A thermochemical indirect deoxidation method for titanium powder or titanium alloy powder

Abstract

This invention provides a thermochemical indirect deoxidation method for titanium powder or titanium alloy powder, specifically relating to the field of pyrometallurgical technology. The method includes: sealing titanium powder or titanium alloy powder in a titanium box to obtain a sealed titanium package; placing the sealed titanium package, a metallic chloride, and a rare earth metal into a titanium crucible to obtain a sealed titanium crucible; placing the sealed titanium crucible, metallic M, and metallic titanium into a stainless steel crucible and sealing it to obtain a sealed stainless steel crucible; and heating the sealed stainless steel crucible for deoxidation, obtaining deoxidized titanium powder or titanium alloy powder in the titanium package. This thermochemical indirect deoxidation method does not introduce impurities during the deoxidation process, effectively reduces the oxygen content in the titanium powder or titanium alloy powder, has simple post-processing, a simple process, low production cost, and high product purity.

Description

Technical Field

[0001] This invention belongs to the field of pyrometallurgical technology, specifically relating to a thermochemical indirect deoxidation method for titanium powder or titanium alloy powder. Background Technology

[0002] With the development of technology, titanium products play a significant role in military, aerospace, medical, and civilian industries. Titanium powder and titanium alloy powder, as important raw materials for manufacturing titanium parts, have oxygen content that affects their mechanical properties. Therefore, deoxidizing titanium powder and titanium alloy powder to reduce oxygen content has become a major research focus.

[0003] Common deoxidation methods for titanium powder or titanium alloy powder include hydrogen-assisted deoxidation, molten salt-assisted alkali metal thermochemical deoxidation, molten salt-assisted rare earth and rare earth chloride deoxidation, electrochemical deoxidation, and calcium vapor deoxidation. In hydrogen-assisted deoxidation, hydrogen gas easily corrodes the titanium powder or titanium alloy powder. In molten salt-assisted alkali metal thermochemical deoxidation and molten salt-assisted rare earth and rare earth chloride deoxidation, alkali metals or rare earth metals and molten salt easily contaminate the titanium powder, generating impurities. While acid washing or vacuum distillation can remove some impurities, they cannot maintain the purity of the titanium powder or titanium alloy powder and may even cause a resurgence in oxygen content. Electrochemical deoxidation not only fails to achieve true sintering of the titanium powder, but molten salt can also penetrate into the intermediate molded body, causing contamination and generating large amounts of wastewater. Calcium vapor deoxidation can obtain titanium powder with lower oxygen content, but the direct action of calcium vapor on the titanium powder introduces calcium impurities, making post-processing difficult. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a thermochemical indirect deoxidation method for titanium powder or titanium alloy powder. The deoxidation method provided by this invention does not introduce impurities during the deoxidation process, effectively reduces the oxygen content in titanium powder or titanium alloy powder, has simple post-processing, a simple process, low production cost, and high product purity.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] This invention provides a thermochemical indirect deoxidation method for titanium powder or titanium alloy powder, comprising the following steps:

[0007] Titanium powder or titanium alloy powder is placed into a titanium box and sealed to obtain a sealed titanium package.

[0008] The sealed titanium bag, the metal chloride salt and the rare earth metal are loaded into a titanium crucible to obtain a sealed titanium crucible.

[0009] The sealed titanium crucible, metal M, and metallic titanium are placed into a stainless steel crucible and sealed to obtain a sealed stainless steel crucible; the metal element in the metal chloride salt is the same as that in metal M.

[0010] The sealed stainless steel crucible is heated to deoxidize, and deoxidized titanium powder or titanium alloy powder is obtained in the titanium container; the heating and deoxidation temperature is higher than the melting point of the metal chloride salt and the melting point of the metal, but lower than the melting point of titanium.

[0011] Preferably, after the heating and deoxidation are completed, the process further includes opening the stainless steel crucible and the titanium crucible, performing vacuum distillation, and separating the titanium package.

[0012] Preferably, the step of loading the sealed titanium bag, the metallic chloride, and the rare earth metal into the titanium crucible comprises:

[0013] After loading some metal chloride salts into a titanium crucible, rare earth metals are laid on top, and then several sealed titanium bags are placed in the crucible with gaps between them. The remaining metal chloride salts are then loaded into the titanium crucible to fill the gaps.

[0014] Preferably, the metal element in the metal chloride salt and the metal M include at least one of Ca, Mg, K and Na.

[0015] Preferably, the rare earth metal includes at least one of Y, Ho, La and Ce.

[0016] Preferably, the heating and deoxygenation time is 40 to 50 hours.

[0017] Preferably, the process of heating and deoxidation is followed by natural cooling.

[0018] Preferably, the vacuum degree of the vacuum distillation is ≤200 Pa;

[0019] The vacuum distillation temperature is greater than or equal to the melting point of the metal chloride salt and lower than the melting point of titanium.

[0020] Preferably, the vacuum distillation process further includes deoxygenation with an inert gas.

[0021] Preferably, the metallic titanium is sponge titanium.

[0022] This invention provides a thermochemical indirect deoxidation method for titanium powder or titanium alloy powder, comprising the following steps: filling and sealing titanium powder or titanium alloy powder in a titanium box to obtain a sealed titanium package; filling the sealed titanium package, a metal chloride, and a rare earth metal into a titanium crucible to obtain a sealed titanium crucible; filling the sealed titanium crucible, metal M, and metallic titanium into a stainless steel crucible and sealing it to obtain a sealed stainless steel crucible; wherein the metal element in the metal chloride is the same as that in metal M; heating the sealed stainless steel crucible for deoxidation, obtaining deoxidized titanium powder or titanium alloy powder in the titanium package; wherein the heating deoxidation temperature is higher than the melting point of the metal chloride and the metal, but lower than the melting point of titanium. The deoxidation mechanism of this invention is shown in formulas 1-3:

[0023] MClx (l)+R(l)→RCl3(l)+M(l) Equation 1,

[0024] [O]+M(l)→cMO y (s) Equation 2,

[0025] MO y +RCl3(l)→MCl x (l)+ROCl(s) Equation 3,

[0026] This invention utilizes metal chloride salts (MCl) x The formation of metallic M and RCl3 during the heating process of titanium powder and rare earth metals (R) increases the deoxidation limit, resulting in titanium powder or titanium alloy powder with lower oxygen content. The resulting metallic M combines with oxygen in the titanium powder or titanium alloy powder to form MO. y RCl3, on the other hand, will capture MO. y Generate RaOCl and MCI x , lower MO y The activity of titanium powder or titanium alloy powder is increased to improve the deoxidation limit. A sealed titanium bag separates the titanium powder or titanium alloy powder from the molten salt, indirectly deoxidizing it and protecting it from contamination. This ensures the titanium powder or titanium alloy powder is free of impurities and facilitates subsequent separation without generating industrial waste. Titanium has a strong affinity for oxygen; the molten salt system removes oxygen from the titanium foil used to prepare the titanium bag, creating a concentration difference between the oxygen content in the titanium foil and the titanium or titanium alloy powder. Oxygen from the high-concentration area migrates to the low-concentration area, reducing the oxygen content of the titanium or titanium alloy powder and achieving deoxidation of the titanium or titanium alloy powder in a sealed environment. The presence of metallic M and metallic titanium in the sealed stainless steel crucible prevents the escape of metallic M generated inside the sealed titanium crucible and the transfer of oxygen from the stainless steel crucible into the sealed titanium crucible, thus avoiding any impact on the deoxidation limit.

[0027] Furthermore, the ROCl generated after deoxidation can be converted into RCl3 through further processing, increasing yield. Using the indirect thermochemical deoxidation method provided by this invention, the oxygen content of the deoxidized titanium powder or titanium alloy powder obtained is below 1500 ppm. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 A schematic flowchart of the indirect thermochemical deoxidation method for titanium powder provided by the present invention. Detailed Implementation

[0030] This invention provides a thermochemical indirect deoxidation method for titanium powder or titanium alloy powder, comprising the following steps:

[0031] Titanium powder or titanium alloy powder is placed into a titanium box and sealed to obtain a sealed titanium package.

[0032] The sealed titanium bag, the metal chloride salt and the rare earth metal are loaded into a titanium crucible to obtain a sealed titanium crucible.

[0033] The sealed titanium crucible, metal M, and metallic titanium are placed into a stainless steel crucible and sealed to obtain a sealed stainless steel crucible; the metal element in the metal chloride salt is the same as that in metal M.

[0034] The sealed stainless steel crucible is heated to deoxidize, and deoxidized titanium powder or titanium alloy powder is obtained in the titanium container; the heating and deoxidation temperature is higher than the melting point of the metal chloride salt and the melting point of the metal, but lower than the melting point of titanium.

[0035] In this invention, unless otherwise specified, all raw materials and equipment used are commercially available products well known in the art.

[0036] This invention involves filling titanium powder or titanium alloy powder into a titanium box and sealing it to obtain a sealed titanium package.

[0037] In this invention, the oxygen content of the titanium powder or titanium alloy powder is preferably ≥1500ppm.

[0038] In this invention, the width of the sealing titanium package is preferably 4-6 mm, the height is preferably 8-12 mm, and the length is preferably 45-55 mm. In a specific embodiment, the width of the sealing titanium package is 5 mm, the height is 10 mm, and the length is 50 mm. This invention controls the width of the sealing titanium package to 5 mm to avoid excessively long heating and deoxidation times.

[0039] In this invention, the titanium box is prepared from titanium foil, and the thickness of the titanium foil is preferably 0.2 to 0.5 mm. In specific embodiments, the thickness of the titanium foil can be 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm.

[0040] In this invention, the step of loading titanium powder or titanium alloy powder into a titanium box preferably includes: filling the titanium box with titanium powder or titanium alloy powder.

[0041] To obtain the sealed titanium package, the present invention loads the sealed titanium package, metal chloride salt, and rare earth metal into a titanium crucible to obtain a sealed titanium crucible.

[0042] In this invention, the metal element in the metal chloride salt preferably includes at least one of Ca, Mg, K and Na.

[0043] In this invention, the metal chloride is preferentially dried before being placed into the titanium crucible. The drying process preferably includes drying the metal chloride at 200°C and 50 Pa for 12 hours, followed by drying at 400°C and 50 Pa for another 12 hours. This invention removes free water at a low temperature first, and then removes bound water by raising the temperature, preventing the molten salt from directly converting into oxides.

[0044] In this invention, the rare earth metal preferably includes at least one of Y, Ho, La and Ce.

[0045] In this invention, the step of loading the sealed titanium bags, metal chloride, and rare earth metal into the titanium crucible preferably includes: loading a portion of the metal chloride into the titanium crucible, then laying rare earth metal on top, and then placing several sealed titanium bags with gaps between them; finally, loading the remaining metal chloride into the titanium crucible and filling the gaps. Specifically, in an embodiment, 1 / 5 of the mass of the metal chloride is loaded into the titanium crucible, then rare earth metal is laid on top, and then several sealed titanium bags are placed with gaps between them; finally, the remaining mass of the metal chloride is loaded into the titanium crucible and filling the gaps.

[0046] The present invention fills the titanium package spacer with metal chloride salt, which is beneficial to uniform heating during deoxidation, and the metal M obtained during the displacement reaction is evenly distributed around the sealed titanium package, ensuring deoxidation efficiency.

[0047] In this invention, the amount of the metal chloride salt preferably satisfies the following condition: during heating and deoxidation, the molten metal chloride salt can completely immerse the titanium package. During the heating and deoxidation process, the liquid molten salt completely immerses the titanium package, ensuring deoxidation efficiency.

[0048] In this invention, during the heating deoxidation process, a displacement reaction occurs between the metal chloride and the rare earth metal. Preferably, the metal chloride participating in the displacement reaction accounts for 10% to 100% of the total mass of the metal chloride. The displacement reaction during heating is shown in Formula 1:

[0049] MCl x (l)+R(l)→RCl3(l)+M(l) Equation 1,

[0050] The molar amount of the metal chloride participating in the displacement reaction is preferably 10% to 100% of the total molar amount of the metal chloride. In specific embodiments, the molar amount of the metal chloride participating in the displacement reaction can be 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% of the total molar amount of the metal chloride. Rare earth metal R is used in conjunction with the metal chloride MCl. x A displacement reaction yields RCl3, which can reduce production costs.

[0051] In this invention, the RCl3 obtained by the substitution reaction and the remaining MCl after the substitution reaction are... x The preferred molar ratio is 2-3:2-3. In a specific embodiment, the RCl3 obtained by the substitution reaction and the remaining MCl after the substitution reaction are... x The molar ratio can be 2:3 or 3:2. In a specific embodiment of the present invention, when the rare earth metal R is Ce, the RCl3 obtained by the substitution reaction and the remaining MCl after the substitution reaction are... x The preferred molar ratio is 3:2; when the rare earth metal R is Y or Ho, the RCl3 obtained by the substitution reaction and the remaining MCl after the substitution reaction are... x The preferred molar ratio is 2:3. The deoxidizing capacity of Y and Ho is greater than that of Ce. This invention controls the ratio of RCl3 obtained from the substitution reaction to the remaining MCl after the substitution reaction. x The molar ratio is such that the lowest economic cost is obtained while maximizing deoxygenation efficiency.

[0052] After obtaining the sealed titanium crucible, the present invention loads the sealed titanium crucible, metal M and metallic titanium into a stainless steel crucible and seals them to obtain a sealed stainless steel crucible.

[0053] In this invention, the metal element in the metal chloride salt is the same as that of metal M, and metal M preferably includes at least one of Ca, Mg, K, and Na. In this invention, the mass of metal M is preferably 8-15 g / 500 mL (8-15 g of metal M per 500 mL of crucible chamber volume). In specific embodiments, the mass of metal M can be 8 g / 500 mL, 10 g / 500 mL, 12 g / 500 mL, or 15 g / 500 mL. Metal M can suppress the volatilization of metals in the metal chloride salt in the sealed titanium crucible. During the heating and deoxidation process, metal M forms metal vapor, increasing the vapor partial pressure of metal M in the stainless steel crucible chamber, thereby suppressing the continued volatilization of metal M generated in the sealed titanium crucible.

[0054] In this invention, the preferred mass of the titanium is 15-25 g / 500 mL (15-25 g of titanium corresponds to every 500 mL of crucible chamber volume). In specific embodiments, the mass of the titanium can be 15 g / 500 mL, 18 g / 500 mL, 20 g / 500 mL, 22 g / 500 mL, or 25 g / 500 mL. The titanium is preferably sponge titanium. Titanium can absorb oxygen from the stainless steel crucible chamber, ensuring that the oxygen partial pressure inside the chamber is at an extremely low level, preventing oxygen from dissolving in the molten salt system and increasing the oxygen ion activity within the molten salt system, thus increasing the deoxidation limit. Sponge titanium has a large specific surface area and a fast oxygen absorption rate.

[0055] After obtaining the sealed stainless steel crucible, the present invention heats and deoxidizes the sealed stainless steel crucible to obtain deoxidized titanium powder or titanium alloy powder in a titanium container.

[0056] In this invention, the heating deoxidation temperature is preferably higher than the melting point of the metal chloride salt and the melting point of the metal, but lower than the powder sintering temperature. In specific embodiments, the heating deoxidation temperature can be 700℃, 750℃, 800℃, or 850℃; the heating deoxidation time is preferably 40-50 hours. In specific embodiments, the heating deoxidation time can be 40 hours, 43 hours, 45 hours, 48 ​​hours, or 50 hours. Controlling the deoxidation temperature at 700-850℃ avoids excessively high temperatures that could cause sintering of the titanium powder or titanium alloy powder, thereby affecting its mechanical properties.

[0057] In this invention, the deoxygenation mechanism is shown in Equations 2 and 3:

[0058] [O]+M(l)→cMO y (s) Equation 2,

[0059] MO y +RCl3(l)→MCl x (l)+ROCl(s) Equation 3,

[0060] RCl3(l) captures MO y Generating RaOCl(s) can reduce MO y The activity of RCl3(l) is increased to improve the deoxidation limit, thereby obtaining titanium powder or titanium alloy powder with lower oxygen content. Furthermore, RCl3(l) captures MO. y Generate ROCl x and MCl x ROCl x It will form a precipitate that settles at the bottom of the titanium crucible, preventing the formation of MO. y Adhering to the outer surface of the sealed titanium liner, it affects the diffusion of oxygen in the later stages, leading to a decrease in deoxidation efficiency. During the heating deoxidation process, because the deoxidizer has a stronger affinity for oxygen, the molten salt system removes oxygen from the titanium platinum used to prepare the titanium liner, resulting in a concentration difference between the oxygen content of the titanium platinum and the oxygen content of the titanium or titanium alloy powder. Oxygen from the high concentration area migrates to the low concentration area. As it continues to migrate, the oxygen content of the titanium or titanium alloy powder decreases, thus achieving deoxidation of the titanium or titanium alloy powder in a sealed environment.

[0061] In this invention, the heating and deoxidation process preferably includes natural cooling. Sudden cooling or water quenching can affect the mechanical properties of the titanium powder.

[0062] In this invention, after the heating and deoxidation are completed, it is preferable to further open the stainless steel crucible and the titanium crucible, and perform vacuum distillation on the titanium crucible to separate the titanium bag.

[0063] In this invention, the process of vacuum distillation preferably includes deoxygenation with an inert gas. Specifically, in this embodiment, an inert gas is used to remove oxygen from the vacuum furnace. This prevents oxygen from re-contaminating the titanium powder or titanium alloy powder. Even at extremely low oxygen content, titanium can still combine with oxygen; removing oxygen from the vacuum furnace avoids re-contamination of the titanium powder or titanium alloy powder.

[0064] In this invention, the vacuum degree of the vacuum distillation is preferably ≤200 Pa. In specific embodiments, the vacuum degree of the vacuum distillation can be 2 Pa, 5 Pa, 10 Pa, 20 Pa, 50 Pa, 80 Pa, 100 Pa, 120 Pa, 150 Pa, 180 Pa, or 200 Pa. The distillation temperature of the vacuum distillation is preferably greater than or equal to the melting point of the metal chloride salt and lower than the sintering temperature of the powder. In specific embodiments, the distillation temperature of the vacuum distillation can be 700℃ or 750℃. During the vacuum distillation process, the deoxidation system volatilizes, exposing the titanium package, and the metal chloride salt and the titanium package separate. Controlling the distillation temperature and setting the separation temperature above the melting point of the molten salt, while preventing sintering of the powder in the titanium package, helps to accelerate the volatilization of the metal chloride salt. The lower the vacuum degree, the faster the molten salt volatilization rate.

[0065] In this invention, the sealed titanium package separated after vacuum distillation is opened to obtain deoxidized titanium powder or titanium alloy powder.

[0066] The method provided by this invention employs an indirect deoxidation method, which protects titanium powder or titanium alloy powder from molten salt contamination. The post-processing is simple, and the resulting product is easy to separate. Furthermore, the oxygen content of the deoxidized titanium powder or titanium alloy powder is less than 1500 ppm.

[0067] A schematic flowchart of the indirect thermochemical deoxidation method for titanium powder or titanium alloy powder provided by this invention is shown below. Figure 1 As shown.

[0068] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. The described embodiments are only some embodiments of the present invention, and not all embodiments. Any modifications, equivalent substitutions, improvements, etc., made to the embodiments of the present invention based on the technical essence and general principles of the present invention without creative effort should be within the protection scope of the present invention.

[0069] Example 1

[0070] MgCl2 was dried at 200℃ and 50Pa for 12 hours, then dried at 400℃ and 50Pa for another 12 hours. After cooling to room temperature, it was removed, bottled, and stored in a glove box for later use. Cerium metal was cut into 5mm pieces, vacuum-sealed, and stored in a glove box for later use.

[0071] After filling a titanium bag with TC4 powder (oxygen content 4570ppm, particle size <100μm) into a titanium bag measuring 4mm in height, 10mm in width, and 50mm in length, the bag is sealed and stored in a glove box for later use. The titanium foil sheet used to make the titanium bag is 0.3mm thick.

[0072] One-fifth of the mass of dried MgCl2 was placed at the bottom of a titanium crucible. 145.70 g of metallic cerium was then placed on top of the dried MgCl2. Eight titanium bags were then placed on top of the cerium, leaving a gap between each bag. The remaining dried MgCl2 was then added to the titanium crucible, filling the gaps. The total mass of dried MgCl2 added was 214.2 g. The molar ratio of the remaining MgCl2 to the CeCl3 obtained after displacement was 2:3. The titanium cap of the titanium crucible was tightly sealed, and the crucible was placed inside a stainless steel crucible. 10 g of metallic Mg and 20 g of sponge titanium were placed on the outside of the titanium crucible inside the stainless steel crucible. The stainless steel crucible was then welded and sealed.

[0073] Place the stainless steel crucible in a resistance furnace, heat it to 800℃ and hold it for 48 hours. After natural cooling, open the stainless steel crucible and place it in a vacuum furnace in which oxygen has been removed from the furnace chamber beforehand with argon. Vacuum distillation is carried out at 750℃ and a vacuum degree of 10 Pa until the molten salt has evaporated completely. After natural cooling, remove the titanium bag, take out the TC4 powder from the titanium bag, and vacuum seal and store it.

[0074] During the deoxidation process, metallic cerium undergoes a displacement reaction with MgCl2 to generate the deoxidizing agent Mg. The reaction equation is as follows:

[0075] 2Ce(s) + 3MgCl2(l) = 2CeCl3(l) + 3Mg(l) Equation 4;

[0076] The deoxygenation mechanism is as follows:

[0077] [O] 在TC4 +Mg(l)=MgO(s) Equation 5;

[0078] MgO(s)+CeCl3(l)=MgCl2(l)+CeOCl(s) Formula 6.

[0079] The oxygen content in the final TC4 powder was analyzed, and the results are shown in Table 1.

[0080] Table 1 Comparison of oxygen content in TC4 powder before and after deoxygenation in Example 1

[0081]

[0082] As shown in Table 1, the deoxidation effect in Example 1 was better, and the obtained titanium alloy powder met the expected target with an oxygen content of less than 1500 ppm.

[0083] Example 2

[0084] Dry NaCl at 200℃ and 50Pa for 12 hours, then at 400℃ and 50Pa for another 12 hours. After cooling to room temperature, remove and bottle the product, then store it in a glove box for later use. Cut metallic yttrium into 5mm pieces, vacuum seal them, and store them in a glove box for later use.

[0085] Ti powder (oxygen content 3950ppm, particle size <100μm) was filled into a titanium bag measuring 4mm in height, 10mm in width, and 50mm in length, then sealed and stored in a glove box for later use. The titanium foil sheet used to make the titanium bag was 0.3mm thick.

[0086] One-fifth of the mass of dried NaCl was placed at the bottom of a titanium crucible, followed by 66.68 g of yttrium. Eight titanium pouches were then placed on top of the yttrium, with a gap between each pouch. The remaining dried NaCl was then added to the titanium crucible, filling the gaps. The total mass of dried NaCl added was 131.63 g. The molar ratio of the remaining NaCl to the resulting YCl3 was 3:2. The titanium cap of the titanium crucible was tightly sealed, and the crucible was placed inside a stainless steel crucible. 10 g of metallic Na and 20 g of sponge titanium were placed on the outside of the titanium crucible inside the stainless steel crucible. The stainless steel crucible was then welded and sealed.

[0087] Place the stainless steel crucible in a resistance furnace, heat it to 800℃ and hold it for 48 hours. After natural cooling, open the stainless steel crucible and place it in a vacuum furnace in which oxygen in the furnace cavity has been removed by argon gas. Vacuum distillation is carried out at 750℃ and 10 Pa vacuum until the molten salt has evaporated completely. After natural cooling, remove the titanium bag, take out the Ti powder from the titanium bag, and vacuum seal and store it.

[0088] During the deoxidation process, metallic yttrium undergoes a displacement reaction with NaCl to generate the deoxidizing agent Na. The reaction equation is as follows:

[0089] Y(s)+3NaCl(l)=YCl3(l)+3Na(l) Formula 7;

[0090] The deoxygenation mechanism is as follows:

[0091] [O] 在Ti +2Na(l)=Na2O(s) Equation 8;

[0092] Na2O(s)+YCl3(l)=2NaCl(l)+YOCl(s) Formula 9.

[0093] The oxygen content in the final Ti powder was analyzed, and the results are shown in Table 2.

[0094] Table 2 Comparison of oxygen content in Ti powder before and after deoxidation in Example 2

[0095]

[0096]

[0097] As shown in Table 2, the deoxidation effect in Example 2 was better, and the obtained titanium powder met the expected target with an oxygen content of less than 1500 ppm.

[0098] Example 3

[0099] MgCl2 was dried at 200℃ and 50Pa for 12 hours, then dried at 400℃ and 50Pa for another 12 hours. After cooling to room temperature, it was removed, bottled, and stored in a glove box for later use. Holmium metal was cut into 5mm pieces, vacuum-sealed, and stored in a glove box for later use.

[0100] Ti-6Al-6V-2Sn powder (oxygen content 5210ppm, particle size <100μm) was filled into a titanium bag with a height of 4mm, a width of 10mm, and a length of 50mm, then sealed and stored in a glove box for later use. The titanium foil sheet used to make the titanium bag was 0.3mm thick.

[0101] One-fifth of the mass of dried MgCl2 was placed at the bottom of a titanium crucible. 123.70 g of holmium metal was then placed on top of the MgCl2. Eight titanium bags were then placed on top of the holmium metal, leaving a gap between each bag. The remaining dried MgCl2 was then added to the titanium crucible, filling the gaps. The total mass of dried MgCl2 added was 214.2 g. The molar ratio of the remaining MgCl2 to the HoCl3 obtained after displacement was 3:2. The titanium cap of the titanium crucible was tightly sealed, and the crucible was placed inside a stainless steel crucible. 10 g of metallic Mg and 20 g of sponge titanium were placed on the outside of the titanium crucible inside the stainless steel crucible. The stainless steel crucible was then welded and sealed.

[0102] Place the stainless steel crucible in a resistance furnace, heat it to 800℃ and hold it for 48 hours. After natural cooling, open the stainless steel crucible and place it in a vacuum furnace in which oxygen in the furnace cavity has been removed beforehand with argon. Vacuum distillation is carried out at 750℃ and a vacuum degree of 10 Pa until the molten salt has completely evaporated. After natural cooling, remove the titanium bag and take out Ti-6Al-6V-2Sn powder from the titanium bag. Vacuum seal and store it.

[0103] During the deoxidation process, metallic holmium undergoes a displacement reaction with MgCl2 to generate the deoxidizing agent Mg. The reaction equation is as follows:

[0104] 2Ho(s)+3MgCl2(l)=2HoCl3(l)+3Mg(l) Formula 10;

[0105] The deoxygenation mechanism is as follows:

[0106] [O] 在Ti-6Al-6V-2Sn+Mg(l)=MgO(s) Equation 11;

[0107] MgO(s)+HoCl3(l)=MgCl2(l)+HoOCl(s) Equation 12.

[0108] The oxygen content in the final Ti-6Al-6V-2Sn powder was analyzed, and the results are shown in Table 2.

[0109] Table 3 Comparison of oxygen content in Ti-6Al-6V-2Sn powder before and after deoxidation in Example 3

[0110]

[0111]

[0112] As shown in Table 3, the deoxidation effect in Example 3 was better, and the obtained titanium alloy powder met the expected target with an oxygen content of less than 1500 ppm.

[0113] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A thermochemical indirect deoxidation method for titanium powder or titanium alloy powder, characterized in that, Includes the following steps: Titanium powder or titanium alloy powder is placed into a titanium box and sealed to obtain a sealed titanium package. The sealed titanium bag, the metal chloride salt, and the rare earth metal are placed into a titanium crucible to obtain a sealed titanium crucible; the metal element in the metal chloride salt and the metal M include at least one of Ca, Mg, K, and Na; the rare earth metal includes at least one of Y, Ho, La, and Ce; The sealed titanium crucible, metal M, and metallic titanium are placed into a stainless steel crucible and sealed to obtain a sealed stainless steel crucible; the metal element in the metal chloride salt is the same as that in metal M. The sealed stainless steel crucible is heated to deoxidize, and deoxidized titanium powder or titanium alloy powder is obtained in the titanium container; the heating and deoxidation temperature is higher than the melting point of the metal chloride salt and the melting point of metal M, but lower than the melting point of titanium.

2. The thermochemical indirect deoxygenation method according to claim 1, characterized in that, After the heating and deoxidation are completed, the process also includes opening the stainless steel crucible and the titanium crucible, performing vacuum distillation, and separating the titanium package.

3. The thermochemical indirect deoxygenation method according to claim 1, characterized in that, The step of loading the sealed titanium bag, metallic chloride, and rare earth metal into the titanium crucible includes: After loading some metal chloride salts into a titanium crucible, rare earth metals are laid on top, and then several sealed titanium bags are placed in the crucible with gaps between them. The remaining metal chloride salts are then loaded into the titanium crucible to fill the gaps.

4. The thermochemical indirect deoxygenation method according to claim 1, characterized in that, The heating and deoxygenation time is 40-50 hours.

5. The thermochemical indirect deoxygenation method according to claim 1, characterized in that, The process of heating and deoxygenating also includes natural cooling.

6. The thermochemical indirect deoxygenation method according to claim 2, characterized in that, The vacuum degree of the vacuum distillation is ≤200Pa; The vacuum distillation temperature is greater than or equal to the melting point of the metal chloride salt and lower than the melting point of titanium.

7. The thermochemical indirect deoxygenation method according to claim 6, characterized in that, The vacuum distillation process also includes deoxygenation with an inert gas.

8. The thermochemical indirect deoxygenation method according to claim 1, characterized in that, The titanium metal is sponge titanium.

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