KR102391845B1 - Improved deoxidation process using titanium or titanium alloy hydride - Google Patents

Abstract

The present invention provides a deoxidation apparatus and a deoxidation process for titanium or a titanium alloy. According to the present invention, the dehydrogenation process and the deoxidation process are sequentially performed using the deoxidation device having a structure in which the deoxidizer is prevented from leaking, thereby reducing the time and cost required compared to the conventional deoxidation process.

Description

Improved deoxidation process using titanium or titanium alloy hydride

The present invention relates to an improved deoxidation process using titanium or titanium alloy hydrides.

Titanium (Ti) is a material with excellent light weight, durability, and corrosion resistance. For this reason, titanium is used in various fields such as aerospace field, marine equipment field, chemical industry field, nuclear power generation field, biomedical field, automobile field, and the like.

Commercial titanium contains about 2,000 ppm to 10,000 ppm oxygen. Therefore, a lot of research has been done to prepare titanium with higher purity.

Titanium high-purity research has been mainly focused on the development of a deoxidation process to control gas impurities. As a method of reducing oxygen in titanium through this deoxidation process, calcium (Ca) is dissolved using a halide-based flux such as calcium chloride (CaCl2) and calcium oxide (CaO), a deoxidation product, is dissolved in the flux. A method has been proposed. However, the method using the halide-based flux has a problem in that it has to undergo a complicated mechanical process such as crushing after deoxidation, and when the raw material is powder, it is difficult to recover a sound powder by applying the process.

In order to solve this problem, in the prior art, titanium scrap generated during processing of a titanium material was manufactured into titanium hydrogenated powder through hydrogenation and pulverization, and then manufactured into titanium powder through a dehydrogenation process (Korean Patent No. 10-1135160) . Thereafter, the prepared powder was prepared as a low-oxygen titanium powder through a solid-state deoxidation process using calcium.

As such, in the prior art, a low-oxygen titanium powder was prepared through a three-step process of hydrogenation-dehydrogenation-deoxidation. However, as the three-step process proceeded individually, there was also a limitation in that the process time was inevitably increased.

In addition, since both the dehydrogenation process and the deoxidation process were heat-treated in a vacuum atmosphere, the use of a vacuum device was inevitable to maintain a high vacuum state during the process, and there was also a problem in that the process cost increased accordingly.

In addition, since each step was moved in the conventional process, there was a problem in that the titanium alloy powder was naturally oxidized due to inevitably exposed to the atmosphere, thereby increasing the oxygen content.

It is an object of the present invention to provide a deoxidation process of titanium or a titanium alloy in which a dehydrogenation process and a deoxidation process are combined.

However, the technical problem to be achieved by the present invention is not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above-mentioned problem, the present invention is an external container pedestal 101; outer container weight 102; and an outer container 100 including an outer container body 103;

a gut pillar 201 formed inside the outer container 100;

A gut accommodating titanium powder or titanium alloy powder, comprising: a gut 202 for separation of a multi-layer structure mounted on the gut pillar 201;

a groove 400 for preventing calcium leakage formed in the outer container pedestal 101;

Separation bolt hole 501 formed in the outer container body 103;

a groove 502 for container separation formed in the outer container pedestal 101; and

It is mounted on the outer container pedestal 101, and provides a titanium or titanium alloy deoxidation device including a deoxidizer cup 600 in which the deoxidizer located inside the gut pillar 201 is charged.

In one embodiment of the present invention, the separation gut 202 is characterized in that it is made of a micro sieve (300).

In another embodiment of the present invention, the gut post 201 is characterized in that it is integral with the outer container pedestal (101).

In another embodiment of the present invention, the deoxidation device is characterized in that it is made of a stainless material.

In another embodiment of the present invention, the deoxidizing agent is characterized in that calcium, copper, aluminum or ferromanganese.

The present invention also provides a process for deoxidation of titanium or titanium alloy comprising the steps of:

hydrogenating titanium or a titanium alloy (S1);

Dehydrogenating the titanium or titanium alloy hydrogenated in step S1 at a temperature of 600 to 750° C. for 30 to 120 minutes in a vacuum (S2); and

Deoxidizing the titanium or titanium alloy dehydrogenated in step S2 by heat treatment at 900 to 1100° C. (S3).

In another embodiment of the present invention, step S3 is characterized in that it is continuously performed after step S2.

In addition, the present invention provides a titanium powder or titanium alloy powder deoxidized through the deoxidation process.

In another embodiment of the present invention, the powder is characterized in that the oxygen content is less than 1000 ppm.

The deoxidation device of titanium or titanium alloy according to the present invention is improved so that the deoxidizer does not leak by forming a groove for preventing leakage of the external container weight and the deoxidizer. In addition, the device has a groove for separating the vessel to facilitate the separation of the deoxidation process.

The deoxidation process of the present invention is characterized in that the hydrogenated titanium powder or titanium alloy powder is charged into the apparatus, so that the dehydrogenation process and the deoxidation process can be performed simultaneously, and the process time is significantly reduced compared to the conventional deoxidation process.

1 schematically shows the deoxidation process of the present invention.
Figure 2 schematically shows a conventional solid-phase deoxidation process.
Figure 3 shows a deoxidation device of titanium powder or titanium alloy powder according to an embodiment of the present invention.
Figure 3 shows a titanium powder and a deoxidation device of the titanium powder according to an embodiment of the present invention.
Figure 4 shows a cross-section of the outer container pedestal according to an embodiment of the present invention.
Figure 5 shows a cross-section of the outer container pedestal according to an embodiment of the present invention.
6 is a view showing the deoxidation process of Example 1 of the present invention.
7 is a view showing the deoxidation process of Example 2 of the present invention.
8 shows the results of comparing the heat treatment time of the deoxidation process according to the method of the present invention and the conventional deoxidation process.

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present invention, the terms include or have is intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features, number, step , it should be understood that it does not preclude in advance the possibility of the presence or addition of an operation, component, part, or combination thereof.

The present invention is to provide a deoxidation process of titanium alloy powder in which the dehydrogenation process and the deoxidation process are combined, and is schematically shown in FIG. 1 .

On the other hand, the conventional titanium deoxidation process is largely composed of three processes: hydrogenation-dehydrogenation-deoxidation, as shown in FIG. 2 . In the hydrogenation process, titanium or titanium alloy scrap is heat-treated through a hydrogenation furnace to manufacture titanium hydride or titanium hydride alloy. In the hydrogenation process, heat treatment is performed at a temperature of 700° C. at 6 bar hydrogen pressure for 2 hours, and then scrap is pulverized to prepare titanium hydride or titanium alloy powder. That is, titanium hydride or titanium alloy powder is manufactured into titanium or titanium alloy powder through a dehydrogenation process in a vacuum heat treatment furnace. At this time, the dehydrogenation process is performed by heat treatment in a vacuum of 5.5 × 10 ⁻⁴ torr at a temperature of 700° C. for 2 hours. After recovering the powder, the powder is charged with calcium at a temperature of 1000° C. It is possible to provide low-oxygen titanium or titanium alloy powder through this.

As such, titanium or a titanium alloy requires a vacuum atmosphere to prevent oxidation during a high-temperature process due to high oxygen affinity, and a high vacuum is also required for dehydrogenation and deoxidation processes to prevent oxidation. In order to maintain a high vacuum, additional costs are required, and a long cooling time is also required after heat treatment due to the characteristics of vacuum heat treatment equipment.

To this end, the present invention combines the dehydrogenation process and the deoxidation process that require a high vacuum atmosphere to shorten the process time and reduce the cost. will proceed with In this case, the deoxidation device used in the deoxidation process uses a multilayer deoxidizer to minimize the reaction between the titanium hydride alloy powder and the metal calcium.

The deoxidation device of the present invention is a continuous improvement of the existing device, and as shown in FIG. 3 , the external container pedestal 101; outer container weight 102; and an outer container 100 including an outer container body 103;

a gut pillar 201 formed inside the outer container 100;

A gut accommodating titanium or a titanium alloy 10, comprising: a gut 202 for separation of a multi-layer structure mounted on the gut pillar 201;

a groove 400 for preventing leakage of a deoxidizer formed in the outer container pedestal 101;

Separation bolt hole 501 formed in the outer container body 103;

a groove 502 for container separation formed in the outer container pedestal 101; and

It is mounted on the outer container pedestal 101, and provides a titanium or titanium alloy deoxidation device including a deoxidizer cup 600 in which the deoxidizer located inside the gut pillar 201 is charged.

In addition, the present invention provides a deoxidation process of titanium or a titanium alloy comprising the following steps as a deoxidation process using the apparatus:

hydrogenating titanium or a titanium alloy (S1);

Dehydrogenating the titanium or titanium alloy hydrogenated in step S1 at a temperature of 600 to 750° C. for 30 to 120 minutes in a vacuum (S2); and

Deoxidizing the titanium or titanium alloy dehydrogenated in step S2 by heat treatment at 900 to 1100° C. (S3).

In the present invention, the outer container 100 includes an outer container pedestal 101; outer container weight 102; and an external container body 103 . The external container weight 102 is to suppress the leakage of the deoxidizer vapor by applying a load to the external container.

The outer container pedestal 101 may block contact with the internal carbon insulator by vacuum heat treatment, thereby sealing the deoxidizer vapor 20 generated from the deoxidizer 21 . The outer container pedestal 101 closes the external container body 103 to seal the deoxidizer vapor 20 .

As shown in Figure 4, the outer container pedestal 101 is formed with a groove 400 for preventing the deoxidizer vapor leakage. The groove is to be able to suppress the leakage of the deoxidizer vapor by giving unevenness on the contact surface of the outer container body 103 and the outer container support 101.

As shown in FIG. 5 , a bolt hole 501 is formed in the outer peripheral surface (wing portion) of the outer container body 103 . When the external container body 103 and the pedestal 101 are adhered by the deoxidizer vapor due to the bolt hole, it can be easily separated.

The outer container pedestal 101 is formed with a groove 502 for container separation. In the deoxidation apparatus of the present invention, a bolt hole 501 and a groove 502 for container separation are formed to facilitate container separation, and after the deoxidation process is completed as described above, after separating the outer container body 101 The deoxidized titanium or titanium alloy charged in the gut can be easily obtained.

4 shows an example of the position of one of the gut pillars in the outer container pedestal 101. A gut post 201 is integrally formed on the outer container pedestal 101 . Four gut pillars may be formed at a predetermined distance from the pedestal.

A gut 202 for separation is formed on the gut post 201 . The separation gut is a gut-shaped frame formed in a multi-layered structure to separate the specimen into multi-layers.

In the present invention, titanium or titanium alloy 10 may be in bulk or powder type. When titanium or a titanium alloy is used in powder form, the separation gut 202 is preferably made of a micro sieve 300, and the size of the micro sieve 300 is smaller than the particle size of the titanium or titanium alloy powder. do.

In the present invention, the deoxidizer 21 may be calcium, copper, aluminum or ferromanganese. The deoxidizer 21 is charged to the deoxidizer cup 600 of the present invention, and the deoxidizer 21 generates deoxidizer vapor 20 by heat in the deoxidation step (S3) to produce dehydrogenated titanium or titanium alloy. can be deoxidized.

Accordingly, the deoxidizer cup 600 must have a melting temperature higher than that of the deoxidizer 21, and is made of a material with excellent thermal conductivity to accommodate the molten deoxidizer when the deoxidizer 21 is melted and the deoxidizer 21 at a high speed. ) is preferably melted. To this end, it is preferable that a heating means capable of heating the deoxidizer cup 600 is additionally installed on the lower or side surface of the deoxidizer cup 600 , and the heating means is a heating wire, a gas torch, an arc heater, a plasma heater , as long as it is a means capable of heating the deoxidizer 21, such as a laser heater, it can be used without limitation.

In the deoxidizer of the present invention, the deoxidizer 21 is evaporated to remove oxygen, and a part of the vaporized deoxidizer 22 is inside the deoxidizer such as the pillar 201, the gut 202, or the outer container body 103 Since it is condensed and precipitated as crystals, it is preferable that the multi-layer deoxidizer be made of a stainless material so that the deoxidizer can be easily washed. Even if the deoxidizer formed of stainless steel is pressed by heating, the deoxidizer can be simply washed with tap water to remove the deoxidizer, thereby reducing maintenance costs because the deoxidizer can be continuously recycled.

The deoxidizer may be used without limitation as long as it is a material capable of removing oxygen from titanium, but preferably calcium, copper, aluminum or ferromanganese may be used, and more preferably calcium may be used.

The method of the present invention is characterized in that the dehydrogenating step (S2) and the deoxidizing step (S3) provide optimal conditions for dehydrogenation and deoxidation.

The hydrogenated titanium or titanium alloy in step S2 is dehydrogenated at a temperature of 600 to 750° C. for 30 to 120 minutes in a vacuum state. If the dehydrogenation is performed for less than 30 minutes, the deoxidation may not be completely performed in the subsequent deoxidation process, and if it is performed over the above time, the process time may increase and process efficiency may be reduced. When the dehydrogenation is performed at less than 600° C., the oxygen reduction rate may be lowered in the deoxidation process because the subsequent dehydrogenation is not completely performed, and if it exceeds 750° C., the oxygen reduction rate may be rather reduced due to side reactions. Preferably, as in the present invention, when it is carried out at a temperature of 620°C to 700°C, more preferably at a temperature of 630°C to 670°C, it has the best oxygen reduction rate.

Step S3 of the present invention is to be sequentially performed immediately following the completion of the dehydrogenation step. The present invention has the effect of significantly reducing the process time by being directly carried out in the same process equipment without changing the equipment for performing the deoxidation process after the dehydrogenation step.

In addition, the present invention may provide deoxidized titanium or a titanium alloy through the above process. The titanium or titanium alloy may have an oxygen content of less than 1000 ppm when the particle diameter of the titanium or titanium alloy is 45 to 100 μm, and the oxygen content may be less than 700 ppm when the particle diameter of the titanium or titanium alloy is 100 to 150 μm, but is limited thereto not.

Hereinafter, preferred embodiments of the present invention will be described so that those of ordinary skill in the art can easily implement them with reference to the accompanying drawings. In addition, in the description of the present invention, if it is determined that a detailed description of a related known function or a known configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, certain features presented in the drawings are enlarged, reduced, or simplified for ease of explanation, and the drawings and components thereof are not necessarily drawn to scale. However, those skilled in the art will readily appreciate these details.

Example 1. Confirmation of change in deoxidation effect according to dehydrogenation time

In this Example 1, it was attempted to confirm the optimized dehydrogenation time condition.

The same deoxidation device as shown in FIG. 3 was manufactured using stainless steel. As the titanium alloy powder used, Ti-6Al-4V hydride powder was used. The hydrogenation process was carried out by maintaining at 700 °C for 2 hours at a temperature increase rate of 5 °C, and the hydrogen pressure was kept constant at 6 bar.

Afterwards, the hydrogenated titanium alloy powder was charged in each gut for separation made of a microsieve mounted on four gut columns, and 50% of the weight of the titanium alloy powder was charged into the deoxidizer cup with calcium (Ca) as a deoxidizer. did For the charged titanium alloy hydride, powder with a particle size of 45 to 150 μm was used.

First, the dehydrogenation of the titanium alloy hydride was induced by maintaining it at 700° C. according to the following time conditions in Table 1 (FIG. 6).

Example 1-1 Example 1-2 Examples 1-3 Examples 1-4 dehydrogenation
time (min) 0 30 60 120

Thereafter, the temperature was continuously raised to 1000° C. to induce a reaction with calcium vapor. The dehydrogenation temperature is applied based on the temperature used in the dehydrogenation process in the existing deoxidation process.

After deoxidation, CaO formed by the reaction of titanium alloy powder and calcium vapor was removed by washing in distilled water for 5 minutes and 10% dilute hydrochloric acid for 5 minutes each. The recovered powder was then recovered and analyzed after drying at 60° C. for 2 hours using a vacuum oven. The powder used for the analysis was analyzed by classifying it into particle sizes of 45-100 μm and 100-150 μm.

In addition, for comparison with the existing solid-state deoxidation process, a titanium alloy powder deoxidized according to the conventional solid-state deoxidation process as shown in FIG. 2 was prepared.

Changes in oxygen content of the recovered titanium alloy powder were measured using an oxygen/nitrogen analyzer. The results are shown in Table 2 below.

Dehydrogenation temperature 700℃ maintenance time change 45-100μm 100~150μm oxygen content reduction rate oxygen content reduction rate scrap 2,000 ppm 2,000 ppm 0 minutes 4,250 ppm 3,370 ppm 30 minutes 990 ppm 52.86% 660 ppm 68.57% 60 minutes 770 ppm 63.33% 570 ppm 72.86% 120 minutes 1,030 ppm 50.95% 770 ppm 63.33% Conventional solid-state deoxidation 730 ppm 65.24% 520 ppm 75.24%

From the above results, the highest oxygen reduction was confirmed when the dehydrogenation holding time was set to 60 minutes. However, the reduction rate was found to be lower than that of the existing solid-state deoxidation method, so other variables were tested below.

Example 2. Confirmation of change in deoxidation effect according to dehydrogenation temperature

Dehydrogenation and deoxidation were carried out in the same manner as in Example 1, but the dehydrogenation time was fixed to 60 minutes at which the highest oxygen reduction effect was confirmed, and the dehydrogenation temperature was performed under the conditions shown in Table 3 below. After (FIG. 7), the titanium alloy powder was recovered by deoxidation.

Example 2-1 Example 2-2 Example 2-3 Example 2-4 Dehydrogenation temperature (℃) 600 650 700 750

Table 4 shows the change in oxygen content by using an oxygen/nitrogen analyzer for the deoxidized alloy powder.

Dehydrogenation time 60 minutes Maintaining temperature change 45-100μm 100~150μm oxygen content reduction rate oxygen content reduction rate scrap 2,000 ppm 2,000 ppm 600℃ 820 ppm 60.95% 650 ppm 69.05% 650℃ 730 ppm 65.24% 520 ppm 75.24% 700℃ 770 ppm 63.33% 570 ppm 72.86% 750℃ 790 ppm 62.38% 600 ppm 71.43% Conventional solid-state deoxidation 730 ppm 65.24% 520 ppm 75.24%

As a result, from the above results, the deoxidation process of the present invention using a hydride maintained at 650° C. for 60 minutes showed oxygen reduction equivalent to that of the existing deoxidation process.

As a result, it was confirmed that when an improved deoxidation process using hydride, which proceeds by combining the dehydrogenation-deoxidation process, is applied, the process time can be reduced, and an oxygen reduction effect equivalent to that of the existing deoxidation process can be obtained through process optimization.

Example 3. Comparison of the optimized deoxidation process and the existing deoxidation process

In this Example 3, the heat treatment time of the deoxidation process of the present invention using a hydride maintained at 650° C. for 60 minutes was compared with the conventional deoxidation process.

The results are shown in FIG. 8 . As confirmed in FIG. 8, in the case of the existing deoxidation process in which the dehydrogenation process and the deoxidation process are separately performed, about 1490 minutes are required until the end of the process, but when the deoxidation process of the present invention is used, it can be seen that about 800 minutes are required . That is, a total of 690 minutes was shortened, and it was confirmed that the process time could be reduced by about 46%.

As a result, it was confirmed that the improved deoxidation process using the hydride applied in the present invention can reduce the process time and cost compared to the existing deoxidation process, and that oxygen reduction equivalent to that of the existing deoxidation can be expected.

As a specific part of the present invention has been described in detail above, for those of ordinary skill in the art, it is clear that this specific description is only a preferred embodiment, and the scope of the present invention is not limited thereby. will be. Accordingly, it is intended that the substantial scope of the present invention be defined by the appended claims and their equivalents.

Titanium or titanium alloy: 10
Deoxidizer Vapor: 20 Deoxidizer: 21
Outer container: 100 Outer container base: 101
Outer container weight: 102 Outer container body: 103
Gut post: 201 Separation gut: 202
Microsieve: 300 Calcium leak prevention groove: 400
Separation bolt hole: 501 Vessel separation groove: 502
Deoxidizer Cup: 600

Claims (9)

delete delete delete delete delete hydrogenating titanium or a titanium alloy (S1);
Putting the titanium or titanium alloy hydrogenated in step S1 into a deoxidation device, and dehydrogenating at a temperature of 600 to 750° C. for 30 to 120 minutes in a vacuum (S2); and
Comprising the step (S3) of deoxidizing the dehydrogenated titanium or titanium alloy in step S2 by heat treatment at 900 to 1100 °C,
The deoxidation device,
an outer container weight for applying a load to the outer container;
an external container body located below the external container weight; and
an outer container including an outer container pedestal in close contact with the lower portion of the outer container body;
a gut pillar formed inside the outer container;
A gut for accommodating titanium or a titanium alloy, comprising: a gut for separation of a multi-layer structure mounted on the gut pillar;
a groove for preventing leakage of a deoxidizer formed in the outer container pedestal to suppress the leakage of deoxidizer vapor by giving irregularities on the contact surfaces of the outer container body and the outer container pedestal;
a bolt hole for separation that is formed on the outer circumferential surface (wing portion) of the outer container body and facilitates separation when the outer container body and the base are adhered by deoxidizer vapor;
a groove for container separation formed in the external container pedestal to facilitate container separation; and
The deoxidation process of titanium or a titanium alloy, which is mounted on the outer container pedestal, and includes a deoxidizer cup in which the deoxidizer located inside the gut pillar is charged.
7. The method of claim 6,
The step S3 is characterized in that continuously performed after step S2, titanium or titanium alloy deoxidation process.
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