JPH0664261B2 - Method for manufacturing eyeglass frame - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing an eyeglass frame, and in particular, to a composite wire material in which a core material is a metal mainly composed of Ti and an outer covering material is a noble metal. And a method of manufacturing an eyeglass frame.

(Prior art) Ti is a material excellent in corrosion resistance, workability, plating property, etc.
In addition, since it is lightweight, it has recently attracted attention as a material for metal eyeglass frames.

However, the spectacle frame is manufactured by brazing the spectacle frame, the vine, and other parts, and Ti is disadvantageous in this respect because the brazing property is poor.

Therefore, there has been proposed a composite wire material in which Ti is used as a core material and a precious metal having an excellent brazing property is clad and pressure-bonded to the surface of the core material.

(Problems to be solved by the invention) However, in this composite wire, the brazing strength is small because an extremely brittle intermetallic compound is formed between the core material and the jacket material during heating for brazing. There is a problem called.

From such a viewpoint, the core material is made of a metal mainly composed of Ti, and is made of a noble metal of the surface layer, and the intermediate layer interposed between the core material and the surface layer is Ti and brittle intermetallic compound at high temperature. There has been proposed a Ti base wire for a spectacle frame, which is composed of a metal that is not formed, for example, a Ni layer.

Although the proposed conventional Ti base wire for eyeglass frames has some advantages, it has a so-called three-layer structure, which makes the production cumbersome and is not suitable for mass production. For spectacle frames, lens grooves are formed, and for vines, both swaging and pressing with a flat cross-section require processing.Therefore, there is no solution to the problem of thinning the surface layer during plastic processing. Since it has not been done, it was just another step for eyeglass frames.

In view of such an actual situation, the present invention is so-called 2 in which the core material is a metal mainly composed of Ti, and the outer covering material is a precious metal excellent in decorativeness.
Even if it is a layered spectacle frame, it does not form or generate an intermetallic compound between the core material and the outer coating material, and the outer coating material is selected even when plastically processing into the shape of the spectacle frame. It does not become thin,
It is an object of the present invention to provide a new method of manufacturing a spectacle frame with excellent decorative properties, which enables easy brazing and ensures the required brazing strength without forming intermetallic compounds.

(Means for solving the problem) The following means will be taken to achieve the above purpose. That is, as a material of the eyeglass frame, a billet core material is a metal mainly composed of Ti which is β-treated and has a crystal grain size of 200 μm or less, and is made of an Au—Ag alloy, an Ag—Pd alloy or a Pd—Cu alloy. The composite billet assembled by using the noble metal as the billet jacket material is hot isostatically extruded at 550 to 700 ° C, and the composite wire rod manufactured by subjecting the extruded material to surface reduction is produced at 550 to 650 ° C for 20 minutes. After annealing, the composite wire rod is plastically worked into a frame shape and a temple shape, and the parts after the plastic working are brazed at 700 ° C. or lower.

(Operation) According to the above means, the composite wire rod, which is the material of the spectacle frame, has the billet core material made of a metal mainly composed of Ti, which is β-processed and has a crystal grain size of 200 μm or less.
-Ag alloy, Ag-Pd alloy and other extrudable, formable composite billet assembled with a noble metal of a specific material as a billet jacket material was hot isostatically extruded, and the obtained extruded material was surface-reduced. Therefore, not only the extruded material, but also the interface between the core material of the composite wire and the jacket material has an extremely smooth property, and the wall thickness of the jacket becomes almost constant, and the thin wall part partially exists in the jacket. It never happens. Further, since the hot isostatic pressing is carried out at 550 to 700 ° C., an intermetallic compound which causes peeling of the jacket is not formed at the interface between the core material and the jacket material. Then, since the composite wire is annealed at 550 to 650 ° C. for 20 minutes or less before plastically working into the frame shape and the vine shape, respectively, while the generation of the intermetallic compound is suppressed at the interface, the core material is suppressed. The deformation resistance between the outer cover material and the outer cover material is reduced and the outer cover material and the outer cover material are made as close to each other as possible, so that it is possible to reliably prevent interfacial fracture due to slippage of the joint interface during plastic working. Furthermore, when brazing various parts, 700 ℃
Since it is carried out below, the formation of intermetallic compounds does not occur at the interface, and it is possible to prevent peeling, which has conventionally occurred remarkably in the brazing portion, as much as possible.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of spectacles 1 having a spectacle frame obtained by the present invention. The spectacle frame is pivotally supported on the spectacle frame 3 through a spectacle frame 3 into which a lens 2 and the like are fitted and a hinge 4. The eyeglass frame is composed of a temple 5 and the like, and at least the portion indicated by reference numeral 6 is brazed.

Referring to FIG. 2, a flow chart of the present invention is shown as an example. A composite wire rod that is a material for an eyeglass frame is made by hot isostatic pressing and surface reduction processing, and the composite wire rod is used to form an eyeglass frame. An eyeglass frame including at least a temple is manufactured by brazing each component.

Thus, the process of making a composite wire rod by hot isostatic pressing and the process of plastic working into a spectacle frame shape and brazing using this composite wire rod can be carried out as a series of steps. However, in the current industrial field structure, the so-called material manufacturer performs the process of making the composite wire rod, and the so-called eyeglass frame processor performs the process of processing into the eyeglass frame shape.
In many cases, each of these processes is carried out separately.

Therefore, for the sake of explanation, a method of making a composite wire will be described in detail first, and then a method of manufacturing an eyeglass frame using the composite wire will be described in detail.

In FIG. 2, A is an ingot serving as a core material, for example, pure titanium such as KS50, KS70, etc. The ingot A is subjected to a hot forging step B, and then a machining step C such as scale removal and size matching. Β processing D is done after
It is subjected to a degreasing step E for cleaning the bonding interface.

On the other hand, a noble metal plate A'which is a covering material is molded B'to form a cylindrical body to form a barrel outer cylinder of an extruded billet described later, and then subjected to a degreasing step C'to clean the bonding interface. It

As a noble metal used as a jacket material, a material that does not easily form an intermetallic compound with Ti, or a large amount of intermetallic compound is generated even at the temperature when brazing is performed during frame molding (usually 500 to 750 ° C) It is necessary to select a material that does not form an intermetallic compound at the softening treatment temperature (usually 500 to 750 ° C.) after molding. Further, the glasses need to be resistant to corrosion because they are exposed to a salt atmosphere due to sweat or the like, and must have excellent corrosion resistance.

Noble metals satisfying the above requirements include platinum (Pt), gold (Au), Pt-Au-Ag, palladium (Pd), Pd-Ag, Au-
Although alloys such as Ag and Au-Ni are conceivable, it is also necessary to consider the ease of extrusion during hot isostatic pressing and the ease of molding and softening.

That is, alloys such as Pt, Pt-Ir, and Pt-Ru have a melting point of 17
At 71 to 1885 ° C, the hot deformation resistance is high and the softening temperature is also high, which is not preferable, and the melting point of Pd and Pd-Ru is relatively high at 1550 to 1580 ° C, and the same can be said. On the other hand, Ag is not preferable because it is soft but poor in sulfidation resistance. In this sense, Pd-Ag alloy and Au-Ag alloy are excellent. That is,
Although the melting point and hardness of Pd-Ag alloys differ depending on the Pd content, 10-80% Pd alloys have high hardness and high wear resistance, and have improved sulfidation resistance compared to Ag and are more organic than Pd. The influence of gas is small. Furthermore, the Au-Ag alloy is also excellent in sulfidation resistance and corrosion resistance, and has a melting point of around 1000 ° C, so that it can be easily molded and softened.

From the above viewpoints, as the noble metal used as the jacket material,
Au-Ag alloy, Ag-Pd alloy and Pd-Cu alloy are suitable. Further, in consideration of suitability of the softening temperature, the ones marked with ◯ in Table 1 are preferable.

Thus, a composite billet 7 shown in FIG. 3 is obtained through a fitting process F and an electron beam welding process G between the core material and the jacket material which have been subjected to the degreasing steps E and C '. Incidentally, prior to the fitting step F,
The core material and the jacket material are cleaned by the degreasing step EC '. By doing so, when the billet is hot isostatically extruded, a metal intermetallic is formed at the interface between the core part of the extruded material and the jacket. It is possible to obtain an extruded material that can suppress the formation of compounds and that has high diffusion bonding strength.

The composite billet 7 is, as shown in FIG. 3, a barrel outer cylinder 9 formed by bending a noble metal plate which is the outer covering material.
And a core portion 8 which is fitted inside the body outer cylinder 9 and is joined to both ends of the body outer cylinder 9 and a core portion 8 formed of the core material.
12 and a bottom portion 10, and a truncated cone portion 12 and a bottom portion 10 are integrally formed under vacuum at both ends of a body outer cylinder 9 fitted with a core portion 8 via a seal portion 11 by electron beam welding. To be
It should be noted that the frusto-conical portion 12 and the bottom portion 10 may be made of an inexpensive copper material, and these are prepared separately after being processed into a predetermined shape, degreased and washed.

Here, prior to the production of the composite billet 7, the core material (titanium) of the ingot was hot worked in the same manner as before at 700 to 900 ° C., and then β-processed to eliminate its anisotropy. Although it is annealed, the treatment temperature and the holding time at this time are the basis for determining the crystal grains of the core material after the β treatment, and it is necessary to select appropriate values.

The crystal grain size of the core material greatly affects the interface property between the core material and the jacket material in the extruded material obtained by hot isostatic pressing of the composite billet, and the finer the crystal grains, the better the interface property. . That is, the surface of the titanium core material needs to be as smooth as possible in order to uniformly apply the thin noble metal layer to the surface of the titanium core material. In order to reduce the crystal grain size, the billet core material may be heated to the β treatment temperature and then the holding time may be shortened as much as possible. Even if the holding time is made as short as possible, the anisotropy is erased even if the holding time is extremely close to 0. Therefore, there is no problem in this respect. Also, the crystal grains become coarser as the β treatment temperature increases, but
Even if cold working is performed after the treatment, fine particles can be obtained.

For example, Fig. 13 (2) shows 20% after β treatment (950 ° C × 30 minutes).
Structure photograph showing the crystal grains of the titanium material that has been cold drawn (magnification 50 times), and using the titanium material as a billet core material,
A composite billet was prepared using a Cu-Ni alloy as a billet jacket material, and a transverse cross-section macrostructure photograph of an extruded material obtained by hot isostatically extruding the composite billet at a magnification of 3.
5 times). The titanium crystal grain size of the billet core material is 50-150
μm, the unevenness of the interface between the extruded core material and the jacket material is 50 μm
It is extremely small, less than m, and has a smooth surface. On the other hand, the
Fig. 13 (1) is a microstructure photograph showing the crystal grains of the titanium material that was only β-treated (950 ° C × 30 minutes) (magnification is the same as in (1)).
When the titanium material is used as a billet core material (the outer coating material is the 13th
(Similar to Figure (1)) A cross-sectional macrostructure photograph of the extruded material (magnification is the same as in (1)), but the titanium crystal grains are coarse and irregular, and the interface of the extruded material is uneven. 200-300
It is about μm, which is quite large.

In addition to the case of Fig. 13 (2), the results of examining the interface of the extruded material by performing hot isostatic extrusion at 650 to 700 ° C under various pretreatment conditions for the titanium material to be the billet core material are shown. The results are shown in Table 2.

From Table 2, it was found that good interfacial properties were obtained when the titanium crystal grain size was 200 μm or less. Further, it can be seen that the crystal grains are finer when the cold working is performed after the β treatment than in the case where the cold working is not performed.

The cold working size is preferably 6 to 20%. If it is less than 6%, the grain refining effect is small, while if it exceeds 20%, seizure during cold working may occur.

The composite billet 7 of which an example is shown in FIG. 3 is subjected to a heating (550 ° C. to 700 ° C.) step shown by a symbol H in FIG. ₂ and has MoS ₂ as a lubricant applied and dried, while Mo
The die coated with the S ₂ paste is extruded by the hot isostatic extrusion method shown by reference numeral I in FIG. 2 to obtain an extruded material in which the noble metal and the Ti joining interface are in the diffusion joining state.

Here, the reason why the composite billet 7 is set in the range of 550 ° C to 700 ° C is as follows.

The higher the billet heating temperature, the smaller the deformation resistance of the work material and the shortening of the manufacturing process due to the processing of highly reduced surface, but when heated to 750 ° C or higher and extruded, a brittle intermetallic compound is formed at the composite material interface. Therefore, the upper limit is set to 700 ° C. That is, as shown in the EPMA analysis results of the extruded material interface in FIGS. 8 (1) and 2 (2), almost no intermetallic compound is formed at the extrusion temperature of 700 ° C. (see FIG. 8 (1)). At the extrusion temperature of 750 ° C., it is clear from the fact that this was seen as shown in FIG. 8 (2).

On the other hand, if the billet heating temperature is lowered, the extrusion ratio becomes small and the number of drawing steps after extrusion increases, which is not preferable as a thin wire manufacturing condition and is set to 550 ° C or higher. This is because the deformation resistance is remarkably reduced at 500 ° C or higher, and the stability in actual operation is taken into consideration. For example, as shown in Fig. 9, the hardness of various precious metals drops sharply at 500 ° C or higher. Is taken care of.

Although the extrusion ratio by hot isostatic pressing varies depending on the extrusion temperature, the lower limit can be set to 4 or less when the billet temperature is set to 600 ° C or higher (750 ° C or lower), but can be set to 4 or higher as a rough guide. .

The extruded material extruded in this way undergoes a descaling step J by pickling and a drawing step K by cold drawing shown in FIG. 2, and then the shape of the vine 5 and the shape of the spectacle frame 3 shown in FIG. However, in the drawing step K, the drawing rate per drawing is 10 to 20%.
In addition, considering the approach angle of the drawing die so that the elongation rates of the core material and the jacket material are constant, wire drawing is performed without annealing, and intermediate annealing is omitted.

That is, usually, although the selection of the die angle is different between the drawing die of the pipe and the drawing die of the wire rod, the die angle of the wire rod is smaller than that of the pipe and a range of 5 to 16 ° is often used. Since is a wire rod, it can be applied to a normal wire rod. However, since the spectacle frame is required to have a surface gloss, it has a large frictional force during drawing, and in order to prevent disconnection at the time of drawing, the area reduction rate is 20% or less. The lower limit of area ratio is 10%
It is said that.

The spectacle frame is plastic-processed using the composite wire manufactured as described above, then brazed, plated and other coatings P, and manufactured by the final inspection Q. In order to do so, the swaging process M ′ shown in FIG.
The plastic processed vine 5A shown in FIG. 6 is obtained by the above, and further the plastic processed vine 5 shown in FIG. 7 is obtained by the press work N ′. The lower processing M by roll rolling is plastically processed from the composite round bar material 3A in FIG. 4 to the composite flat material 3B, and further plastically processed by the groove processing N by drawing or roll rolling to form the lens groove 2A. (Before and after the processing is shown in FIG. 5).

By the way, as described above, the plastic working is required for both the eyeglass frame 3 and the temple 5 of the eyeglass frame. Since this is a strong work, a heat treatment is required before the working.

On the other hand, the composite wire has the above-mentioned two-layer structure, and in consideration of the brazing process O such as high frequency and resistance welding shown in FIG. It is important to prevent this, and it is also important to prevent the outer covering material from becoming thin due to plastic working.For this reason, the deformation resistance of the core material and the outer covering material should be as close as possible. , In order to eliminate the interfacial fracture due to the slip of the joint interface, the sign L. As shown by L ', it is subjected to an annealing process at 550 ° C to 650 ° C for 20 minutes or less.

In FIG. 2, the annealing process is shown separately for convenience of explanation, but it is needless to say that the extruded composite wire may be annealed without performing the annealing process separately.

Thus, the annealing process L. The reason for specifying the annealing temperature and time in L'will be described with reference to FIGS. 10, 11 and 12 (1) to (4).

That is, when the heat treatment temperature is high, an intermetallic compound is generated, and the jacket material in this example is an Ag-Pd alloy and the core material is KS50, both of which soften at 500 ° C or higher. Considering operational stability, the upper limit of heat treatment temperature is 650 ° C. That is, although the upper limit may be 700 ° C in practice, when annealing is performed for 20 minutes at a temperature of 650 ° C as shown in Fig. 12 (1) (2), the boundary as shown in Fig. (1) is obtained. Although no intermetallic compound was found in the part, when annealing was performed at 700 ℃ for 20 minutes, the same figure (3),
Since the formation of intermetallic compounds is observed as shown in (4), the annealing time is set to 20 minutes or less, and 2 to 10 minutes is optimal considering the actual operability. For safety, the upper limit temperature is 650 ° C.

On the other hand, the softening property of KS-50, which is the core material of the composite material, markedly decreases the hardness at 520 ° C or higher as shown in Fig. 11, so the lower limit of the annealing temperature is set at 550 ° C with a margin. -ing

In addition, the spectacle frame material is subjected to plastic working such as press molding from a round wire of 1.5 to 4.0 mmφ into a flat plate, or it is grooved, and the core material is a metal mainly composed of Ti. In the case of a composite wire material in which the covering material is a noble metal, since the covering material is softer than the core material and the covering material tends to be locally thin, it is significant to perform heat treatment (intermediate annealing).
By specifying the temperature range, the hardness ratio between the jacket material and the core material should be as close to 1.0 as possible, that is, the deformation resistance between Ti and the noble metal should be as close as possible to prevent interfacial fracture due to slippage of the joint interface. Can be lost (No.
(See Figure 10). From this point as well, the annealing temperature is set to 550 ° C to 650 ° C, and the time is set to 20 minutes or less.

In addition, as the timing of such heat treatment, it is desirable to use an intermediate step of round drawing with a continuous drawing rate of 90% or more. Thus, the composite wire in this case used as a spectacle frame material is capable of continuous drawing and has a proven continuous drawing rate of 98%, and the hardness (Hv) of the continuous drawn material depends on the composition ratio of Ag-Pd alloy. Different, but 15
It is 0 to 200, and KS-50 is 260 to 280.

The frame material thus annealed prior to plastic working is subjected to downward pressing M and groove processing N as shown in FIG. 2 to form the eyeglass frame 3 as a component of the eyeglass frame.
The swaging M'and the press working N'are performed to form the vines 5 as parts of the spectacle frame, and the parts including these are brazed at various places shown in FIG. 1 by high frequency or resistance welding.

This brazing uses BAg-4 as the brazing material and the temperature is 600 ° C.
Experiments were carried out at 650 ° C, 700 ° C, 750 ° C and 800 ° C with a heating time of 2 minutes.

As a result of observing the cross section of the sample and examining the quality of the intermetallic compound at the interface between the core material KS-50 and the silver-palladium alloy, almost no intermetallic compound was formed below 700 ° C.
The above compounds were observed at the interface at ℃ and 800 ℃.

In addition, the brazing time is a so-called flow work in the manufacture of the eyeglass frame as a practical problem, and it does not matter because it is completed in an instant, and the lower limit of the brazing temperature depends on the selection and workability of the brazing material. become.

(Effect of the Invention) According to the present invention, the core material of the composite billet to be subjected to hot isostatic pressing is formed of a metal mainly composed of Ti which has been subjected to β treatment and whose crystal grain size is 200 μm or less. Extrudability of Au-Ag alloy, Ag-Pd alloy, etc.
Since it is made of a noble metal of a specific material with good formability, the wall thickness of the extruded material and the jacket material of the composite wire becomes almost uniform during hot isostatic extrusion and subsequent plastic working, resulting in partial thin-walled parts. No, you can get a negative frame with excellent quality. Further, the hot isostatic extrusion temperature is set to 550 ° C to 700 ° C.
Since the annealing before the plastic working into a predetermined shape was stopped at 550 ° C. to 650 ° C. for 20 minutes or less as well as at 0 ° C., generation of an intermetallic compound at the interface between the core material and the jacket material was suppressed. In addition, it is possible to prevent interfacial destruction due to slippage of the joint interface during plastic working. Further, when brazing the parts after plastic working, the brazing temperature is 700 ° C. or less, so that the formation of intermetallic compounds at the interface is suppressed,
It is possible to prevent the exfoliation of the outer covering material that has conventionally occurred remarkably at the brazing portion as much as possible.

As described above, the method of manufacturing the eyeglass frame of the present invention, the strict quality control,
High quality is ensured by temperature control, and it is excellent as a product that can manufacture good quality eyeglass frames with high decorativeness while suppressing the production cost.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an example of glasses obtained according to the present invention, FIG. 2 is a flow chart showing an example of the present invention, and FIG. 3 is a sectional view showing an example of a composite billet. FIG. 4 is a cross-sectional view showing an example of downward pressing of a spectacle frame, FIG. 5 is a cross-sectional view showing an example of same groove processing, FIG. 6 is a perspective view of an example of swaging of the same vine, and FIG. 7 is the same. Perspective view of an example of press working,
Fig. 8 shows the EPMA analysis results of the extruded material interface, Fig. 9 is a graph showing the relationship between the heating temperature and the hardness of various precious metals and Ti, and Figs. 10 and 11 show the relationship between the hardness and the annealing conditions. Fig. 12 is a graph showing Fig. 12, (1) to (4) showing EPMA analysis results at the boundary portion during annealing of the composite wire, and Fig. 13 (1).
(2) is a metallographic photograph showing the titanium crystal structure of the billet core material and the cross-sectional structure of the extruded material, respectively. 1 …… Glasses, 3 …… Glasses frame, 5 …… Cranes, 6 …… Brazing part, I …… Hydrostatic extrusion process, L. L '... Annealing process,
M. M '. N. N '... plastic working process, O ... brazing process.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Arimura 7-3 Takamaru, Tarumi-ku, Kobe-shi, Hyogo (72) Inventor Akio Saito 23-23, Kitagawa-cho, Moji-ku, Kitakyushu, Fukuoka (56) Reference Literature JP-A-61-159617 (JP, A) JP-A-57-5851 (JP, A) Actually developed JP-A-57-88114 (JP, U)

Claims (1)

[Claims] 1. A β-processed crystal grain size of 200 μm
A composite billet assembled at 550 to 700 ° C. using a metal mainly composed of the following as a billet core material and a noble metal composed of Au-Ag alloy, Ag-Pd alloy or Pd-Cu alloy as a billet jacket material. Hot isostatic extrusion was performed, the extruded material obtained was subjected to surface reduction processing to obtain a composite wire, and the composite wire was annealed at 550 to 650 ° C. for 20 minutes or less, and then plastically processed into a spectacle frame shape and a vine shape, respectively. Then, the method of manufacturing a spectacle frame, characterized in that the respective parts after the plastic working are brazed at 700 ° C. or lower.