RU2266345C1 - Construction material from pure titanium and method for manufacturing the same - Google Patents

Abstract

FIELD: metallurgy, in particular, titanium-based materials resistant to change of color.

SUBSTANCE: construction material of pure titanium contains, wt%: Fe 0.08 or less; Nb 0.02 or less; Co 0.02 or less, and is provided with surface oxide film having thickness of 170Å or less. Method involves producing material from pure titanium; etching and heating to temperature X( C) within the range of from 130 C to 280 C for time T (min) satisfying condition of T≥239408xX^-2,3237.

EFFECT: increased resistance to change of color for prolonged time as compared to traditional materials.

3 cl, 2 dwg, 4 tbl, 3 ex

Description

BACKGROUND OF THE INVENTION

Field of Invention

The present invention relates to a building material of pure titanium, resistant to color change for a long time, for the construction of the outer walls of buildings and reinforcing elements, and to a method for manufacturing such material from pure titanium.

Description of the Related Art

The titanium material has an oxide film coated surface that has excellent rust resistance, excellent corrosion resistance and the required mechanical properties. Titanium building materials are of particular interest due to their excellent properties.

The modern development of port areas and modern gradually deteriorating environmental conditions around buildings due to acid rain create a variety of problems. The current harsh environmental conditions to which building materials from titanium are exposed cause a color change of building materials from titanium from silver-white to brownish with aging. Titanium materials that have changed color do not have the glitter inherent in beautiful metallic colors and damage the aesthetic design of buildings. Although there is the possibility of updating the original beautiful appearance of titanium materials that have changed color during aging by repair work including grouting or polishing, such repair work is very expensive, and for some parts of buildings such repair work is excluded. Accordingly, research has been conducted on the development of materials made of titanium that are resistant to color change for a long time.

The titanium material, or titanium alloy material described in JP-A-10-8234, has a surface finally finished to a surface roughness of Ra = 3 μm or less and coated with an oxide film of a thickness of 20 Å or more to suppress color change for a long time time. The materials of titanium and titanium alloy described in Japanese patent No. 3255610, have an oxide film with a thickness of 100 Å or less and a surface layer having a certain content C.

A technology designed to solve problems arising from a color change over a long period of time by providing a certain C content in the surface layer is also described in JP-A-2001-348634. In the manufacturing process of a titanium sheet in accordance with this technology, an cold-rolled titanium sheet is annealed at a temperature of from 750 to 800 ° C for 3-5 minutes to remove a layer having a high C content, which is considered to cause a color change for a long time.

The requirements for restraining color changes over a long time of titanium building materials have been gradually tightened in recent years, and there is an urgent need to develop titanium materials that are even more resistant to color changes over time. The test data referred to in the preceding three reference documents are qualitative, not quantitative. Titanium materials must be evaluated using more accurate grading systems to develop titanium materials that meet today's stringent requirements.

Although a variety of pure titanium-resistant building materials that are resistant to color changes for a long time are already on the market, pure titanium building materials are required that have even better resistance to color changes over time because the structural rigidity of buildings is gradually increasing, and The cost of repairs has been increasing gradually in recent years.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide pure titanium material having a greater color change resistance over time than traditional titanium materials.

A variety of titanium materials were studied in order to solve the above problems, and a rigorous assessment was made of the resistance to color change over time of titanium materials. As a result, it was found that certain impurities contained in titanium materials have an effect on the color fastness of titanium materials over time.

Pure titanium and titanium alloys are used to make pure titanium building materials. Building materials from the purest titanium are prepared from industrial grade pure titanium JIS Grade 1 (Japanese Industrial Standards), which contains small amounts of impurities and has excellent formability. Even if titanium building materials are prepared from a material that does not contain titanium scrap, but contains only industrial grade JIS grade 1 titanium, i.e. sponge titanium, titanium building materials inevitably contain various impurities in small quantities. The chemical requirements for JIS Grade 1 industrial titanium determine the content of impurities, including oxygen and iron, in terms of formability. While improving the color fastness for a long time, no attention was paid to the content of such impurities.

The inventors of the present invention found that pure building materials made from pure titanium having certain impurity contents below predetermined values hardly undergo a color change for a long time, and created the present invention.

In accordance with the present invention, pure titanium building material is made of pure titanium having an Fe content of 0.08 mass% or lower, an Nb content of 0.02 mass% or lower, and a Co content of 0.02 mass% or lower.

Preferably, the pure titanium building material has a surface oxide film of a thickness of 170 Å or less. Although pure titanium building material having a thicker surface oxide film has lower color fastness for a long time, pure titanium building material has a beautiful silver-white color, and surface oxide film growth can be effectively restrained when building pure titanium material has a composition as defined above and the thickness of the surface oxide film is 170 Å or less. Consequently, pure titanium building material having a surface oxide film of 170 Å or less is not susceptible to color change for a long time to a value that spoils the aesthetic design and retains a silver-white appearance.

A method of manufacturing a building material from pure titanium in accordance with the present invention includes the steps of: preparing a building material from pure titanium having an Fe content of 0.08 mass% or lower, an Nb content of 0.02 mass% or lower and a Co content of 0.02 wt.% or lower, etching of building material from pure titanium; and heating the etched building material from pure titanium at a temperature of X (° C) in the range from 130 to 280 ° C during the heating time T (min) in order to satisfy the condition expressed as: T≥239408 × X ^-2.3237 .

At the heating stage, a surface oxide film of an appropriate thickness is formed, effective in containing harmful staining, and the content of impurities, which also cause a color change, is reduced. Thus, a pure titanium building material produced by a method for manufacturing a pure titanium building material has a high color change resistance for a long time.

Having a very high resistance to color change for a long time, much higher than that of traditional building materials from titanium or a titanium alloy, the building material from pure titanium of the present invention is very useful as a building material in the construction of buildings for which aesthetic requirements design are significant, which are exposed to sea wind and acid rain, which require expensive maintenance and which are difficult to repair. Thus, the pure titanium building material of the present invention is very useful from the point of view of its industrial use.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objectives, features and advantages of the present invention will be more apparent from the following description, which is considered in connection with the accompanying drawings, in which:

Figure 1 is a graph explaining the OES method of measuring the thickness of the oxide film; and

Figure 2 is a graph showing the relationship between heating time and heating temperature, effective in increasing color fastness for a long time.

DESCRIPTION OF PREFERRED EMBODIMENTS

The most distinctive feature of pure titanium building material in accordance with the present invention is that the color change over time of pure titanium building material is very slow, even when pure titanium building material is used to construct a building subject to harsh environmental conditions. Wednesday.

Although building materials made of titanium or titanium alloy that are resistant to color change for a long time are commercially available, their resistance to color change for a long time is insufficient. Even traditional corrosion-resistant pure titanium building materials change color over time. It has been found that certain impurities contained in a pure titanium building material affect the color change of a pure titanium building material for a long time and that a pure titanium building material containing a controlled amount of impurities is highly resistant to color change over a long time time even in harsh environmental conditions, which led to the creation of the present invention.

Pure titanium building material in a preferred embodiment according to the present invention is prepared from pure titanium having an Fe content of 0.08 mass% or lower, an Nb content of 0.02 mass% or lower and a Co content of 0.02 mass% or lower. Fe, Nb, and Co contained in pure titanium, which is part of a pure titanium building material, cause a color change over time of a pure titanium building material. This fact was discovered by the inventors. The manifestation of a color change over a long time of a building material of pure titanium can be significantly slowed down by controlling the values of Fe, Nb and Co in pure titanium below previously determined values of the content of Fe, Nb and Co. When determining the content of impurities, the expression "X wt.% Or lower" means that pure titanium does not contain impurities at all or contains impurities in a negligible amount. The content is expressed in “percent by weight”, which can simply be further presented as “percent”. Preferably, the Fe content is 0.06% or lower (more preferably 0.05% or lower) the Nb content is 0.015% or lower (more preferably 0.01% or lower) and the Co content is 0.015% or lower (more preferably 0 , 01% or lower).

To obtain pure titanium having Fe, Nb and Co contents not exceeding previously determined values of Fe, Nb and Co contents, such values of Fe, Nb and Co contents in raw titanium material have been established. More specifically, the content of impurities in sponge titanium, i.e. in raw titanium material, are measured, and sponge titanium is used if it has values of Fe, Nb and Co not exceeding the previously determined content of Fe, Nb and Co.

The term "pure titanium" as used here means a substance containing Fe, Nb and Co in amounts not exceeding certain values of the contents of Fe, Nb and Co, inevitable impurities, and Ti, as the rest.

Preferably, the surface oxide film thickness of the prepared pure titanium building material is 170 Å or less. Pure titanium building material having a surface oxide film of a thickness of 170 Å or less and having a composition as defined by the present invention has a beautiful silver-white color characterizing titanium. The pure titanium building material of the present invention effectively inhibits the growth of a surface oxide film that causes a color change and, therefore, the pure titanium building material is excellent as a building material.

The thickness of the surface oxide film can be adjusted by adjusting the growth conditions of the surface oxide film during the manufacture of building material from pure titanium. The surface oxide film grows when pure titanium building material is exposed to the oxygen contained in the atmosphere during the annealing process and is removed by etching. Therefore, the thickness of the surface oxide film can be adjusted by adjusting the vacuum during vacuum annealing, the temperature of the workpiece at the beginning of exposure to the vacuum-annealed part, or the degree of washing after the etching process. More specifically, the thickness of the surface oxide film of the sample and the conditions for the formation of the surface oxide film are repeatedly adjusted to determine the desired conditions.

Although there are no particular restrictions on the method for measuring the thickness of a surface oxide film, the thickness can be measured, for example, by Auger electron spectroscopy. As shown in FIG. 1, the thickness of the surface oxide film can be determined by multiplying the spraying time required to reduce the oxygen concentration to the average oxygen concentration between the maximum oxygen concentration and the main oxygen concentration, by the spraying rate, i.e. (Surface oxide film thickness) = (Spray time t) × (Spray speed). The deposition rate can be determined by the deposition rate at which the SiO ₂ film is deposited by deposition, in accordance with the conditions of the deposition measurement.

In general, a method for manufacturing a pure titanium building material of the present invention includes at least an ingot manufacturing process, a hot rolling process, a cold rolling process, and a finishing process. The conditions for these processes may be the same as for well-known processes. The finishing process following the cold rolling process must be carefully planned because the finishing process has a significant effect on the surface properties of the titanium material.

For example, the finishing process for finishing the titanium material is a vacuum annealing process (BO process) or atmospheric annealing and etching process (AOT final finishing process). It is understood that the surface oxide film of a titanium material finally finished by the BO process contains a large amount of C which causes a color change for a long time. Therefore, in the final finishing of the titanium material, an etching process is preferably used. A method of manufacturing a building material from pure titanium may include an additional process, provided that the additional process does not spoil the etching effect. For example, an etched workpiece can be finally finished by light rolling (passing along the surface layer) using matting rollers on a matte surface to improve the design (clarity) of the workpiece.

When the surface of the workpiece is treated by etching during the finishing process, titanium material having a high color change resistance for a long time can be obtained by heat treatment of the pickled workpiece, in which the pickled workpiece is heated at a temperature of X (° C ) in the range from 130 to 280 ° C during the heating time T (min) in order to satisfy the condition expressed as T≥239408 × X ^-2.3237 . Heating the workpiece at temperatures ranging from 130 to 280 ° C does not cause a harmful color change that spoils the design, and a heat treatment process that satisfies the condition presented by this expression further improves color fastness for a long time. Although the reason why the heat treatment process improves color fastness for a long time is not exactly known, it is assumed that the heat treatment process changes the structure of the oxide film.

Sometimes a harmful color change occurs when the workpiece is heated to a high temperature, not lower than 250 ° C (from 250 to 280 ° C) for a long time in the atmosphere. Thus, it is required to heat the workpiece for no more than 30 minutes, more preferably 10 minutes or less, when the workpiece must be heated to such a high temperature. Even if a color change occurs, the workpiece is painted at the initial stage of the color change in a very light golden color, which improves the design instead of spoiling it. In some cases, the heating can be stopped at such an initial stage to provide a color change of the building material from pure titanium to a very light golden color.

During the heat treatment, the workpiece is heated either in a vacuum atmosphere or in an ambient atmosphere. Any upper limit of the heating time is determined for the heat treatment process in which the workpiece is heated in a vacuum atmosphere, because the color change of the workpiece is not possible under conditions when the workpiece is heated in a vacuum atmosphere.

The pure titanium building material of the present invention, made in this way, has a very high color fastness for a long time compared to traditional building materials of titanium or titanium alloy.

Examples of the present invention will be described below.

Example 1

Samples

Samples No. 1-21 of high-purity titanium (5N, Purity: 99.999% or higher) containing impurity elements at predetermined impurity element content values and, accordingly, having different chemical compositions, were made to study the effect of impurity content on color change during a long time.

Raw titanium materials, respectively, having the chemical compositions shown in Table 1, were melted in a vacuum melting furnace with a gate valve and ingots weighing in the range from 100 to 200 g were obtained. The ingots were heated by the first heating process at 1000 ° C for one hours, then the ingots were hot rolled by a first hot rolling process to produce 6 mm thick plates. The 6 mm thick plates were heated by a second heating process at 1000 ° C. for 10 minutes and by the third heating process at 850 ° C. for one hour, the 6 mm thick plates thus heated were hot rolled by a second hot rolling process to obtain sheets with a thickness of 3 mm. Such hot rolled sheets were annealed by an annealing process at 800 ° C. for 10 minutes and the annealed sheets 3 mm thick were air-cooled. The dross formed on one surface of each of the calcined sheets with a thickness of 3 mm was removed by grinding the surface to a depth of 0.5 mm. Thereafter, sheets of 3 mm thickness were cold rolled by a cold rolling process to obtain sheets of pure titanium with a thickness of about 1 mm. Pure titanium sheets of approximately 1 mm thickness were subjected to a final finishing process in which annealing of pure titanium sheets of approximately 1 mm thickness was performed under the following annealing conditions:

Temperature: 650 ° C

Heating time to 650 ° C: 5 hours

Exposure Time: 3 hours

Vacuum: 10 ^-6 Torr

Cooling: exposed to atmosphere at 200 ° C or lower

Test: (color fastness test for a long time).

The effect of Fe, Nb, and Co as impurities on the color change for a long time was tested by immersing sheets of pure titanium in samples No. 1 to 21 in a solution of sulfuric acid at pH 4, heated to 60 ° C, for three days, for to simulate a situation in which building materials are exposed to acid rain and sea wind, samples No. 1-21 were washed to remove the sulfuric acid solution remaining on samples No. 1 to 21, so that the sulfuric acid solution could not contribute to color change, then image Tsy No. 1 to 21 were dried. Further, the color difference (ΔE *) of the samples was measured using a color difference meter.

In determining the color difference, a three-dimensional color space was assumed, the color of the sample was decomposed into three axial components, i.e. component along one axis in brightness (black / white) and two axes in shades of color (red / green and yellow / blue), and the color is represented in three-dimensional coordinates. A color difference is a color difference between samples, represented by the distance between points defined by coordinates representing colors. A smaller color difference corresponds to a lesser degree of color change. When ΔE * is less than 5, it is believed that the color change for a long time is satisfactorily restrained. The measured data are shown in table 1, in which the underlined values are outside the range defined by the present invention.

As can be seen from table 1, samples No. 13-15 having an Fe content that is outside the range of the Fe content determined by the present invention noticeably changed their color, i.e. color differences are large. Similarly, samples No. 16 and 17 having an Nb content and a Co content outside the range of the Nb content and the range of the Co content defined by the present invention, samples No. 19 and 21 having an Nb content outside the defined range of the Nb content, and samples Nos. 18 and 20, having a Co content that goes beyond a certain Co content range, have extremely changed their color and have color differences ΔE * exceeding 5, even if these samples have an Fe content within a certain range of Fe content.

On the other hand, samples No. 1-12 having Fe, Nb, and Co contents within a certain range of Fe, Nb, and Co contents have color differences ΔE * of less than 5 and a high color change resistance for a long time.

Example 2

Samples

Sheets of pure titanium with a thickness of about 1 mm in samples No. 22-45, having the chemical compositions shown in table 2, were obtained as a result of a process similar to that by which samples No. 1-21 were obtained in example 1.

Samples No. 22 and 23 were etched instead of vacuum annealing in the latter process; those. samples No. 22 and 23 were processed by atmospheric annealing at 700 ° C for 20 seconds after cold rolling, immersion in salt at 550 ° C for 15 seconds and etching to a thickness of 40 μm using a mixture heated to 40 ° C and containing 15 wt.% nitric acid and 1.5 wt.% hydrofluoric acid.

Test

The thickness of the surface oxide film of each of the samples was measured before immersion of the samples in a solution of sulfuric acid to test the resistance to color change for a long time. More specifically, the samples were sonicated in acetone, the samples were dried and the oxygen concentration was measured under the following conditions:

Device: scanning Auger electron spectroscope, PH1650 (Parkin Elmer Co)

Primary Electrons: Energy 5 keV. Current 300 nA. Angle of incidence 30 ° to the perpendicular to the sample

Analyzed area: approximately 10 μm × 10 μm

Ion sputtering: Energy 3 keV. Current 25 mA. The angle of incidence is approximately 58 ° to the perpendicular to the sample. The deposition rate is approximately 1.9 nm / min (SiO ₂ equivalent).

The thickness of the surface oxide film was calculated using the measured data. The thickness was determined by multiplying the spraying time (measured time) required for the oxygen concentration to decrease to the average oxygen concentration between the maximum oxygen concentration and the main oxygen concentration, by the spraying rate of about 1.9 nm / min.

The color differences ΔE * of the samples were measured similarly after measuring the thickness of the surface oxide film. The measured data are shown in table 2.

As can be seen from table 2, materials from pure titanium having a content of Fe, Nb and Co within a certain range of content of Fe, Nb and Co have color differences ΔE * less than 5 and high resistance to color change for a long time.

The color differences ΔE * of the samples finally finished by vacuum annealing are larger than the samples finally finished by etching. Thus, it is preferable to finally finish building materials from pure titanium by etching.

It was found that samples having surface oxide films of a thickness of not more than 170 Å preferably have small color differences ΔE * and sufficient resistance to color change for a long time.

Example 3

Samples

Pure titanium sheets in samples No. 46-83 were produced using an etching process similar to that used in Example 2. In samples No. 46-83, the Fe content was 0.06 or 0.03 mass%, the Nb content was 0.001 wt.% and the content of Co is 0.001 wt.%. Samples were finished by heat treatment under the conditions given in table 3. Values of 239,408 × X ^-2.3237 were calculated.

Test

The color differences of samples No. 46-83 were measured similarly to the color differences of the samples in Example 1. The measured data are shown in table 4.

The measured data shown in Table 4 proves that the finishing of building materials from pure titanium through a finishing process including etching and subsequent heat treatment significantly improves color fastness over time.

The heating time for the heat treatment processes P, Q, and R was shorter than the minimum heating time, expressed as 239,408 × X ^-2.3237 , and therefore the effect of the heat treatment processes P, Q, and R is somewhat smaller. Thus, it was known that the heating time T should satisfy the expression T≥239408 × X ^-2.3237 to further improve the color fastness for a long time. Figure 2 shows the relationship between heating time and heating temperature.

Despite the fact that the sample subjected to the heat treatment process S has a slight color difference ΔE *, it was colored golden due to heating in the atmosphere at a high temperature of 280 ° C for a long time of 150 minutes. Although pure titanium building materials painted in such a golden color are unsuitable when unpainted pure titanium building materials are required, pure titanium building materials painted in such a golden color have application.

Despite the fact that the color difference ΔE * of the sample processed by the heat treatment process L, which is characterized by a heating temperature of 280 ° C and a heating time of 120 minutes, is larger than this difference in the sample processed by the heat treatment process S, the color difference ΔE * satisfactory little. A sample treated by the heat treatment process L was dyed less than that processed by the heat treatment process S and was painted golden.

The heating time should be 30 minutes or less, more preferably 10 minutes or less, in order to prevent discoloration due to high temperature heating in the atmosphere.

Table 1 Sample No. Fe content (wt.%) Nb content (wt.%) Co content (wt.%) ΔЕ * 1 0.08 0.02 0.02 4.5 2 0.08 0.01 0.01 4.0 3 0.08 0.005 0.005 3.3 4 0.08 0.001 0.001 2.9 5 0.06 0.02 0.02 2.5 6 0.06 0.01 0.01 2.4 7 0.06 0.005 0.005 2.1 8 0.06 0.001 0.001 1.9 nine 0.03 0.02 0.02 2.2 10 0.03 0.01 0.01 2.1 eleven 0.03 0.005 0.005 1.8 12 0.03 0.001 0.001 1.3 thirteen 0.10 0.001 0.001 9.1 14 0.15 0.001 0.001 14.7 fifteen 0.20 0.001 0.001 18.2 16 0.08 0.03 0.03 8.9 17 0.03 0.03 0.03 6.9 eighteen 0.08 0.005 0.03 6.6 19 0.08 0.03 0.005 6.3 twenty 0.03 0.005 0.03 5.4 21 0.03 0.03 0.005 5.7

table 2 Sample No. Fe content (wt.%) Nb content (wt.%) Co content (wt.%) The process is finished. finishes Oxide Thickness (Å) ΔЕ * 22 0.08 0.02 0.02 Etching 140 2.8 23 0.08 0.01 0.01 Etching 120 1.6 24 0.08 0.005 0.005 Etching 110 1.2 25 0.08 0.001 0.001 Etching 120 0.8 26 0.06 0.02 0.02 Etching 100 2.1 27 0.06 0.01 0.01 Etching 130 1.3 28 0.06 0.005 0.005 Etching 160 1.0 29th 0.06 0.001 0.001 Etching 150 0.7 thirty 0.03 0.02 0.02 Etching 160 1.8 31 0.03 0.01 0.01 Etching 170 1.1 32 0.03 0.005 0.005 Etching 170 0.8 33 0.03 0.001 0.001 Etching 110 0.6 34 0.08 0.02 0.02 Vacuum annealing 130 4.5 35 0.08 0.01 0.01 Vacuum annealing 140 4.0 36 0.08 0.005 0.005 Vacuum annealing 130 3.3 37 0.08 0.001 0.001 Vacuum annealing 150 2.9 38 0.06 0.02 0.02 Vacuum annealing 150 2.5 39 0.06 0.01 0.01 Vacuum annealing 160 2.4 40 0.06 0.005 0.005 Vacuum annealing 170 2.1 41 0.06 0.001 0.001 Vacuum annealing 110 1.9 42 0.03 0.02 0.02 Vacuum annealing 90 2.2 43 0.03 0.01 0.01 Vacuum annealing 80 2.1 44 0.03 0.005 0.005 Vacuum annealing 160 1.8 45 0.03 0.001 0.001 Vacuum annealing 120 1.3

Table 3 Sample No. Heating conditions 239,408 × X ^-2.3237 Heating temperature (° C) Holding time (min) (A) 130 3 Atmosphere 2.93 (IN) 130 20 atmosphere 2.93 (FROM) 130 60 atmosphere 2.93 (D) 130 120 atmosphere 2.93 (E) 200 1.1 Atmosphere 1.08 (F) 200 20 atmosphere 1.08 (G) 200 60 atmosphere 1.08 (H) 200 120 atmosphere 1.08 (1) 280 0.5 atmosphere 0.49 (J) 280 20 atmosphere 0.49 (TO) 280 60 atmosphere 0.49 (L) 280 120 atmosphere 0.49 (M) 130 120 Vacuum 2.93 (N) 200 120 Vacuum 1.08 (ABOUT) 280 120 Vacuum 0.49 (R) 130 2 Atmosphere 2.93 (Q) 200 0.5 atmosphere 1.08 (R) 280 0.2 Atmosphere 0.49 (S) 280 150 atmosphere 0.49

Table 4 Sample No. Fe content (wt.%) The content of Mb (wt.%) Co content (wt.%) The process will end. finishes Heat treatment process ΔЕ * 46 0.06 0.001 0.001 Etching (A) 0.4 47 0.06 0.001 0.001 Etching (IN) 0.4 48 0.06 0.001 0.001 Etching (FROM) 0.3 49 0.06 0.001 0.001 Etching (D) 0.3 fifty 0.06 0.001 0.001 Etching (E) 0.4 51 0.06 0.001 0.001 Etching (F) 0.3 52 0.06 0.001 0.001 Etching (G) 0.3 53 0.06 0.001 0.001 Etching (H) 0.2 54 0.06 0.001 0.001 Etching (I) 0.3 55 0.06 0.001 0.001 Etching (J) 0.3 56 0.06 0.001 0.001 Etching (TO) 0.2 57 0.06 0.001 0.001 Etching (L) 0.2 58 0.06 0.001 0.001 Etching (M) 0.4 59 0.06 0.001 0.001 Etching (N) 0.3 60 0.06 0.001 0.001 Etching (ABOUT) 0.3 61 0.03 0.001 0.001 Etching (A) 0.3 62 0.03 0.001 0.001 Etching (IN) 0.2 63 0.03 0.001 0.001 Etching (FROM) 0.2 64 0.03 0.001 0.001 Etching (D) 0.2 65 0.03 0.001 0.001 Etching (E) 0.2 66 0,03 0.001 0.001 Etching (F) 0.2 67 0.03 0.001 0.001 Etching (G) 0.2 68 0.03 0.001 0.001 Etching (H) 0.1 69 0.03 0.001 0.001 Etching (I) 0.2 70 0.03 0.001 0.001 Etching (J) 0.1 71 0.03 0.001 0.001 Etching (TO) 0.1 72 0.03 0.001 0.001 Etching (L) 0.1 73 0.03 0.001 0.001 Etching (M) 0.2 74 0.03 0.001 0.001 Etching (N) 0.2 75 0.03 0.001 0.001 Etching (ABOUT) 0.2 76 0.06 0.001 0.001 Etching (R) 0.7 77 0.06 0.001 0.001 Etching (Q) 0.7 78 0.06 0.001 0.001 Etching (R) 0.7 79 0.06 0.001 0.001 Etching (S) 0.1 80 0.03 0.001 0.001 Etching (P) 0.6 81 0.03 0.001 0.001 Etching (Q) 0.6 82 0.03 0.001 0.001 Etching (R) 0.6 83 0.03 0.001 0.001 Etching (S) 0

Claims (2)

1. Building material from pure titanium, characterized in that it contains, wt.%: Fe 0.08 or less, Nb 0.02 or less and Co 0.02 or less and has a surface oxide film with a thickness of 170 Å or less. 2. A method of manufacturing a building material from pure titanium, comprising obtaining a material from pure titanium, characterized in that a material is obtained containing, wt.%: Fe 0.08 or less, Nb 0.02 or less and Co 0.02 or less , then the material is etched and heated to a temperature of X (° C) in the range 130 - 280 ° C for a time T (min) satisfying the condition T≥239408 · X ^-2.3237 .

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