Patent Description:
The present invention relates generally to methods for producing titanium alloy materials through reduction of titanium tetrachloride (TiCl<NUM>) in an AlCl<NUM>-based reaction media. More particularly, the titanium alloy materials are formed through reducing the Ti<NUM>+ in the TiCl<NUM> to a lower valence form of titanium (e.g., Ti<NUM>+ and Ti<NUM>+), followed by a disproportionation reaction of Ti<NUM>+. Optionally, other alloying elements may also be formed from a salt to the alloy in a reduction and/or disproportionation process.

Titanium alloy materials that include aluminum, such as titanium-aluminum (Ti-Al) based alloys and alloys based on titanium-aluminum (Ti-Al) inter-metallic compounds, are very valuable materials. However, they can be difficult and expensive to prepare, particularly in a powder form, and there are certain alloys inaccessible by traditional melt processes. This expense of preparation limits wide use of these materials, even though they have highly desirable properties for use in aerospace, automotive and other industries.

Reactors and methods for forming titanium-aluminum based alloys and inter-metallic compounds have been disclosed. For example, <CIT> teaches a stepwise method for the production of titanium-aluminum based alloys and inter-metallic compounds via a two stage reduction process, based on the reduction of titanium tetrachloride with aluminum. <CIT> discloses a reactor adapted to address one of the problems associated with the reactors and methods disclosed in <CIT>, when such are used under the conditions that would be required to form low-aluminum titanium-aluminum based alloys.

However, the discussion of the chemical processes that actually occur in the processes described by <CIT> and <CIT> do not represent a complete understanding of the actual reactions occurring to form the metal alloy from metal halide precursors. <CIT> relates to a method for producing a titanium-aluminum alloy containing less than about 15wt% aluminum.

In view of these teachings, a need exists for a better understanding of the chemical processes for producing titanium aluminum alloys through reduction of titanium tetrachloride TiCl<NUM>, as well as improved processing techniques for such reactions.

The above references to the background art do not constitute an admission that such art forms a part of the common general knowledge of a person of ordinary skill in the art.

A process is generally provided for producing a titanium alloy material, such as a titanium aluminum alloy. In one embodiment, the process includes adding TiCl<NUM> to an input mixture at a first reaction temperature such that at least a portion of the Ti<NUM>+ in the TiCl<NUM> is reduced to Ti<NUM>+ to form a first reaction product. The input mixture may include aluminum, and, optionally AlCl<NUM> and/or optionally one or more alloying element halides. After TiCl<NUM> addition is stopped, the first reaction product may be heated at drying conditions to complete reduction of Ti<NUM>+ or to remove substantially all of any remaining TiCl<NUM> to form a first intermediate mixture that is an AlCl<NUM>-based salt solution that includes Ti<NUM>+. The first intermediate mixture may then be heated to a second reaction temperature such that at least a portion of the Ti<NUM>+ is reduced to a second intermediate mixture that is an AlCl<NUM>-based salt solution that includes Ti<NUM>+. The second intermediate mixture is then further heated to a third reaction temperature such that the Ti<NUM>+ forms the titanium alloy material via a disproportionation reaction.

In one embodiment, the process for producing a titanium alloy material, may include: reducing an amount of TiCl<NUM> with an amount of aluminum, AlCl<NUM> and at least one metal chloride at a temperature below <NUM> to form a first intermediate product comprising Ti<NUM>+; and reducing the first intermediate product to a temperature below <NUM> to form a titanium aluminum alloy.

In one embodiment, the process for producing a titanium-containing material may include: mixing Al particles, AlCl<NUM> particles, and, optionally, particles of at least one other alloy element chloride to form an input mixture; adding TiCl<NUM> to the input mixture; reducing Ti<NUM>+ in the TiCl<NUM> in the presence of the input mixture at a first reaction temperature (e.g., lower than about <NUM>) to form a first intermediate mixture comprising Ti<NUM>+.

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended Figs. , in which:.

Chemical elements are discussed in the present disclosure using their common chemical abbreviation, such as commonly found on a periodic table of elements. For example, hydrogen is represented by its common chemical abbreviation H; helium is represented by its common chemical abbreviation He; and so forth.

As used herein, the term "titanium alloy material", or the like, is to be understood to encompass an alloy based on titanium or an alloy based on a titanium intermetallic compound and optionally other additional alloying elements in addition to Ti and Al. Similarly, the term "titanium-aluminum alloy", or the like, is to be understood to encompass an alloy based on titanium-aluminum or an alloy based on titanium-aluminum intermetallic compounds and optionally other additional alloying elements in addition to Ti and Al.

As used herein, the term "aluminum chlorides" is to be understood to refer to aluminum chloride species or a mixture of such aluminum chloride species, including AlCl<NUM> (solid, liquid, or vapor) or any other Al-Cl compounds or ion species (e.g., AlCl, AlCl<NUM>, (AlCl<NUM>)-, Al<NUM>Cl<NUM> and (Al<NUM>Cl<NUM>)). The use of AlClx refers to the term "aluminum chlorides" and is to be understood to refer to such aluminum chloride species or a mixture of such aluminum chloride species, no matter the stoichiometric ratio.

As used herein, the term "titanium chloride" is to be understood to refer to titanium trichloride (TiCl<NUM>) and/or titanium dichloride (TiCl<NUM>), or other, combinations of titanium and chlorine, but not to TiCl<NUM>, which is referred to herein as titanium tetrachloride. In some sections of the specification, the more general term "TiClx" may be used, which is to be understood to refer to titanium chloride species and forms of titanium tetrachloride (TiCl<NUM>), titanium trichloride (TiCl<NUM>), titanium dichloride (TiCl<NUM>) and/or other combinations of titanium and chlorine in solid, liquid or vapor forms. Since various solution phases and titanium chloride complexes also exist, the specific oxidation state of the Ti ion (e.g., Ti<NUM>+, Ti<NUM>+, and Ti<NUM>+) in a general phase (i.e., salt mixture) is referred to herein rather than any specific chemical compounds.

As used herein, the term "alloying element halides" refers to an alloying element ion coupled with a halide (e.g., a chloride, a fluoride, a bromide, an iodide, or an astatide). The alloying element can be any element that would be included within the final titanium alloy material, such as metals and other elements. The "alloying element halide" can be represented by MXx, where M is the alloying element ion and X is a halide (i.e., a halogen ion), no matter the stoichiometric ratio (represented by x). For example, an alloying element chloride can be represented by MClx.

Processes are generally provided for producing titanium alloy materials (e.g., titanium aluminum alloys) through reduction of TiCl<NUM>, which includes a titanium ion (Ti<NUM>+). More particularly, the titanium alloy materials are formed through reducing the Ti<NUM>+ in the TiCl<NUM> to a lower valence form of titanium (e.g., Ti<NUM>+ and Ti<NUM>+), followed by a disproportionation reaction of Ti<NUM>+ to form the titanium alloy material. It is noted that the valence form of titanium (e.g., Ti<NUM>+, Ti<NUM>+, and/or Ti<NUM>+) may be present in the reaction and/or intermediate materials as a complex with other species in the mixture (e.g., chlorine, other elements, and/or other species such as chloro-aluminates, metal halo aluminates, etc.), and may not necessarily be present in pure form of TiCl<NUM>, TiCl<NUM>, and TiCl<NUM>, respectively. For example, metal halide aluminates can be formed by MXx complexed with AlCl<NUM> in these intermediates, such as described below. Generally, AlCl<NUM> provides the reaction media that the reactive species (e.g., Ti<NUM>+, Ti<NUM>+, Ti<NUM>+, Al, Al+, Al<NUM>+, Al<NUM>+, also alloying element ions) for all reactions. Without wishing to be bound by any particular theory, it is believed that the existence of salt solutions in the stage <NUM> and stage <NUM> reactions allows for the Ti<NUM>+ reduction to Ti<NUM>+ and for the Ti<NUM>+ reduction to Ti<NUM>+ to occur in the condensed state (e.g., solid and liquid), such as at temperatures of about <NUM> or less (e.g., about <NUM> or less).

<FIG> shows a general flow diagram of one exemplary process <NUM> that reduces TiCl<NUM> to a titanium alloy material. The process <NUM> is generally shown in sequential stages: reaction precursors at <NUM> (including forming an input mixture at <NUM>), a stage <NUM> reaction at <NUM>, a stage <NUM> reaction at <NUM>, and post processing at <NUM>.

The reaction precursors for the stage <NUM> reaction <NUM> in the process <NUM> of <FIG> include, at a minimum, TiCl<NUM> and an input mixture that includes aluminum (Al), either alone or with additional chloride components. In one embodiment, the reaction precursors include an input mixture as a solid material at ambient conditions (e.g., about <NUM> and <NUM> atm), and TiCl<NUM> in liquid form. Additional materials (e.g., AlCl<NUM> and/or other alloying element halides) may be included in the reaction precursors at various stages of process <NUM>, such as included within the input mixture, within the TiCl<NUM>, and/or as a separate input into the stage <NUM> and/or stage <NUM> reactions. That is, one or more alloying element chlorides can optionally be inputted into the stage <NUM> reaction materials (e.g., into the input mixture if a solid, into the TiCl<NUM> if a liquid or a soluble solid material, and/or directly into the stage <NUM> reaction vessel independently), dissolved into another component of the input materials, and/or may optionally be inputted into the Stage <NUM> reaction materials. In certain embodiments, particularly where the alloying element halide is added to liquid TiCl<NUM> (e.g., soluble within), the liquid TiCl<NUM> may be filtered so as to remove any particulate within the liquid stream. Such a filter may, in particular embodiments, refine the liquid stream by removing oxygen species from the liquid, since the solubility of oxygen and oxygenated species is extremely low. As such, filtering of the TiCl<NUM> liquid (with or without any alloying element halide dissolved therein) may tailor the chemistry of the liquid and remove oxygen species therefrom.

For example, the reaction precursors can include some or all alloy elements to achieve a desired chemistry in the titanium alloy material. In one embodiment, the alloying element halide (MXx) may be an alloying element chloride (MClx). 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> at <NUM>, the input mixture is formed from aluminum (Al), optionally an aluminum chloride (e.g., AlCl<NUM>), and optionally one or more alloying element chloride. Without wishing to be bound by any particular theory, it is presently believed that AlCl<NUM> is useful as a component in the input mixture, but is not necessarily required if there is an alloying element chloride that is soluble or miscible in the TiCl<NUM> at the stage <NUM> reaction conditions to form AlClx in situ from the alloying element chloride and aluminum. In one embodiment, AlCl<NUM> is included as a material in the input mixture. However, in another embodiment, the input mixture may be substantially free from AlCl<NUM>. As used herein, the term "substantially free" means no more than an insignificant trace amount present and encompasses "completely free" (e.g., "substantially free" may be <NUM> atomic % up to <NUM> atomic %). If AlCl<NUM> is not present in the input mixture, then Al and other metal chlorides are present and utilized to form AlCl<NUM> such that the stage <NUM> reaction can proceed.

If in a solid state at ambient conditions, one or more alloying element chlorides (MClx) can optionally be included into the input mixture to form the input mixture. Particularly suitable alloying element chlorides in a solid state to be included with the aluminum and optional AlCl<NUM> include, but are not limited to, VCl<NUM>, CrCl<NUM>, CrCl<NUM>, NbCl<NUM>, FeCl<NUM>, FeCl<NUM>, YCl<NUM>, BCl<NUM>, MnCl<NUM>, MoCl<NUM>, MoCl<NUM>, SnCl<NUM>, ZrCl<NUM>, NiCl<NUM>, CuCl, CuCl<NUM>, WCl<NUM>, WCl<NUM>, BeCl<NUM>, ZnCl<NUM>, LiCl, MgCl<NUM>, ScCl<NUM>, PbCl<NUM>, Ga<NUM>Cl<NUM>, GaCl<NUM>, ErCl<NUM>, CeCl<NUM>, and mixtures thereof. One or more of these alloy element chlorides can also be included at other stages in the process including, but not limited to, titanium tetrachloride and/or after Stage <NUM>.

In one embodiment, the input mixture is in the form of a plurality of particles (i.e., in powder form). For example, the input mixture is formed by milling a mixture of the aluminum (Al), optionally an aluminum chloride (e.g., AlCl<NUM>), and optionally one or more alloying element halides (e.g., alloying element chlorides). The material of the input mixture can be combined as solid materials and milled together to form the plurality of particles having a mixed composition. In one embodiment, a mixture of aluminum particles, optionally aluminum chloride particles, and optionally particles of one or more alloying element chlorides is mixed and resized (e.g., milled) together to form the plurality of particles of the input mixture. For example, the aluminum particles can be aluminum particles that have a pure aluminum core with an aluminum oxide layer formed on the surface of the particles. Alternatively, the aluminum particles can include a core of aluminum and at least one other alloying element or a master alloy of aluminum and an alloying element. The aluminum particles may have any suitable morphology, including a flake like shape, substantially spherical shape, etc..

Since the aluminum particles generally form a layer of aluminum oxide on the surface of the particles, the milling process is performed in an atmosphere that is substantially free of oxygen to inhibit the formation of any additional aluminum oxides within the input mixture. For example, the milling process can be performed in an inert atmosphere, such as an argon atmosphere, having a pressure of about <NUM> kPa (<NUM> torr) to about <NUM> kPa (<NUM> torr). Without wishing to be bound by any particular theory, it is believed that a reaction between AlCl<NUM> and surface Al<NUM>O<NUM> during milling of Al(s) such that AlCl<NUM> converts Al<NUM>O<NUM> to AlOCl (e.g., via Al<NUM>O<NUM> + AlCl<NUM> → 3AlOCl). The Al<NUM>O<NUM> surface layer protects the underlying Al(s), and then converting this Al<NUM>O<NUM> surface layer to AlOCl during milling allows Al to dissolve and diffuse into the salt, as Al+ of Al<NUM>+. Without wishing to be bound by any particular theory, it is believed that having a partial pressure of oxygen below that required to stabilize Al<NUM>O<NUM> (i.e., in an inert atmosphere) allows for these reactions to convert Al<NUM>O<NUM>, which is otherwise very stable in oxygen. As such, the resulting particles are an "activated" Al powder.

Additionally, reducing the size of the particles allows the surface area of the particles to increase to expand the availability of aluminum surface area in the subsequent reduction reactions. The plurality of particles may have any suitable morphology, including a flake like shape, substantially spherical shape, etc. In particular embodiments, the plurality of particles of the input mixture have a minimum particle dimension on average of about <NUM> to about <NUM> (e.g., about <NUM> to about <NUM>), which is calculated by averaging the minimum dimension of the particles. For example, in one embodiment, the flake may define a planar particle having dimensions in an x-y plane, and a thickness in a z-dimension with the minimum dimension on average of about <NUM> to about <NUM> (e.g., about <NUM> to about <NUM>), while the x- and y-dimensions having larger average sizes. In one embodiment, milling is performed at a milling temperature of about <NUM> or less to inhibit Al particle agglomeration.

Milling can be achieved using a high intensity process or a low intensity process to produce the plurality of particles of the input mixture, such as using a ball milling processes, grinding processes, or other size reduction methods.

As stated, the reaction precursors include, at a minimum, TiCl<NUM> in liquid or vapor form and an input mixture in powder form that includes aluminum (Al), and may include additional materials (e.g., AlCl<NUM> and/or other alloying element chlorides). The TiCl<NUM> may be a pure liquid of TiCl<NUM> or liquid mixed with other alloy chlorides. Mixtures of TiCl<NUM> and another alloy chloride(s) may be heated, in certain embodiments, to ensure that the resulting solution is not saturated, which could result in components precipitating out of the solution. An example of mixed liquid precursors includes a mixture of TiCl<NUM> and VCl<NUM> to form a vanadium containing titanium alloy. Various metal chlorides (i.e., AlCl<NUM>, VCl<NUM>, VCl<NUM>, MClx, etc) may be dissolved into TiCl<NUM>(l), which can be represented by (TiCl<NUM>)x(AlCl<NUM>)y(MClx)z where M is any suitable metal, as discussed herein, and x, y, and z are the mole fraction of the particular components of the salt solution. Such a salt solution can be generally defined in short hand as [Ti<NUM>+:salt], with the brackets [ ] represent the material as a solution phase having Ti<NUM>+ as the major species of solvent and "salt" represents all of the minor species or alloying elements.

These reaction precursors are added together for reduction of the Ti<NUM>+ to Ti<NUM>+ at the stage <NUM> reaction <NUM>. For the stage <NUM> reaction, the reaction precursors are heated to a first reaction temperature that is high enough to cause the chemical reduction but low enough to inhibit liquid TiCl<NUM> from forming. For example, the stage one reaction may be performed with the reaction precursors heated to a first reaction temperature that is about <NUM> or less (e.g., about <NUM> to about <NUM>, such as about <NUM> to about <NUM>). In one embodiment, the input mixture is heated to the first reaction temperature prior to adding the TiCl<NUM> to the input mixture. Alternatively or additionally, the TiCl<NUM> can be added to the input mixture simultaneously with heating the input mixture to the first reaction temperature.

Without wishing to be bound by any particular theory, it is believed that the aluminum (e.g., in a form of metallic aluminum or a salt of aluminum such as AlCl<NUM> and/or AlClx) present the input mixture reduces the Ti<NUM>+ in the TiCl<NUM> to Ti<NUM>+ by an alumino-thermic process at the first reaction temperature, where AlCl<NUM> serves as the reaction media in the form of a AlCl<NUM> salt solution. Additionally, it is believed that Ti<NUM>+ and Al dissolve in AlCl<NUM> and in TiCl<NUM>(AlCl<NUM>)x formed from the input mixture reaction products, such that the Ti<NUM>+ and Al can react. It is also believed that Al dissolves in the salt as Al+ or Al<NUM>+, and that these Al species diffuse to the Ti<NUM>+ and react to form new TiCl<NUM>(AlCl<NUM>)x reaction product. Finally, it is believed that Al(s) dissolves into the salt solution through an AlCl<NUM> or AlOCl surface layer on the Al(s). For example, without wishing to be bound by any particular theory, it is believed that the Ti<NUM>+ in the TiCl<NUM> is reduced to Ti<NUM>+ in the form of TiCl<NUM> complexed with metal chloride(s), such as TiCl<NUM>(AlCl<NUM>)x with x being greater than <NUM>, such as greater than <NUM> to <NUM> (e.g., x being <NUM> to <NUM>), which is either a continuous solid solution between TiCl<NUM> and AlCl<NUM> or two solutions TiCl<NUM>-rich TiCl<NUM>(AlCl<NUM>)x and AlCl<NUM>-rich AlCl<NUM>(TiCl<NUM>)x where both solutions have similar crystal structures. Thus, it is believed that substantially all of the Ti<NUM>+ species formed are in the form of such a metal chloride complex, instead of pure TiCl<NUM>.

As such, the resulting reaction product is an AlCl<NUM>-based salt solution that includes the Ti<NUM>+ species. Similar to the [Ti<NUM>+:salt] discussion above, various metal chlorides (i.e., AlCl<NUM>, VCl<NUM>, VCl<NUM>, MClx, etc.) dissolve in TiCl<NUM> (solid or liquid), which may be represented by (TiCl<NUM>)x(AlCl<NUM>)y(MClx)z where M is any suitable metal and x, y, and z represent the mole fraction of the salt solution. TiCl<NUM>(AlCl<NUM>)x is a sub-set of the larger solution phase, even though all of the alloying element chlorides, MClx, dissolve into this solution phase. Additionally, Ti<NUM>+ also dissolves into this solution phases, which can be described as the Cl-rich side of the phase field. As TiCl<NUM> is added into the reaction mixture, at some point there may be more TiCl<NUM>/TiCl<NUM> than AlCl<NUM>, making the salt TiCl<NUM>-rich. Such a salt solution can be generally defined in short hand as [Ti<NUM>+:salt], with the brackets [ ] represent the material as a solution phase having Ti<NUM>+ as the major species of solvent and "salt" represents all of the minor species or alloying elements.

This reaction can be performed as TiCl<NUM> is added in a controlled manner to the input mixture at the first reaction temperature. For example, the TiCl<NUM> can be added continuously or in a semi batch manner. In one embodiment, excess Al is included in the reaction to ensure substantially complete reduction of Ti<NUM>+ to Ti<NUM>+ and for subsequent reductions. As such, TiCl<NUM> may be added to obtain a desired Ti/Al ratio to produce a desired salt composition.

During the reaction, the input mixture can substantially remain a solid at the first reaction conditions (e.g., the first reaction temperature and the first reaction pressure). In particular embodiments, the stage <NUM> reaction is performed in a plow reactor, a ribbon blender, or another liquid/solid/vapor reactor. For example, the Ti<NUM>+ reduction reaction can be performed in an apparatus to reflux during the reaction phase and/or to distill after the reaction phase any unreacted TiCl<NUM> vapor for continued reduction and/or to prevent loss of TiCl<NUM> (g) during the reaction.

The stage <NUM> reaction is performed in an inert atmosphere (e.g., comprising argon). As such, the uptake of oxygen (O<NUM>), water vapor (H<NUM>O), nitrogen (N<NUM>), carbon oxides (e.g., CO, CO<NUM>, etc.) and/or hydrocarbons (e.g., CH<NUM>, etc.) by aluminum and/or other compounds can be avoided during the reduction reaction. The inert atmosphere has a pressure of <NUM> atmosphere (e.g., about <NUM> kPa (<NUM> torr)) and about <NUM> atmospheres (e.g., about <NUM> kPa (<NUM> torr)), such as about <NUM> kPa (<NUM> torr) to about <NUM> kPa (<NUM> torr). Although pressures less than about 101kPa (<NUM> torr) could be utilized in certain embodiments, it is not desirable in most embodiments due to possible oxygen, water, carbon oxide and/or nitrogen ingress at such lower pressures. For example, the inert atmosphere has a pressure of <NUM> atmosphere (e.g., about <NUM> kPa (<NUM> torr)) and about <NUM> atmospheres (e.g., about <NUM> kPa (<NUM> torr)), such as about <NUM> kPa (<NUM> torr) to about <NUM> kPa (<NUM> torr).

Following the stage <NUM> reaction reducing Ti<NUM>+ to Ti<NUM>+, the first reaction product can be dried at drying conditions to remove substantially all of any remaining unreacted TiCl<NUM> (due to kinetic limitations) to form an intermediate mixture. For example, the first reaction product can be dried by heating and/or vacuum conditions. In one embodiment, any entrained TiCl<NUM> is removed from the first reaction product by heating to a temperature that is above the boiling point of TiCl<NUM> (e.g., about <NUM>) but below the temperature where Ti<NUM>+ is further reduced (e.g., over about <NUM>), such as a drying temperature of about <NUM> to about <NUM> (e.g., about <NUM> to about <NUM>).

However, it is noted that Al is capable of reducing Ti<NUM>+ to Ti<NUM>+ and Ti<NUM>+ to Ti<NUM>+ at all temperatures, including below <NUM>. The temperatures identified above are due to kinetic limitations and/or solid state transport in the reaction products. Also, without wishing to be bound by any particular theory, it is believed that the Ti<NUM>+ to Ti<NUM>+ reduction cannot occur while Ti<NUM>+ exists in the stage <NUM> reaction products due to the Gibbs phase rule and phase equilibria of the Ti-Al-Cl-O system. That is, Al oxidation can drive both reduction steps at the same temperature, but the sequential aspect of these reactions is due to the present belief that Ti<NUM>+ and Ti<NUM>+ cannot exist at the same time in the same location of an isolated system. Thus, the reactions are sequentially performed such that substantially all of the Ti<NUM>+ is reduced to Ti<NUM>+ prior to the formation of Ti<NUM>+ in the system. Thus, the reduction process is performed by the presently disclosed methods in a sequential nature.

After drying the first reaction mixture and before heating the intermediate mixture to the second reaction temperature for the stage <NUM> reaction described below, the intermediate mixture containing the [Ti<NUM>+:salt] can be stored, such as in an inert atmosphere prior to further reaction. In one embodiment, the intermediate mixture containing the Ti<NUM>+ complexes can be cooled to a temperature below about <NUM>, such below about <NUM>, or below about <NUM>, for storage.

Referring to <FIG>, a process schematic <NUM> of one exemplary embodiment of the reaction precursors at <NUM> (including forming an input mixture at <NUM>) and the stage <NUM> reaction at <NUM> of the exemplary process <NUM> of <FIG>. In the embodiment shown, a first liquid storage tank <NUM> and an optional second liquid storage tank <NUM> are in liquid communication with a liquid mixing apparatus <NUM> so as to supply liquid reaction precursors thereto via supply line <NUM>. Generally, the first liquid storage tank <NUM> includes liquid <NUM> of TiCl<NUM>, as a pure liquid of TiCl<NUM> or liquid mixed with other alloying element chlorides. Valve <NUM> and pump <NUM> control flow of liquid <NUM> from the liquid storage tank <NUM> into the liquid mixing apparatus <NUM>. Similarly, the second liquid storage tank <NUM> is in liquid communication with the liquid mixing apparatus <NUM> so as to supply liquid reaction precursors thereto via supply line <NUM>. The second liquid storage tank <NUM> includes, in one embodiment, a liquid <NUM> of at least one alloying element chloride. Valve <NUM> and pump <NUM> control flow of liquid <NUM> from the liquid storage tank <NUM> into the liquid mixing apparatus <NUM>.

Also as shown in <FIG>, solid reaction precursors are supplied to the ball milling apparatus <NUM> from an Al storage apparatus <NUM>, an optional aluminum chloride (e.g., AlCl<NUM>) storage apparatus <NUM>, and optionally one or more alloying element chloride storage apparatus <NUM>. Although shown as a ball milling apparatus <NUM>, any suitable size reduction apparatus (e.g., a milling apparatus) can be utilized in accordance with this process. As shown, the aluminum chloride storage apparatus <NUM> and the one or more alloying element chloride storage apparatus <NUM> are supplied via an optional mixing apparatus <NUM> to the milling apparatus <NUM>. From the milling apparatus <NUM>, an input mixture <NUM> is provided to the stage <NUM> reaction apparatus <NUM> via a hopper <NUM>. Additionally, the mixed liquid from the liquid mixer <NUM> is added to the stage <NUM> reaction apparatus <NUM> in a controlled manner via supply tube <NUM> with the flow of the mixed liquid controlled by the pump <NUM> and valve <NUM>. Optionally, the aluminum chloride storage apparatus <NUM> and the one or more alloying element chloride storage apparatus <NUM> can be supplied via an optional mixing apparatus <NUM> directly to the hopper <NUM>.

Within the stage <NUM> reaction apparatus <NUM>, the Ti<NUM>+ is reduced to Ti<NUM>+ at the conditions described above to form a first reaction product. The first reaction product can be dried at the end of the stage <NUM> reaction apparatus <NUM>, such as in a drying zone <NUM> having drying conditions, such as discussed above, to remove substantially all of any remaining TiCl<NUM> via condenser <NUM> to form an intermediate mixture (including Ti<NUM>+, such as in the form of TiCl<NUM> complexed with metal chloride(s), such as TiCl<NUM>(AlCl<NUM>)x) supplied to product line <NUM> for further reduction of titanium. As shown, any remaining TiCl<NUM> or liquid mixture can be evaporated and optionally recycled (e.g., via a distillation process, not shown) in recycle loop line <NUM>. In alternative embodiments, the size reduction apparatus can be integrated within the stage <NUM> reaction apparatus <NUM>. In one embodiment, the conditions of the stage <NUM> reaction apparatus <NUM> during reaction keep liquid in reactor or condense vapor to return to stage <NUM> reactor. Then, during drying the condenser is heated to a temperature above the boiling point of the liquid mixture to allow for drying.

The intermediate mixture (including Ti<NUM>+, such as in the form of TiCl<NUM> complexed with other materials) can be stored after drying but before further reduction processes. In one embodiment, the intermediate mixture is stored in an inert atmosphere to inhibit and prevent the formation of any aluminum oxides, other oxide complexes, or oxy-chloride complexes within the intermediate mixture.

At the stage <NUM> reactions at <NUM> in the process <NUM>, the Ti<NUM>+ and any alloying elements halides MXx of the intermediate mixture are reduced to Ti<NUM>+ and M sub-halides by heating to a second reaction temperature and reacting with Al present as solid Al or as an Al species dissolved in a complex, and then the Ti<NUM>+ is reduced to Ti alloy via an endothermic disproportionation reaction at a third reaction temperature that is greater than the second reaction temperature. The metal sub-halides are also reduced via Al reduction to form base alloying metal M at temperatures within the range of the stage <NUM> process. In one embodiment, these reactions can be performed in sequential reactions at different temperatures in a single step reaction or as separate steps as a two-step process or more (e.g., in stages as the temperature is increased).

Without wishing to be bound by any particular theory, it is believed that the aluminum (e.g., in a form of metallic aluminum or a salt of aluminum such as AlCl<NUM> and/or AlClx) present the intermediate mixture reduces the Ti<NUM>+ in the TiCl<NUM> complexed with metal chloride(s), such as TiCl<NUM>(AlCl<NUM>)x, to Ti<NUM>+ at the second reaction temperature. For instance, without wishing to be bound by any particular theory, it is believed that the reaction may form Ti<NUM>+ in a TiCl<NUM> complexed with metal chloride(s), to form salt solutions based on titanium aluminum chloride complexes, such as TiAlCl<NUM>, Ti(AlCl<NUM>)<NUM>), or a mixture thereof, with optionally additionally alloying elements or element halides, or element chloro-aluminates.

Without wishing to be bound by any particular theory, it is generally believed that there are three forms of TiCl<NUM> possible: (<NUM>) substantially pure TiCl<NUM> that only dissolves a small amount of anything, (<NUM>) TiAlCl<NUM>(s) that also does not dissolve much of anything else and is probably only stable up to about <NUM>, and (<NUM>) {Ti(AlCl<NUM>)<NUM>}n that is likely an inorganic polymeric material existing as a liquid or gas, glassy material and fine powder (long chain molecules). That is, { Ti(AlCl<NUM>)<NUM>}n has a large composition range (e.g., n can be <NUM> to about <NUM>, such as <NUM> to about <NUM>, such as <NUM> to about <NUM>, such as <NUM> to about <NUM>) and dissolves all the alloy element chlorides. In one particular embodiment, the gaseous { Ti(AlCl<NUM>)<NUM>}n helps remove unreacted salt from the Ti-alloy particles (e.g., at a low temperature in a later stage of the reaction). As a result, the reaction product comprising Ti<NUM>+ is a phase based on the complex between TiCl<NUM> and AlCl<NUM> (e.g., Ti(AlCl<NUM>)<NUM>, etc.). Such a complex can be a salt solution defined in short hand as [Ti<NUM>+:salt], with the brackets [ ] represent the material as a solution phase having AlCl<NUM> as the major species of solvent, Ti<NUM>+ and "salt" represents all of the minor species or alloying elements.

The reduction of Ti<NUM>+ to Ti<NUM>+ is performed at second reaction temperature of about <NUM> to about <NUM>. Without wishing to be bound by any particular theory, it is believed that at least a portion of the Ti<NUM>+ is in the form of TiCl<NUM> complexed with metal chloride(s).

Without wishing to be bound by any particular theory, it is believed that AlCl<NUM> is chemically bound in TiCl<NUM>(AlCl<NUM>)x, TiAlCl<NUM>, and {Ti(AlCl<NUM>)<NUM>}n in this process. Due to its significant chemical activity (e.g., < <NUM>), AlCl<NUM> does not evaporate as would be expected for pure AlCl<NUM>, and there is no significant AlCl<NUM> evaporation until reaction temperatures reach or exceed about <NUM>. Thus, AlCl<NUM> provides the reactor medium to allow the reaction to take place, and AlCl<NUM> provides the chemical environment that stabilizes the Ti<NUM>+ ion and allows conversion of Ti<NUM>+ to Ti<NUM>+ at reaction temperatures less than about <NUM> (e.g., about <NUM> to about <NUM>).

After the Ti<NUM>+ of the TiCl<NUM> complexed with metal chloride(s) (e.g., in the form of TiCl<NUM>-(AlCl<NUM>)x and/or TiAlCl<NUM> (g)) is reduced to Ti<NUM>+ (e.g., in the form of TiCl<NUM> complexed with metal chloride(s)), the Ti<NUM>+ can be converted to Ti alloy via a disproportionation reaction. In one embodiment, TiAlCl<NUM> (g) may be present to help remove Ti<NUM>+ by-products from the Ti-alloy formation and/or recycling Ti<NUM>+ within the reaction chamber. The third reaction temperature has an upper temperature limit of about <NUM>. The Ti<NUM>+ is reduced to Ti alloy via a disproportionation reaction at a third reaction temperature of about <NUM> up to about <NUM> (e.g., about <NUM> to about <NUM>, such as about <NUM> to about <NUM>). Without wishing to be bound by any particular theory, it is believed that keeping the third reaction temperature below about <NUM> ensures that any oxygen contaminants present in the reaction chamber remain stable volatile species that can be driven off so as to limit oxygen in the resulting Ti alloy product. On the other hand, at reaction temperatures above <NUM>, the oxygen contaminants are no longer in the form of volatile species making it more difficult to reduce residual oxygen. Any other volatile species, such as oxychlorides, chlorides, and/or oxides containing carbon, can be removed by thermal distillation.

Generally, this reaction of Ti alloy formation can be separated into an alloy formation stage via disproportionation reaction (e.g., at a disproportionation reaction temperature about <NUM> to about <NUM>) and a distillation stage (e.g., at a distillation temperature of about <NUM> to about <NUM>).

For example, the Ti alloy formation can be divided into two processes: nucleation and particle growth (which may also be referred to as particle coarsening). During nucleation, the first Ti alloy forms from the [Ti<NUM>+:SALT] at lower temperatures (e.g., about <NUM> to about <NUM>). The local composition of the salt (component activities), surface energy, and kinetics of disproportionation determine the resulting Ti alloy composition. Then, the particle growth occurs where the Ti alloy continues to grow from the [Ti<NUM>+:SALT] at higher temperatures (e.g., about <NUM> to about <NUM>) in the condensed state and at temperatures of greater than <NUM> (e.g., about <NUM> to about <NUM>) in as a gas solid reaction. These higher temperature reactions (e.g., greater than about <NUM>) can also be described as a distillation process where Cl is removed from the Ti alloy product, which is occurring simultaneously with the Ti alloy particle grown. Both of these processes are based on a disproportionation reaction, but could produce Ti alloys of different compositions. It is also noted that there is a disproportionation reaction for both Ti and Al in the reaction process: Ti<NUM>+ = <NUM>/<NUM>[Ti] + <NUM>/3Ti<NUM>+ and Al+ = <NUM>/<NUM>[Al] + <NUM>/3Al<NUM>+. The equipment design for this process may be configured for independent control of the residence time at each temperature (e.g., thermal zone), which may help control the process.

In one embodiment, the intermediate mixture having the Ti<NUM>+ is maintained at the third reaction temperature until substantially all of the Ti<NUM>+ is reacted to the titanium alloy material. In the reaction, any Ti<NUM>+ formed during the disproportionation reaction can be internally recycled to be reduced to Ti<NUM>+ by thermos alumic reduction and further reacted in a disproportionation reaction. Additionally, Ti<NUM>+ (e.g., in the form of TiCl<NUM>) may be formed by a competing Ti disproportionation reaction, which can be evacuated out of the reaction system as a gas by-product for continued reaction (e.g., reducing back to Ti<NUM>+ then to Ti<NUM>+) or as a take-off by-product (e.g. carried out via an inert gas counter flow).

The stage <NUM> reactions (e.g., Ti<NUM>+ to Ti<NUM>+ and/or Ti<NUM>+ to Ti alloy) are performed in an inert atmosphere, such as comprising argon and/or substantially free of oxygen, nitrogen, moisture, hydrocarbons, and other impurities. In particular embodiments, the inert atmosphere has a pressure between about <NUM> atmosphere (e.g., about <NUM> kPa (<NUM> torr)) and about <NUM> atmospheres (e.g., about <NUM> kPa (<NUM> torr)), such as about <NUM> kPa (<NUM> torr) to about <NUM> kPa (<NUM> torr). As shown in <FIG>, an inert gas can be introduced as a counter flow to regulate the reaction atmosphere, and to carry gaseous titanium chloride complexes and AlClx away from the titanium alloy material and back into the reflux reaction zone of Ti<NUM>+ to Ti<NUM>+ and/or Ti<NUM>+ to Ti alloy. Additionally or alternatively, any TiCl<NUM> produced during the reaction may be carried out of the reactor as a take-off by-product. Thus, the reaction can be performed efficiently without any significant waste of Ti materials.

For example, the Ti is formed in a Ti-Al based alloy from the Ti<NUM>+ in salt solution (condensed and vapor) by disproportionation and the formation of Ti<NUM>+ in a salt solution (condensed and vapor), as described above (Ti<NUM>+ = <NUM>/<NUM>[Ti] + <NUM>/3Ti<NUM>+). Similar corresponding disproportionation reactions are occurring simultaneously for Al+/Al/Al<NUM>+ and other alloying elements dissolved in the salt solutions and forming in the Ti-Al based alloys. Thus, pure-Ti products are not formed during these disproportionation reactions. Without wishing to be bound by any particular theory or specific reaction sequence, the Ti-Al alloy formation is believed to occur via an endothermic reaction which involves the input of heat to drive the reaction to towards the Ti-Al alloy products.

The Ti-Al alloy formed by the reactions above can be in the form of an Ti-Al alloy mixed with other metal materials. Alloying elements may also be included in the titanium chloro-aluminates consumed and formed in the disproportionation reactions above. Through control of the system, fine, uniformly alloyed particulates can be produced of the desired composition through control of at least temperature, heat flux, pressure, gas flowrate, Al/AlCl<NUM> ratio, and particle size/state of aggregation of the Ti<NUM>+/Al/AlCl<NUM> mixture entering the stage <NUM> reaction.

As a reaction product of the stage <NUM> reactions, a titanium alloy material is formed that includes elements from the reaction precursors and any additional alloying elements added during the stage <NUM> reaction and/or the stage <NUM> reactions. For example, Ti-6Al-4V (in weight percent), Ti-<NUM> intermetallic (48Al, 2Cr, and 2Nb in atomic percent) can be formed as the titanium alloy material. In one embodiment, the titanium alloy material is in the form of a titanium alloy powder, such as a titanium aluminide alloy powder (e.g., Ti-6Al-4V, Ti-<NUM>, etc.).

Referring to <FIG>, a process schematic <NUM> of one exemplary embodiment of the stage <NUM> reaction at <NUM> and post processing at <NUM> of the exemplary process of <FIG>. In the embodiment shown, the intermediate mixture is supplied via line <NUM> into a stage <NUM> reaction apparatus <NUM> after passing through an optional mixing apparatus <NUM>. Within the stage <NUM> reaction apparatus <NUM>, the Ti<NUM>+ of the intermediate mixture is reduced to Ti<NUM>+ by heating to a second reaction temperature, and then the Ti<NUM>+ is reduced to Ti alloy via a disproportionation reaction at a third reaction temperature that is greater than the second reaction temperature, as described in greater detail above. The exemplary stage <NUM> reaction apparatus <NUM> shown is a single stage reactor that includes a zone heating apparatus <NUM> surrounding a reaction chamber <NUM>. The zone heating apparatus <NUM> allows for a variable, increasing temperature within the reaction chamber <NUM> as the intermediate mixture flows through reaction chamber <NUM>. For example, the zone heating apparatus <NUM> can have a first reaction temperature towards the input end of the reaction chamber <NUM> (e.g., a first zone <NUM>) and a second reaction temperature at the output end of the reaction chamber <NUM> (e.g., a second zone <NUM>). The apparatus may also have a gradation in reaction temperature between <NUM> or more zones. The apparatus may also have a gradation in reaction temperature between <NUM> or more zones. This process is designed to allow for uniform mixing and continuous flow through the temperature gradient.

Vapor reaction products, such as AlCl<NUM>, Al<NUM>Cl<NUM>, TiCl<NUM>, TiAlCl<NUM>, AlOCl, TiOCl(AlOCl)x, etc., can be removed from the reaction chamber <NUM> utilizing a counterflow gas stream of inert gas. For example, an inert gas can be supplied to the second zone <NUM> of the reaction chamber <NUM> via a supply tube <NUM> from an inert gas supply <NUM>. The inert gas can then flow counter to the solid materials progressing through the reaction chamber <NUM> to carry gaseous titanium chloride complexes away from the titanium alloy material forming in the second zone <NUM> and back into the lower temperature reaction of Ti<NUM>+ to Ti<NUM>+ occurring in the first zone <NUM>. Additionally or alternatively, gaseous titanium chloride complexes produced during the reaction may be carried back in the reaction chamber <NUM> where they condense at lower temperature, and thus control the Ti stoichiometry of the reacting salts. Any remaining AlClx and any TiCl<NUM> formed during disproportionation are removed from the reactor <NUM> by vent line <NUM>, which may be a heated line to prevent condensation and blockage, and collected in condenser/sublimator <NUM> (e.g., a single-stage condenser or a multi-stage condenser) for recapture. Thus, the reaction can be performed efficiently without any significant waste of Ti materials.

The use of a low impurity inert gas (e.g., low impurity argon gas, such as a high purity argon gas) process gas is preferred to minimize the formation of oxychloride phases such as TiOClx and AlOClx in the process, and to ultimately inhibit the formation of TiO, TiO<NUM>, Al<NUM>O<NUM>, and/or TiO<NUM>-Al<NUM>O<NUM> mixtures. Other inert gases can also be used, such as helium or other noble gases, which would be inert to the reaction process.

In-process monitoring can be used to determine reaction completion by measuring the balance, temperature, pressure, process gas chemistry, output product chemistry, and by-product chemistry.

The titanium alloy material can be collected via <NUM> to be provided into a post processing apparatus <NUM>, such as described below. The post processing step may be performed in a separate apparatus or may be performed in the same or connected apparatus that is used for the Stage <NUM> process.

After formation, the titanium alloy material may be processed at <NUM>. For example, the titanium alloy powder can be processed for coarsening, sintering, direct consolidation, additive manufacturing, bulk melting, or spheroidization. For example, the titanium alloy material may be high temperature processed to purify the Ti alloy by removing residual chlorides and/or allowing diffusion to reduce composition gradients, such as at a processing temperature of about <NUM> or higher (e.g., about <NUM> to about <NUM>,<NUM>).

In one embodiment, the high temperature processing also continues disproportionation reactions to produce Ti alloy from any residual Ti<NUM>+.

The process described here can be explained in the most general and simplest terms by inspecting the overlaid stability diagrams (Gibbs energy per mole of Cl<NUM> vs. absolute T) for the Ti-Cl and Al-Cl systems as shown in <FIG>.

While alloy or salt solutions are not considered, it shows the maximum available chemical energy in the Ti-Al-Cl system. At temperatures below <NUM> (<NUM>) Ti<NUM>+, as TiCl<NUM>(l,g), can be reduced to Ti<NUM>+, as TiCl<NUM>(s), and subsequently to Ti<NUM>+, asTiCl<NUM>(s), by the oxidation of Al metal to Al<NUM>+ (in the form of AlCl<NUM>(s), Al<NUM>Cl<NUM>(g) and / or AlCl<NUM>(g) ), but Ti<NUM>+ cannot be reduced to metallic Ti by oxidation of metallic Al. In this process, metallic titanium alloyed with Al[Ti] can form in the temperature range <NUM> to <NUM> (<NUM> to <NUM>) via disproportionation of Ti<NUM>+ (Ti<NUM>+ = <NUM>/<NUM>[Ti] + <NUM>/3Ti<NUM>+) in a salt solution [Ti<NUM>+:salt] producing [Ti] particles and Ti<NUM>+ as a salt solution [Ti<NUM>+:salt] or vapour. Al-driven reduction of Ti<NUM>+ and Ti<NUM>+ is an exothermic process and is carried out in the stage one, S1, reactor and low temperature part of stage two, S2, reactor at temperatures below <NUM> or <NUM>), while Ti<NUM>+ disproportionation is an endothermic process and is carried out at an intermediate temperature range in the S2 reactor.

The reduction of Ti<NUM>+, Ti<NUM>+ (and other alloying elements, Mx+), oxidation of Al and subsequent disproportionation mean this process is fundamentally an electrochemical process. The process describe here does not rely on electrodes or external electrical circuits, as a result charge neutrality is expected throughout interaction zones. This means that alloy particles can form homogeneously from the [Ti<NUM>+:salt] provided the local heat flux and composition supports the endothermic disproportionation reaction. This is a significant advantage this process has over electrochemical deposition and related processes.

Additionally, without wishing to be bound by any particular theory, it is believed that metallic Al and other alloying elements, M, precipitate from the salt simultaneously with Ti<NUM>+ and via corresponding disproportionation reactions (i.e., for Al: Al+ = <NUM>/<NUM>[Al] + <NUM>/3Al<NUM>+ [<NUM>] and for M: Mx+ = <NUM>/(x+<NUM>)[M] + x/(x+<NUM>)M(x+<NUM>)+) and the supply of low oxidation state ions from the salt to the growth front of alloy particles is not hindered. Further, the low temperature nature of this process means that the crystal structure and phase boundaries typically observed with conventional processing routes (i.e., solidification and thermo-mechanical work) do not necessarily form or are even expected.

Keeping the general / high level features of this process in mind the details of the process will be described. In particular embodiments, the following processes may be performed after ensuring that the starting reactants (TiCl<NUM>, AlCl<NUM>, and alloy element halides, MXx) are effectively free of H<NUM>O and O, since all metal halides react strongly with H<NUM>O and once oxygen is introduced it can be difficult to remove form some salts. Additionally, it is believed that oxygen contamination in salt stabilizes Ti<NUM>+ over Ti<NUM>+, which hiders Ti<NUM>+ formation and thus influences the composition of alloy that forms.

A chemical reduction reaction of Ti<NUM>+, initially in the form of TiCl<NUM>(l) to Ti<NUM>+, as TiCl<NUM>(AlCl<NUM>)x, was performed in the stage <NUM> reactor and evaluated in an inert environments. The input mixture included <NUM> Al flake, <NUM> AlCl<NUM>, <NUM> NbCl<NUM> and <NUM> of CrCl<NUM> that was loaded under a high purity argon atmosphere into a sealed ball milled and milled for <NUM> hours at close to room temperature (multiple ball mills provide feed for each stage <NUM> run. The milled material was sieved at <NUM> sieve size and <NUM> grams, nominally from two mills, were loaded into a plow mixer reactor, under a high purity argon atmosphere. The reactor was maintained at a pressure of <NUM> bar with a low flow (less than <NUM>/min) of high purity argon flowing through the reactor. The reactor and charge was preheated to <NUM> and stabilized before <NUM> of TiCl<NUM>(l) was injected at a rate of <NUM>±<NUM>/min while continuously mixing. During the time TiCl<NUM>(l) is injected it initially evaporates, but overtime TiCl<NUM>(l) forms as the reactor wall is maintained at about <NUM>, while the bulk free flowing in process charge, {salt + Al}, can reach temperatures up to <NUM>. Following addition of all TiCl<NUM>(l) reactor wall temperature is maintained <NUM> for nominally the same time taken for TiCl<NUM> injection, during which the condensed TiCl<NUM>(l), was absorbed in the input mixture and reaction product salt, continues to reaction and is reduced. After the majority of condensed TiCl<NUM>(l) is reduced (indicated by a reduction in bulk change temperature and gas temperature above the mixed charge) the reactor wall temperature was increased to <NUM> and held. This ensures all the condensed TiCl<NUM>(l) at the reactor wall was able to reduced or can be removed. Intermediate material was cooled and removed from the reactor. Representative samples taken from the product of the described process were characterized, provided suitable precautions are taken to stop reaction with air, using XRD, ICP, Cl titration and electron microscopy and EDS analysis to evaluate form of the metal chlorides. The results of this characterization confirmed the product of residual unreacted Al particles with consistent shape and size observed in the milled product loaded into the plough reaction and also the amount consistent with reduction of TiCl<NUM> added. The microstructure observed with SEM show the Al particles were surrounded by a graded layer of product salt, the salt in contact the Al surface is AlCl<NUM>-rich and it is common to observe segregation of O at this interface as an oxy-chloride layer "AlOCl". Further form the surface of the Al particle, the TiCl<NUM>(AlCl<NUM>)x phase existed and represented the bulk of the product of this reaction. This salt product had poor mechanical properties and easily separated the core Al particle and can exist isolated from Al particles. XRD analysis showed the TiCl<NUM>(AlCl<NUM>)x salt phase exists as the α phase, hexagonal close packed structure. This crystal structure was consistent with AlCl<NUM>(TiCl<NUM>)x, and there was evidence of a continuous solid solution. The measured composition of the bulk sample composition was consistent with XRD and the observed microstructure.

Balance of the material was fed into a HED rotary kiln reactor with Ar counter flow gas with <NUM> zones with zone temperatures of about <NUM> to about <NUM>, about <NUM> to about <NUM>, and about <NUM> to about <NUM>. After reaction in the rotary kiln through to a maximum temperature of <NUM>, the sample material was collect and analyzed by XRD, ICP, Cl titration and electron microscopy and EDS and showed formation of gamma titanium aluminide metal alloy powder with a size of < <NUM> particle size and with a composition of <NUM> ± <NUM> wt% Al, <NUM> ± <NUM> wt% Ti, <NUM> ± <NUM> wt% Cr, <NUM> ± <NUM> wt% Nb as well as a small amount of residual chlorine content (<NUM> wt%).

A chemical reduction reaction was performed and evaluated in an inert environment. The input mixture includes <NUM> Al flake, <NUM> AlCl<NUM>, <NUM> NbCl<NUM> and <NUM> of CrCl<NUM> and milled at room temperature for <NUM> hours. The milled material was sieved at <NUM> sieve size and <NUM> grams (nominally product from two mills) were loaded into a plow mixer reactor. The reactor was preheated to <NUM> and TiCl<NUM> was injected at a rate of <NUM>/min while mixing. Following addition of <NUM> of TiCl<NUM>, reactor temperature was increased to <NUM> and held to dry/remove excess TiCl<NUM>. Intermediate material was cooled and removed from the reactor. The material from <NUM> similar stage one processes was fed into a HED rotary kiln reactor with Ar counter flow gas with <NUM> zones with all zone temperatures set to <NUM>. The {Al + TiCl<NUM>(AlCl<NUM>)x} product from the above stage one reaction was feed into the rotary kiln at a constant rate of <NUM> ± <NUM>/hr passed through the heated zone at a range of velocities controlled by the rotation speed of the work tube (<NUM> RPM residence time of about <NUM>; <NUM> RPM residence time of about <NUM>; <NUM> RPM residence time of about <NUM>). In-process samples were collected throughout the run and were characterized using XRD, ICP, Cl titration and electron microscopy and EDS analysis. Results showed that the starting {Al + TiCl<NUM>(AlCl<NUM>)x} material quickly reacted in the rotary kiln. The Al particles remained in the XRD spectrum and also clearly visible in the microstructure, but the amount was reduced. This was consistent with continued oxidation to reduce Ti<NUM>+ to Ti<NUM>+. The characteristic XRD peaks for α-TiCl<NUM>(AlCl<NUM>)x disappeared leaving only the peaks for starting Al and alloy. The bulk composition of the sample, microstructure and amount of condensed AlCl<NUM> vapour collected confirms the bulk of the collected sample is salt and this salt does not have a defined crystal structure (i.e., an amorphous, glass or polymeric material), which shows that Al easily reduces Ti<NUM>+ as TiCl<NUM>(AlCl<NUM>)x to Ti<NUM>+ as Ti(AlCl<NUM>)<NUM> at temperatures below <NUM> without a significant amount of AlCl<NUM> evaporation. The Ti(AlCl<NUM>)<NUM> phase is known in the literature to be non-crystalline.

In addition to low temperature reduction of Ti<NUM>+, this result shows without an ambiguity that Ti-alloy starts forming at temperatures as low as <NUM> from the salt phase (via a simultaneous disproportionation reaction). The conditions of the reaction described here are not optimized, and a wide range of alloys were formed: α-[Ti], α2-Ti<NUM>Al, γ-TiAl, TiAl<NUM>, TiAl<NUM> also containing Nb and Cr. This alloy particles coexist with salt and unreacted Al particles. The wide range of alloy phases is expected to due to a wide range of salt compositions / inhomogeneous. This experimental run was conducted to prove the ease of reducing Ti<NUM>+ to Ti<NUM>+ and prove that Ti-Alloy forms via a simultaneous disproportionation process.

Claim 1:
A process for producing a titanium alloy material, comprising:
adding TiCl<NUM> to an input mixture at a first reaction temperature such that at least a portion of the Ti<NUM>+ in the TiCl<NUM> is reduced to Ti<NUM>+ to form a first reaction product, wherein the input mixture comprises aluminum, and, optionally AlCl<NUM> and/or optionally one or more alloying element halides; wherein adding the TiCl<NUM> to the input mixture is performed in an inert atmosphere having a pressure of <NUM> kPa (<NUM> torr) to <NUM> kPa (<NUM> torr) and at a first reaction temperature of <NUM> to <NUM>;
after TiCl<NUM> addition is stopped, heating the first reaction product at drying conditions to complete reduction of Ti<NUM>+ or to remove all of any remaining TiCl<NUM> to form a first intermediate mixture, wherein the first intermediate mixture is an AlCl<NUM>-based salt solution that includes Ti<NUM>+;
heating the first intermediate mixture to a second reaction temperature such that at least a portion of the Ti<NUM>+ is reduced to Ti<NUM>+ in a second intermediate mixture, wherein the second intermediate mixture is an AlCl<NUM>-based salt solution that includes the Ti<NUM>+, wherein the Ti<NUM>+ is in the form of TiCl<NUM> complexed with AlCl<NUM>; wherein heating the first intermediate mixture to the second reaction temperature is performed in an inert atmosphere having a pressure of <NUM> kPa (<NUM> torr) to <NUM> kPa (<NUM> torr) and at a second reaction temperature of <NUM> to <NUM>; and
further heating the second intermediate mixture to a third reaction temperature such that the Ti<NUM>+ forms the titanium alloy material via a disproportionation reaction; wherein reacting the Ti<NUM>+ via the disproportionation reaction to form the titanium alloy material is performed in an inert atmosphere having a pressure of <NUM> kPa (<NUM> torr) to <NUM> kPa (<NUM> torr) and at the third reaction temperature of <NUM> to <NUM>.