RU2734225C1 - Obtaining titanium alloys by reducing titanium tetrachloride - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: group of inventions relates to methods of producing titanium alloys. Titanium alloy is obtained by adding TiCl₄ to the incoming mixture at temperature of the first reaction. Part of Ti⁴⁺ in TiCl₄ is reduced to Ti³⁺ to form a first reaction product. Incoming mixture contains aluminium and, possibly, AlCl₃ and/or, possibly, at least one halogenide of alloying element. After stopping the addition of TiCl₄, the first reaction product is heated under drying conditions to complete reduction of Ti⁴⁺ or to remove remaining TiCl₄ to form a first intermediate mixture. First intermediate mixture is a solution of a salt based on AlCl₃, which contains Ti³⁺, wherein Ti³⁺ in the first intermediate mixture is in form of TiCl₃ (AlCl₃)_x, where x is greater than 0–10. First intermediate mixture is heated to second reaction temperature. Part of Ti³⁺ is reduced to the second intermediate mixture, which is a solution of AlCl₃ based salt, which contains Ti²⁺. Additionally, the second intermediate mixture is heated to the temperature of the third reaction, wherein Ti²⁺ forms a titanium alloy by a disproportionation reaction.

EFFECT: invention enables to obtain titanium alloy materials by improved processing techniques of the titanium tetrachloride reduction reaction in AlCl₃ based reaction media.

31 cl, 2 ex, 4 dwg

Description

Priority information

This application claims priority October 21, 2016 filing date US Provisional Patent Application No. 62/411205, which is incorporated herein by reference.

Technology area

The present invention relates generally to processes for the preparation of titanium alloys by reduction of titanium tetrachloride (TiCl ₄ ) in AlCl _3- based reaction media. More specifically, titanium alloys are prepared by reducing Ti ⁴⁺ in TiCl ₄ to a lower titanium valence (eg Ti ³⁺ and Ti ²⁺ ), followed by a Ti ²⁺ disproportionation reaction. It is also possible for other alloying elements to form from salt to alloy in the reduction and / or disproportionation process.

State of the art

Titanium alloys that contain aluminum, such as titanium-aluminum alloys (Ti-Al) and titanium-aluminum intermetallic alloys (Ti-Al), are very valuable materials. However, their preparation can be difficult and expensive, especially in powder form, and there are certain alloys that are not available with traditional smelting methods. This cost of production limits the widespread use of these materials, even though they have highly desirable properties for applications in the aerospace, automotive and other industries.

Known reactors and methods for the formation of alloys based on titanium and aluminum and intermetallic compounds. For example, WO 2007/109847 shows a stepwise process for preparing titanium-aluminum-based alloys and intermetallic compounds by a two-step reduction process based on the reduction of titanium tetrachloride with aluminum. WO 2009/129570 describes a reactor adapted to solve one of the problems associated with the reactors and methods described in WO 2007/109847 when used under the conditions required to form titanium-aluminum-based alloys with a low aluminum content.

However, the discussion of the chemical processes that actually take place in the methods described in WO 2007/109847 and WO 2009/129570 does not provide a complete understanding of the actual reactions that take place in the formation of a metal alloy from metal halide precursors.

Given these studies, there is a need for a better understanding of the chemical processes for producing titanium-aluminum alloys through the reduction of titanium tetrachloride TiCl ₄ , as well as for improved processing technologies for such reactions.

The above references to the prior art do not imply that such prior art forms part of the general knowledge of a person skilled in the art.

Brief description of the invention

Aspects and advantages of the invention will be set forth in part in the description that follows, or they may be obvious from the description, or may be learned by practice of the invention.

In general, a method is provided for producing a titanium alloy such as an aluminum titanium alloy. In one embodiment, the method comprises adding TiCl ₄ to the feed mixture at a first reaction temperature such that at least a portion of the Ti ⁴⁺ in TiCl _{4 is} reduced to Ti ³⁺ to form the first reaction product. The incoming mixture may contain aluminum and optionally AlCl ₃ and / or optionally one or more alloying element halides. After the addition of TiCl _{4 is} stopped, the product of the first reaction can be heated under drying conditions to complete the Ti ⁴⁺ reduction or to remove substantially all of any remaining TiCl ₄ to form a first intermediate mixture, which is an AlCl ₃ -based salt solution that contains Ti ³⁺ . The first intermediate mixture can then be heated to the second reaction temperature such that at least a portion of the Ti ^{3+ is} reduced to a second intermediate mixture, which is an AlCl ₃ -based salt solution that contains Ti ²⁺ . The second intermediate mixture is then further heated to the third reaction temperature so that Ti ²⁺ forms a titanium alloy through a disproportionation reaction.

In one embodiment, a method for producing a titanium alloy may include reducing TiCl _{4 with} aluminum, AlCl ₃ and at least one metal chloride at a temperature below 180 ° C to form a first intermediate product containing Ti ³⁺ , and reducing the first intermediate product at a temperature below 900 ° C to form titanium-aluminum alloy.

In one embodiment, a method for preparing a titanium-containing material may include mixing Al particles, AlCl ₃ particles, and optionally at least one other alloying element chloride particles to form an input mixture, adding TiCl ₄ to the input mixture, reducing Ti ⁴⁺ to TiCl ₄ in the presence of the feed mixture at a first reaction temperature (eg, below about 180 ° C) to form a first intermediate mixture containing Ti ³⁺ .

These and other features, aspects and advantages of the present invention will be better understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, show embodiments of the invention and, together with the description, serve to explain the principles of the invention.

Brief Description of Drawings

A complete and useful description of the present invention, including its best method, intended for a person skilled in the art, is set forth in the technical description, which refers to the accompanying drawings, in which:

in FIG. 1 is a diagram of an exemplary method according to one embodiment of the present invention,

in FIG. 2 is a schematic diagram of one exemplary embodiment of the step 1 reaction of the exemplary method of FIG. 1,

in FIG. 3 is a schematic diagram of one exemplary embodiment of the reactions of Step 2 of the exemplary method and further processing of the resulting titanium alloy of the approximate method of FIG. 1, and

in FIG. 4 shows an equilibrium stability diagram (Gibbs energy per mole Cl ₂ versus absolute temperature) for the Ti — Cl and Al — Cl systems overlap in order to show the reduction potential of Al metal. Only pure elements (Ti, Al and Cl ₂ ) and pure compounds of salts (TiCl ₄ , TiCl ₃ , TiCl ₂ and AlCl ₃ ) are taken into account, because there are no established thermodynamic data for the phases of saline solutions (TiCl ₄ (AlCl ₃ ) _x , TiCl ₃ (AlCl ₃ ) _x , TiCl ₂ (AlCl ₃ ) _x ).

The reuse of reference numbers in this technical description and in the drawings is intended to represent the same or similar features or elements of the present invention.

Detailed description of the invention

Now, embodiments of the invention are explained in detail, one or more examples of which are shown in the drawings. Each example is provided for the purpose of explaining the invention and not limiting the invention. In fact, those skilled in the art will appreciate that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For example, features shown or described as part of one embodiment may be used with another embodiment to provide yet another additional embodiment. Thus, it is intended that the present invention covers such modifications and variations that fall within the scope of the appended claims and their equivalents.

As used herein, the terms "first", "second" and "third" can be used interchangeably to distinguish one component from another, and are not intended to denote the position or importance of individual components.

Chemical elements are discussed in the present invention using their usual chemical abbreviations, such as can usually be found in the Periodic Table of the Elements. For example, hydrogen is represented by its usual chemical abbreviation H, helium is represented by its usual chemical abbreviation He, etc.

As used herein, the term "titanium alloy" or a similar term should be understood to encompass any titanium-based alloy or any titanium intermetallic compound-based alloy, and possibly other additional alloying elements besides Ti and Al. Likewise, the term "titanium-aluminum alloy" or a similar term should be understood to encompass a titanium-aluminum-based alloy or an alloy based on titanium-aluminum intermetallic compounds and possibly other additional alloying elements besides Ti and Al.

As used herein, the term "aluminum chlorides" should be understood to refer to compounds of aluminum chlorides or mixtures of such compounds of aluminum chlorides, including AlCl ₃ (solid, liquid or vapor phase) or any other compounds or ionic compounds of Al - Cl (for example, AlCl , AlCl ₂ , (AlCl ₄ ) ^- , Al ₂ Cl ₆ and (Al ₂ Cl ₇ ) ^- ). The use of AlCl _x refers to the term "aluminum chlorides" and is to be understood as an expression referring to such aluminum chloride compounds or mixtures of such aluminum chloride compounds, regardless of the stoichiometric ratio.

As used herein, the term "titanium chloride" should be understood to refer to titanium trichloride (TiCl ₃ ) and / or titanium dichloride (TiCl ₂ ) or other combinations of titanium and chlorine, but not TiCl ₄ , which is referred to herein as titanium tetrachloride. In some sections of the technical description, the more general term "TiCl _x " may be used, which is to be understood as referring to titanium chloride compounds and encompassing titanium tetrachloride (TiCl ₄ ), titanium trichloride (TiCl ₃ ), titanium dichloride (TiCl ₂ ) and / or other combinations of titanium and chlorine in solid, liquid or vapor forms. Since there are also different solution phases and titanium chloride complexes, this document refers to the specific oxidation state of the Ti ion (for example, Ti ²⁺ , Ti ³⁺ and Ti ⁴⁺ ) in the general phase (that is, a mixture of salts), and not specific chemical connections.

As used herein, the term "dopant halide" refers to an ion of a dopant attached to a halide (eg, chloride, fluoride, bromide, iodide, or astatide). The alloying element can be any element that must be included in the final titanium alloy, such as metals or other elements. A "dopant halide" can be represented as MX _x , where M is a dopant ion and X is a halide (ie, a halogen ion), regardless of the stoichiometric ratio (represented as x). For example, dopant chloride can be represented as MCl _x .

In general, methods are disclosed for preparing titanium alloys (eg titanium aluminum alloys) by reducing TiCl ₄ , which contains a titanium ion (Ti ⁴⁺ ). More specifically, titanium alloys are formed by reducing Ti ⁴⁺ in TiCl ₄ to a lower titanium valence (eg, Ti ³⁺ and Ti ²⁺ ), followed by a Ti ²⁺ disproportionation reaction to form the titanium alloy. It should be noted that the valence of titanium (for example, Ti ⁴⁺ , Ti ³⁺ and / or Ti ²⁺ ) can be present in the reaction and / or intermediate materials as a complex with other compounds in the mixture (for example, chlorine, other elements and / or other compounds such as chloroaluminates, metalhaloaluminates, etc.) and optionally may be present in pure form TiCl ₄ , TiCl ₃ and TiCl ₂ , respectively. For example, metal halide aluminates can be complexed MX _x with AlCl ₃ in these intermediates, such as those described below. In general, AlCl ₃ provides reaction media that are reactive compounds (eg Ti ⁴⁺ , Ti ³⁺ , Ti ²⁺ , Al, Al ⁺ , Al ²⁺ , Al ³⁺ , also other alloying ions) for all reactions ... Without wishing to be bound by any particular theory, the authors believe that the presence of saline solutions in stage 1 and stage 2 reactions allows the reduction of Ti ⁴⁺ to Ti ³⁺ and the reduction of Ti ³⁺ to Ti ²⁺ , which occurs in the condensed state (for example, solid and liquid), for example, at a temperature of about 700 ° C or less (for example, about 300 ° C or less).

FIG. 1 shows a general flow diagram of one exemplary process 100 in which TiCl _{4 is} reduced to a titanium alloy. Process 100 is generally shown in sequential steps: reaction precursors 101 (including formation of feed mixture 102), step 1 reaction 104, step 2 reactions 106, and subsequent treatment 108.

1. Precursors of the reaction

The reaction precursors for the Step 1 reaction 104 in Process 100 of FIG. 1 include at least TiCl ₄ and a feed mixture that contains aluminum (Al), either alone or with additional chloride components. In one embodiment, the reaction precursors comprise the feed mixture as a solid at ambient conditions (eg, about 25 ° C and 100 kPa (1 atm.)) And TiCl ₄ in liquid form. Additional materials (e.g., AlCl ₃ and / or other alloying element halides) may be included in the reaction precursors at various stages of process 100, such as included in the feed mixture with TiCl ₄ and / or as a separate charge entering the reaction of stage 1 and / or step 2. That is, one or more chloride of the alloying element can, if necessary, be introduced into the reaction materials of step 1 (for example, into the incoming mixture, if they are solid, in TiCl ₄ , if they are liquid or soluble solid materials, and / or directly independently into the reaction vessel of step 1), dissolved in another component of the input materials, and / or they can, if necessary, be introduced into the reaction materials of step 2. In some embodiments, especially when the dopant halide is added to the liquid TiCl ₄ (e.g., soluble in it), liquid TiCl ₄ can be filtered to remove any particles in the liquid stream. Such a filter can, in specific embodiments, purify a liquid stream by removing oxygen compounds from the liquid, since the solubility of oxygen and oxidized substances is extremely low. Actually, filtration of liquid TiCl ₄ (with or without any alloying element halide dissolved in it) can adjust the chemical composition of the liquid and remove oxygen substances from it.

For example, reaction precursors can include some or all of the alloy elements to achieve the desired titanium alloy chemistry. In one embodiment, the dopant halide (MX _x ) may be dopant chloride (MCl _x ). Particularly suitable alloying elements (M) include, but are not limited to, vanadium, chromium, niobium, iron, yttrium, boron, manganese, molybdenum, tin, zirconium, silicon, carbon, nickel, copper, tungsten, beryllium, zinc, germanium, lithium, magnesium, scandium, lead, gallium, erbium, cerium, tantalum, osmium, rhenium, antimony, uranium, iridium and combinations thereof.

As shown in FIG. 1 number 102, the input mixture is formed from aluminum (Al), optionally aluminum chloride (eg AlCl ₃ ), and optionally one or more dopant chlorides. Without wishing to be bound by any particular theory, the authors believe that AlCl ₃ is useful as a component of the incoming mixture, but it is not necessarily required if chloride of the alloying element is present, which is soluble in TiCl ₄ or mixed with it under the reaction conditions of step 1 to form in situ AlCl _x from alloying element chloride and aluminum. In one embodiment, AlCl _{3 is} included as a material in the feed mixture. However, in another embodiment, the feed mixture may be substantially free of AlCl ₃ . As used herein, the term “substantially free” means the presence of no more than a minor trace amount and includes “completely free” (eg, “substantially free” can range from 0 atomic% to 0.2 atomic%). If AlCl _{3 is} not present in the feed mixture, then Al and other metal chlorides are present and are used to form AlCl ₃ so that the reaction of step 1 can continue.

If it is solid under ambient conditions, one or more dopant chlorides (MCl _x ) may optionally be included in the feed to form the feed. Particularly suitable alloying element chlorides in the solid state, included with aluminum and optionally AlCl ₃ , include, but are not limited to, VCl ₃ , CrCl ₂ , CrCl ₃ , NbCl ₅ , FeCl ₂ , FeCl ₃ , YCl ₃ , BCl ₃ , MnCl ₂ , MoCl ₃ , MoCl ₅ , SnCl ₂ , ZrCl ₄ , NiCl ₂ , CuCl, CuCl ₂ , WCl ₄ , WCl ₆ , BeCl ₂ , ZnCl ₂ , LiCl, MgCl ₂ , ScCl ₃ , PbCl ₂ , Ga ₂ Cl ₄ , GaCl ₃ , ErCl ₃ , CeCl ₃ and mixtures thereof. One or more of these alloying element chlorides may also be included in other process steps including, but not limited to titanium tetrachloride and / or after step 1.

In one embodiment, the feed mixture is in particulate form (ie, in powder form). For example, the incoming mixture is formed by grinding a mixture of aluminum (Al), optionally aluminum chloride (eg AlCl ₃ ) and optionally one or more dopant halides (eg dopant chloride). The material of the feed mixture can be combined as solid materials and ground together to form particles having a mixed composition. In one embodiment, a mixture of aluminum particles, optionally aluminum chloride particles, and optionally one or more chloride alloying element particles are mixed and together resized (eg, milled) to form a plurality of inlet mixture particles. For example, the aluminum particles can be aluminum particles that have a pure aluminum core with an alumina layer formed on the surface of the particles. Alternatively, the aluminum particles may comprise an aluminum core and at least one other alloying element or alloy of aluminum and alloying element. The aluminum particles can have a suitable morphology, including a flake-like shape, a substantially spherical shape, and the like.

Since the aluminum particles generally form a layer of alumina on the surface of the particles, the milling process is performed in an atmosphere that is substantially oxygen free to suppress the formation of any additional alumina in the feed mixture. For example, the milling process can be performed under an inert atmosphere, such as an argon atmosphere, at a pressure of about 93.3 kPa to about 506.5 kPa (about 700 Torr to about 3800 Torr). Without wishing to be bound by any particular theory, the authors believe that in the reaction between AlCl ₃ and surface Al ₂ O ₃ during grinding Al (s), AlCl ₃ converts Al ₂ O ₃ to AlOCl (for example, via Al ₂ O ₃ + AlCl ₃ → 3AlOCl). The surface layer of Al ₂ O ₃ protects the underlying Al (s), and then the transformation of this surface layer of Al ₂ O ₃ to AlOCl during grinding allows Al to dissolve and diffuse into the salt in the form of Al ⁺ from Al ²⁺ . Without wishing to be bound by any particular theory, the authors believe that a partial pressure of oxygen below that required to stabilize Al ₂ O ₃ (that is, in an inert atmosphere) allows these reactions to convert Al ₂ O ₃ , which in other cases is very stable to oxygen. Actually, the resulting particles are "activated" Al powder.

In addition, the reduction in particle size allows an increase in surface area to increase the availability of aluminum surface area in subsequent reduction reactions. The particles can have any suitable morphology, including flake-like, substantially spherical, and the like. In specific embodiments, the particles of the feed mixture have a minimum particle size of from about 0.5 microns to about 25 microns on average (eg, from about 1 micron to about 20 microns), which is calculated by averaging the minimum particle size. For example, in one embodiment, the flake particle can be a planar particle having dimensions in the x-y plane and thickness in the z-direction with a minimum average size of about 0.5 microns to about 25 microns (e.g., from about 1 microns to about 20 μm), while the dimensions in the x- and y-directions have large average dimensions. In one embodiment, milling is performed at a milling temperature of about 40 ° C or less to suppress agglomeration of Al particles.

Milling can be carried out using a high intensity method or a low intensity method to obtain particles of the incoming mixture, for example, using ball milling methods, crushing methods, or other size reduction methods.

2. Reaction of stage 1 (reduction of Ti ⁴⁺ to Ti ³⁺ )

As indicated, the reaction precursors include at least TiCl ₄ in liquid or vapor form and a feed mixture in powder form that contains aluminum (Al) and may contain additional materials (eg AlCl ₃ and / or other doping chlorides). TiCl ₄ can be a pure TiCl ₄ liquid or a liquid mixed with other alloying chlorides. In some embodiments, mixtures of TiCl ₄ and other dopant chlorides may be heated to ensure that the solution is unsaturated, which would precipitate the components from solution. An example of mixed liquid precursors includes a mixture of TiCl ₄ and VCl ₄ to form a vanadium-containing titanium alloy. Various metal chlorides (i.e., AlCl ₃ , VCl ₄ , VCl ₃ , MCl _x , etc.) can be dissolved in TiCl ₄ (l), which can be represented as (TiCl ₄ ) _x (AlCl ₃ ) _y (MCl _x ) _z , where M is any suitable metal discussed herein, and x, y and z are mole fractions of particular components of the brine. Such a saline solution can be generally defined in short form as [Ti ⁴⁺ : salt], where the brackets [] represent the material as a solution phase containing Ti ⁴⁺ as the main solvent material and a "salt" representing all minor compounds, or alloying elements.

These reaction precursors are added together to reduce Ti ⁴⁺ to Ti ³⁺ in the reaction 104 of Step 1. For the Step 1 reaction, the reaction precursors are heated to a first reaction temperature that is high enough to cause chemical reduction, but low enough to suppress the formation of liquid TiCl ₄ . For example, the reaction of step 1 can be performed with the reaction precursors heated to a first reaction temperature of about 180 ° C or less (e.g., from about 100 ° C to about 165 ° C, such as from about 140 ° C to about 160 ° C). In one embodiment, the feed is heated to the first reaction temperature prior to adding TiCl ₄ to the feed. Alternatively or additionally, TiCl ₄ can be added to the feed mixture simultaneously with heating the feed mixture to the first reaction temperature.

Without wishing to be bound by any particular theory, the authors believe that aluminum (for example, in the form of metallic aluminum or an aluminum salt such as AlCl ₃ and / or AlCl _x ) present in the incoming mixture reduces Ti ⁴⁺ in TiCl ₄ to Ti ³⁺ by the aluminothermal process at the temperature of the first reaction, in which AlCl ₃ serves as the reaction medium in the form of an AlCl ₃ saline solution. In addition, it is believed that Ti ⁴⁺ and Al dissolve in AlCl ₃ and in TiCl ₃ (AlCl ₃ ) _x formed from the reaction products of the input mixture, so that Ti ⁴⁺ and Al can react. It is also believed that Al dissolves in the salt as Al ⁺ or Al ²⁺ and these Al compounds diffuse into Ti ⁴⁺ and react to form the new reaction product TiCl ₃ (AlCl ₃ ) _x . Finally, it is believed that Al (s) dissolves in the brine through the surface layer of AlCl ₃ or AlOCl on Al (s). For example, without wishing to be bound by any particular theory, the authors believe that Ti ⁴⁺ in TiCl _{4 is} reduced to Ti ³⁺ in the form of a TiCl ₃ complex, with a metal chloride (s) such as TiCl ₃ (AlCl ₃ ) _x with x is greater than 0, for example, from greater than 0 to 10 (for example, x is from 1 to 5), which is either a continuous solid solution of TiCl ₃ and AlCl ₃ , or two solutions of TiCl ₃ rich TiCl ₃ (AlCl ₃ ) _x and AlCl ₃ rich AlCl ₃ (TiCl ₃ ) _x , where both solutions have the same crystal structures. Thus, it is believed that substantially all of the Ti ³⁺ compounds formed are in the form of such metal chloride complexes, instead of pure TiCl ₃ .

Actually, the resulting reaction product is a saline solution based on AlCl ₃ , which contains Ti ³⁺ compounds. Similarly to [Ti ⁴⁺ : salt] discussed above, various metal chlorides (ie, AlCl ₃ , VCl ₄ , VCl ₃ , MCl _x , etc.) dissolve in TiCl ₃ (solid or liquid), which can be represented by (TiCl ₃ ) _x (AlCl ₃ ) _y (MCl _x ) _z where M is any suitable metal and x, y and z represent the mole fractions of the brine. TiCl ₃ (AlCl ₃ ) _x is a variation of the larger solution phase, even if all the chlorides of the alloying elements, MCl _x , are dissolved in this solution phase. In addition, Ti ⁴⁺ also dissolves in this solution phase, which can be described as the Cl-rich side of the phase field. As TiCl _{4 is} added to the reaction mixture, there may be more TiCl ₄ / TiCl ₃ than AlCl ₃ at some point, making the salt rich in TiCl ₃ . Such a saline solution can be briefly defined as [Ti ³⁺ : salt], with brackets [] representing the material as a solution phase containing Ti ³⁺ as the main compound of the solution, and "salt" representing all minor compounds or alloying elements ...

This reaction can be carried out as TiCl _{4 is} added in a controlled manner to the feed mixture at the temperature of the first reaction. For example, TiCl ₄ can be added continuously or semi-continuously. In one embodiment, excess Al is included in the reaction to allow substantially complete reduction of Ti ⁴⁺ to Ti ³⁺ and for subsequent reductions. As such, TiCl ₄ can be added to obtain the desired Ti / Al ratio to obtain the desired salt composition.

During the reaction, the feed mixture may remain substantially solid under the conditions of the first reaction (eg, the temperature of the first reaction and the pressure of the first reaction). In specific embodiments, the stage 1 reaction is performed in a plow reactor, ribbon blender, or other liquid / solid / vapor reactor. For example, the Ti ⁴⁺ reduction reaction can be performed in a device to reflux the stream during the reaction phase and / or to distill after the reaction phase of any unreacted TiCl ₄ vapor to continue reduction and / or to prevent loss of TiCl ₄ (g) during the reaction.

The reaction of step 1 can be performed under an inert atmosphere (eg, containing argon). In fact, oxygen (O ₂ ), water vapor (H ₂ O), nitrogen (N ₂ ), carbon oxides (e.g. CO, CO ₂ , etc.) and / or hydrocarbons (e.g. , CH ₄ , etc.) with aluminum and / or other compounds. In certain embodiments, the inert atmosphere has a pressure of from 100 kPa (1 atm.) (For example, about 760 Torr) to 500 kPa (5 atm.) (For example, about 3800 Torr), for example, from about 100 kPa (760 Torr) to about 200 kPa (1500 Torr). While pressures of less than about 100 kPa (760 Torr) may be used in some embodiments, this is undesirable in most embodiments due to the possible supply of oxygen, water, carbon monoxide and / or nitrogen at such low pressures. For example, an inert atmosphere has a pressure of 92 kPa (0.92 atm.) (For example, about 700 Torr) to about 500 kPa (5 atm.) (For example, about 3800 Torr), such as about 0.92 kPa to about 200 kPa (from about 700 Torr to about 1500 Torr).

After the reaction of step 1 of reducing Ti ⁴⁺ to Ti ^{3+, the} first reaction product may be dried under drying conditions to remove substantially all of any remaining unreacted TiCl ₄ (due to kinetic limitations) to form an intermediate mixture. For example, the product of the first reaction can be dried by heating and / or under vacuum conditions. In one embodiment, any entrained TiCl _{4 is} removed from the first reaction product by heating to a temperature that is above the boiling point of TiCl ₄ (e.g., about 136 ° C), but below the temperature at which Ti ^{3+ is} further reduced (e.g., above about 180 ° C), such as a drying temperature of about 160 ° C to about 180 ° C (e.g., about 160 ° C to about 170 ° C).

However, it should be noted that Al is capable of reducing Ti ⁴⁺ to Ti ³⁺ and Ti ³⁺ to Ti ²⁺ at all temperatures, including temperatures below 20 ° C. The temperatures defined above are due to kinetic constraints and / or solid transfer in the reaction products. Also, not wishing to be bound by any particular theory, the authors believe that the reduction of Ti ³⁺ to Ti ²⁺ cannot occur when Ti ^{4+ is} present in the reaction products of stage 1 due to the Gibbs phase rule and phase equilibria of the Ti- Al-Cl-O. That is, the oxidation of Al can drive both stages of the reaction at the same temperature, however, the aspect of the sequence of these reactions is due to the real belief that Ti ⁴⁺ to Ti ²⁺ cannot exist simultaneously in the same position of an isolated system. Thus, the reactions are carried out sequentially so that substantially all of the Ti ^{4+ is} reduced to Ti ³⁺ prior to the formation of Ti ²⁺ in the system. Thus, the recovery method is performed by the presently described methods in a sequential manner.

After drying the first reaction mixture and before heating the intermediate mixture to the second reaction temperature for the reaction of step 2 described below, the intermediate mixture containing [Ti ³⁺ : salt] can be stored, for example, in an inert atmosphere until further reaction. In one embodiment, the intermediate mixture containing the Ti ³⁺ complexes can be cooled for storage to a temperature below about 100 ° C, such as below about 50 ° C or below about 25 ° C.

Referring to FIG. 2, it is a flow chart 200 of one exemplary embodiment of reaction precursors 101 (including formation of feed mixture 102) and reaction 104 of step 1 of exemplary process 100 of FIG. 1. In the illustrated embodiment, a first liquid storage tank 202 and an optional second liquid storage tank 204 are in fluid communication with a liquid mixer 206 so as to feed liquid reaction precursors thereto through a feed line 208. In general, a first liquid storage tank 202 contains liquid 201 TiCl ₄ in the form of pure liquid TiCl ₄ or liquid mixed with other chlorides of alloying elements. Valve 210 and pump 212 control the flow of fluid 201 from fluid storage tank 202 to fluid mixer 206. Likewise, second liquid storage tank 204 is in fluid communication with liquid mixer 206 so as to feed liquid reaction precursors thereto via feed line 214. Second liquid storage tank 204 contains, in one embodiment, a liquid 205 of at least one alloying element chloride. Valve 216 and pump 218 control the flow of fluid 205 from fluid storage tank 204 to fluid mixer 206.

Also, as shown in FIG. 2, the solid reaction precursors are fed to the ball mill 220 from an Al storage device 222, an optional aluminum chloride storage device 224 (eg, AlCl ₃ ) and possibly a storage device 226 for one or more alloying element chlorides. Although the device is shown as a ball mill 220, any suitable size reduction device (eg, a grinding device) can be used in that method. As shown, aluminum chloride storage device 224 and storage device 226 for one or more alloying element chlorides are supplied via optional mixer 228 to mill 220. From mill 220, feed mixture 221 is provided to stage 1 reaction device 230 via feed hopper 232. In addition, mixed liquid from mixer 206, liquids are added to stage 1 reaction device 230 in a controlled manner through feed pipe 234 with mixed liquid flow controlled by pump 236 and valve 238. In some cases, aluminum chloride storage device 224 and storage device 226 of one or more alloying element chloride may supply via optional mixer 228 directly into feed hopper 232.

In the step 1 reaction apparatus 230, Ti ^{4+ is} reduced to Ti ³⁺ under the conditions described above to form the first reaction product. The first reaction product can be dried at the end of the stage 1 reaction apparatus 230, for example, in a drying zone 229 having drying conditions such as discussed above to remove substantially all of any remaining TiCl ₄ via condenser 231 to form an intermediate mixture (containing Ti ³⁺ for example in the form of a complex of TiCl ₃ with metal chloride (s), such as TiCl ₃ (AlCl ₃ ) _x ), supplied to product line 244 for additional titanium reduction. As shown, any remaining TiCl ₄ or liquid mixture can be vaporized and, if necessary, recirculated (eg, via a distillation process, not shown) to line 246 of the recirculation loop. In alternative embodiments, the downscaling device may be combined with the stage 1 reaction device 230. In one embodiment, the conditions of the stage 1 reaction device 230 retain liquid in the reactor during the reaction or condense the vapor for return to the stage 1 reactor. The condenser is then heated to a temperature during drying. above the boiling point of the liquid mixture in order to ensure drying.

The intermediate mixture (containing Ti ³⁺ , for example, in the form of a complex of TiCl ₃ with other materials) can be stored after drying before further reduction methods. In one embodiment, the intermediate mixture is stored under an inert atmosphere to suppress the formation and prevent the formation of any aluminum oxides, other oxide complexes, or oxychloride complexes in the intermediate mixture.

3. Stage 2 reactions (Ti ³⁺ to Ti ²⁺ and Ti ²⁺ to Ti alloy)

In the reactions 106 of step 2 in the process 100, Ti ³⁺ and any halides of the alloying elements MX _{x of the} intermediate mixture are reduced to Ti ²⁺ and M subhalides by heating to the temperature of the second reaction and reaction with Al present as solid Al or as Al compounds, dissolved in the complex, and then Ti ^{2+ is} reduced to Ti alloy by an endothermic reaction at a third reaction temperature that is higher than the second reaction temperature. The metal subhalides are also reduced by reduction of Al to form the base alloy metal M at temperatures in the range of step 2 of the process. In one embodiment, these reactions can be performed sequentially at different temperatures in a single reaction step, or as separate steps in a two-step or more process (eg, in steps as the temperature rises).

Without wishing to be bound by any particular theory, the authors believe that aluminum (for example, in the form of metallic aluminum or an aluminum salt such as AlCl ₃ and / or AlCl _x ) present in the intermediate mixture reduces Ti ³⁺ to TiCl ₃ complexes with metal chloride (s), such as TiCl ₃ (AlCl ₃ ) _x , to Ti ²⁺ at the second reaction temperature. For example, without wishing to be bound by any particular theory, the authors believe that the reaction can form Ti ²⁺ in TiCl ₂ , which forms a complex with the chloride (s) of the metal (s), with the formation of salt solutions based on complexes of titanium and aluminum chloride such as TiAlCl ₅ , Ti (AlCl ₄ ) ₂ or mixtures thereof with optional additional alloying elements or halides or chloroaluminates.

Without wishing to be bound by any particular theory, the authors believe that there are three possible forms of TiCl ₂ : (1) essentially pure TiCl ₂ , which dissolves only a small amount of any material, (2) TiAlCl ₅ (s), which also does not dissolves a large number of other materials and is possibly only stable up to about 200 ° C, and (3) {Ti (AlCl ₄ ) ₂ } _n , which is probably an inorganic polymer material, existing as a liquid or gas, glassy material and fine powder (long chain molecules). That is, {Ti (AlCl ₄ ) ₂ } _n has a large compositional range (for example, n can be from 2 to about 500, for example, from 2 to about 100, for example, from 2 to about 50, for example, from 2 to about 10) and dissolves all chlorides of alloying elements. In one particular embodiment, the {Ti (AlCl ₄ ) ₂ } _n gas assists in removing unreacted salt from the titanium alloy particles (eg, at a low temperature in the last stage of the reaction). As a result, the reaction product containing Ti ²⁺ is a phase based on a complex of TiCl ₂ and AlCl ₃ (for example, Ti (AlCl ₄ ) ₂ , etc.). Such a complex may be a saline solution, briefly defined as [Ti ²⁺ : salt], with brackets [] representing the material as a solution phase containing AlCl ₃ as the main solvent compound, Ti ²⁺ and a "salt" representing all minor compounds or alloying elements.

The reduction of Ti ³⁺ to Ti ²⁺ can be performed at a second reaction temperature of about 180 ° C or higher (e.g., about 180 ° C to about 900 ° C, such as about 180 ° C to about 500 ° C, or about 180 ° C to approx. 300 ° C). Without wishing to be bound by any particular theory, we believe that at least part of the Ti ²⁺ is in the form of a complex of TiCl ₂ with the chloride (s) of the metal (s).

Without wishing to be bound by any particular theory, the inventors believe that in this process AlCl _{3 is} chemically bonded to TiCl ₃ (AlCl ₃ ) _x , TiAlCl ₅ and {Ti (AlCl ₄ ) ₂ } _n . Due to its significant reactivity (eg <1), AlCl ₃ does not evaporate as would be expected for pure AlCl ₃ , and there is no significant evaporation of AlCl ₃ until the reaction temperatures are reached or exceeded about 600 ° C. ... Thus, AlCl ₃ provides a reactor environment for the reaction to proceed and AlCl ₃ provides a chemical environment that stabilizes the Ti ^{2+ ion} and converts Ti ³⁺ to Ti ²⁺ at reaction temperatures less than about 250 ° C (for example, from about 180 ° C to approx. 250 ° C).

After Ti ³⁺ in the complex of TiCl ₃ with the chloride (s) of the metal (s) (for example, in the form of TiCl ₃ - (AlCl ₃ ) _x and / or TiAlCl ₆ (g)), it is reduced to Ti ²⁺ (for example , in the form of a complex of TiCl ₂ with the chloride (s) of the metal (s), Ti ²⁺ can be converted to a Ti alloy by a disproportionation reaction. In one embodiment, TiAlCl ₆ (d) may be present to aid in the removal of Ti ^{3+ by} -products from Ti alloy formation and / or recycling the Ti ³⁺ in the reaction chamber. For example, a Ti ²⁺ can be converted to a Ti alloy through a disproportionation reaction at a third reaction temperature of 250 ° C or higher (eg, from about 250 ° C to about 1000 ° C, such as from about 500 ° C to about 1000 ° C). While in some embodiments the temperature of the third reaction may reach about 1000 ° C, in other embodiments the temperature of the third reaction has an upper temperature limit of about 900 ° C. For example, Ti ²⁺ can be reduced to Ti alloy through a disproportionation reaction at a third reaction temperature of about 300 ° C to about 900 ° C (e.g., about 300 ° C to about 900 ° C, such as about 500 ° C to about 900 ° C). Without wishing to be bound by any particular theory, it is believed that keeping the third reaction temperature below about 900 ° C ensures that any oxygen contaminants present in the reaction chamber remain stably volatile substances that can volatilize so as to limit the oxygen in the resulting product. titanium alloy. On the other hand, at a reaction temperature above 900 ° C, the oxygen contaminants are no longer in the form of volatile compounds, making it more difficult to reduce the residual oxygen. Any other volatile substances such as oxychlorides, chlorides and / or carbon-containing oxides can be removed by thermal distillation.

In general, this titanium alloy forming reaction can be divided into an alloying step through a disproportionation reaction (for example, at a disproportionation reaction temperature of about 250 ° C to about 650 ° C) and a distillation step (for example, at a distillation temperature of about 650 ° C to about 650 ° C). approx. 1000 ° C).

For example, the formation of a titanium alloy can be divided into two methods: nucleation and particle growth (which can also be called particle coarsening). During nucleation, the first titanium alloy is formed from [Ti ²⁺ : salt] at lower temperatures (eg, from about 250 ° C to about 400 ° C). The local composition of the salt (activity of the components), surface energy and kinetics of disproportionation determine the resulting composition of the titanium alloy. Particle growth then occurs as the titanium alloy continues to grow from [Ti ²⁺ : salt] at higher temperatures (for example, about 400 ° C to about 700 ° C) in a condensed state and at temperatures above 700 ° C (for example, from about 700 ° C to about 1000 ° C) in the reaction of gas and solid. These reactions at higher temperatures (eg, greater than about 700 ° C) can also be described as a distillation process in which Cl is removed from the titanium alloy product, which occurs concurrently with the growth of the titanium alloy particles. Both of these methods are based on the disproportionation reaction, but they can produce titanium alloys with different compositions. It should also be noted that there is a disproportionation reaction for both Ti and Al in the reaction method: Ti ²⁺ = 1/3 [Ti] + 2 / 3Ti ³⁺ and Al ⁺ = 2/3 [Al] + 1 / 3Al ³⁺ . The design of the equipment for this method can be made to independently control the residence time at each temperature (for example, in a thermal zone), which can help control the method.

In one embodiment, the intermediate mixture containing Ti ²⁺ is maintained at the third reaction temperature until substantially all of the Ti ²⁺ has reacted to the titanium alloy. In the reaction, any Ti ³⁺ formed during the disproportionation reaction can be internally recycled for reduction to Ti ²⁺ by thermal aluminum reduction and for further reaction in the disproportionation reaction. In addition, Ti ⁴⁺ (e.g., in the form of TiCl ₄ ) can be formed by a parallel Ti disproportionation reaction, which can be pumped out of the reaction system as a gaseous by-product for an ongoing reaction (e.g., reduction back to Ti ³⁺ , then to Ti ²⁺ ) or in the form of a sampled by-product (for example, carried out by means of a countercurrent flow of an inert gas).

Step 2 reactions (e.g., Ti ³⁺ to Ti ²⁺ and / or Ti ²⁺ to Ti alloy) can be performed in an inert atmosphere, such as containing argon and / or substantially free of oxygen, nitrogen, moisture, hydrocarbons and other impurities ... In specific embodiments, the inert atmosphere has a pressure of from about 100 kPa (1 atm.) (For example, about 760 Torr) to about 500 kPa (5 atm.) (For example, about 3800 Torr), such as from about 100 kPa (760 Torr) up to about 200 kPa (1500 Torr). As shown in FIG. 1, an inert gas can be introduced countercurrently to regulate the reaction atmosphere and to remove the titanium chloride and AlCl _x complexes away from the titanium alloy and back into the reverse flow of the reaction zone T ³⁺ to Ti ²⁺ and / or Ti ²⁺ to Ti alloy. Additionally or alternatively, any TiCl ₄ produced during the reaction can be removed from the reactor as a withdrawn by-product. Thus, the reaction can be carried out efficiently without any significant loss of Ti materials.

For example, Ti is formed in a Ti-Al based alloy from Ti ²⁺ in brine (condensed and vapor) by disproportionation and formation of Ti ³⁺ in brine (condensed and vapor) as described above (Ti ²⁺ = ^1/3 [Ti] + 2 / 3Ti ³⁺ ). Similar corresponding disproportionation reactions occur simultaneously for Al ⁺ / Al / Al ³⁺ and other alloying elements dissolved in saline solutions and during the formation of Ti-Al-based alloys. Thus, pure titanium products are not formed during these disproportionation reactions. While not wishing to be bound by any particular theory or sequence of reactions, we believe that the formation of the Ti — Al alloy occurs through an endothermic reaction that involves the supply of heat to drive the reaction towards the Ti — Al alloy products.

The Ti — Al alloy formed by the above reactions may be in the form of a Ti — Al alloy mixed with other metallic materials. Alloying elements can also be included in titanium chloroaluminates consumed and formed in the above disproportionation reaction. By adjusting the system, fine, uniformly fused particles of the desired composition can be obtained by controlling at least the temperature, heat flow, pressure, gas flow rate, Al / AlCl ₃ ratio and particle size / state of aggregation of the Ti ²⁺ / Al / AlCl ₃ mixture entering reaction of stage 2.

As a product of the reactions of step 2, a titanium alloy is formed which contains elements from the reaction precursors and any additional alloying elements added during the reaction of step 1 and / or reactions of step 2. For example, Ti-6Al-4V (in wt%), intermetallic Ti-4822 (48Al, 2Cr and 2Nb in atomic%) can be formed as a titanium alloy. In one embodiment, the titanium alloy is in the form of a titanium alloy powder, such as titanium aluminide alloy powder (eg, Ti-6Al-4V, Ti-4822, and the like).

Referring to FIG. 3, it is a flow chart 300 of one exemplary embodiment of the step 2 reaction 106 and subsequent processing 108 of the exemplary process of FIG. 1. In the embodiment shown, the intermediate mixture is fed through line 224 to stage 2 reaction apparatus 302 after passing through an optional mixer 306. In stage 2 reaction apparatus 302, the Ti ^{3+ of the} intermediate mixture is reduced to Ti ²⁺ by heating to the second reaction temperature and then Ti ^{2 + is} reduced to a Ti alloy by a disproportionation reaction at a third reaction temperature that is higher than the second reaction temperature, as described in more detail above. The exemplary stage 2 reaction apparatus 302 is a one-stage reactor that includes a hot zone apparatus 304 surrounding the reaction chamber 306. The hot zone apparatus 304 provides a variable, increasing temperature within the reaction chamber 306 as the intermediate mixture flows through the reaction chamber. For example, hot zone device 304 may have a first reaction temperature toward the inlet of reaction chamber 306 (eg, first zone 308) and a second reaction temperature downstream of reaction chamber 306 (eg, second zone 310). The device can also have a reaction temperature gradient between 2 or more zones. This method is designed to provide uniform mixing and continuous flow through a temperature gradient.

Steam reaction products such as AlCl ₃ , Al ₂ Cl ₆ , TiCl ₄ , TiAlCl ₆ , AlOCl, TiOCl (AlOCl) _x , etc. can be removed from the reaction chamber 306 using a counterflow of an inert gas. For example, an inert gas can be supplied to the second zone 310 of the reaction chamber 306 through a feed pipe 312 from an inert gas supply 313. The inert gas can then flow against the advancement of the solid materials through the reaction chamber 306 to withdraw the titanium chloride gas complexes from the titanium alloy formed in the second zone 310 and back to the reaction at a lower temperature for reducing Ti ³⁺ to Ti ²⁺ occurring in the first zone. 308.

Additionally or alternatively, the titanium chloride gaseous complexes produced during the reaction can be withdrawn back to the reaction chamber 306 in which they condense at a lower temperature and thus control the titanium stoichiometry in the reacting salts. Any remaining AlCl _x and any TiCl ₄ formed during disproportionation are removed from reactor 306 via vent line 315, which may be a heated line to prevent condensation and fouling, and collected in condenser / sublimator 317 (e.g., single stage condenser or multistage condenser ) to recapture. Thus, the reaction can be carried out efficiently without any significant loss of Ti materials.

The use of an inert gas with a low impurity content (e.g., a low impurity argon gas such as high purity argon gas) as the process gas is preferred to minimize the formation of oxychloride phases such as TiOCl _x and AlOCl _x in the process and to ultimately suppress the formation of TiO, TiO ₂ , Al ₂ O ₃ and / or TiO ₂ -Al ₂ O ₃ mixtures. You can also use other inert gases, such as helium or other noble gases, which must be inert for the reaction method.

Method monitoring can be used to determine the completion of a reaction by measuring balance, temperature, pressure, process gas chemistry, outlet chemistry, and by-product chemistry.

The titanium alloy can be collected by means 314 provided in a post-processing device 316, such as described below. The post-processing step can be performed in a separate device, or can be performed in the same device as used for the method of step 2, or a device connected thereto.

4. Subsequent processing of titanium alloy

Once the titanium alloy is formed, it can be processed 108. For example, the titanium alloy powder can be processed for coarsening, sintering, direct hardening, layer-by-layer synthesis, bulk melting, or spheroidization. For example, a titanium alloy can be heat treated to purify the titanium alloy by removing residual chlorides and / or allowing diffusion to reduce composition gradients, for example, at a processing temperature of about 800 ° C or higher (for example, from about 800 ° C to about 1000 ° C. ).

In one embodiment, the high temperature treatment also continues disproportionation reactions to produce a titanium alloy from any residual Ti ²⁺ .

Examples of

The method described here can be explained in its most general form and simplest terms by reviewing the superimposed stability diagrams (Gibbs energy per mole Cl ₂ versus absolute temperature) for the Ti-Cl and Al-Cl systems as shown in FIG. 4.

Although the alloy or brines are not included, this shows the maximum available chemical energy in the Ti-Al-Cl system. At temperatures below 1000K (730 ° C), Ti ⁴⁺ in the form of TiCl ₄ (l, g) can be reduced to Ti ³⁺ in the form of TiCl ₃ (s) and then to Ti ²⁺ as TiCl ₂ (s) by oxidizing the metal Al to Al ³⁺ (in the form of AlCl ₃ (solid), Al ₂ Cl ₆ (g) and / or AlCl ₃ (g)), however, Ti ² cannot be reduced to metallic Ti by oxidizing metallic Al. In this method, titanium metal alloyed with Al [Ti] can be formed in the temperature range from 523 to 923K (250 to 650 ° C) by disproportionation of Ti ²⁺ (Ti ²⁺ = 1/3 [Ti] + 2 / 3Ti ³⁺ ) in brine [Ti ²⁺ : salt] to form [Ti] and Ti ³⁺ particles as brine [Ti ³⁺ : salt] or vapor. Driven Al reduction of Ti ⁴⁺ and Ti ³⁺ is exothermic and is performed in the reactor of stage one, S1, and the reactor of the low temperature part of stage two, S2, at temperatures below 523K or 250 ° C, whereby Ti ²⁺ disproportionation is endothermic. and it is carried out at intermediate temperatures in the reactor S2.

Reduction of Ti ⁴⁺ , Ti ³⁺ (and other alloying elements, M ^{x +} ), oxidation of Al and subsequent disproportionation means that this method is inherently an electrochemical method. The method described here is not based on electrodes or external electrical circuits, as a result, charge neutrality is expected through interaction zones. This means that alloy particles can be uniformly formed from [Ti ²⁺ : salt] provided there is local heat flux and if the composition supports an endothermic disproportionation reaction. This is a significant advantage of this method over electrochemical deposition and related methods.

In addition, without wishing to be bound by any particular theory, the authors believe that metallic Al and other alloying elements M are deposited from the salt simultaneously with Ti ²⁺ through appropriate disproportionation reactions (that is, for Al: Al ⁺ = 2/3 [ Al] + 1 / 3Al ³⁺ [9] and for M: M ^{x +} = 1 / (x + 1) [M] + x / (x + 1) M ^{(x + 1) +} ) and the supply of ions at low The oxidation state from the salt to the growth front of the alloy particles is not hindered. Further, the low temperature nature of this process means that the crystal structure and phase boundaries usually observed with conventional processing routes (ie, curing and thermomechanical work) are not necessarily formed or even expected.

With the general / high level of features of this method in mind, the details of the method are described. In specific embodiments, the following methods can be performed by making sure that the starting reagents (TiCl ₄ , AlCl ₃ and alloying element halides, MX _x ) effectively do not contain H ₂ O and O, since all metal halides strongly react with H ₂ O even after the introduction of oxygen it can be difficult to remove it from some salts. In addition, it is believed that oxygen contamination in the salt stabilizes Ti ³⁺ against Ti ²⁺ , which makes it difficult for Ti ²⁺ to form and thus affects the composition of the resulting alloy.

Example 1

The chemical reduction reaction of Ti ⁴⁺ , initially in the form of TiCl ₄ (l), to Ti ³⁺ in the form of TiCl ₃ (AlCl ₃ ) _{x was} performed in the reactor of stage 1 and evaluated in inert media. The incoming mixture containing 201.8 g of Al flakes, 100.5 g of AlCl ₃ , 34.3 g of NbCl ₅ and 20.1 g of CrCl ₃ was charged under a high purity argon atmosphere into a sealed ball mill and milled for 16 hours at close to room temperature (ball mills provide raw materials for each cycle of stage 1). The milled material was sieved through a 150 µm sieve, and 594.1 g, nominally from two mills, was loaded into a scraper mixing reactor under a high frequency argon atmosphere. The reactor is maintained at a pressure of 120 kPa g. (1.2 barg) with a low flow (less than 1 L / min) high purity argon flowing through the reactor. The reactor and charge were preheated to 130 ° C and stabilized before the introduction of 1164 g of TiCl ₄ (g) at a rate of 6.5 ± 2.0 g / min, while continuously stirring. During the TiCl ₄ pumping time (g), it initially evaporates, but eventually TiCl ₄ (g) forms, as the reactor wall is maintained at about 130 ° C, with the volume freely flowing in the charging process, {salt + Al } can reach temperatures up to 145 ° C. After adding all TiCl ₄ (g), the reactor wall temperature is maintained at 130 ° C for nominally the same time as for injection of TiCl ₄ , during which the condensed TiCl ₄ (g) was absorbed in the incoming mixture and the resulting salt in the reaction, continuing react and recover. After most of the condensed TiCl ₄ (l) was reduced (as indicated by a decrease in the volumetric change in temperature and gas temperature above the mixed charge), the reactor wall temperature was raised to 160 ° C and maintained at this temperature. This ensures that all of the condensed TiCl ₄ (l) on the reactor wall can be reduced or removed. The intermediate material was cooled and removed from the reactor. Representative samples taken from the product of the described method were characterized by taking appropriate precautions and stopping the reaction with air using X-ray diffraction, inductively coupled plasma, Cl titration and electron microscopy and energy dispersive spectroscopy analysis to evaluate the shape of metal chlorides. The results of this characterization confirmed the receipt of residual unreacted Al particles with the corresponding shape and size observed in the milled product charged to the reaction, as well as in an amount corresponding to the reduction of added TiCl ₄ . The microstructure observed by scanning electron microscopy shows that the Al particles were surrounded by a gradually changing layer of salt product, the salt in contact with the Al surface is rich in AlCl ₃ , and O is usually observed at this interface as an oxychloride layer "AlOCl" ... An additional surface shape of Al particles, the TiCl ₃ (AlCl ₃ ) _x phase, existed and represented the volume fraction of the product of this reaction. This salt product had poor mechanical properties and the Al particles of the core were easily separated, and it could exist separately from the Al particles. X-ray diffraction analysis showed that the TiCl ₃ (AlCl ₃ ) _x salt phase exists as an α phase, with a tightly packed hexagonal structure. The crystal structure was consistent with AlCl ₃ (TiCl ₃ ) _x , and this was evidence of a continuous solid solution. The measured composition of the bulk sample was consistent with X-ray diffraction and the observed microstructure.

The remainder of the material was fed to a 5-zone Ar gas countercurrent rotary kiln HED reactor with zone temperatures from about 250 ° C to about 300 ° C, from about 300 ° C to about 650 ° C, and from about 650 ° C to about 1000 ° C. After reaction in a rotary kiln at a maximum temperature of 800 ° C, the sample material was collected and analyzed by X-ray diffraction, inductively coupled plasma, Cl titration and electron microscopy and energy dispersive spectroscopy analysis, which showed the formation of titanium gamma aluminide metal alloy powder with a particle size of <150 μm and with a composition of 32.0 ± 1.0 mass. % Al, 61.4 ± 1.7 wt. t% Ti, 2.6 ± 0.1 wt. % Cr, 4.5 ± 0.1 mass. % Nb, as well as with a small amount of residual chlorine (0.6 wt.%).

Example 2

The chemical reduction reaction was performed and evaluated in an inert atmosphere. The incoming mixture contained 250 g Al flakes, 62.5 g AlCl ₃ , 42.75 g NbCl ₅ and 25.0 g CrCl ₃ and was milled at room temperature for 16 hours. The milled material was sieved through a 150 micron sieve and 714 grams (nominal product from two mills) was loaded into a scraper reactor-mixer. The reactor was preheated to 130 ° C and was pumped with TiCl ₄ at a rate of 6.5 g / min with stirring. After adding 1541 g of TiCl ₄ , the reactor temperature was raised to 160 ° C and held to dry / remove excess TiCl ₄ . The intermediate material was cooled and removed from the reactor. Material from 3 similar steps of the same process was fed to a 5 zone Ar gas countercurrent rotary kiln HED reactor with zone temperatures set at 250 ° C. The product {Al + TiCl ₃ (AlCl ₃ ) _x } from the above reaction of stage 1 was fed into the rotary kiln at a constant rate of 1.0 ± 0.2 kg / h, passing through the heated zone in the range of speeds controlled by the speed of rotation of the working tube ( at 6 rpm the residence time is about 13 minutes, at 4 rpm the residence time is about 20 minutes, at 2 rpm the residence time is about 40 minutes). Samples from the method were collected throughout the cycle and their characteristics were determined using X-ray diffraction, inductively coupled plasma, Cl titration and electron microscopy and energy dispersive spectroscopy. The results showed that the starting material {Al + TiCl ₃ (AlCl ₃ ) _x } reacted quickly in the rotary kiln. Al particles remained in the X-ray diffraction spectrum and are also clearly visible in the microstructure, but their number decreased. This corresponded to an ongoing oxidation with reduction of Ti ³⁺ to Ti ²⁺ . The characteristic X-ray diffraction peaks for α-TiCl ₃ (AlCl ₃ ) _x disappeared, leaving only the peaks for the parent Al and alloy. The volumetric composition of the sample, the microstructure and the amount of collected condensed AlCl ₃ vapor confirm that the volume of the collected sample is a salt, and this salt does not have a specific crystalline structure (that is, it is an amorphous, glass or polymer material), which shows that Al easily reduces Ti ³⁺ as TiCl ₃ (AlCl ₃ ) _x to Ti ²⁺ as Ti (AlCl ₄ ) ₂ at temperatures below 250 ° C without significant evaporation of AlCl ₃ . It is known from the literature that the Ti (AlCl ₄ ) ₂ phase is not crystalline.

In addition to the low temperature reduction of Ti ^3+, this result clearly shows that the titanium alloy begins to form at temperatures as low as 250 ° C from the salt phase (through a simultaneous disproportionation reaction). The reaction conditions described here are not optimized and a wide range of alloys was formed: α- [Ti], α2-Ti ₃ Al, γ-TiAl, TiAl ₂ , TiAl ₃ , also containing Nb and Cr. These alloy particles coexist with the salt and unreacted Al particles. It is believed that the wide range of alloy phases is due to the wide range of salt compositions / heterogeneity. This experimental cycle was carried out in order to prove the ease of reduction of Ti ³⁺ to Ti ²⁺ and to prove that the titanium alloy is formed by the simultaneous disproportionation process.

Throughout this description, examples are used to describe the invention, including the best mode, and to enable any person skilled in the art to practice the invention, including the manufacture and use of any devices or systems and any methods included. The scope of the invention is defined by the claims and may include other possible embodiments. Such other embodiments are within the scope of the claims if they include structural elements that do not differ from the literal formulations of the claims, or if they include equivalent structural elements that do not substantially differ from the literal claims.

Claims (40)

1. A method of obtaining a titanium alloy, including adding TiCl ₄ to the feed mixture at the temperature of the first reaction, wherein at least part of the Ti ⁴⁺ in TiCl _{4 is} reduced to Ti ³⁺ to form the first reaction product, the feed mixture containing aluminum and possibly AlCl ₃ , and / or, possibly at least one alloying element halide, after stopping the addition of TiCl _4, heating the product of the first reaction under drying conditions to complete the reduction of Ti ⁴⁺ or to remove the remaining TiCl ₄ to form a first intermediate mixture, the first intermediate mixture being an AlCl ₃ -based salt solution containing Ti ³⁺ , wherein Ti ³⁺ in the first intermediate mixture is in the form TiCl ₃ (AlCl ₃ ) _x , where x is greater than 0-10, heating the first intermediate mixture to the temperature of the second reaction, wherein at least part of the Ti ^{3+ is} reduced to the second intermediate mixture, wherein the second intermediate mixture is an AlCl _3- based salt solution that contains Ti ²⁺ , and additional heating of the second intermediate mixture to the temperature of the third reaction, whereby Ti ²⁺ forms a titanium alloy through a disproportionation reaction. 2. The method according to claim 1, in which the input mixture contains a plurality of particles that contain aluminum, AlCl ₃ and, possibly, one or more chloride of the alloying element, and in addition, the plurality of particles of the input mixture have a minimum size of 0.5 μm up to 25 microns. 3. A method according to claim 2, wherein one or more dopant chlorides are present in the feed mixture and at least one dopant chloride comprises VCl ₃ , CrCl ₂ , CrCl ₃ , NbCl ₅ , FeCl ₂ , FeCl ₃ , YCl ₃ , BCl ₃ , MnCl ₂ , MoCl ₃ , MoCl ₅ , SnCl ₂ , ZrCl ₄ , NiCl ₂ , CuCl, CuCl ₂ , WCl ₄ , WCl ₆ , BeCl ₂ , ZnCl ₂ , LiCl, MgCl ₂ , ScCl ₃ , PbCl ₂ , Ga ₂ Cl ₄ , GaCl ₃ , ErCl ₃ , CeCl ₃ or mixtures thereof. 4. The method of claim 1, wherein the feed mixture comprises a reaction mixture to form Ti-6Al-4V (wt%). 5. A process according to claim 1, wherein the feed mixture comprises a reaction mixture to form Ti-48Al-2Cr-2Nb (at%). 6. The method of claim 1, wherein the first reaction temperature is 100 ° C to 165 ° C. 7. The method of claim 1, wherein the aluminum present in the feed mix reduces Ti ⁴⁺ in TiCl ₄ to Ti ³⁺ . 8. The method according to claim 1, wherein the TiCl _{4 is} added as a liquid or vapor mixed with other dopant chlorides. 9. The method of claim 1, wherein the reduction of Ti ⁴⁺ to TiCl ₄ to form Ti ^{3+ is} performed in a scraper reactor, ribbon mixer, or other liquid / solid / vapor reactor. 10. The method of claim 1, wherein the addition of TiCl ₄ to the feed mixture is performed under an inert atmosphere at a pressure of 100 kPa (760 Torr) to 200 kPa (1500 Torr). 11. A method according to claim 1, wherein the Ti ³⁺ in the first intermediate mixture is in the form of a complex of TiCl ₃ with at least one metal chloride. 12. The method of claim 1, wherein the second reaction temperature is from 180 ° C to 500 ° C. 13. The method of claim 1, wherein heating the first intermediate mixture to the second reaction temperature is performed in at least one rotary kiln. 14. The method of claim 1, wherein heating the first intermediate mixture to the second reaction temperature is performed in an inert atmosphere at a pressure of 100 kPa (760 Torr) to 500 kPa (3800 Torr). 15. The method of claim 1, wherein the first intermediate mixture is maintained at the second reaction temperature until Ti ³⁺ in the first intermediate mixture is reduced to Ti ²⁺ and at least part of the Ti ²⁺ is in the form of a TiCl complex ₂ with metal chloride (s). 16. The process according to claim 1, wherein the reduction of Ti ³⁺ to Ti ²⁺ and the reaction of Ti ²⁺ by a disproportionation reaction are performed in a single reactor. 17. The method of claim 1, wherein the reduction of Ti ³⁺ to Ti ²⁺ and the reaction of Ti ²⁺ by disproportionation reaction is performed in a multi-zone reaction chamber. 18. The method according to claim 1, further comprising passing an inert gas through a multi-zone reaction chamber, wherein a stream of inert gas is passed against the advance of the reaction products, and an inert gas is introduced in countercurrent to withdraw gaseous titanium chloride complexes from the formed titanium alloy and back to the reaction zone for reactions Ti ³⁺ to Ti ²⁺ and / or Ti ²⁺ to Ti alloy. 19. A process according to claim 18, wherein the TiCl ₄ produced during the reaction is reduced with aluminum chloride or removed from the reactor as a withdrawn by-product. 20. The method of claim 1, wherein the reaction of Ti ²⁺ via a disproportionation reaction to form a titanium alloy is performed in an inert atmosphere at a pressure of from 100 kPa (760 Torr) to 500 kPa (3800 Torr). 21. The process of claim 1, wherein the Ti ³⁺ formed during the disproportionation reaction is recycled internally for reduction to Ti ²⁺ and further reaction in the disproportionation reaction. 22. The method of claim 1, wherein the third reaction temperature is from 300 ° C to 900 ° C. 23. The method of claim 1, wherein the titanium alloy is titanium alloy powder. 24. The method of claim 1, further comprising high-temperature treatment of the titanium alloy material at a treatment temperature to purify the Ti alloy by removing residual chlorides and / or allowing diffusion to reduce composition gradients. 25. The method of claim 24, wherein the high temperature treatment also continues disproportionation reactions to produce a Ti alloy from the residual Ti ²⁺ , and wherein the high temperature treatment also continues to distill unreacted metal subhalides. 26. The method of claim 24, wherein the processing temperature is 800 ° C or higher. 27. The method of claim 1, further comprising adding halides of alloying elements to the input mixture during the reaction for forming the first intermediate mixture, during the reaction for forming the second intermediate mixture, during the disproportionation reaction, or during subsequent processing. 28. A method for producing a titanium alloy, comprising reducing TiCl _{4 with} aluminum, AlCl ₃ , and at least one metal chloride at a temperature below 180 ° C to form a first intermediate product containing Ti ³⁺ , and reducing the first intermediate at temperatures below 900 ° C to form a second intermediate and then a titanium-aluminum alloy, wherein the second intermediate containing Ti ²⁺ is the complex [TiCl ₂ (AlCl ₃ )] _x , where x is greater than 0. 29. The method of claim 28, wherein the first intermediate is a solid salt solution containing a TiCl ₃ (AlCl ₃ ) _x complex, where x is greater than 0. 30. A method for producing titanium-containing material, including: mixing Al particles, AlCl ₃ particles and optionally particles of at least one other chloride of the alloying element to form an incoming mixture, adding TiCl ₄ to the incoming mixture, reduction of Ti ⁴⁺ to TiCl ₄ in the presence of an input mixture at the temperature of the first reaction with the formation of a first intermediate mixture containing Ti ³⁺ , where the temperature of the first reaction is below 180 ° C, and Ti ³⁺ in the first intermediate mixture is in the form of TiCl ₃ (AlCl ₃ ) _x , where x is greater than 0-10. 31. The method of claim 30, wherein the Ti ^{3+ of the} first intermediate mixture is in the form of a complex of TiCl ₃ with the chloride (s) of the metal (s).

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