KR20190131342A - Electrolytic solution for uniform anodic oxide film formation of titanium base material and manufacturing method of titanium base material using this same - Google Patents

Abstract

The present invention relates to an electrolytic solution of a titanium base material used for mechanical and aircraft parts and a method of manufacturing the titanium base material. The method of manufacturing the titanium base material for the mechanical and aircraft parts comprises: a pretreatment step of removing foreign matters stuck to the titanium base material constituting the mechanical or aircraft parts; and an oxidation process of depositing the titanium base material in an electrolyte and applying direct current to form an anodized film. The pretreatment step includes: a degreasing step of depositing the titanium base material in a degreasing solution to remove foreign matters stuck to the titanium base material; a washing step of washing the titanium base material after the degreasing step; an etching step of removing the foreign matters remaining in the titanium base material by depositing the titanium base material in an etching solution; and a washing step of washing the titanium base material after the etching step. By changing the degreasing solution and the etching solution according to the pretreatment of the titanium base material, the conditions according to the formation of the anodized film can be optimized, thereby improving the durability and wear resistance of the aircraft or mechanical parts.

Description

Electrolytic solution for uniform anodic oxide film formation of titanium base material and manufacturing method of titanium base material using this same}

The present invention relates to a method for manufacturing a titanium base material used in a machine or an aircraft part, in particular, to optimize the degreasing solution and etching solution required for the pretreatment of the titanium base material, as well as to optimize the electrolyte solution required for the anodization of the titanium base material oxide film The present invention relates to an electrolyte solution for forming a uniform anodized film of a titanium base material to improve its characteristics, and a method of manufacturing a titanium base material using the same.

In general, metals are subjected to anodization as a method for improving strength and hardness as well as corrosion resistance and abrasion resistance. Particularly, when titanium or titanium alloys are surface-treated through anodization, the pores may be finely improved. Therefore, it is widely applied to aviation materials and precision machine parts.

Here, the anodization is one of the most widely known methods for treating the surface of metals. When anodization is conducted through a metal base material (for example, a titanium base material) deposited in an electrolyte, the base material is formed by oxygen generated from the anode. As the surface is oxidized, an oxide film is formed to improve physical properties of the base material.

That is, oxygen ions or hydroxide ions in the electrolyte penetrate into the oxide film formed on the surface of the base material and combine with metal ions to form an oxide layer, thereby forming a porous oxide film and a hydroxide film near the interface between the base material and the oxide layer. By further improving the physical properties of the base material.

Therefore, in increasing the physical properties of the titanium or titanium alloy (hereinafter referred to as titanium) by the anodization, the most important variables of the anodization include voltage, type and temperature of electrolyte solution, purity of base metal, It is of utmost importance to properly set various functions such as preprocessing.

For example, the present applicant (see prior documents) proposed a method of selectively controlling the voltage as a key parameter of the anodization, and in particular, the titanium base material was performed for a total of 50 to 80 minutes using a DC rectifier, but 0 to 50V. Up to 10 ± 2V in 2 ± 1 minutes, and up to 51 ~ 90V in 5 ± 2V in 2 ± 1 minutes, up to 91 to 130V was performed for 1600 to 2000 seconds.

By the way, since the oxide film having a thickness of 5 to 10 μm is formed on the surface of the titanium base material, it has physical properties suitable for aviation materials and the like, but it is insufficient to reach the characteristics of the oxide film targeted by the present applicant.

Therefore, the method of forming the oxide film by adjusting the voltage proposed by the present applicant can be mass-produced at low cost, so that the industrial value is high, and it can be quickly applied to special fields such as aircraft and precision machine parts. The anodization is expected to be of great help in the development of the surface treatment industry.

KR 10-1432671 B1 KR 10-1726260 B1

Accordingly, the present invention has been invented to solve the above problems, as well as optimizing the conditions according to the pretreatment of the titanium base material, as well as the type of electrolyte required for the anodization of the titanium base material suitable for aircraft parts or machine parts, etc. It is an object of the present invention to provide an electrolyte solution for forming a uniform anodized film of a titanium base material to obtain the characteristics of the oxide film and a method of manufacturing a titanium base material using the same.

The electrolyte for achieving the above object is; An anodizing electrolyte of titanium base materials for machinery and aircraft parts, including a main material and auxiliary materials as a means for forming an anodized film on the titanium base material constituting the machine or aircraft parts, wherein the main material is 12 g / l potassium hydroxide or third Any one of 5.5 g / l sodium phosphate or a mixture thereof, and the auxiliary material is any one of ethylene glycol 10 g / l, polyethylene glycol 2,000 5 g / l, sodium metasilicate 1.2 g / l, and ammonium fluoride 6 g / l Is a mixture of.

The manufacturing method for achieving the above object; A pretreatment step of removing foreign matter from the titanium base material constituting the machine or aircraft parts; As a method of manufacturing a titanium base material for machinery and aircraft parts comprising the oxidation step of depositing the titanium base material in an electrolyte and applying a direct current to form an anodized film,

The pretreatment step includes a degreasing step of depositing the titanium base material in a degreasing solution to remove foreign substances stuck to the titanium base material; A washing step of washing the titanium base material after the degreasing step; Etching the titanium base material in an etchant to remove foreign substances remaining in the titanium base material; And a washing step of washing the titanium base material through the etching step.

The oxidation process is stepped up by 10 ± 2V every 30 seconds in the 0 to 60V section, 5 ± 1V every 120 seconds in a 61 to 100V section, and 1 ± 0.2V every 40 seconds in a 101 to 120V section. 1 to 0.2V every 60 seconds in the 121 to 140V section, and maintained for 750 seconds in a section of 140V or more to form an oxide film having a thickness of 8 to 15㎛ on the titanium base material.

As described above, the present invention includes at least the following effects.

First, by changing the degreasing solution and etching solution required for the pretreatment of the titanium base material to optimize the conditions according to the formation of the anodized film, it is possible to improve the durability and wear resistance of the aircraft or mechanical parts.

Second, by forming an oxide film having a thickness of 8 to 15㎛ in the titanium base material by changing the electrolyte solution and voltage conditions of the anodizing device, it is possible to improve the durability and wear resistance of the aircraft or mechanical parts.

Third, by densely forming the pores of the titanium base material by changing the electrolyte solution and voltage conditions of the anodizing device, it is possible to produce a product having excellent colorability as well as forming a hard oxide film on the titanium base material.

1 is an electron micrograph applying the electrolyte A according to the present invention,
2 is an electron micrograph to which the electrolyte solution B according to the present invention is applied;
3 is an electron micrograph to which the electrolyte solution C according to the present invention is applied;
4 is an electron micrograph to which the electrolyte solution D is applied according to the present invention;
5 is an electron micrograph to which the electrolyte solution E according to the present invention is applied.

The present invention, a pre-treatment step for removing various foreign matter pressed to the titanium base material; And an oxidation step of forming an anodized film on the surface of the titanium base material, wherein the pretreatment step includes a degreasing step, a washing step, an etching step, and a washing step, and the oxidation step includes a voltage application step.

Hereinafter, the pretreatment process according to the present invention will be described.

The degreasing step is to remove various foreign substances such as abrasive oil or oxide that was pressed to the surface through a chemical reaction in the state of depositing the titanium base material in the degreasing solution to improve the adhesion, as shown in Table 1, the degreasing solution As the sodium hydroxide (NaOH), sodium carbonate (Na ₂ CO ₃ ), nonionic surfactant (PC-10) of at least one or a mixture thereof is preferable.

division No. Item Standard concentration M (mol / l) Dry bath concentration main ingredient One NaOH (Sodium Hydroxide) 1.0 40 g / l Supplementary Ingredients 2 Na ₂ CO ₃ (sodium carbonate) 0.2 20 g / l 3 PC-10 (nonionic surfactant) -  1 g / l

As shown in Table 2, the degreasing step is performed by setting the degreasing temperature of the titanium base material to 40 ± 2 ℃ and injecting air for 10 ± 2 minutes in the state in which the titanium base material is immersed in the degreasing solution.

The degreasing temperature showed a similar degreasing efficiency in the temperature range of 38 ℃ to 42 ℃, especially the stirring efficiency was similar when maintaining more than 8 minutes in the stirring time of the degreasing liquid.

No. Item Contents One Temperature 40 ± 2 ℃ 2 Agitation Air blowing 3 Time 10 ± 2 minutes

In addition, the etching step is a step of removing various foreign substances including oxides not removed by the degreasing step. As shown in Table 3, hydrochloric acid (HCl) is preferably used as the etching solution of the etching step.

No. Item Standard concentration Dry bath concentration One HCl (HCl) 15wt.% 150 g / l

As shown in Table 4, the etching step is performed by agitating while injecting air for 70 ± 80 seconds while maintaining the titanium base material at 50 ± 2 ° C. while the titanium base material is deposited in the etching solution. .

In the case of the etching temperature of the etching solution showed a similar nicking efficiency in the temperature range of 48 ℃ to 52 ℃, especially in the case of the stirring time of the etching solution, the stirring efficiency was similar.

No. Item Contents One Temperature 50 ± 2 ℃ 2 Stirring Air blowing 3 Processing time 75 ± 5sec

In addition, the washing step is to remove the remaining foreign matter once again by washing with deionized water the chemicals attached to the surface of the titanium base material after the degreasing step or after the etching step, the components or temperature or water washing of the deionized water Since time is a known technique, a detailed description thereof will be omitted.

Hereinafter, the oxidation process according to the present invention will be described.

① Plating material of anodizing device

Titanium base material applied to the present invention has a purity of 98 ~ 99% and says the grades 1 to 4 in the ASTM standard, the titanium base material contains a trace amount of oxygen, nitrogen, carbon, hydrogen, iron to improve the strength. The trace alloy has excellent corrosion resistance and weldability, and in particular, as the content of impurities such as oxygen, nitrogen, and hydrogen increases, the strength increases but the elongation decreases. ) Is stable up to 300 ° C, but it is known that a sudden decrease in strength with increasing temperature.

② Voltage of anodizing device

The oxidation process includes a setting step of receiving an electrolyte solution in the anodizing device and installing a titanium base material on the anode of the anodizing device, and applying a voltage to the titanium base material by applying a direct current to form an anodized film. In the state in which the titanium base material is accommodated in the electrolyte solution, it is carried out for 50 to 70 minutes.

No. Item Contents 10 PEO
(plasma
Electrolytic oxidation) the year before
Condition Step shape Voltage section Boosting condition Time One Ramp 0 to 60 V 10 ± 2V / 30sec 180 sec 2 Ramp 61 to 100 V 5 ± 1V / 120sec 960 sec 3 Ramp 105 V 1 ± 0.2V / 40sec 200 sec 4 Ramp 110 V 1 ± 0.2V / 40sec 200 sec 5 Ramp 115 V 1 ± 0.2V / 40sec 200 sec 6 Ramp 120 V 1 ± 0.2V / 40sec 200 sec 7 Ramp 125 V 1 ± 0.2V / 60sec 300 sec 8 Ramp 130 V 1 ± 0.2V / 60sec 300 sec 9 Ramp 135 V 1 ± 0.2V / 60sec 300 sec 10 Dwell 140 V - 760sec 11 Delivery time 3,600sec (1 hour)

The setting step refers to the step of installing a titanium base material constituting a mechanical or aircraft component on the anode of the anodization device filled with the electrolyte, the voltage application step is a direct current to the titanium base material positioned on the anodization device It means a step of forming an oxide film by applying a current, the voltage application step is applied a voltage of 140V from OV to the titanium base material for a certain time.

As shown in Table 5, 10 ± 2V preferably every 10 seconds in 0 to 60V section, preferably 10V step-up for a total of 180 seconds over a total of six steps, 5 ± 1V every 120 seconds in a 61 to 100V section, preferably 5V each. Boost up to 100V for a total of 960 seconds in 8 steps, boost up to 800 seconds in 20 steps for 1 ± 0.2V every 20 seconds in the 101V to 120V range, preferably 1V every 20 seconds in the 121V to 140V range. ± 0.2V increments, preferably 1V increments in 10 steps for a total of 600 seconds, and maintains more than 760 seconds in the 140V section.

③ Type and content ratio of electrolyte

As shown in Table 6, the electrolyte solution comprises a main material and an auxiliary material, the main material is any one or a mixture of 12 ± 2 g / l potassium hydroxide or 5.5 ± 1 g / l sodium phosphate, and the auxiliary The material is preferably any one or a mixture of ethylene glycol 10 ± 2 g / l, polyethylene glycol 2,000 5 ± 1 g / l, sodium metasilicate 1.2 ± 0.2 g / l, ammonium fluoride 6 ± 1 g / l.

The potassium hydroxide (KOH) and sodium triphosphate (Na ₃ PO ₄ · 12H ₂ O) is a representative strong base material, soluble in water, the ethylene glycol (HOC ₂ H ₄ OH) is the simplest dihydric alcohols It is used as a surfactant because of its viscosity and excellent hygroscopicity, and it is characterized by being glycolic acid or oxalic acid during oxidation.

The polyethylene glycol 2,000 (H (CH ₂ CH ₂ O) nOH 2,000) is a hygroscopic similar to ethylene glycol, and was added for the purpose of generating a uniform PEO (plasma electrolytic oxidation) at the anode interface due to the role of a surfactant in the electrolyte. , Sodium metasilicate (Na ₂ SiO ₃ · 9H ₂ O) is a conductive salt added to improve the thickness of the oxide film according to the increase in current efficiency by reducing the arc (Arc) generation voltage during PEO (plasma electrolytic oxidation) .

The ammonium fluoride (NH ₄ F) is dissociated in an aqueous solution, it was confirmed that the application of magnesium (Mg) anodization has a characteristic of decreasing the size of the pores (pore) and increasing the number of pores, meta Like sodium silicate (Na ₂ SiO ₃ · 9H ₂ O), it has the same effect of reducing arc generation voltage during PEO (plasma electrolytic oxidation), so it can be added to confirm the effect of conduction salt and pore size and quantity control. It was.

Electrolyte Type division Chemical M concentration Dry bath concentration A Main material  KOH (Potassium Hydroxide) 0.213 mol / l 12 g / l Na ₃ PO _{4 12} H ₂ O (trisodium triphosphate) 0.014 mol / l 5.4 g / l B Main material  KOH (Potassium Hydroxide) 0.213 mol / l 12 g / l Na ₃ PO _{4 12} H ₂ O (trisodium triphosphate) 0.014 mol / l 5.4 g / l Auxiliary material H (CH ₂ CH ₂ O) nOH 2,000 (polyethylene glycol 2,000)   0.0025 mol / l  5 g / l C Main material  KOH (Potassium Hydroxide) 0.213 mol / l 12 g / l Na ₃ PO _{4 12} H ₂ O (trisodium triphosphate) 0.014 mol / l 5.4 g / l Auxiliary material HOC ₂ H ₄ OH (ethylene glycol) 0.161 mol / l 10 g / l Auxiliary material Na ₂ SiO ₃ · 9H ₂ O (Sodium Metasilicate) 0.004 mol / l 1.2 g / l D Main material  KOH (Potassium Hydroxide) 0.213 mol / l 12 g / l Na ₃ PO _{4 12} H ₂ O (trisodium triphosphate) 0.014 mol / l 5.4 g / l Auxiliary material Na ₂ SiO ₃ · 9H ₂ O (Sodium Metasilicate) 0.070 mol / l 20 g / l E Main material  KOH (Potassium Hydroxide) 0.213 mol / l 12 g / l Na ₃ PO _{4 12} H ₂ O (trisodium triphosphate) 0.014 mol / l 5.4 g / l Auxiliary material NH ₄ F 0.162 mol / l   6 g / l

On the other hand, even though the potassium hydroxide contained 10 to 14g / l, there was no change in the thickness of the oxide film, and even if the trisodium phosphate contains 4.5 to 6.5g / l, it is understood that there is no change in the thickness of the oxide film The potassium hydroxide may include 12 g / l, and the trisodium phosphate may include 5.5 g / l.

Even though the ethylene glycol contained 8 to 12 g / l, there was no change in the thickness of the oxide film, and even though the sodium metasilicate contained 1.0 to 1.4 g / l, it was found that there was no change in the thickness of the oxide film. Preferably, the ethylene glycol contains 10 g / l and the sodium metasilicate contains 1.2 g / l.

Even if the polyethylene glycol 2000 contained 4 to 6 g / l, there was no change in the thickness of the oxide film. The ammonium fluoride contained no change in the thickness of the oxide film, although the polyethylene glycol 2000 contained 5 to 7 g / l. Preferably it contains 5 g / l silver and said ammonium fluoride contains 6 g / l.

Accordingly, in the present invention, 12 g / l of potassium hydroxide, 5.5 g / l of trisodium phosphate, 10 g / l of ethylene glycol, 1.2 g / l of sodium metasilicate, 5 g / l of polyethylene glycol 2000, It was found that ammonium fluoride is preferably at least one of 6 g / l or a mixture thereof.

④ Selection of electrolyte

The thickness and thickness uniformity of the anodized film of the titanium base material according to the type of the electrolyte (A, B, C, D, E) were evaluated, and the film thickness was measured by non-destructive film thickness by Eddy Current. Was used.

Item / Division Measurement result Electrolyte Type A B C D E Measuring point P1 5.67μm 5.21 μm 9.69 μm 15.00μm 7.10 μm P2 5.59 μm 5.56 μm 9.56 μm 15.13 μm 6.80μm P3 5.38 μm 5.41 μm 9.61 μm 15.22 μm 6.80μm P4 5.68μm 5.68μm 9.59 μm 15.01 μm 6.30 μm P5 5.77 μm 5.80μm 9.63 μm 15.07 μm 6.90 μm Average thickness 5.62μm 5.53 μm 9.62 μm 15.09 μm 6.78 μm Max.-Min. 0.39μm 0.59 μm 0.13 μm  0.22 μm 0.80 μm Ti Oxidation Rate 0.094μm / min 0.092 μm / min 0.160 μm / min 0.252 μm / min 0.113 μm / min

As shown in Table 7, the evaluation result of the film thickness, the electrolyte value of the average value is 8μm or more was confirmed as the electrolyte solution C (9.62μm) and the electrolyte solution D (15.09μm), the thickness uniformity evaluation results, the deviation of the maximum thickness and the minimum thickness The standard electrolyte solution C was the best at 0.13 μm, and even in the case of the electrolyte D, which was considerably thick, 0.22 μm, it was found that no significant difference occurred.

As shown in Table 5, the plasma electrolytic oxidation (PEO) is formed by the formation of the plasma layer by the destruction of the oxide film layer due to the dielectric breakdown potential and the discharge of the exposed base material layer due to the arc generation during the anodization of the titanium. The thickness of the oxide film can be formed to be thick while repeating the growth. The electrolyte solution C and the electrolyte solution D having a film thickness of 8 μm or more are electrolytes containing sodium metasilicate (Na ₂ SiO ₃ · 9H ₂ O). It is determined that the arc generation voltage is reduced during electrolytic oxidation so that the arc is easily generated even at a low voltage, thereby improving the thickness of the anodized film.

However, in the case where the ammonium fluoride is added, the electrolyte solution E has a higher film thickness than the electrolyte solution A and the electrolyte B, but is added to the electrolyte solution C and the electrolyte D to which the sodium metasilicate (Na ₂ SiO ₃ · 9H ₂ O) is added. Compared with the trend of at least 3μm, the effect is relatively insignificant.

In particular, the increase in the amount of the sodium metasilicate was found to be very closely related to the increase in the thickness of the film, but the side effects of the surface roughness caused by the increase in the amount of addition, the hygroscopic like the ethylene glycol It was found that excellent surfactant value is absolutely necessary.

Therefore, although the electrolyte solution which showed the characteristic of the outstanding film thickness by this invention is judged as the said electrolyte solution C, it is not limited to this.

⑤ Evaluation of film surface structure and composition according to electrolyte solution

As shown in FIGS. 1 to 5, the surface state photographed at a magnification X1,000 using a field emission scanning electron microscope (FE-SEM) was observed. As a result, the smoothness reference electrolyte C> A> B> D> The surface state of the titanium anodizing film using the electrolyte solution C in the order of E was the best. When the plasma anodization technique is used in the titanium anodization, it can be seen that the structure is vulnerable to cracks during the formation of the discharge channel by the micro arc.

As a result of evaluating the presence of cracks, the electrolyte D was observed macroscopically at a magnification X1,000, but the electrolyte E was not observed at a magnification X1,000 and space gas cracks were connected at a high magnification X10,000. Appeared in the form.

In the case of the electrolyte B, minute cracks were observed at the magnification X10,000 in the form of perforated pores, but no cracks were found at the magnifications X1,000 and X10,000 in the case of the electrolyte A and the electrolyte C.

As a result of observing the shape of pores using the field emission scanning electron microscope (FE-SEM), when the plasma electrolytic oxidation (PEO) technique is used, the shape of the pores shows a crater-shaped round shape, but in the case of the electrolyte B It showed the form of the perforated and connected between the pores.

In the case of the electrolytes A, C, and E, relatively uniform pore morphology showed a regular distribution, and in particular, the electrolyte E showed very small and many pores as seen in the magnification X1,000. This is consistent with the increase in pore size and number of pores derived from the application of magnesium (Mg) anodization, which shows the same tendency in titanium anodization.

As a result of the pore size measurement, except for the electrolyte D, the electrolyte A showed a somewhat larger average size of 2.54 μm, but the remaining electrolytes C, D, and E showed an average size of 2 μm or less without significant difference. However, as a result of checking the uniformity of the pores, it can be seen that the electrolyte C formed pores having the most uniform size in the order of the composition of the electrolyte solution C> D> E.

The anodized electrolyte solution exhibiting the most excellent properties when considering the surface structure and crack characteristics of the titanium anodized film according to the electrolytes A, B, C, D, and E and the surface properties such as the shape, size, and uniformity of the pores is C composition. Judging by

The trace elements detected in the component analysis using the SEM-EDS were mostly metal components of the composition of the electrolyte at the level of the analysis error. In particular, in the case of the electrolyte D, the average thickness of the titanium anodizing film was 15.09 μm, which was Si 31.82wt. % Of the electrolyte C, which was the second highest at 9.62 μm and the average thickness of the film, was detected as 5.12 wt.% Of Si. This is because the Si component of the sodium metasilicate was detected. As a result, the results were consistent with the cause of increased film thickness.

⑥ Evaluation of film surface roughness according to electrolyte

The three-dimensional surface imaging by using an atomic force microscope (AFM) showed the characteristics similar to the imaging results of the scanning electron microscope (FE-SEM) described above, such as the shape, size and distribution of pores. It showed uniform pore morphology and distribution.

However, when the surface roughness was measured, the surface roughness according to the electrolyte solution was 218 to 484 nm based on the centerline average roughness (Ra), which was not a significant difference, which is a result of measuring the local area (Scan Size 10μm x 10μm) when measuring the surface roughness. Although it is somewhat unreasonable to represent the whole, the maximum height of the electrolyte solution D on the basis of Rmax is shown as the highest 3.197μm, the rough tendency of the surface roughness could be confirmed.

On the other hand, as a result of performing a total of 4mm (5 times each 0.8mm) using a two-dimensional surface roughness measuring instrument, the electrolyte composition satisfying the center line average roughness (Ra) 1μm or less is the electrolyte A, B, C, E The average Ra was 0.66 ~ 0.85μm, the deviation 0.22 ~ 0.43μm was almost no significant difference, but the electrolyte D was roughest with Ra 2.05μm, which is consistent with the AFM results.

As a result of measuring the surface roughness of the electrolyte solution C, D, which is an electrolyte solution containing silicon (S) i among the electrolyte solutions A, B, C, D, and E, the surface roughness was improved as the content of sodium metasilicate decreased. Although the formation rate of the oxide film is increased by lowering the arc generation voltage during plasma electrolytic oxidation according to the addition of the sodium metasilicate, there is a possibility that the surface roughness may occur when a large amount is contained. I think it is absolutely necessary.

⑦ Evaluation of Breakdown Voltage

The breakdown voltage test is a representative method of the insulation test. It is an electrical stability method to check whether there is insulation, a risk of breakage, or abnormal proximity in order to use it in machinery and aircraft parts. Since it can be confirmed indirectly, the breakdown voltage characteristics according to the type of electrolyte were evaluated.

The coating withstand voltage is a general characteristic that is highly related to the thickness and texture characteristics of the anodized film. However, in the present invention, the film thickness was 15.09 μm and the anodized film of the thickest electrolyte D showed the lowest withstand voltage, which was the lowest characteristic in the evaluation of the smoothness and crack form, pore form and uniformity, surface roughness, etc. of the surface tissue. This is in accordance with the above electrolyte D.

The anodized films of electrolytes A and C, which showed smoothness of the surface structure, regular distribution of cracks and pores, had the highest withstand voltage, and in particular, the electrolyte C had an excellent withstand voltage of 576V. The biggest factor is expected to be the pore shape, uniformity and crack shape of the anodized film.

⑧ Evaluation of film color display value (△ E * ab = dE * ab) according to the type of electrolyte

Coloring was almost impossible to visually observe, but color spectrometry was possible using Spectro Photo Meter and Chroma Meter. The color display values of the yellow colorimeter and the color difference meter were slightly different, but the overall tendency was similar, and as the thickness of the titanium anodized film became thicker, the color display value increased.

Compared to the color difference meter, the spectrophotometer divides light reflected from an object in the visible range (380 to 780 nm) into prism and measures the reflectance of each wavelength band with about 20 to 40 sensors, which cannot be detected by the human eye. Since it is a device for measuring all the color components, it is determined that the color display value of the spectrophotometer is relatively accurate.

Electrolyte
Kinds Measuring point Film thickness Color display value (dE * ab) Eddy Current Spectrophotometer
(Spectro Photo Meter) Color difference meter
(Chroma Meter) ISO 2360, ASTM D 7091 ASTM E 1164 JIS Z 8722 A P1 5.67㎛ 23.2 27.0 P2 5.59㎛ 23.1 26.8 P3 5.38 ㎛ 22.8 26.8 P4 5.68㎛ 23.3 27.0 P5 5.77㎛ 23.4 27.2 Average 5.62 μm 23.2 27.0 Max.-Min. 0.39㎛  0.6  0.4

Electrolyte
Kinds Measuring point Film thickness Color display value (dE * ab) Eddy Current Spectrophotometer
(Spectro Photo Meter) Color difference meter
(Chroma Meter) ISO 2360, ASTM D 7091 ASTM E 1164 JIS Z 8722 B P1 5.21㎛ 22.7 26.6 P2 5.56㎛ 23.0 27.0 P3 5.41 μm 22.9 26.8 P4 5.68㎛ 23.2 27.2 P5 5.80㎛ 23.0 26.8 Average 5.53㎛ 23.0 26.9 Max.-Min. 0.59 μm  0.5  0.6

Electrolyte
Kinds Measuring point Film thickness Color display value (dE * ab) Eddy Current Spectrophotometer
(Spectro Photo Meter) Color difference meter
(Chroma Meter) ISO 2360, ASTM D 7091 ASTM E 1164 JIS Z 8722 C P1 9.69 μm 28.2 30.2 P2 9.56 μm 28.0 30.0 P3 9.61 μm 28.1 30.2 P4 9.59 μm 28.1 30.0 P5 9.63 μm 28.1 30.2 Average 9.62 μm 28.1 30.1 Max.-Min. 0.13 μm  0.2  0.2

Electrolyte
Kinds Measuring point Film thickness Color display value (dE * ab) Eddy Current Spectrophotometer
(Spectro Photo Meter) Color difference meter
(Chroma Meter) ISO 2360, ASTM D 7091 ASTM E 1164 JIS Z 8722 D P1 15.00㎛ 34.8 34.5 P2 15.13 μm 35.0 34.6 P3 15.22 μm 35.1 34.7 P4 15.01 μm 34.9 34.5 P5 15.07㎛ 34.9 34.5 Average 15.09㎛ 34.9 34.6 Max.-Min. 0.22㎛  0.3  0.2

Electrolyte
Kinds Measuring point Film thickness Color display value (dE * ab) Eddy Current Spectrophotometer
(Spectro Photo Meter) Color difference meter
(Chroma Meter) ISO 2360, ASTM D 7091 ASTM E 1164 JIS Z 8722 E P1 7.10 ㎛ 26.0 29.1 P2 6.80㎛ 25.8 28.7 P3 6.80㎛ 25.9 28.9 P4 6.30㎛ 25.7 28.7 P5 6.90㎛ 26.0 28.9 Average 6.78 μm 25.9 28.9 Max.-Min. 0.80 μm  0.3  0.4

Among the electrolytes A, B, C, D, and E, the electrolyte C is represented by the maximum deviation 0.2 based on the spectrophotometer and the maximum deviation 0.2 based on the color gamut, which is the best color reproducibility in all the measurement equipment of the spectrophotometer and the color difference meter. Showed.

As described above, the present invention is not limited to the above-described embodiments, and obvious modifications can be made by those skilled in the art without departing from the technical spirit of the present invention as claimed in the claims. Such modifications are within the scope of the present invention.

Claims (6)

As an electrolyte for forming a uniform anodized film of a titanium base material including a main material and an auxiliary material as a means for forming an anodized film on the surface of the titanium base material,
The main material is any one or a mixture of 12 ± 2 g / l potassium hydroxide or 5.5 ± 1 g / l trisodium phosphate,
The auxiliary material is any one or a mixture of ethylene glycol 10 ± 2 g / l, polyethylene glycol 2,000 5 ± 1 g / l, sodium metasilicate 1.2 ± 0.2 g / l, ammonium fluoride 6 ± 1 g / l , Electrolyte for forming a uniform anodized film of titanium base material. A pretreatment step of removing foreign matters stuck to the titanium base material; And depositing the titanium base material in an electrolyte and applying a direct current to form an anodized film, the method of manufacturing a titanium base material using an electrolyte solution for forming an anodized film.
The pretreatment step is;
A degreasing step of depositing the titanium base material in a degreasing solution to remove foreign substances pressed onto the titanium base material; A washing step of washing the titanium base material after the degreasing step; Etching the titanium base material in an etchant to remove foreign substances remaining in the titanium base material; And a washing step of washing the titanium base material through the etching step.
The oxidation process is;
In the 0 to 60V section, the voltage is increased by 10 ± 2V every 30 seconds, in the 61 to 100V section, the voltage is boosted by 5 ± 1V every 120 seconds, and in the 101 to 120V section, the voltage is boosted by 1 ± 0.2V every 40 seconds and 121 to 140V. 1 ± 0.2V every 60 seconds in the section, and maintained for 750 seconds in a section of 140V or more, to form an oxide film having a thickness of 8 to 15㎛ in the titanium base material, an electrolyte solution for forming anodized film Method for producing a titanium base material using. The method of claim 2, wherein the degreasing step,
The temperature of the degreasing solution is set to 40 ± 2 ℃ and stirring while injecting air for 10 ± 2 minutes, characterized in that the manufacturing method of the titanium base material using an electrolyte for forming anodized film. The method of claim 3, wherein the degreasing liquid,
Preparation of a titanium base material using an electrolyte for forming anodized film, characterized in that any one or a mixture of sodium hydroxide (NaOH), sodium carbonate (Na ₂ CO ₃ ), nonionic surfactant (PC-10). Way. The method of claim 2, wherein the etching step,
The temperature of the etching solution is set to 50 ± 2 ℃ and stirring while injecting air for 75 ± 5 seconds, characterized in that the manufacturing method of the titanium base material using an electrolyte for forming anodized film. The method of claim 5, wherein the nicking liquid,
Method for producing a titanium base material using an electrolyte for forming anodized film, characterized in that the hydrochloric acid (HCl).

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