JP7345903B2 - Production method of titanium metal powder - Google Patents

Description

The present invention relates to a method for producing high-purity titanium metal powder or titanium alloy powder that can be used in various fields. Specifically, the present invention relates to a method for producing titanium metal powder or titanium alloy powder that utilizes a multi-step reduction process to enable mass production and cost reduction.

Titanium metal and titanium alloys are lightweight, have excellent mechanical properties, and have excellent high-temperature properties and corrosion resistance, making them suitable for medical, chemical, aerospace, and other fields where it is difficult to use other traditional iron-based alloys. It has been considered as a material with a long history. However, titanium-based materials have the problem of not only expensive raw materials but also high manufacturing costs.

Despite titanium's excellent properties, due to its high cost, various manufacturing methods have been developed since the 1950s to reduce costs.

As a known method for producing titanium, sponge titanium is produced using the Kroll process, and ingots are produced using the VAR (Vacuum Arc Remelting) method, and processed materials are processed through extrusion, rolling, etc. There is a method to create .

Currently, the Kroll process is most commonly used to produce titanium metal, but the final product is in the form of a sponge rather than a powder. In the crawl process, pure titanium ore is charged with an electrical charge in a special electric furnace, converting it into a sponge form. This process is carried out in a chlorinator, where chlorine gas passes through the charge, forming titanium tetrachloride (TiCl ₄ ) in liquid form. The titanium tetrachloride thus formed is purified through a complex distillation process. After the distillation process, magnesium or sodium is added to the purified titanium tetrachloride and reacted to produce metallic titanium sponge and magnesium or sodium chloride. After that, the titanium sponge is crushed and crimped. The crushed titanium sponge is melted using the vacuum arc melting method (VAR). The crawling process has problems in that it is complicated, difficult to handle, and low in energy efficiency.

Powder metallurgy (PM) technology is attracting attention because compared to ingot technology, it can provide titanium in complex shapes at lower cost without compromising mechanical properties. Powder metallurgy (PM) technology has great potential in terms of producing titanium at low cost, but the physical properties of titanium products produced by existing powder metallurgy processes are not satisfactory. However, it is not commonly used because it does not have the expected cost reduction effect. Therefore, manufacturing titanium using powder metallurgy techniques requires methods that not only reduce costs but also improve the physical properties of the final product.

International publication patent WO 2014/187867 discloses a method for producing a wide range of metal powders, metal alloy powders, intermetallic compound powders and/or hydride powders thereof. Calcium hydride powder or granules are used, or calcium hydride is used directly in one or more metal oxides, with or without the presence of another metal, to produce metal alloy powders.

U.S. Patent No. 6,264,719 discloses a method for producing titanium alumina suspended with a small amount of aluminum oxide as a metal matrix composite powder when a small amount of titanium dioxide is reacted with an aluminum metal powder. There is.

Although various methods of producing titanium metal powder or titanium alloy powder have been attempted, there is no method that can produce titanium metal powder or titanium alloy powder of excellent quality at low cost and that can be mass-produced on an industrial scale. However, further development is still required.

The present invention provides a titanium metal powder or titanium alloy powder that can produce high quality titanium metal powder or any type of titanium alloy powder at low cost and can be easily scaled up and implemented on an industrial scale. The purpose is to provide a method for manufacturing.

The above-mentioned problem consists of: a) partially reducing each of at least one metal oxide and a titanium oxide; b) mixing the partially reduced metal oxide and the titanium oxide; c) mixing the first mixture and calcium hydride to produce a second mixture, and d) completely reducing the second mixture to reduce titanium hydride. The method of manufacturing titanium metal powder or titanium alloy powder includes the steps of manufacturing metal or titanium alloy.

Further, the object of the present invention is to: a) partially reduce at least one of at least one metal oxide and titanium oxide; and b) a metal oxide that partially reduces one of the metal oxides c) mixing the first mixture and calcium hydride to produce a second mixture; d) mixing the first mixture with calcium hydride to produce a second mixture; This is achieved by a method for producing titanium metal powder or titanium alloy powder, which includes the step of completely reducing a mixture of 2 and 2 to produce titanium metal or titanium alloy.

Preferably, a step of partially reducing the first mixture is included between the step b) and the step c).

Preferably, the partial reduction in step a) and the complete reduction in step d) are performed by heat treatment at a temperature of 1,000° C. to 1,500° C. and under a hydrogen atmosphere for 1 to 10 hours.

Preferably, the partial reduction in step a) and the complete reduction in step d) are performed by heat treatment at a temperature of 1,000° C. to 1,500° C. under a hydrogen atmosphere for 1 to 10 hours.

Preferably, said metal oxide is selected from the group consisting of CaO, V ₂ O ₅ , Cr ₂ O ₃ , Nb ₂ O ₅ , MoO ₃ , WO ₃ , Y ₂ O ₃ and ZrO ₂ .

Also preferably, the stoichiometric ratio of the first mixture and the calcium hydride is 1:1.1 to 1.25.

Preferably, the second mixture further includes aluminum and vanadium oxide (V ₂ O ₅ ) powder.

Also preferably, the titanium alloy powder is Ti-6Al-4V powder.

Preferably, the titanium metal powder and titanium alloy powder have an oxygen content of less than 0.3% by weight and a particle size distribution of less than 50 μm.

The present invention can provide a low-cost manufacturing method that can produce superior quality titanium metal powder and titanium alloy powder that can be used in more application fields. Through the present invention, the use of titanium and its alloy powder can be extended not only to general industrial use but also to fields that require titanium metal powder of excellent quality, such as aerospace, medical, or military use.

1 is a scanning electron micrograph showing the morphology of titanium metal powder produced according to the present invention. 1 is an X-ray diffraction pattern showing the material phase of titanium metal powder manufactured according to the present invention. FIG. 3 is a diagram showing the particle size distribution of titanium metal powder produced according to the present invention. 1 is a scanning electron micrograph showing the morphology of titanium alloy (Ti-6Al-4V) powder manufactured according to the present invention. FIG. 3 is a diagram showing the particle size distribution of a titanium alloy (Ti-6Al-4V) powder product produced according to the present invention.

Unless otherwise defined, all technical terms used in the present invention have the definitions below and are accorded the meanings as commonly understood by one of ordinary skill in the art to which the present invention relates. Further, although preferred methods and samples are described in this specification, methods similar or equivalent thereto are also included within the scope of the present invention.

The term 'about' refers to 30, 25, 20, 15, 10, 9, 8, 30, 25, 20, 15, 10, 9, 8, relative to a reference amount, level, value, number, frequency, percentage, dimension, size, quantity, weight or length. means an amount, level, value, number, frequency, percentage, dimension, size, quantity, weight or length that varies by as much as 7, 6, 5, 4, 3, 2 or 1%.

In this specification, unless the context otherwise requires, the word "comprising" includes a recited step or component, or group of steps or components, but includes any other step or component, or step. or must be understood as implying that a group of constituent elements is not excluded.

The method for producing titanium metal powder or any form of titanium alloy powder according to the present invention is characterized by including multiple reduction steps. Preferably, it is characterized by including two reduction stages. More preferably, it includes the following steps:

a) partially reducing each of the at least one metal oxide and the titanium oxide (first reduction step);
b) mixing the partially reduced metal oxide and titanium oxide to produce a first mixture (first mixing step);
c) mixing the first mixture and calcium hydride to produce a second mixture (second mixing stage);
d) heat-treating the second mixture to completely reduce it to produce titanium metal or a titanium alloy (second reduction step);

According to an embodiment of the present invention, the method further includes the step of e) crushing and powdering the produced titanium metal or titanium alloy (powdering step).

Each stage will be explained in detail below.

First, at least one metal oxide and each of the titanium oxides are partially reduced (first reduction step).

The first reduction step is performed by heat-treating the metal oxide and titanium oxide as raw materials at a temperature of 1,000° C. to 1,500° C. and under a hydrogen atmosphere for 1 to 10 hours, respectively. The heat treatment temperature is preferably 1,100°C to 1,300°C, more preferably 1,100°C to 1,200°C. The treatment time is preferably 2 to 4 hours. The hydrogen atmosphere has a hydrogen gas flow of 1.5 l/min or more, preferably 1.5 l/min to 5 l/min, which varies depending on the size of the heat treatment furnace and the amount of raw material.

In the first reduction step, a metal oxide or titanium oxide is placed in a crucible made of stainless steel and has a semicircular cross section, and heated in a heat treatment area of a furnace. A tube furnace may be used as the heat treatment furnace. The heat treatment furnace used in the present invention has two separate heat treatment zones for the first reduction stage and the second reduction stage. Any type of heating furnace can be used, preferably operating at a temperature of 1,500° C. and operating under a gas atmosphere capable of promoting the reduction reaction. The heat treatment furnace must be compatible with operations using gases such as hydrogen and argon.

Each heat treatment region can individually generate a hydrogen gas flow.

In this step, heat treatment reduces the oxygen content of the metal oxides and titanium oxides of the raw materials to form oxides that can be easily reduced in the second reduction step.

The metal oxide is one or more selected from the group consisting of CaO, V ₂ O ₅ , Cr ₂ O ₃ , Nb ₂ O ₅ , MoO ₃ , WO ₃ , Y ₂ O ₃ and ZrO ₂ , and more Preferably it is CaO. The titanium oxide is _TiO2 or TiO, more preferably _TiO2 .

According to an embodiment of the invention, when producing titanium alloy _powder , the metal oxides are CaO and _V2O5 , and aluminum or aluminum oxide can also be used together with the metal oxide. In this case, the titanium alloy powder is Ti-6Al-4V.

Preferably, the metal oxide and titanium oxide are in powder form.

According to an embodiment of the present invention, the first reduction step comprises a1) a first partial reduction step of partially reducing each of the calcium oxide and the titanium oxide; and a2) the partially reducing step. and a second partial reduction step in which the first mixture of calcium oxide and titanium oxide is partially reduced again.

By carrying out the first reduction step in two stages as described above, a uniformly reduced and mixed mixture of calcium oxide and titanium oxide can be obtained.

According to another embodiment of the present invention, only one of the metal oxide and the titanium oxide may be partially reduced in the first reduction step.

Next, mixing the partially reduced metal oxide and titanium oxide to produce a first mixture (first mixing step), and mixing the first mixture and calcium hydride. to produce a second mixture (second mixing stage).

In this step, it is preferable that the first mixture and calcium hydride are mixed at a stoichiometric ratio of 1:1.1 to 1.25.

The calcium hydrogen may be in the form of powder or granules, and the particle size is preferably 0.02 to 2 mm. The calcium hydride used in the present invention can be a commercially available product, but preferably the calcium hydride used in the present invention is in the form of calcium metal shavings or calcium metal granules. ) is converted into calcium hydride pieces or granules by heating at a temperature of 550 to 750° C. for 1 to 10 hours in a hydrogen gas atmosphere.

Next, the second mixture is heat-treated to completely reduce it to produce titanium metal or titanium alloy (second reduction step).

The heat treatment is performed at a temperature of 1,000° C. to 1,500° C. in a hydrogen atmosphere for 1 to 10 hours. The heat treatment temperature is preferably 1,100°C to 1,300°C, more preferably 1,100°C to 1,200°C. The treatment time is preferably 2 to 4 hours. The hydrogen atmosphere has a hydrogen gas flow of 1.5 l/min or more, preferably 1.5 l/min to 5 l/min, which varies depending on the size of the heat treatment furnace and the amount of raw material. The heat treatment furnace used in the second reduction stage is as described in the first reduction stage.

In this step, the partially reduced metal oxide and titanium oxide mixture and the reducing agent calcium hydride react under a hydrogen atmosphere to form titanium metal or titanium alloy. The titanium metal or titanium alloy thus formed is recovered.

Finally, the powder produced in the e) recovery step is pulverized through a washing and drying step. According to one embodiment of the present invention, the recovered titanium metal or titanium alloy is in bulk form and can be ground using high energy ball milling equipment prior to the cleaning and drying steps.

In the washing and drying steps, the ground powder may be mixed with water to form a slurry and washed while stirring. A solvent such as acetic acid can be added to the slurry to enhance the cleaning effect.

After washing, in the drying step, the powder can be dried in an open low temperature oven at a temperature of 80-90°C.

The titanium metal or titanium alloy produced in the present invention is in powder form, has a particle size distribution of 50 μm or less, preferably 10-50 μm, and has an oxygen content of less than 0.3% by weight.

The term 'powder' used in the present invention refers to particles with a particle size of less than 1 mm.

'X50' used in the present invention indicates the particle size distribution of the final powder, and indicates the median diameter or median value of the particle size distribution. Preferably, X50 indicates a particle size distribution of 50 μm or less, or 40 μm or less, more preferably 20 μm or less.

Hereinafter, the present invention will be explained in detail through Examples, but the scope of the present invention is not limited by these Examples.

The starting materials used in the examples of the present invention are shown in Table 1 below.

Table 2 below shows the equipment used to analyze the titanium metal powder and titanium alloy powder finally produced in the present invention.

Example 1: Production of titanium metal powder 50 g of CaO powder with a purity of 99.5% and 50 g of TiO ₂ powder with a purity of 99% are each placed in a SUS310S crucible, and heated in a hydrogen gas atmosphere of 2 to 3 L/min in the heat treatment area of a tubular tube furnace. Partial reduction was carried out at 1100° C. for 2 hours. A second mixture was prepared by completely mixing 100 g of a first mixture of partially reduced CaO and TiO ₂ with 130 g of calcium hydride powder (particle size: 0.02-2 mm). The stoichiometric ratio of calcium hydride to the first mixture is between 1.1 and 1.25 . Next, the second mixture was placed in a SUS310S crucible and completely reduced in a heat treatment area of a tubular tube furnace at 1100° C. for 2 hours under a hydrogen gas atmosphere of 2 to 3 L/min. The resulting bulk material was ground in a ball mill, mixed with water and acetic acid, washed with stirring, and completely dried at 90°C. The physical properties of the metal powder were measured using the apparatus shown in Table 2 above. A scanning electron micrograph of the produced powder is shown in FIG. In addition, in order to confirm the substance of the manufactured powder, the X-ray diffraction pattern was measured and shown in FIG. 2, and the particle size distribution of the powder was measured and shown in FIG. 3 and Table 3. Looking at FIG. 2, it can be confirmed that the produced powder is titanium (Ti) metal. Furthermore, looking at FIG. 3 and Table 3, it can be confirmed that the particle size distribution range of the produced powder is 10 to 50 μm. Furthermore, the residual oxygen content of the produced powder was confirmed and was found to be 0.19 wt%. The amount of residual oxygen in the titanium metal powder produced by the present invention is significantly lower than that in titanium metal powder produced by a known method.

Reference Example 2: Production of titanium alloy (Ti-6Al-4V) powder 150 g of a mixture of 50 g of CaO powder with a purity of 99.5% and TiO ₂ powder with a purity of 99% was placed in a SUS310S crucible, and the heat treatment area of a tubular tube furnace was placed. Partial reduction was carried out at 1100° C. for 2 hours in a hydrogen gas atmosphere of 2 to 3 L/min. A first mixture of partially reduced CaO and TiO ₂ , 7.13 g of V ₂ O ₅ powder with a purity of 99.6% and 6 g of aluminum metal powder with a purity of 99.5%, and calcium hydride powder (particle size A second mixture was prepared by thoroughly mixing 207 g of the mixture (with a diameter of 0.02 to 2 mm). The stoichiometric ratio of calcium hydride to the first mixture is between 1.1 and 1.25 . Next, the second mixture was placed in a SUS310S crucible and completely reduced in a heat treatment area of a tubular tube furnace at 1100° C. for 2 hours under a hydrogen gas atmosphere of 2 to 3 L/min. The resulting bulk material was ground in a ball mill, mixed with water and acetic acid, washed with stirring, and completely dried at 90°C. The physical properties of the metal powder were measured using the apparatus shown in Table 2 above. A scanning electron micrograph of the produced powder is shown in FIG. In addition, the particle size distribution of the manufactured powder was measured and shown in FIG. 5 and Table 4. Furthermore, looking at FIG. 5 and Table 4, it can be confirmed that the particle size distribution range of the produced powder is 9.5 to 75 μm. Furthermore, the amount of residual oxygen in the produced powder was confirmed and was found to be 0.28 wt%. The amount of residual oxygen in the titanium alloy powder produced by the present invention is significantly lower than that in titanium alloy powder produced by a known method.

Reference Example 3: Production of titanium alloy (Ti-6Al-4V) powder 150 g of a mixture of 50 g of CaO powder with a purity of 99.5% and TiO ₂ powder with a purity of 99% was placed in a SUS310S crucible and placed in the heat treatment area of a tubular tube furnace. Partial reduction was carried out at 1100° C. for 2 hours in a hydrogen gas atmosphere of 2 to 3 L/min. A first mixture of partially reduced CaO and TiO ₂ , 7.13 g of 99.6% pure V ₂ O ₅ powder and 7.1 g of 99.5% pure aluminum oxide powder, and calcium hydride powder ( A second mixture was prepared by thoroughly mixing 207 g of particles (particle size 0.02-2 mm). The stoichiometric ratio of calcium hydride to the first mixture is between 1.1 and 1.25 . Next, the second mixture was placed in a SUS310S crucible and completely reduced in a heat treatment area of a tubular tube furnace at 1100° C. for 2 hours under a hydrogen gas atmosphere of 2 to 3 L/min. The obtained material in bulk form was crushed in a ball mill, mixed with water and acetic acid, washed with stirring, and completely dried at 90°C to obtain titanium alloy (Ti-6Al-4V) powder. Obtained.

Although specific parts of the present invention have been described in detail above, those with ordinary knowledge in the art will understand that such specific descriptions are merely preferred embodiments and that the scope of the present invention is limited thereto. Obviously, there is no limitation. It is therefore said that the substantial scope of the invention is defined by the appended claims and their equivalents.
Below, the matters described in the original claims of the present application are added.
[1] a) Partially reducing each of at least one metal oxide and titanium oxide;
b) mixing the partially reduced metal oxide and titanium oxide to produce a first mixture;
c) mixing the first mixture and calcium hydride to produce a second mixture;
d) Completely reducing the second mixture to produce titanium metal or titanium alloy. A method for producing titanium metal powder or titanium alloy powder.
[2] a) Partially reducing at least one metal oxide or titanium oxide;
b) mixing a metal oxide obtained by partially reducing any one of the above and titanium oxide to produce a first mixture;
c) mixing the first mixture and calcium hydride to produce a second mixture;
d) Completely reducing the second mixture to produce titanium metal or titanium alloy. A method for producing titanium metal powder or titanium alloy powder.
[3] The method for producing titanium metal powder or titanium alloy powder according to [1] or [2], including a step of partially reducing the first mixture between the step b) and the step c). .
[4] The partial reduction in step a) and the complete reduction in step d) are performed by heat treatment at a temperature of 1,000° C. to 1,500° C. in a hydrogen atmosphere for 1 to 10 hours. The method for producing titanium metal powder or titanium alloy powder according to [1] or [2].
[5] The partial reduction in step a) and the complete reduction in step d) are performed by heat treatment at a temperature of 1,000° C. to 1,500° C. in a hydrogen atmosphere for 1 to 10 hours. The method for producing titanium metal powder or titanium alloy powder according to [3].
[6] The production of titanium metal powder or titanium alloy powder according to [1] or [2], further comprising the step of e) pulverizing the produced titanium metal or titanium alloy to powder. Method.
[7] The metal oxide is selected from the group consisting of CaO, V ₂ O ₅ , Cr ₂ O ₃ , Nb ₂ O ₅ , MoO ₃ , WO ₃ , Y ₂ O ₃ and ZrO ₂ . The method for producing titanium metal powder or titanium alloy powder according to [1] or [2].
[8] The metal oxide is selected from the group consisting of CaO, V ₂ O ₅ , Cr ₂ O ₃ , Nb ₂ O ₅ , MoO ₃ , WO ₃ , Y ₂ O ₃ and ZrO _{2 .} The method for producing titanium metal powder or titanium alloy powder according to [3].
[9] The titanium metal according to [1] or [2], wherein the stoichiometric ratio of the first mixture and the calcium hydride is 1:1.1 to 1.25. Method for producing powder or titanium alloy powder.
[10] The method for producing titanium metal powder or titanium alloy powder according to [1] or [2], wherein the second mixture further contains aluminum and vanadium oxide (V 2 O 5 ₎ powder _. .
[11] The method for producing titanium metal powder or titanium alloy powder according to [10], wherein the titanium alloy is Ti-6Al-4V.
[12] The titanium according to [1] or [2], wherein the titanium metal and titanium alloy have an oxygen content of less than 0.3% by weight and a particle size distribution of less than 50 μm. A method for producing metal powder or titanium alloy powder.
[13] A titanium metal powder or titanium alloy powder produced by the method described in [1] or [2], having an oxygen content of less than 0.3% by weight and a particle size distribution of less than 50 μm.

Claims (7)

a) partially reducing each of the at least one metal oxide and the titanium oxide;
b) mixing the partially reduced metal oxide and titanium oxide to produce a first mixture;
c) mixing the first mixture and calcium hydride to produce a second mixture;
d) completely reducing the second mixture to produce titanium metal ;
Titanium, wherein the metal oxide is selected from the group consisting of CaO, V ₂ O ₅ , Cr ₂ O ₃ , Nb ₂ O ₅ , MoO ₃ , WO ₃ , Y ₂ O ₃ and ZrO ₂ . Method for producing metal powder. The method for producing titanium metal powder according to claim 1, further comprising a step of partially reducing the first mixture between the step b) and the step c). The partial reduction in step a) and the complete reduction in step d) are performed by heat treatment at a temperature of 1,000° C. to 1,500° C. in a hydrogen atmosphere for 1 to 10 hours. A method for producing titanium metal powder according to claim 1. The partial reduction in step a) and the complete reduction in step d) are performed by heat treatment at a temperature of 1,000° C. to 1,500° C. in a hydrogen atmosphere for 1 to 10 hours. The method for producing titanium metal powder according to claim 2. The method of manufacturing titanium metal powder according to claim 1, further comprising the step of: e) pulverizing the manufactured titanium metal into powder. The method for producing titanium metal powder according to claim 1, wherein the stoichiometric ratio of the first mixture and the calcium hydride is 1:1.1 to 1.25. The method for producing titanium metal powder according to claim 1, wherein the titanium metal has an oxygen content of less than 0.3% by weight.