TITANIUM MATERIAL AND METHOD FOR MANUFACTURING TITANIUM MATERIAL

Abstract

In a titanium material, when a chemical composition of a surface is analyzed by X-ray photoelectron spectroscopy, the titanium material contains, as a composition of the surface, Zn: 0.1 atom% or more and Ca: 0.5 atom% or more, and the titanium material contains, as a composition of a surface oxide film, C: 20.0 atom% or less and F: 5.0 atom% or less.

Claims

1. A titanium material, wherein, when a chemical composition of a surface is analyzed by X-ray photoelectron spectroscopy, the titanium material contains, as a composition of the surface; Zn: 0.1 atom% or more, and Ca: 0.5 atom% or more, and the titanium material contains, as a composition of a surface oxide film; C: 20.0 atom% or less, and F: 5.0 atom% or less.

2. The titanium material according to claim 1, wherein the surface oxide film has a thickness of 5 to 20 nm.

3. A method for manufacturing a titanium material, comprising: cleaning a titanium raw material, wherein the cleaning includes; immersing the titanium raw material in an aqueous solution having a temperature of 40° C. to 60° C. for 1.0 minutes or longer, where the aqueous solution contains, a zinc salt: 0.00030 to 0.65000 mass% in terms of Zn, a calcium salt: 0.00060 to 0.40000 mass% in terms of Ca, HF: 1.0 to 6.0 mass%, and HNO.sub.3: 4.0 to 10.0 mass%, and washing the titanium raw material lifted from the aqueous solution with water.

4. The method for manufacturing a titanium material according to claim 3, wherein the zinc salt is 0.00030 to 0.00100 mass% in terms of Zn, and the calcium salt is 0.00060 to 0.00108 mass% in terms of Ca.

5. The method for manufacturing a titanium material according to claim 3, wherein the zinc salt is ZnCl.sub.2.

6. The method for manufacturing a titanium material according to claim 3, wherein the calcium salt is CaCl.sub.2.

7. The method for manufacturing a titanium material according to claim 5, wherein the calcium salt is CaCl.sub.2.

8. The method for manufacturing a titanium material according to claim 3, further comprising: heating the titanium raw material after the cleaning to 300° C. to 900° C. in an inert atmosphere.

9. The method for manufacturing a titanium material according to claim 5, further comprising: heating the titanium raw material after the cleaning to 300° C. to 900° C. in an inert atmosphere.

10. The method for manufacturing a titanium material according to claim 6, further comprising: heating the titanium raw material after the cleaning to 300° C. to 900° C. in an inert atmosphere.

11. The method for manufacturing a titanium material according to claim 7, further comprising: heating the titanium raw material after the cleaning to 300° C. to 900° C. in an inert atmosphere.

12. The method for manufacturing a titanium material according to claim 4, wherein the zinc salt is ZnCl.sub.2.

13. The method for manufacturing a titanium material according to claim 4, wherein the calcium salt is CaCl.sub.2.

14. The method for manufacturing a titanium material according to claim 12, wherein the calcium salt is CaCl.sub.2.

15. The method for manufacturing a titanium material according to claim 4, further comprising: heating the titanium raw material after the cleaning to 300° C. to 900° C. in an inert atmosphere.

16. The method for manufacturing a titanium material according to claim 12, further comprising: heating the titanium raw material after the cleaning to 300° C. to 900° C. in an inert atmosphere.

17. The method for manufacturing a titanium material according to claim 13, further comprising: heating the titanium raw material after the cleaning to 300° C. to 900° C. in an inert atmosphere.

18. The method for manufacturing a titanium material according to claim 14, further comprising: heating the titanium raw material after the cleaning to 300° C. to 900° C. in an inert atmosphere.

Description

EXAMPLES

[0081] Hereinafter, the embodiment of the present invention will be specifically described while showing examples. The examples to be shown below are merely examples of the present invention, and the present invention is not limited to the following examples.

Example 1

[0082] Titanium cold-rolled sheets (titanium substrates) of types shown in Table 2 were manufactured, a plurality of samples having a variety of sizes were cut out from each of these cold-rolled sheets, and an immersion treatment was carried out under conditions shown in Table 2. Table 2 shows the immersion treatment conditions. Subsequently, the cold-rolled sheets after the immersion treatment were washed with water by the following method. That is, the cold-rolled sheets after the immersion treatment were immersed in a water washing bath at room temperature (25° C.) for 1 minute, thereby removing a pickling liquid on the surfaces.

[0083] No. 1 in Table 2 is an example in which a cleaning step was not carried out (an example of a sheet as cold-rolled and annealed), and No. 2 is an example in which a zinc salt and a calcium salt were not contained in an aqueous solution that was used in the immersion treatment in the cleaning step. CP1 shown in the item of the titanium raw material type in Table 2 indicates commercially pure titanium of JIS Class 1, CP2 indicates commercially pure titanium of JIS Class 2, and CP3 indicates commercially pure titanium of JIS Class 3. Underlined conditions in Table 2 indicate that the conditions are outside the scope of the present invention.

TABLE-US-00002 No. Titanium substrate Zinc salt Calcium salt HF content (mass%) HNO.sub.3 content (mass%) Temperature (°C) Time (minutes) Inert atmosphere annealing after cleaning step Note Kind Content (mass%) Kind Content (mass%) 1 CP1 - - - - - - - - - Comparative Example 2 CP1 - - - - 2.0 4.5 40 1.0 - Comparative Example 3 CP1 ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 2.0 4.5 40 1.0 - Present Invention Example 4 CP1 Zn(NO.sub.3).sub.2 0.00092 CaCl.sub.2 0.00108 2.0 4.5 40 1.0 - Present Invention Example 5 CP1 ZnCl.sub.2 0.00096 Ca(NO.sub.3).sub.2 0.00098 2.0 4.5 40 3.0 - Present Invention Example 6 CP1 ZnCl.sub.2 0.00048 CaCl.sub.2 0.00072 2.0 4.5 40 3.0 - Present Invention Example 7 CP1 ZnCl.sub.2 0.00024 CaCl.sub.2 0.00108 2.0 4.5 40 1.0 - Comparative Example 8 CP1 ZnCl.sub.2 0.00096 CaCl.sub.2 0.00036 2. 0 4.5 40 1.0 - Comparative Example 9 CP1 ZnCl.sub.2 0.00129 CaCl.sub.2 0.00108 2.0 4.5 40 1.0 - Present Invention Example 10 CP1 ZnCl.sub.2 0.00096 CaCl.sub.2 0.00163 2.0 4.5 40 3.0 - Present Invention Example 11 CP1 ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 1.0 4.0 40 3.0 - Present Invention Example 12 CP1 ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 6.0 10 40 3.0 - Present Invention Example 13 CP1 ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 0.5 3.0 40 1.0 - Comparative Example 14 CP1 ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 8.0 12 40 1.0 - Comparative Example 15 CP1 ZnCO.sub.3 0.00104 CaCO.sub.3 0.00120 1.0 4.0 40 1.0 - Present Invention Example 16 CP1 ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 2.0 4.5 60 3.0 - Present Invention Example 17 CP1 ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 2.0 4.5 30 3.0 - Comparative Example 18 CP1 ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 2.0 4.5 40 05 - Comparative Example 19 CP1 ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 2.0 4.5 40 1.0 Ar, 500° C., 1.0 h Present Invention Example 20 CP2 ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 2. 0 4.5 40 1.0 - Present Invention Example 21 CP3 ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 2.0 4.5 40 3.0 - Present Invention Example 22 Ti-1Cu ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 2.0 4.5 40 3.0 - Present Invention Example 23 Ti-3Al-2.5V ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 2.0 4.5 40 3.0 - Present Invention Example 24 Ti-5Al-1Fe ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 2.0 4.5 40 1.0 - Present Invention Example 25 Ti-0.05Pd ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 2.0 4.5 40 1.0 - Present Invention Example 26 Ti-0.35Pd ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 2.0 4.5 40 1.0 - Present Invention Example 27 Ti-15V-3Al-3Cr-3Sn ZnCl.sub.2 0.00096 CaCl.sub.2 0.00108 2.0 4.5 40 1.0 - Present Invention Example 28 CP2 ZnCl.sub.2 0.00024 CaCl.sub.2 0.00108 2.0 4.5 40 1.0 - Comparative Example 29 CP3 ZnCl.sub.2 0.00024 CaCl.sub.2 0.00108 2.0 4.5 40 3.0 - Comparative Example 30 Ti-1Cu ZnCl.sub.2 0.00024 CaCl.sub.2 0.00108 2.0 4.5 40 1.0 - Comparative Example 31 Ti-3Al-2.5V ZnCl.sub.2 0.06024 CaCl.sub.2 0.00108 2.0 4.5 40 1.0 - Comparative Example 32 Ti-5Al-1Fe ZnCl.sub.2 0.00024 CaCl.sub.2 0.00108 2. 0 4.5 40 1.0 - Comparative Example 33 Ti-0.05Pd ZnCl.sub.2 0.00024 CaCl.sub.2 0.00108 2.0 4.5 40 1.0 - Comparative Example 34 Ti-0.15Pd ZnCl.sub.2 0.110024 CaCl.sub.2 0.00108 2.0 4.5 40 3.0 - Comparative Example 35 Ti-15V-3Al-3Cr-3Sn ZnCl.sub.2 0.00024 CaCl.sub.2 0.00108 2.0 4.5 40 3.0 - Comparative Example

[0084] Surface composition qualitative analysis, quantitative analysis, and depth-direction analysis were carried out by XPS on the surfaces of the samples that had been washed with water, and then washed with ultrasonic waves for 60 seconds by immersing the samples in acetone. Analysis conditions by XPS were as described below. [0085] Apparatus: VersaProbe III manufactured by ULVAC-PHI, Inc. [0086] X-ray source: mono-AlKα (hv: 1486.6 eV) [0087] Beam diameter: 200 .Math.mΦ (≈ analysis region) [0088] Detection depth: 2 to 8 nm [0089] Sputtering conditions: Ar.sup.+, sputtering rate 2.0 nm/min. (SiO.sub.2 conversion value)

[0090] The SiO.sub.2 conversion value is the sputtering rate obtained under the same measurement conditions using a SiO.sub.2 film the thickness of which has been measured in advance using an ellipsometer.

(Color Unevenness)

[0091] In order to evaluate color unevenness on the surface of a titanium material, L*, a.sup.∗, and b.sup.∗ were measured in accordance with JIS Z 8730: 2009 at a total of 10 points (5 points on each of the front and rear surfaces: 1 point at the sample central part and 4 points at the sample corner portions) on a 200 mml, × 300 mmw × 0.3 mmt sample after a water washing treatment, and color differences ΔE*ab between the measurement points were used as evaluation criteria. The color difference was obtained using the luminosity L.sup.∗ and the chromaticities a.sup.∗ and b.sup.∗ at each measurement point obtained in accordance with JIS Z 8730:2009 from differences ΔL.sup.∗, Δa.sup.∗, and Δb.sup.∗, thereof between the measurement points in accordance with color difference ΔE.sup.∗ab = [(ΔL.sup.∗).sup.2 + (Δa.sup.∗).sup.2 + (Δb.sup.∗).sup.2].sup.½

[0092] The color differences were measured with a light source C using a color difference meter CR-200b manufactured by Konica Minolta Japan Inc. Specifically, samples where the maximum value of the color differences AE*ab between the measurement points was 5 or less were determined to have favorable evaluation results (OK), and samples where the maximum value of the color differences AE*ab was more than 5 were determined to have poor evaluation results (NG).

(Weather Resistance)

[0093] A 50 mmL × 25 mmw × 0.3 mmt piece was cut out from the water-washed sample, and a discoloration acceleration test was carried out thereon. In the discoloration acceleration test, the sample was immersed in a sulfuric acid aqueous solution having a pH of 3 at 80° C. for 4 days. L*a*b* of the surface of the titanium material before and after the discoloration acceleration test was measured to obtain color differences AE*ab before and after the discoloration acceleration test. The color differences were measured and calculated in the same manner as described above. The color differences were measured on the front and rear surfaces at 1 point in the central part and 4 points in the corner portions of the sample, and the color difference AE*ab obtained on average from a total of 10 points was used for the evaluation of weather resistance.

[0094] Since the threshold value of the color difference AE*ab at which discoloration is visually recognized is 8.0, in a case where the color difference AE*ab before and after the discoloration acceleration test was less than 8.0, the weather resistance was determined as favorable (OK), and, in a case where the color difference ΔE*ab before and after the discoloration acceleration test was 8.0 or more, the weather resistance was determined as poor (NG).

(Whiteness)

[0095] Furthermore, for the water-washed samples, L.sup.∗, a.sup.∗, and b.sup.∗ were measured in accordance with JIS Z 8730:2009, and the whiteness was evaluated by comparing L.sup.∗, a.sup.∗, and b.sup.∗ with L.sup.∗ before the cleaning step. Regarding the measurement positions of the whiteness, the whiteness was measured on the front and rear surfaces at 1 point in the central part and 4 points in the corner portions of the sample in the same manner as described above, and L.sup.∗ obtained on average from a total of 10 points was used for the evaluation of whiteness.

[0096] Since L.sup.∗ (whiteness) of the sample before the cleaning step was about 65, whiteness that was different enough to be clearly recognized visually by comparing the sample before the cleaning step was used as an evaluation criterion. Specifically, samples having L.sup.∗ of 70 or more were determined to have favorable evaluation results (OK), and samples having L.sup.∗ of less than 70 were determined to have poor evaluation results (NG). The results are shown in Table 3. “-” in Table 3 indicates that the value was the detection limit or less. In addition, underlined conditions in the items of the XPS analysis and the surface oxide film in Table 3 indicate that the conditions are outside the scope of the present invention, and underlined numerical values in the items of the weather resistance, the color unevenness, and the whiteness in the same table indicate that the evaluation results were NG.

TABLE-US-00003 No. XPS analysis Surface oxide film Weather resistance Color unevenness Whiteness Note Zn content (atom%) Ca content (atom%) C content (atom%) F content (atom%) Thickness (nm) Color difference ΔE.sup.∗ab Evaluation result Color difference ΔE.sup.∗ab Evaluation result L.sup.∗ Evaluation result 1 - - 22.8 8.1 9 20.0 NG 0 OK 65 NG Comparative Example 2 - 0.3 3.1 3.0 10 15.3 NG 1.2 OK 74 OK Comparative Example 3 0.3 0.7 3.1 5.0 11 6.8 OK 1.5 OK 74 OK Present Invention Example 4 0.3 0.8 3.2 4.8 10 7.0 OK 1.3 OK 75 OK Present Invention Example 5 0.3 0.7 3.1 4.9 9 7.1 OK 1.1 OK 77 OK Present Invention Example 6 0.2 0.8 2.5 4.9 11 7.0 OK 0.9 OK 74 OK Present Invention Example 7 - 0.7 3.1 4.8 10 14.0 NG 1.1 OK 75 OK Comparative Example 8 0.3 0.1 2.8 45 9 15.0 NG 1.2 OK 76 OK Comparative Example 9 1.0 0.8 3.1 4.7 21 6.5 OK 7.6 NG 62 NG Present Invention Example 10 0.4 1.5 3.0 4.9 22 5.7 OK 9.8 NG 61 NG Present Invention Example 11 0.3 0.8 2.1 5.0 10 7.5 OK 0.8 OK 73 OK Present Invention Example 12 0.4 0.8 3.3 5.0 9 7.8 OK 1.8 OK 75 OK Present Invention Example 13 0.1 0.4 5.5 1.0 10 18.0 NG 1.2 OK 68 NG Comparative Example 14 0.5 1.0 0.5 23.4 9 25.4 NG 1.5 OK 73 OK Comparative Example 15 0.9 1.3 15.6 4.5 10 7.9 OK 1.4 OK 65 NG Present Invention Example 16 0.4 0.8 3.2 5.0 11 7.3 OK 1.0 OK 75 OK Present Invention Example 17 0.3 0.9 23.4 7.5 15 21.3 NG 15.3 NG 54 NG Comparative Example 18 0.2 0.5 24.3 8.2 16 19.8 NG 18.0 NG 55 NG Comparative Example 19 0.3 0.7 1.5 2.5 12 4.1 OK 0.7 OK 74 OK Present Invention Example 20 0.4 0.6 2.0 5.0 10 6.5 OK 1.1 OK 74 OK Present Invention Example 21 0.5 0.5 3.5 4.8 11 7.1 OK 1.5 OK 74 OK Present Invention Example 22 0.6 0.8 5.0 3.0 10 6.5 OK 1.4 OK 75 OK Present Invention Example 23 0.5 0.7 6.0 4.0 10 7.1 OK 1.2 OK 76 OK Present Invention Example 24 0.6 0.7 3.0 4.5 11 7.5 OK 1.3 OK 74 OK Present Invention Example 25 0.3 0.8 4.0 3.0 10 4.2 OK 1.6 OK 73 OK Present Invention Example 26 0.4 0.5 4.5 3.0 10 3.0 OK 1.8 OK 75 OK Present Invention Example 27 0.3 0.5 4.2 3.1 9 5.5 OK 1.4 OK 72 OK Present Invention Example 28 - 0.8 2.5 4.8 10 15.1 NG 0.8 OK 76 OK Comparative Example 29 - 0.5 3.5 4.9 10 16.0 NG 0.9 OK 75 OK Comparative Example 30 - 0.8 5.4 3.5 10 15.5 NG 1.1 OK 73 OK Comparative Example 31 - 0.7 7.0 4.1 10 17.4 NG 1.3 OK 75 OK Comparative Example 32 - 0.8 5.0 3.5 11 18.0 NG 1.2 OK 74 OK Comparative Example 33 - 1.0 4.0 4.5 10 14.0 NG 1.5 OK 76 OK Comparative Example 34 - 0.9 4.0 3.2 10 13.8 NG 1.4 OK 75 OK Comparative Example 35 - 0.8 5.6 4.8 9 16.7 NG 1.6 OK 72 OK Comparative Example

[0097] As shown in Tables 2 and 3, when the chemical composition of the surface of the titanium material analyzed by XPS was Zn: 0.1 atom% or more and Ca: 0.5 atom% or more, and the composition of the surface oxide film was C: 20.0 atom% or less and F: 5.0 atom% or less, the titanium materials were favorable in terms of weather resistance. Furthermore, the samples where the thickness of the surface oxide film was 5 to 20 nm were also favorable in terms of evaluation results of the color unevenness and the whiteness L*.

[0098] Hitherto, the preferable embodiment of the present invention has been described in detail, but the present invention is not limited to such examples. It is evident that a person skilled in the art of the present invention is able to conceive a variety of modification examples or correction examples within the scope of the technical concept described in the claims, and it is needless to say that such examples are also understood to be in the technical scope of the present invention.