JP2005240169A - Titanium alloy, its production method and accessory - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a titanium alloy combining a decorative function and a health promoting or treatment/healing function. <P>SOLUTION: The titanium alloy 1 comprises germanium and titanium. The titanium alloy 1 comprises the germanium of 1 to 15 mass% based on the total mass of the titanium alloy 1. Thus, the titanium alloy 1 has an excellent decorative function, and can give a health promoting or treatment/healing effect based on far-infrared rays. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a titanium alloy, a method for producing the same, and a jewelry using the same.

  As a material used for a health appliance, for example, a stainless-germanium alloy is known. Such a stainless-germanium alloy contains germanium in a stainless steel based on a stainless steel material, and an austenitic stainless steel material containing chromium or nickel is used as the stainless steel material. This stainless-germanium alloy can be manufactured by, for example, melting a stainless steel material and germanium by an arc melting method.

Stainless steel products using this stainless-germanium alloy have excellent workability, improved elasticity compared to ordinary stainless steel, have an aesthetics comparable to precious metals such as platinum, and corrosion resistance of stainless steel It is said to have corrosion resistance equivalent to or better than In addition, it is said that by containing germanium, it is possible to realize health promotion and therapeutic effect by the far-infrared effect (for example, see Patent Document 1).
JP 2003-293096 A

  However, the stainless steel product described in Patent Document 1 is excellent in aesthetics and corrosion resistance, and has effects such as health promotion. However, since it is based on an austenitic stainless steel material containing nickel or chromium, May occur. For this reason, the person with a metal allergy cannot use the above-mentioned stainless steel product. In addition, wearing glasses or the like composed of the above-described stainless-germanium alloy for a long time may cause pain and the like because the specific gravity of the stainless steel material is large and heavy. Therefore, it is not appropriate to use the above-described stainless-germanium alloy as a material for glasses or the like.

  In recent years, titanium alloys have attracted attention as a material that is lightweight and does not have to worry about metal allergies. Titanium alloys are often used in accessories such as watches and glasses, but titanium alloys for the purpose of treatment / healing and health promotion have not yet been provided.

  On the other hand, when a titanium alloy is manufactured by the above-described arc melting method, problems such as reaction between titanium and / or titanium alloy and crucible, reduction of metal vapor pressure and dissociated oxygen, and damage to the mold (bright mold) occur. In order to solve such a problem, it is conceivable to manufacture a titanium alloy by an electron beam melting method (EB melting method). However, an expensive manufacturing facility is required and the melting cost is high. In particular, problems such as being unsuitable for alloying titanium with a metal having a large melting point difference arise.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a titanium alloy having both a decorative function and a health promotion or treatment / healing function. Another object of the present invention is to provide a method for producing such a titanium tool simply and inexpensively. Furthermore, an object of the present invention is to provide a jewelry using such a titanium alloy.

  In order to solve the above object, the titanium alloy of the present invention is a titanium alloy containing germanium and titanium, and the content of the germanium is 1 to 15% by mass based on the total mass of the titanium alloy. Features.

  Since the titanium alloy of the present invention contains germanium, the appearance thereof has a white color tone and an excellent decorative function, and the germanium effect, that is, the health promotion or treatment / healing effect based on far infrared rays (for example, an increase in skin temperature) , Prevention of stiff shoulders). Furthermore, deodorizing and antifungal effects can be exhibited based on the above-mentioned far infrared radiation. Moreover, the titanium alloy of the present invention can exhibit a titanium effect, that is, release of negative ions, a photocatalytic function, a deodorizing effect and the like. Furthermore, the titanium alloy of the present invention is lightweight and has no fear of metal allergy.

  The titanium alloy of the present invention may further contain 2 to 15% by mass of tin based on the total mass of the titanium alloy. Thereby, since the alloy structure is stabilized, the rollability (stretchability), hardness and elasticity of the titanium alloy can be improved.

  Furthermore, the titanium alloy of the present invention may further contain 3 to 20% by mass of niobium based on the total mass of the titanium alloy. Thereby, the discoloration (for example, blackening) by oxidation of titanium can be suppressed and a white color tone can be maintained. Furthermore, in addition to mechanical properties such as strength, malleability, ductility and elasticity, the titanium alloy is excellent in workability such as brazing, polishing and machinability.

  In addition, the titanium alloy of the present invention may further contain 1 to 5% by mass of zirconium based on the total mass of the titanium alloy. As a result, the elasticity and strength are more reliably improved, and the brazing property is further improved.

  As described above, the titanium alloy of the present invention is suitable as a material for accessories as it has excellent mechanical strength and workability as well as decorativeness, and is useful as a material for temples of glasses, for example.

  Further, it is preferable that the germanium forms fine particles, and the fine particles are exposed on the surface. When germanium fine particles are exposed on the surface of the alloy in this way, far infrared rays are less likely to be absorbed on the way to the skin than when germanium fine particles are not exposed, and health promotion based on far infrared rays is promoted. And can fully exhibit therapeutic and healing effects.

The number of germanium atoms is preferably 10 ²⁰ or more per cm ³ . Thereby, it becomes possible to enhance the emission of far infrared rays, and it is possible to enhance the health promotion and therapeutic / healing effects more reliably. The number of germanium atoms per unit volume can be measured by electron beam microanalysis (EPMA, manufactured by Shimadzu Corporation) under the conditions of an acceleration voltage of 20 KV, a sample current of 0.01 μA, and an X-ray beam diameter of 2 μm.

  The titanium alloy of the present invention further contains 0.5 to 10% by mass of at least one metal selected from the group consisting of platinum, rhodium, palladium, iridium, gold and silver, based on the total mass of the titanium alloy. You may do it. Thereby, the decoration function of a titanium alloy can be improved further.

  Furthermore, the titanium alloy of the present invention may further contain 10 to 20% by mass of indium based on the total mass of germanium. Indium is a group III element and becomes an acceptor when added to a semiconductor, resulting in a p-type. Therefore, by adding indium to germanium, which is a semiconductor, germanium becomes a p-type semiconductor, and far-infrared radiation is further enhanced. Therefore, health promotion and treatment / healing functions based on far-infrared rays can be expressed more reliably.

  The titanium alloy production method of the present invention is a production method of a titanium alloy containing germanium and titanium, in which a titanium melting step of heating and melting titanium prepared in a heating vessel, and in the heating vessel A germanium melting step in which 1 to 15% by mass of germanium is added and melted on the basis of the total mass of the material to form the titanium alloy; and a temperature higher than the melting point of the germanium and a temperature lower than the melting point of the titanium. And an alloying step for forming a titanium alloy. Moreover, in the germanium melting step described above, 2 to 15% by mass of tin may be further added.

  According to this manufacturing method, a titanium alloy having both a decorative function and health promotion or treatment / healing function can be obtained simply and inexpensively. Further, by performing the alloying step in the above temperature range lower than the melting point of titanium, the alloy composition can be stabilized, and a titanium alloy having germanium exposed on the surface can be obtained. In addition, problems such as reaction between titanium and / or titanium alloy and crucible, reduction of vapor pressure and dissociated oxygen of metal, damage to mold (bright mold), etc. are solved. Alloying with a large metal is possible. Further, by adding tin in the above-described germanium melting step, a titanium alloy having excellent rolling properties (extensibility), hardness, and elasticity can be easily obtained.

  Furthermore, the manufacturing method of the titanium alloy of the present invention is a manufacturing method of a titanium alloy containing niobium, germanium and titanium, and 3 to 20% by mass of niobium based on the total mass of the material to form the titanium alloy. 1-15% by mass based on the total mass of the preparation step of preparing a mixture containing titanium in a heating vessel, the mixture melting step of heating and melting the mixture, and the material to form the titanium alloy A germanium melting step in which germanium is added and melted in the heating vessel, and a casting step in which the casting immediately starts after the vapor no longer rises from the surface of the molten metal in the heating vessel may be provided. This makes it possible to easily and inexpensively manufacture a titanium alloy having a decorative function and a health promotion or treatment / healing function and having germanium exposed on the surface. Moreover, the said mixture may further contain 1-5 mass% of zirconium on the basis of the total mass of the material which should form the said titanium alloy.

  Furthermore, the accessory of the present invention is characterized by being composed of the above-described titanium alloy of the present invention. Since the accessory of the present invention uses the above-described titanium alloy, it has an excellent decorative function, and can be worn with its outer surface in contact with the skin.・ A sufficient healing and health promotion effect can be obtained. In addition, even if the outer surface of the titanium alloy comes into contact with the skin, there is no concern about metal allergy because the titanium alloy described above is used.

  Moreover, at least a part of the surface of the accessory may be covered with a titanium oxide film. Thereby, the decoration function can be further enhanced by vivid colors of titanium oxide.

  ADVANTAGE OF THE INVENTION According to this invention, the titanium alloy which has a decoration function, health promotion, or a treatment / healing function can be provided. Further, according to the present invention, it is possible to provide a method for producing such a titanium tool simply and inexpensively, and it is also possible to provide a jewelry using such a titanium alloy.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted. Further, the dimensional ratios in the drawings do not necessarily match those described.

(Titanium alloy)
FIG. 1 is a schematic cross-sectional view of a titanium alloy according to this embodiment. A titanium alloy 1 shown in FIG. 1 contains germanium and titanium, and germanium fine particles 2 are exposed on the surface (outer surface). Since the titanium alloy 1 exhibits a white color tone and can emit far infrared rays, the titanium alloy 1 can have both a decorative function and a health promotion function.

  The germanium content is 1 to 15% by mass based on the total mass of the titanium alloy 1, but preferably 1 to 10% by mass, more preferably 4 to 8% by mass, and even more preferably 5 to 8% by mass. is there. If the content of germanium is less than 1% by mass, the decorative function, the treatment / healing based on far infrared rays, and the health promotion effect are lowered. On the other hand, when the content exceeds 15 parts by mass, the dispersibility and workability of the germanium fine particles 2 are lowered, and cracks are likely to occur. When the titanium alloy 1 is a binary alloy of germanium and titanium, the content of germanium is preferably 1 to 10% by mass, more preferably 4 to 8 from the viewpoint of obtaining the above-described germanium effect and titanium effect more reliably. % By mass.

  Further, the titanium alloy 1 can further contain tin. The tin content is preferably 2 to 15% by mass based on the total mass of the titanium alloy 1, but more preferably 4 to 10% by mass. If the tin content is less than 2% by mass, the elasticity tends to be insufficient. On the other hand, when the content exceeds 15 parts by mass, the alloyability and workability tend to be insufficient. In addition, when the titanium alloy 1 is a ternary alloy of germanium, tin, and titanium, it is preferable that content of germanium is 4-5 mass% from a viewpoint of alloy property, workability, and an elasticity improvement. The present inventors have confirmed that a titanium-germanium alloy containing 4% by mass of tin is improved in Vickers hardness by 15 Hv compared to a titanium-germanium alloy containing 3% by mass of niobium. The Vickers hardness is measured using a Vickers hardness meter.

  The titanium alloy 1 may further contain niobium. The content of niobium is preferably 3 to 20% by mass based on the total mass of the titanium alloy 1, more preferably 4 to 10% by mass, and still more preferably 5 to 8% by mass. When the content of niobium is less than 3% by mass, the suppression of titanium oxidation is insufficient and the decorative function tends to be lowered. On the other hand, when the content exceeds 20 parts by mass, since niobium has a higher specific gravity than titanium, the specific gravity of the titanium alloy increases and the lightness tends to be impaired.

  The titanium alloy 1 can further contain zirconium. You may contain 1-5 mass% zirconium on the basis of the total mass of the titanium alloy 1. FIG. The zirconium content is more preferably 2 to 5% by mass, still more preferably 3 to 5% by mass. If the zirconium content is less than 1% by mass, elasticity and strength tend to be insufficient. On the other hand, when the content exceeds 5 parts by mass, the workability tends to decrease.

  Furthermore, the titanium alloy 1 is preferably 0.5 to 10% by mass of at least one metal selected from the group consisting of platinum, rhodium, palladium, iridium, gold and silver, based on the total mass of the titanium alloy 1. More preferably, it may be contained in an amount of 2 to 8% by mass, and more preferably 2 to 5% by mass. By containing the metal within the above range, the decorative function of the titanium alloy 1 can be further enhanced.

  In addition, content of titanium is the remainder remove | excluding the total mass of germanium and another metal from the total mass of the titanium alloy 1, when the titanium alloy 1 contains metals other than germanium and titanium.

  The average particle size of the germanium fine particles 2 is preferably 0.01 to 50 μm, more preferably 0.01 to 30 μm, and still more preferably 0.01 to 5 μm.

  Further, although the germanium fine particles 2 are intrinsic semiconductors, the Fermi energy level is in the middle of the band gap in order to create a relatively deep impurity level by containing niobium. Therefore, as compared with the case of the n-type semiconductor, the distribution of holes near the valence band is easily changed by heat and light. Therefore, the present inventors speculate that indirect transition germanium has a long recombination lifetime of electrons and holes, and can emit far-infrared rays when the excited holes return to the ground state.

  In the present embodiment, a part or all of the germanium fine particles 2 may be a germanium alloy containing a group III element (for example, a germanium-indium alloy). The average particle size of the germanium alloy fine particles is the same as that of the germanium fine particles 2 described above.

  Since indium is a group III element, it becomes an acceptor when added to a semiconductor such as germanium, resulting in a p-type. In general, the far-infrared effect of germanium is remarkably exhibited in the p-type as compared with the n-type or intrinsic semiconductor. Therefore, by using the germanium-indium alloy fine particles as the germanium fine particles 2, Radiation becomes noticeable. In order to make such an effect sufficient, the content of indium is preferably 0.01 to 20% by mass, more preferably 1% by mass or more, based on the total mass of germanium. In this way, the far-infrared effect by p-type germanium can be more reliably obtained while improving the workability. In addition, the content may be 3% by mass or less. If it does in this way, while setting it as a jewelry, sufficient hardness can be obtained and the far-infrared effect by p-type germanium can be improved more.

The mechanism by which p-type germanium fine particles emit far-infrared rays is not clear, but the present inventors infer as follows. Germanium is an indirect transition type semiconductor having a band gap energy of 0.67 eV. There are two types of holes in semiconductor germanium: heavy holes (H) and light holes (L). In a p-type germanium microcrystal, these two bands are very close in energy and wavenumber at room temperature. The Fermi level is in the vicinity of the valence band, and the hole has an energy of 25 meV (kT, k = 1.38 × 10 ⁻³⁴ , T = 300 K) at room temperature. For this reason, heavy holes (H) are easily excited to a level of 2.5 meV corresponding to far-infrared rays having a wavelength of 100 microns at room temperature. Therefore, the heavy hole (H) is easily thermally excited from that band to the light hole (L) band, and the heavy hole (H) emits far infrared rays and returns to the original heavy hole (H) band. Thus, it is considered that the p-type germanium microcrystal emits far-infrared rays having a wavelength of 100 microns at room temperature, thereby causing a thermal action on the human body and exerting the above-described effect.

The number of atoms constituting the germanium fine particles 2 is preferably 10 ²⁰ or more per cm ³ , and more preferably 10 ²¹ or more per cm ³ . If the number of germanium atoms present per cm ³ is less than 10 ²⁰ , radiation of infrared rays may be insufficient, and treatment / healing and health promotion effects may not be sufficiently obtained. On the other hand, if the number of existence per 1 cm ³ is too large (eg, ¹⁰²³ or more), the decorative function (eg, color tone, gloss) of the titanium alloy 1 may be impaired.

  In addition, as a form of the titanium alloy 1, a wire, a bar, a plate, rolling, forging, a billet, a slab, an ingot, etc. are mentioned, The intermediate processing goods which processed these temporarily may be sufficient.

(Production method of titanium alloy)
First, 1st Embodiment of the manufacturing method of a titanium alloy is described. The titanium alloy manufacturing method according to the present embodiment includes a titanium melting step, a germanium melting step, and an alloying step. For the production of the titanium alloy, for example, a vacuum high-frequency melting furnace, a skull melting furnace, or the like can be used.

  First, germanium and titanium are prepared. The proportions of germanium and titanium are then determined. In this case, the ratio of germanium and titanium is within the range of the content ratio described above. In addition, when a titanium alloy contains another metal other than germanium and titanium, the mass of titanium is the remainder except the total mass of germanium and another metal.

Next, a titanium melting step is performed. In the titanium melting step, for example, a titanium ingot is mounted in a heating container. Next, the inside of the heating container is evacuated in order to prevent the reaction between oxygen, nitrogen and carbon-containing components present in the heating container and titanium. The vacuum condition is, for example, 1.3 × 10 ^{−2 to} 1.3 × 10 ⁻⁸ Pa (10 ⁻⁴ to 10 ⁻¹⁰ torr), and preferably 1.3 × 10 ⁻² Pa (10 ⁻⁴ torr). ). Next, an inert gas such as argon is injected into the heating container to bring the pressure to normal pressure (atmospheric pressure) or higher than normal pressure. By injecting the inert gas, the reaction between titanium and oxygen, nitrogen and carbon-containing components and titanium can be prevented. Furthermore, volatilization of the molten metal can be prevented by injecting an inert gas to a pressure higher than atmospheric pressure. Similarly, in the germanium melting step and the alloying step, which will be described later, an inert gas may be injected under pressurized conditions (pressure conditions higher than normal pressure). The titanium is then heated to melt. The melting temperature of titanium is a temperature about 30 to 100 ° C. higher than the melting point of titanium. Specifically, when the melting point of titanium is 1660 ° C., it is 1700 to 1750 ° C. The titanium melting step may be performed under the above-described vacuum conditions. Moreover, as a heating container, a crucible can be used, for example. Such a crucible is preferably dried before the titanium melting step.

  Next, a germanium melting step is performed. In the germanium melting step, germanium is added to the heating vessel and melted. The amount of germanium to be used is 1 to 15% by mass based on the total mass of the materials for forming the titanium alloy 1. The melting temperature of germanium is preferably higher than the melting point of germanium and lower than the melting temperature of titanium. Specifically, when the melting point of titanium is 1660 ° C., the melting temperature of germanium is 1650 to 1680 ° C. Thereby, volatilization of germanium can be prevented by suppressing the vapor pressure. As germanium, a germanium ingot is preferably used from the viewpoint of preventing volatilization of germanium.

  In the germanium melting step described above, another metal may be further added. Examples of the other metal include at least one of 2 to 15% by mass of tin, 3 to 20% by mass of niobium, and 1 to 5% by mass of zirconium based on the total mass of the titanium alloy 1. Such other metals can be added before the addition of germanium, after the addition of germanium or simultaneously with the germanium. When germanium and other metals are added simultaneously, a mixture of germanium and other metals or an alloy of germanium and other metals can be used. Among these, from the viewpoint of preventing volatilization of germanium and other metals, an ingot of an alloy of germanium and another metal (for example, germanium-tin alloy) is preferably used. Furthermore, instead of the above-described germanium, a germanium-indium alloy containing 0.01 to 20% by mass of indium based on the total mass of the germanium may be used.

  Next, an alloying process is performed. In such an alloying process, the alloy is completely alloyed at a temperature higher than the melting point of germanium and lower than the melting point of titanium. In such a temperature range, germanium is in a molten state and titanium is in a semi-molten state. As a result, the alloy composition is stabilized and germanium can be deposited on the outer surface of the alloy. The alloying temperature is 400 to 750 ° C., preferably about 600 to 720 ° C. higher than the melting point of germanium, and 10 to 150 ° C., preferably about 10 to 100 ° C. lower than the melting point of titanium. It is. Specifically, when the melting point of titanium is 1660 ° C., the alloying temperature of titanium and germanium is 1600 to 1650 ° C., and the alloying temperature of titanium, germanium and tin is 1550 to 1650 ° C. Such alloying temperature is about 100 to 150 ° C. lower than the alloying temperature of the titanium-niobium-germanium alloy. This makes it possible to increase the hardness of the titanium-germanium-tin alloy.

  Next, a casting process is performed. In the casting process, cast irons, rolled steel materials (SS materials), molds such as carbon split molds (bright molds) can be used. Since the alloy is formed at a temperature lower than the melting point of titanium in the alloying step, there is no fear of breakage even if the above-described mold is used.

  Next, a second embodiment of the titanium alloy manufacturing method will be described. The titanium alloy manufacturing method according to the present embodiment includes a preparation process, a mixture melting process, a germanium melting process, and a casting process.

  In the above preparation process, niobium, germanium, and titanium are first prepared. Next, the content ratios of niobium, germanium and titanium are determined. In this case, the ratio of each material is within the range of the content ratio described above. The same applies when the titanium alloy contains other metals such as zirconium and tin in addition to niobium, germanium and titanium. Moreover, as niobium, titanium, and other metals, those in powder form or ingot form can be used.

  Next, a mixture containing niobium and titanium is prepared in a heating container. Similarly, when the titanium alloy contains the other metal described above, it is prepared in the heating container. The mixture may be mixed in advance before being put into the heating container, or may be mixed after being put into the heating container.

Next, a mixture melting step is performed. In the mixture melting step, the above-mentioned mixture is heated and melted. As a method for melting the above-mentioned mixture, a vacuum melting method or an electron beam melting method (EB melting method) can be used. The vacuum condition is, for example, 1.3 × 10 ^{−2 to} 1.3 × 10 ⁻⁸ Pa (10 ⁻⁴ to 10 ⁻¹⁰ torr), preferably 1.3 × 10 ⁻² Pa (10 ^{− 4} torr). Moreover, melting temperature is 1,800-1,900 degreeC, for example.

  Next, a germanium melting step is performed. In the germanium melting step, the above-described germanium is added to the heating vessel and melted. It is preferable that germanium is melted under the above-described conditions by a vacuum melting method or an EB melting method. The shape of germanium is preferably not a powder but a lump to prevent germanium from being scattered or volatilized. Further, a germanium alloy may be used instead of germanium. As the germanium alloy, for example, a germanium alloy containing a group III element or the like can be used. Examples of germanium alloys containing group III elements include germanium-indium alloys.

  Next, a casting process is performed. In the casting process, casting is performed immediately after the steam does not rise from the surface of the molten metal in the heating vessel. In this way, an ingot of titanium alloy with germanium fine particles exposed on the surface is obtained.

  Next, the obtained ingot may be subjected to a solution treatment. By this solution treatment, it is possible to eliminate crystal distortion generated during the production of the titanium alloy, homogenize the internal structure, and form a dense crystal structure. In the solution treatment, for example, the ingot is heated to 800 to 950 ° C., and the elements constituting the ingot are once dissolved in the matrix and then rapidly cooled.

  Next, after performing forging at a surface temperature of the ingot of 750 to 900 ° C., scratches and craters on the surface of the ingot may be removed by cutting. Subsequently, it shape | molds to a board | plate material and a wire by hot processing or cold processing (cold roll processing). The plate material is processed to, for example, about 10 mm / t, while the wire material is processed to, for example, about φ20 mm. Furthermore, after hot working or after cold working, annealing (for example, vacuum annealing or atmospheric annealing) may be performed, and in cold working, it is preferable to repeatedly perform cold working and annealing.

(Jewelry)
The accessory according to this embodiment is formed and processed into glasses, a watch, a ring, a necklace, a pendant, a bracelet, an anklet, an earring, a broach, and the like, using the above-described titanium alloy plate or wire. And as for this accessory, the outer surface which contacts skin in the state worn by the body should just be comprised with the titanium alloy mentioned above. By doing so, the accessory can be lightweight, and can have both a decorative function and health promotion or treatment / healing function. In addition, metal allergy is unlikely to occur even when the skin contacts the outer surface of the jewelry.

  Further, in the accessory according to this embodiment, at least a part of the outer surface may be covered with a titanium oxide film. The formation of the titanium oxide film on the outer surface of the accessory can be performed, for example, by an anodic oxidation method or a thermal oxidation method. When a titanium oxide film is formed on the outer surface of the accessory by an anodic oxidation method, the outer surface of the accessory is washed with an acidic solution, and then the accessory is connected to the anode and immersed in the electrolytic solution. Then, a voltage is applied to the electrodes to oxidize the outer surface of the accessory to form a titanium oxide film. In this case, by adjusting the voltage at the time of anodizing, seven colors can be developed on the outer surface of the accessory. For example, when a voltage of 30 V is applied, the outer surface of the accessory is blue, and when a voltage of 50 V is applied, the outer surface of the accessory is light yellow. On the other hand, in the case of the thermal oxidation method, for example, a titanium oxide film can be formed on the outer surface of the accessory by heating the accessory to 700 to 900 ° C. in an oxygen atmosphere. In this thermal oxidation method, the outer surface of the accessory is colored differently depending on the thickness of the titanium oxide film. For example, when the thickness of the titanium oxide film is thin (for example, about 200 nm), the outer surface of the jewelry is blue. On the other hand, when the thickness of the titanium oxide film is thick (for example, about 300 nm), the outer surface of the jewelry is Presents a red color.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to a following example at all.

(Example 1)
A mixture of 90% by mass of titanium, 5% by mass of niobium and 1% by mass of zirconium was prepared. Next, this mixture was put into a heating container and then heated to 1,700-1800 ° C. under a vacuum condition of 1.3 × 10 ⁻² Pa (10 ⁻⁴ torr) to be completely melted. . Subsequently, 4 mass% germanium was added in the heating container, and it was made to vacuum-dissolve on the same conditions as the above. And after the vapor | steam did not rise from the surface of the molten metal in a heating container, it casted immediately and obtained the titanium alloy ingot.

  Next, the obtained ingot was heated to 800 to 950 ° C., and then rapidly cooled to perform solution treatment. Next, forging was performed at a surface temperature of 750 to 900 ° C., and then cutting was performed. And the plate material of 10 mm / t was obtained by hot processing. It was confirmed that the titanium alloy plate thus obtained had a white color tone and had an excellent decorative function.

  Subsequently, the surface of the obtained titanium alloy was observed with an optical microscope, and an optical microscope photograph was taken. The optical micrograph is shown in FIG. From this optical micrograph, it was confirmed that germanium fine particles having a particle size of 4 μm or less were present on the surface of the titanium alloy.

  Next, electron beam microanalysis (EPMA) was performed on the outer surface of the titanium alloy. FIG. 3 is a diagram showing an X-ray image of niobium constituting the titanium alloy, and FIG. 4 is a diagram showing an X-ray image of germanium constituting the titanium alloy. FIG. 5 is a view showing an X-ray image of zirconium constituting the titanium alloy, and FIG. 6 is a view showing an X-ray image of titanium constituting the titanium alloy. From these X-ray images, it was confirmed that more germanium was distributed on the outer surface of the titanium alloy than niobium and zirconium.

(Example 2)
After obtaining an ingot of titanium alloy by the same method as in Example 1, solution treatment, forging, cutting and hot working were performed to obtain a φ20 mm wire. It was confirmed that the obtained titanium alloy wire had a white color tone and had an excellent decorative function.

(Example 11)
After drying a crucible of a vacuum melting furnace equipped with a high-frequency heating device, a titanium ingot was mounted in the crucible. In addition, a titanium ingot is 95 mass% on the basis of the total mass of the material which should form a titanium alloy, and melting | fusing point is 1700 degreeC. The crucible used is made of porous calcia ceramic (CaO).

Next, the inside of the crucible was evacuated to 1.3 × 10 ⁻² Pa (10 ⁻⁴ torr) and then replaced with argon gas. Next, the output of the high-frequency heating apparatus was increased to heat the inside of the crucible to 1,700 ° C. And the output of the high frequency heating apparatus was controlled, the temperature in the crucible was kept at 1700 ° C., and the titanium ingot was melted.

  Next, after the output of the high-frequency heating device was lowered to lower the temperature in the crucible to 1680 ° C., a 5 mass% germanium ingot was charged into the crucible. Then, the output of the high-frequency heating device was controlled so that the temperature in the crucible was 1600 to 1680 ° C., and titanium and germanium were completely alloyed, and then cast to obtain a titanium alloy ingot.

(Example 12)
After the crucible was dried, a titanium ingot was mounted in the crucible. In addition, the manufacturing apparatus and the titanium ingot used the same thing as Example 11, and the usage-amount of a titanium ingot is 92 mass% on the basis of the total mass of the material which should form a titanium alloy.

  Next, the inside of the crucible was evacuated and then replaced with argon gas. Next, the crucible was heated by raising the output of the high-frequency heating device in the same manner as in Example 11, and the temperature in the crucible was maintained at 1680 ° C. to melt the titanium ingot.

  Next, the output of the high-frequency heating device was lowered to lower the temperature in the crucible to 1650 ° C., and then an ingot of germanium-tin alloy was put into the crucible. The germanium-tin alloy was added in an amount of 4% by mass based on the total mass of materials for forming the titanium alloy. Then, the output of the high-frequency heating device was controlled so that the temperature in the crucible became 1550 to 1650 ° C., and titanium, germanium, and tin were completely alloyed, and then cast to obtain a titanium alloy ingot.

It is sectional drawing of the titanium alloy which concerns on this embodiment. It is a figure which shows the optical microscope photograph of the surface of the titanium alloy which concerns on an Example. It is a figure which shows the X-ray image of the structural component (Nb) of the titanium alloy which concerns on an Example. It is a figure which shows the X-ray image of the structural component (Ge) of the titanium alloy which concerns on an Example. It is a figure which shows the X-ray image of the structural component (Zr) of the titanium alloy which concerns on an Example. It is a figure which shows the X-ray image of the structural component (Ti) of the titanium alloy which concerns on an Example.

Explanation of symbols

  1 ... titanium alloy, 2 ... fine particles of germanium.

Claims (15)

A titanium alloy containing germanium and titanium,
The titanium alloy, wherein the germanium content is 1 to 15% by mass based on the total mass of the titanium alloy.   The titanium alloy according to claim 1, further comprising 2 to 15% by mass of tin based on the total mass of the titanium alloy.   The titanium alloy according to claim 1 or 2, further comprising 3 to 20% by mass of niobium based on the total mass of the titanium alloy.   The titanium alloy according to any one of claims 1 to 3, further comprising 1 to 5% by mass of zirconium based on the total mass of the titanium alloy.   The titanium alloy according to any one of claims 1 to 4, wherein the germanium forms fine particles, and the fine particles are exposed on the surface. 6. The titanium alloy according to claim 1, wherein 10 ²⁰ or more germanium atoms are present per 1 cm ³ .   2. The metal composition according to claim 1, further comprising at least one metal selected from the group consisting of platinum, rhodium, palladium, iridium, gold and silver in an amount of 0.5 to 10% by mass based on the total mass of the titanium alloy. The titanium alloy as described in any one of -6.   The titanium alloy according to any one of claims 1 to 7, further comprising 0.01 to 20% by mass of indium based on the total mass of the germanium. A method for producing a titanium alloy containing germanium and titanium,
A titanium melting step of heating and melting titanium prepared in a heating vessel;
A germanium melting step in which 1 to 15% by mass of germanium is added and melted on the basis of the total mass of the material to form the titanium alloy in the heating container;
An alloying step of forming a titanium alloy by heating to a temperature lower than the melting point of titanium at a temperature higher than the melting point of germanium;
A manufacturing method comprising:   10. The method according to claim 9, wherein in the germanium melting step, 2 to 15% by mass of tin is further added based on a total mass of materials to form the titanium alloy. A method for producing a titanium alloy containing niobium, germanium and titanium,
A preparation step of preparing a mixture containing 3 to 20% by mass of niobium and titanium in a heating container based on a total mass of materials to form the titanium alloy;
A mixture melting step of heating and melting the mixture;
A germanium melting step in which 1 to 15% by mass of germanium is added into the heating vessel and melted based on the total mass of materials to form the titanium alloy;
A casting step of casting immediately after the steam no longer rises from the surface of the molten metal in the heating vessel,
A manufacturing method comprising:   12. The method according to claim 11, wherein the mixture further contains 1 to 5% by mass of zirconium based on the total mass of materials to form the titanium alloy.   A titanium alloy obtainable by the production method according to any one of claims 9 to 12.   A jewelry comprising the titanium alloy according to any one of claims 1 to 8.   The accessory according to claim 14, wherein at least a part of the surface is covered with a titanium oxide film.

Images