improving the mechanical properties of the alloy through its solid solution strengthening effect, and the whitening effect of the copper alloy color tone. In addition, by adding Ti instead of Zn, there is an effect of improving seasonal cracking resistance. In addition, Ti has an effect of reducing the conductivity of the alloy, and thus preventing a malfunction caused by eddy current generation to the needle detector. If the Ti content is less than 1% by mass, it would be impossible to expect the whitening effect of the copper alloy tint, whereas if the Ti content is 7% by mass or more, a large amount of oxide is produced upon melting, thus making melt casting difficult. In addition, it will no longer be possible to secure sufficient cold workability, and the material cost will increase.

X is at least one element selected from the group consisting of Al, Sn, Ag and Mn; By adding these elements to the above-mentioned Cu-Zn-Ti alloy within the range of 0.1-4 mass% (an upper limit and a lower limit are not included), the following effect can be anticipated.

Al and Sn have an effect of improving seasonal crack resistance through the formation of a stable oxide film on the alloy surface. In addition, these have the effect of improving the mechanical properties of the alloy through their solid solution strengthening effect, and the alloy price reduction effect. If the content is 0.1 mass% or less, the seasonal cracking resistance of the alloy will be insufficient, and the reinforcing effect will also be insufficient. In addition, if the content is 4% by mass or more, the structure will be formed into an α + β phase, and thus it will no longer be possible to secure sufficient cold workability.

Ag has an effect of improving the mechanical properties of the alloy through its solid solution strengthening effect, and whitening of the copper alloy color tone. In addition, by adding Ag instead of Zn, there is an effect of improving seasonal cracking resistance. If the Ag content is 0.1 mass% or less, the whitening effect of the copper alloy color tone will be reduced. In addition, if the Ag content is 4% by mass or more, it will no longer be possible to secure sufficient cold workability and the material cost will increase.

Mn has a whitening effect of the copper alloy tint. Moreover, by adding Mn instead of Zn, there is an effect of improving seasonal cracking resistance. In addition, Mn has an effect of reducing the conductivity of the alloy, and therefore, an effect of preventing malfunction caused by eddy current generation to the needle detector can be expected. If the Mn content is 0.1 mass% or less, the whitening effect of the copper alloy color tone will be reduced. Moreover, if the Mn content is 4 mass% or more, a large amount of oxide will be generated upon melting, thus causing problems with the properties of the product, and furthermore, it will no longer be possible to secure sufficient cold workability and also magnetization. Will increase, and thus the needle detector will malfunction.

Through the structure of the alloy consisting of a single α-phase, it is possible to make excellent cold workability and to lessen the tendency of the malfunction of the needle detector.

Moreover, with magnetization below 80 memu / g at a magnetic field of 18 kOe, the needle detector will not cause malfunction when the irradiation is performed using the needle detector for the identification of the pin in the finished product, ie the alloy is a good needle detector. Can cope with. Typically, alloys can be made to have needle detector coping capabilities by making magnetization in an 18 kOe magnetic field less than or equal to 200 memu / g, but in the present invention such magnetization is less than or equal to 80 memu / g as described above, The alloy therefore has a better needle detector coping capability.

In addition, conductivity below 20% IACS is a very effective condition that makes eddy currents less susceptible during measurement with a needle detector.

With respect to the above-mentioned composition, when the Zn content is 2 to 13% by mass and the Ti content is 3 to 6% by mass (including the upper and lower limits), the alloys are those of ordinary nickel silver or high manganese Cu-Mn copper alloys. It has comparable whiteness and is much better in terms of processability.

In the production of alloys having these characteristic properties required by the present invention, the alloy is obtained by preparing a material alloy (starting alloy) having the above-described composition, heating the alloy to 700 to 885 ° C, and then cooling it. Can be. Specifically, in the preparation of the material alloy, the magnetization of the material alloy at a magnetic field of 18 kOe will be at least 80 memu / g, but by heating the material alloy to 700 to 885 ° C. and then cooling it, The magnetization is less than 80 memu / g, ie the magnetization is reduced, thus making the resulting alloy have better needle detector coping capability, ie the resulting alloy will not cause malfunction of the needle detector. If the heating temperature is below the above-mentioned temperature range, precipitation will be present, and thus magnetization may occur, and the structure will no longer be a single α-phase, and thus cold workability will be poor. In addition, if the heating temperature is conversely higher than the above-mentioned temperature range, the alloy will be heated above the eutectic temperature of Cu-Ti and will be in a molten state (solid-liquid coexistence state), leading to a deterioration of the product.

In this method, cooling after heating is important, and it is important to perform such cooling quickly by quenching or the like. As the cooling method, high-speed cooling by quenching using water, air, gas or other refrigerant is preferable. In particular, it is preferable to make the cooling rate during cooling into at least 10 K / s. By carrying out the cooling in this way, the structure becomes a single α-phase useful for cold working, and thus an alloy which is also useful in terms of working can be provided.

Alloys produced through the present invention range from -2 <a * <7 and -3 <b * <20 based on the chromaticity diagram of the (L *, a *, b *) colorimetric system defined in JIS Z 8729.

'Tint' referred to herein is indicated using the color notation of an object as defined in JIS Z 8729 and includes brightness index L * (brightness: L star) and chromaticity index a * (green-red: a star) and b * Note that it is displayed as a value of (blue-yellow: b star). In particular, the characteristic feature of the present invention is that the color tone is white, and thus the closer to the colorless the better, the color tone is specified by the chromaticity indices a * and b * as described above.

Further, in the present invention, since the alloy itself is an alloy which does not cause the malfunction of the needle detector, a coating layer can be formed on the surface of the alloy. Even if the coating is peeled off, there will be no problem that the needle detector malfunctions and thus becomes unable to identify the pin. In the case of forming the coating layer, the range of a * and b * should be set to be similar to those for the alloy described above, and by forming the coating layer, a more whiter material can be provided. Also in this case, even if the coating layer is peeled off, since the substrate-forming alloy has a color close to that of the coating layer, there is no problem in particular with respect to color.

Examples of such coating layers are Sn plating layers, Cr plating layers, Ag plating layers, and Cu—Sn plating layers, but coating layers other than these plating layers may also be used as long as the coating layers exhibit the color tone as described above. In the case of forming a coating layer, the technique may be wet or dry plating; For example, as the wet plating, electrolytic plating, electroless plating, hot dip plating, or the like may be used, and as dry plating, physical vapor deposition (PVD), chemical vapor deposition (CVD), or the like may be used.

Regarding the thickness of the coating layer, 0.001 to 10 [mu] m is expected to be effective for the coating and does not cause problems such as peeling and is also an effective range in view of cost. Also, depending on the application, these materials can be put into post-processing such as cutting or bending. In this case, in consideration of peeling, abrasion, etc. resulting from such processing, it is preferable to make the thickness of a coating layer into 0.005-5 micrometers.

Example

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the following Examples. In the examples below, all% are expressed in mass% unless otherwise specified.

Test Samples Made from Alloys of the Invention :

As shown in Tables 1 and 2, test samples made from the alloy of the present invention were prepared and evaluated as follows. Test samples of comparative examples are also prepared in the same manner.

Pure Cu (99.9%), pure Zn (99.9 to 99.99%), pure Ti (99.9%), pure Al, pure Sn, pure Ag, pure Mn and pure Ni for each of the prescribed compositions shown in Tables 1 and 2 Measurement was made to construct a 200 cm ³ ingot. Each composition is put into high frequency melting in Ar atmosphere (10 cmHg) and left for 4 minutes, and then the melt is poured into a copper mold (40 mm in diameter x 28 mm in length). The obtained ingot (200 cm ³ ) is cut to a length of about 7 mm, resulting in a billet for extrusion.

The extrusion is carried out at a billet temperature of 800 ° C. and a container temperature of 600 ° C. The extrudate (diameter 8 mm x approximately 1300 mm in length) is subjected to a heat treatment (hereinafter referred to as 'heat treatment') including furnace cooling followed by heating at 800 ° C. for 1 hour. After this heat treatment, the extrudate (wire) is further heated to a temperature of 700 to 885 ° C. and then quenched using water as a refrigerant; The material obtained is taken as a test sample.

Alloy composition (mass%) hue conductivity Ni Allergy rescue magnetization Cu Zn Ti Mn Ni IACS% memu / g Embodiment of the present invention One Remainder 10 One - - White 11 O α -4 2 Remainder 10 3 - - White 10 O α -9 3 Remainder 13 5 - - White 9 O α -8 4 Remainder 27 2 - - White 10 O α -7 5 Remainder 26 3 - - White 9 O α -3 6 Remainder 21 2 - - White 9 O α -5 7 Remainder 28 2 - - White 9 O α -7 8 Remainder 6 2 - - White 12 O α -One 9 Remainder 5 3 - - White 12 O α -2 Comparative Example One Remainder 35 0.5 - - yellow 20 O α -2 2 Remainder 20 10 - - White 8 O α + β -5 3 Remainder 15 - - - yellow 37 O α - 4 Remainder 24 - - 14 White 7 X α - 5 Remainder 15 - 10 - White 3 O α 157

Alloy composition (mass%) hue conductivity Ni Allergy rescue magnetization Cu Zn Ti Al Sn Ag Mn Ni IACS% memu / g Embodiment of the present invention One Remainder 10 One 0.4 - - - - White 11 O α -4 2 Remainder 10 3 - - - 2 - White 6 O α 47 3 Remainder 13 5 0.5 - - - - White 9 O α -8 4 Remainder 27 2 0.3 - - - - White 10 O α -7 5 Remainder 26 3 One One - - - White 9 O α -3 6 Remainder 21 2 One - - - - White 9 O α -5 7 Remainder 28 2 2 - - - - White 9 O α -7 8 Remainder 6 2 - - - 2 - White 7 O α 49 9 Remainder 5 3 - - One - - White 12 O α -2 Comparative Example One Remainder 35 0.5 0.2 - - - - yellow 3 O α -2 2 Remainder 20 10 - 5 - - - yellow 3 O α + β -5 3 Remainder 15 2 - - - 10 - White 3 O α 157 4 Remainder 24 - - - - - 14 White 7 X α -

Evaluation of the test sample:

Regarding the color tone, the obtained test sample was mirror-polished using SiC abrasive paper and diamond paste, and measured using a colorimeter (CR-300, manufactured by Minolta Co., Ltd.), and the measurement result was JIS Z 8729. Represented by L *, a * and b * as defined in FIG. If a * and b * are expressed as being within the aforementioned range, the hue is recorded as 'white', whereas otherwise the subject color is recorded. For all of the test samples of the present invention, the hue is white, specifically near white.

In terms of conductivity, the surface of the sample taken from each test sample is mirror-polished, a measurement probe of a digital conductivity meter (AutoSigma 3000, manufactured by Hocking Kabushiki Kaisha) is placed in contact with the sample surface, and then the conductivity value is measured. For the test samples of the present invention, the value was found to be extremely good below 12% IACS. Thus, it can be seen that eddy currents will occur very difficult during measurement with the needle detector. In order to cope with the needle detector, this is a very important characteristic with the magnetization described below.

Regarding the nickel allergy, the evaluation is carried out depending on whether the test sample contains Ni, the symbol 'o' is given to the one containing no Ni, and the symbol 'x' is given to the one containing Ni. All of the test samples of the present invention did not contain Ni and were therefore free of allergic problems due to nickel.

Regarding the structure, the obtained test sample is put into the structure observation. The test sample of the present invention consisted only of the α-phase.

The magnetization of each test sample obtained was measured using an alternating gradient force magnetometer (model AFGM 2900-04C, manufactured by Princeton Measurements Corp.); Approximately 0.1 g of the test sample is placed in the magnetic field of the electromagnet, an 18 kOe magnetic field is generated using the electromagnet, and the magnetization of the test sample is measured by changing the magnetic field. The measurement speed is 50 msec / point. The test sample of the present invention was found to have extremely low magnetization of 50 memu / g or less even at a strong magnetic field of 18 kOe. In the table, note that the minus value of magnetization represents diamagnetic and means that the magnetization is close to zero. Moreover, '-' indicates that no measurement was taken.

It can be seen from the above results that in order to obtain an excellent material in terms of magnetization and conductivity, it is very important to use the alloy composition according to the present invention and the manufacturing method according to the present invention.

In addition, for the test sample of the present invention, the hardness was 100 Hv or more, no cracks or the like existed after 80% deformation, and excellent results were also obtained for discoloration resistance and seasonal cracking resistance.

According to the production method of the nickel-free and nickel-free copper alloy of the present invention, the alloy has excellent strength and hardness, is flexible, has excellent workability, corrosion resistance, discoloration resistance and seasonal cracking resistance, and excellent whiteness. And therefore an alloy with high decorative value can be provided; In addition, since the alloy does not contain nickel, there is no nickel allergy problem. In addition, the magnetization is extremely small, even at a strong magnetic field of 18 kOe, so that the alloy does not cause the needle detector to malfunction when conducting irradiation with the needle detector to identify pins in the article. Because of these points, alloys are extremely useful as alloys used for accessories, especially alloys used for articles attached by sewing. Moreover, according to the manufacturing method of the nickel-free copper alloy of the present invention, an alloy having excellent characteristics as described above can be easily produced, and thus an alloy having excellent characteristics as described above can be provided for various uses. Can be.

Claims (11)

Nickel-free white copper alloy for accessories represented by the formula Cu _a Zn _b Ti _c , wherein b and c are by mass%, 0.5 ≦ b ≦ 30 and 1 ≦ c <7, a being the balance, and other unavoidable elements And nickel alloy copper alloy obtained by heating and cooling the material to 700-885 ° C., wherein the alloy is composed of a single α-phase at room temperature. Nickel-free white copper alloy for accessories represented by the formula Cu _a Zn _b Ti _c X _d , wherein X is at least one element selected from the group consisting of Al, Sn, Ag and Mn, b, c and d being mass %, 0.5 <b <30, 1 <c <7 and 0.1 <d <4, a is the balance, possibly containing other unavoidable elements, and the alloy is a single α-phase at room temperature Nickel-free copper alloy, which is obtained by heating and cooling the material to 700-885 ° C. delete The nickel-free white copper alloy according to claim 1 or 2, having a magnetization of 80 memu / g or less in a magnetic field of 18 kOe. The nickel-free white copper alloy of claim 1 or 2 having a conductivity of 20% IACS or less. The nickel-free white copper alloy according to claim 1 or 2, wherein b and c are in mass%, 2 ≦ b ≦ 13 and 3 ≦ c ≦ 6. Constructing an alloy represented by the formula Cu _a Zn _b Ti _c ; Heating the alloy to 700 to 885 ° C .; And Characterized by cooling the alloy, As a method of manufacturing a nickel-free copper alloy for accessories, Where b and c are mass%, 0.5 ≦ b ≦ 30 and 1 ≦ c <7, a is the balance and possibly contains other unavoidable elements, and the alloy is a single α-phase at room temperature a process for producing a nickel-free copper alloy. Constructing an alloy represented by the formula Cu _a Zn _b Ti _c X _d ; Heating the alloy to 700 to 885 ° C .; And Characterized by cooling the alloy, As a method of manufacturing a nickel-free copper alloy for accessories, Wherein X is at least one element selected from the group consisting of Al, Sn, Ag and Mn, b, c and d are by mass, 0.5 ≦ b ≦ 30, 1 ≦ c <7 and 0.1 <d <4 And a is the balance and possibly contains other unavoidable elements, and the alloy is composed of a single α-phase at room temperature. delete 9. The method of claim 7 or 8, wherein the nickel-free white copper alloy has a magnetization of 80 memu / g or less in a magnetic field of 18 kOe. 10. The method of claim 7 or 8, wherein the nickel-free white copper alloy has a conductivity of 20% IACS or less.