KR20050035861A - Alloy, especially for spectacle frames - Google Patents

Abstract

An alloy, especially for spectacle frames, jewelry and for other metal parts to be worn on the body or on items of clothing in contact with said body. The alloy consists of the following components: Sn 8-14 wt. %, Zn 1-8 wt. %, Mn 0.001- 3 wt. %, P 0. 001 0.3 wt. %, Fe 0.001 0.5 %, the remainder being Cu.

Description

Alloy for eyeglass frames {ALLOY, ESPECIALLY FOR SPECTACLE FRAMES}

The present invention relates, in particular, to eyeglass frames, ornaments and other metal alloys which are hung over or provided in clothing and in contact with the body. The present invention also relates to glasses such as spectacle frames, ornaments and metal parts for garments made using such alloys, and to intermediates such as wires, bands or rod materials made using such alloys in particular. It is about the material.

In the manufacture of eyeglass frames, ornaments, metal parts to be spread over the body or other metal parts which may come into contact with the body, special criteria relating to the suitability of the metal parts apply. Therefore, especially in the case of eyeglass frames that are at least partially in constant contact with the skin of the person wearing the glasses, the wires used to make the eyeglass frames do not contain nickel in order to avoid widespread contact allergy. It is proved to be preferable to consist of an alloy which does not. Nevertheless, the non-nickel wires used to make the spectacle frames are machined on the spectacle frames as well as conventional alloy wires that do not contain nickel, such as, for example, wires made of a new silver alloy. Must meet specific requirements. Likewise, in order to be able to manufacture eyeglass frames inexpensively, wires made of alloys containing no nickel must have at least comparable deformation possibilities.

In German Patent Application No. 100 43 278, there is already known an alloy having a hardness which satisfies the above-mentioned requirements profile and in particular still meets the requirements posed to the spectacle frame even in the deformation range of at least 70%.

1 is a hardness-strain-diagram showing the comparable hardness waveform of an embodiment of the alloy as compared to the silver containing 18% nickel,

2A is a strength- / hardness-strain diagram associated with the alloy described above,

FIG. 2B is a table of values associated with the diagram shown in FIG. 2A, and FIG.

3A is a strength- / hardness-temperature-diagram associated with the alloy described above,

3B is a table of values associated with the diagram of FIG. 3A.

The object of the present invention is to enable more economical fabrication of corresponding metal parts, in particular eyeglass frames, in particular by having a much improved deformation potential and generally improved processability compared to known alloys applied in the manufacture of eyeglass frames. It is to provide an alloy which does not contain nickel and is excellent in the possibility of deformation.

This object is achieved by an alloy having the features of claim 1.

Alloys containing no nickel in accordance with the present invention have good solderability and good cutting properties, drilling properties and embossing properties in addition to good deformation possibilities with a degree of deformation that can be 80% or more. Such good solderability is obtained, in particular, by allowing the alloy according to the invention to allow a soldering process without the use of a melting agent due to its alloy composition. In this case it has proved particularly desirable to apply an inductive soldering method using a protective gas.

The excellent cutting properties, drilling properties and embossing properties of the alloy according to the present invention can result from the unusual ductility of the alloy material in which the cutting edge is actually formed by shearing by allowing the cutting of the fabrication material edge without large breaks. Thus, neat cut edges can be formed in a simple manner, so that only a slight polishing process is required for the finishing process.

Despite the good deformability, the alloy material according to the invention has sufficient hardness for good polishing potential.

Overall, the alloy according to the present invention exhibits material properties that can be compared with the material properties of the silver alloy, so that the machining of the corresponding alloy material, in particular the corresponding alloy wire, is provided with known tools from the machining of the silver alloy. It is possible on conventional machines, in which case there is no need to change important machine parameters. This fact has a favorable effect on the economic manufacture of the corresponding product.

Another particular advantage of the alloy according to the invention is that, in spite of the positive processing properties described above, in wires made using the alloy according to the invention, springs allow for good restoring properties and also good daily utility. The property can be achieved.

A particularly preferred embodiment of the alloy has a composition corresponding to claim 2.

If the alloy according to the invention is used as a fabrication material for spectacle frames, the above-mentioned advantages that can be achieved by the use of the material can be used in a particularly large range. The comparable content applies, in particular, to ornaments made using the alloy according to the invention, which are formed in wire and band shapes or also as rod materials, or to clothing metal parts.

Embodiments of the alloy are described in detail below with reference to the drawings.

Figure 1 shows the hardness waveforms labeled E of an example of a wire alloy designated CuSn12Zn2 below. The CuSn12Zn2 alloy comprises 12% Sn, 2.1% Zn, 0.008% Mn, 0.002% P, 0.003% Fe and the remaining copper. In comparison, the graph labeled S reproduces the hardness waveform of the silver alloy containing 18% nickel.

As the comparative example shows, alloy E has a relatively large hardness over the entire deformation range exceeding 80%.

Fig. 2A shows the curing of CuSn12Zn2-alloy according to the deformation, and the table of values shown in Fig. 2B on which the base is based is shown in addition to the wire diameter obtained from the strain waveform and the strength and hardness values shown in Fig. 2A. , Given the diameter, the reduction of the individual cross section [QV] and the likelihood of individual expansion.

In FIG. 3A the recrystallization resulting in strength and hardness values is shown for temperature fluctuations. The value table shown in FIG. 3B and based on FIG. 3A includes the wire diameter of the alloy wire CuSn12Zn2 and the expansion potential of the alloying material resulting from recrystallization in addition to the strength and hardness values shown in FIG. 3A.

The following briefly describes the possibility of producing a wire of CuSn12Zn2 alloy, which is particularly suitable for the manufacture of eyeglass frames.

The alloy production of the alloy CuSn12Zn2 is first made by dissolution at temperatures from 900 ° C to 1000 ° C, from the alloying components mentioned in the introduction. Immediately following a continuous casting diameter of 12 mm to 14 mm or by a subsequent linear extrusion process for example reduced to 12 mm to 14 mm of the above-mentioned continuous casting diameter, for example 65 mm to 85 mm By continuous casting of a continuous cast product having a diameter of, the semifinished product is used for further processing to produce the wire. A stepwise diameter reduction by the cooling roller proceeds, for example a diameter reduction of up to 8 mm. The wire raw material thus produced is then annealed at a protective gas atmosphere and at a temperature of 500 ° C. to 800 ° C. for an annealing time of half to 5 hours. The diameter reduction is then further achieved by drawing over several stages, optionally by intermediate annealing between the selected diameter reduction stages, for example up to a desired wire final diameter of 2.5 mm.

Finally, surface treatment can be carried out, for example by etching the wire to remove any oxide layers.

CuSn12Zn2 alloys, which are particularly suitable for producing spectacle frames, have a Vickers hardness (HV ₁₀ ) of about 100 HV ₁₀ in softening annealing, which increases with increasing strain. At 80% strain, the Vickers hardness is always about 280 HV ₁₀ . That is, the hardness may be about three times by deformation.

Tensile strength in the soft annealed state is from 430 N / mm ² to 450 N / mm ² and rises to a value of 1100 N / mm ² to 1150 N / mm ² as the strain increases (FIG. 2A).

In addition to the alloy CuSn12Zn2 described above, alloy CuSn12Zn4 has also been found to be particularly suitable for the manufacture of eyeglass frames, the CuSn12Zn4 alloy having the same composition as the first mentioned alloy and containing 2% more zinc and 2% less copper. Increasing the zinc content with a correspondingly reduced copper content, for example, has a positive effect on the elastic properties of the wire.

As in the case of the alloy CuSn12Zn2, the metal parts made of CuSn12Zn4 may be connected to each other using resistance welding. Furthermore, the two alloys described above are suitable for coating by conventional coating methods used in the optical industry.

Claims (6)

In particular in eyeglass frames, ornaments and other metal alloys which are hung over the body or provided in clothing and in contact with the body, An alloy comprising the following composition (% by weight): Sn 8-14% Zn 1 to 8% Mn 0.001 to 3% P 0.001 to 0.3% Fe 0.001-0.5% Cu rest. The method of claim 1, An alloy characterized in that the alloy has the following composition (% by weight): Sn 11-13% Zn 1.5-4% Mn 0.001 to 0.1% P 0.001 to 0.05% Fe 0.001-0.02% Cu rest Glasses frame produced using the alloy according to claim 1. Jewelry made using the alloy according to claim 1. Clothing metal part manufactured using the alloy according to claim 1 or 2. Intermediate product or initial material, in particular wire-, band- or rod material, made using the alloy according to claim 1.