JP2815643B2 - Colored titanium material which is hard to be scratched and has good adhesion and a method for producing the same - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a colored titanium material having good adhesion and a method for producing the same, and particularly to a titanium which has significantly improved the difficulty of forming a scratch and the adhesion of a colored film. Material and manufacturing method.

[Related Art] In recent years, titanium has been evaluated for its properties such as excellent corrosion resistance and specific strength. In addition to marine and aerospace structures, building materials such as roofs and wall materials are subjected to coloring treatment. Or, various panel members such as furniture, and further, accessories such as earrings and tie pins are being used. As a coloring method of titanium for such an application, mainly, a high-temperature oxidation method and an anodic oxidation method have been known for a long time.

The high-temperature oxidation method according to the present invention means that the titanium material to be treated is 450 to 7 in the atmosphere or in an atmosphere gas containing oxygen.
Heat to a high temperature of about 50 ° C to form an oxide film on the surface,
This is a method of generating interference colors of various hues corresponding to the film thickness, while the anodic oxidation method is performed in an aqueous solution of phosphoric acid or the like.
In this method, an oxide film having an interference color is formed on the surface by applying a voltage using the titanium material to be treated as an anode.

Conventionally, various improvements and applied techniques have been studied for these methods, mainly for anodization. For example, as an applied technique, there is a method proposed in Japanese Patent Application Laid-Open No. 52-22534 or Japanese Patent Application Laid-Open No. 62-224698 as a method of emitting a beautiful interference color. The former proposal is a method in which a titanium material before anodizing treatment is heated and held in an inert gas atmosphere to coarsen crystal grains, and then a crystal pattern is revealed to obtain a beautiful interference color. This is a method in which color is adjusted by anodizing or high-temperature oxidation after pre-treatment such as particle size adjustment or dull roll finishing is performed to adjust the color appearance in advance.

[Problems to be Solved by the Invention] As described above, various applications and utilization techniques relating to the titanium coloring method have been proposed. However, in fact, the conventional titanium coloring methods including the above-mentioned application and utilization techniques are almost the same. There are common difficulties, that is, scratches are easily formed and the wear resistance is poor, and the adhesion of the oxide film is poor. As a conventional countermeasure against this problem, a method of coating an organic film or an inorganic film after a coloring treatment or a method of performing a heat treatment (idling) under anodizing treatment is disclosed in JP-A-56-60 / 1988.
No. 414, JP-A-63-4095 and JP-A-62-861
No. 97 has been proposed.

However, the methods according to these proposals are essential improvement measures because the color tone of the colored film is easily deteriorated due to the presence of a coating film or an oxide film generated during baking, and the effect of improving wear resistance is small. It is hard to say.
Further, in the case of the high-temperature oxidation method, there is no proposal, and when colored by a method (for example, adjustment of crystal grain size) as proposed in the above-mentioned Japanese Patent Application Laid-Open No. 62-224698, a flaw is easily formed and a film is not easily formed. Adhesion is also poor, and there are inevitable restrictions on applications.

Means for Solving the Problems In view of the problems described above, the present inventors have studied various methods for improving the adhesion and abrasion resistance of an oxide film having an interference color by a high-temperature oxidation method. It was found that the amount of oxygen solid solution of the surface layer of the base titanium material forming the oxide film having a color greatly affects the adhesion of the oxide film, and that there is an oxygen solution range suitable for improving the adhesion, Further, the present invention has been made by finding a rational solution for a manufacturing method that simultaneously satisfies the characteristics such as anti-abrasion property.

That is, one of the present invention is that the amount of oxygen solid solution of the surface layer is 1.0 to 1
It is intended to provide a colored titanium material obtained by coloring a surface of a metal titanium material having a weight of 0.0% by a high-temperature oxidation method.

Further, another one of the present invention is to heat the titanium material in the air or in an oxidizing atmosphere at 800 to 1200 ° C. for 2 to 100 minutes, and then form the titanium mainly composed of TiO ₂ and TiO formed on the surface of the titanium material. After removing all oxide films, an oxygen diffusion layer having an oxygen solid solution content of 1.0 to 10.0% by weight appears as a titanium metal surface layer, and then heated at a heating rate of 20 ° C./min or more in air or an oxidizing atmosphere. At 450 ℃ ~ 7
This is a method for producing a colored titanium material which is hardly flawed and has good adhesion, characterized in that it is heated to 50 ° C., held for 1 to 100 minutes, and cooled.

[Operation] Here, the titanium material used in the present invention may be either a pure titanium material or an alloy titanium material, and may have a previous history (such as an ingot, a hot-rolled sheet, or an annealed sheet) or a shape thereof. There is no particular restriction.

In the present invention, such a titanium material whose surface has been cleaned is subjected to a pretreatment for forming an oxygen diffusion layer (oxygen-enriched layer). That is,
A heat treatment is performed at 800 to 1200 ° C. for 2 to 100 minutes in the air or an oxidizing atmosphere. By the heat treatment under such conditions, the structure near the surface of the titanium material roughly becomes TiO ₂ , TiO, an oxygen diffusion layer, and a matrix from the outermost surface toward the inside. The amount of oxygen solid solution in the oxygen diffusion layer is high on the titanium oxide film (TiO) side and about 10% or more, while the amount of oxygen solid solution in the mother phase is asymptotic to that of the mother phase.

In this case, if the oxygen diffusion layer is a region on the mother phase side where the amount of component (average) oxygen of the base material is twice or more, the thickness is about 5 to 200 μm within the conditions of the present invention.

The reason why such an oxygen diffusion layer is formed is that titanium has an extremely high solid solubility limit of oxygen (10% or more), and oxygen has a strong tendency to diffuse into the titanium material.

In the present invention, a layer having a specific amount of solid solution of oxygen in the oxygen diffusion layer is exposed as a surface layer (that is, a titanium oxide layer such as TiO ₂ and TiO is removed) and a coloring treatment by high-temperature oxidation is performed. An important feature of the method is to improve the properties such as the adhesion of the colored film and the abrasion resistance by hardening the base titanium material.

If the heating temperature of the pretreatment in an oxidizing gas atmosphere or air is less than 800 ° C. or the heating time is less than 2 minutes, the oxygen diffusion layer is insufficiently formed and the thickness is too thin. If the heating time exceeds 100 minutes, the material loss increases, the oxide film or oxygen diffusion layer develops remarkably, the surface properties of the titanium material deteriorate, or the oxygen concentration of the parent phase becomes too high, resulting in poor processing characteristics. Problems such as deterioration occur.

After the pretreatment, in the present invention, an oxide film of titanium such as TiO ₂ or TiO is removed, and an oxygen diffusion layer having an oxygen solid solution amount of 1.0 to 10.0% by weight is removed by mechanical polishing, chemical polishing or pickling. Put out. When removing an oxide film such as TiO ₂ by pickling or the like, it is efficient to add processing strain such as rolling in advance.

The reason for specifying the oxygen solid solution amount as 1.0 to 10.0% by weight is that if the oxygen solid capacity is less than 1.0% by weight, the effect of improving the adhesion of the colored film formed in the next step is small, and the degree of surface hardening of the underlying titanium material Is insufficient to improve the wear resistance. On the other hand, if the amount of oxygen solid solution exceeds 10.0% by weight, the variation in the oxygen amount depending on the site is large and coloring unevenness is likely to occur. Oxides are mixed, and embrittlement of the surface layer becomes remarkable, which may cause hair cracks and the like.

By increasing the amount of oxygen dissolved in the surface layer of the titanium material in this way, the adhesion and wear resistance of the subsequently formed colored oxide film are improved because of the difference between the colored oxide film and the base titanium material. This is due to improved consistency (high continuity of the atomic arrangement between the oxide film and the base titanium material). This is also the reason why a beautiful colored film having a deep color appearance with less turbidity of the color can be obtained in the present invention.

After an oxygen diffusion layer having a specific oxygen solid solution amount is exposed on the surface of the titanium material, a high-temperature oxidation treatment is performed. In the present invention, the high-temperature oxidation treatment is performed by heating to 450/750 ° C. at a heating rate of 20 ° C./min or more in the air or an oxidizing atmosphere to 1 to 100 ° C.
This is done by holding for a minute and then cooling.

When the heating rate is less than 20 ° C./min, when the oxygen partial pressure of the oxidizing atmosphere gas is high (for example, in the air), the color clarity of the colored film decreases due to the effect of oxidation during heating. The heating rate was 20 ° C./min or more. The upper limit of the heating rate is not particularly limited, and the earlier the heating rate is, the more desirable it is from the viewpoint of suppressing the formation of an oxide film during heating.

Since the heating holding temperature and the holding time are the main controlling factors of the thickness of the oxide film, it directly affects the color, that is, the hue of the colored film. Other factors affecting the thickness of the oxide film include the oxygen partial pressure in the atmosphere gas and the crystal grain size of the titanium material to be treated. In particular, regarding the latter crystal grain size, the larger the crystal grain size is, the less the influence of heterogeneous oxidation at the crystal grain boundaries is, and the like, so that coloring of various hues becomes easy. In addition, even under the same heating conditions, the thickness of the oxide film varies depending on the crystal orientation, so that a rich color tone appears.

If the heating temperature is less than 450 ° C or the heating holding time is less than 1 minute, the formation of an oxide film is insufficient, so that almost no color can be formed, while the heating temperature exceeds 750 ° C or the heating holding time exceeds 100 minutes. Then, an oxide film is formed to be thick and the adhesion becomes insufficient, or the color tends to be turbid. Note that the appropriate heating temperature and holding time may be appropriately selected so as to obtain a desired color tone or color appearance while considering the oxygen partial pressure of the atmosphere gas. For example, in air heating at 600 ° C., a green interference color appears from blue to purple through heating and holding for 5 to 100 minutes, but if the heating time is prolonged, the color tone becomes turbid, so it is clear if desired. When a green color is desired to be developed, it is preferable to increase the heating temperature and keep the temperature for a short time (for example, at 650 ° C. for 5 minutes).

The heating conditions are not only a method of heating the titanium material to be treated to a uniform temperature, but also a method of blowing a cooling gas or pressing a cooling plate to the surface of the titanium material in any form. A variety of colored patterns can be produced by making changes.

 Hereinafter, the present invention will be described in detail with reference to examples.

[Example] From a pure titanium and an alloy titanium (6% Al-4% V) ingot plates having an oxygen content of 0.20% by weight and 0.18% by weight, respectively, a plate having a surface thickness of 3 mm was cut out from a flat plate,
A colored titanium plate was manufactured under the pretreatment conditions and coloring conditions shown in Table 1. The state of the amount of oxygen and the like on the surface to be colored (appeared after the washing with hydrofluoric acid and nitric acid) was examined by EPMA (electron beam scanning micro analyzer) and X-ray analysis.

The adhesion of the colored film of the colored titanium material thus prepared, the surface hardness of the surface to be treated, the abrasion resistance, the appearance such as the color tone, etc. were evaluated, and the results were evaluated including the comprehensive evaluation (5 grades (good is 5)). Are also shown in Table 1.

In addition, the adhesion of the colored film is obtained by engraving a 2 mm square base pattern on the plate surface, bonding it to a jig with an epoxy-based adhesive, and then peeling it off. evaluated. On the other hand, the abrasion resistance was measured using a sand erosion tester, and the color film was 95%
The time until deletion was measured and evaluated.

As is clear from the evaluation results in Table 1, according to the present invention, a colored titanium material having remarkably excellent properties such as adhesion and abrasion resistance can be produced and provided as compared with Comparative Examples.

[Effects of the Invention] As is clear from the above description, according to the present invention, it is possible to produce and provide a colored titanium material having a small flaw and good adhesion, which is difficult with the prior art, and provides a beautiful color tone. -Titanium for arts and crafts such as accessories, pots, ornaments, etc., as well as various office furniture, as well as building materials panels that require abrasion resistance due to sand and dust etc. The present invention greatly expands the uses of the present invention, and the effect of the present invention on these related industrial fields is extremely large.

Claims (2)

(57) [Claims] Claims 1. A colored titanium film having a good adhesion with a scratch resistant, characterized by having a colored film formed by a high-temperature oxidation method on the surface of a titanium metal having a surface layer having an oxygen solid solution amount of 1.0 to 10.0% by weight. Wood. 2. After pre-heating the titanium material at 800 to 1200 ° C. for 2 to 100 minutes in the air or in an oxidizing atmosphere, all titanium oxide films mainly composed of TiO ₂ and TiO formed on the titanium surface are removed. Removed and the oxygen solid solution amount is 1.0 to 10.
The oxygen diffusion layer of 0% by weight appears as a titanium metal surface layer, and then at 20 ° C. in air or an oxidizing atmosphere.
/ 450 to 750 ° C at a heating rate of 1 / min or more and 1 to 100
A method for producing a colored titanium material which is hardly flawed and has good adhesion, which is characterized in that the titanium material is cooled after being held for one minute.