A preparation process for improving lanthanum yield and uniformity in high-temperature alloy

Abstract

The application discloses a preparation process for improving the yield and uniformity of lanthanum in high-temperature alloy, and belongs to the technical field of high-temperature alloy preparation, and aims at solving the problems of low yield and uneven distribution of lanthanum in lanthanum-containing high-temperature alloy, and comprises the following steps: preparing lanthanum-containing intermediate alloy; high-temperature alloy batching; smelting; argon filling; lanthanum adding; pouring; and the intermediate alloy containing lanthanum is used to replace elemental lanthanum in the smelting process, the element composition of the intermediate alloy is limited, the physical properties such as the melting point and the density of the intermediate alloy are closer to those of the high-temperature alloy, the metallurgical problems such as easy oxidation, easy volatilization and easy burning loss of the elemental lanthanum in the smelting of the high-temperature alloy can be effectively overcome, the uneven composition distribution caused by the floating of the elemental lanthanum on the surface of the high-temperature alloy melt is solved, the loss of the lanthanum element in the casting process is obviously reduced, the use cost of raw materials is reduced, and the yield of the lanthanum in the high-temperature alloy is basically stabilized at 75% to 90%.

Description

Technical Field

[0001] A preparation process for improving the lanthanum yield and uniformity in high-temperature alloys. This invention belongs to the field of high-temperature alloy preparation technology, specifically relating to a preparation process for improving the lanthanum yield and uniformity in high-temperature alloys. Background Technology

[0002] High-temperature alloys, with their excellent high-temperature strength, good oxidation resistance, and hot corrosion resistance, are widely used in hot-end components such as aero-engines, gas turbine turbine disks, and turbine blades. Lanthanum is an effective trace active element in high-temperature alloys, typically segregating at grain boundaries, phase interfaces, and surfaces. It not only purifies grain boundaries and improves metallurgical quality but also enhances the mechanical properties and stability of the alloy. Furthermore, lanthanum can improve the high-temperature oxidation resistance and corrosion resistance of alloys by modifying the viscosity and chemical composition of the oxide film.

[0003] In traditional lanthanum-containing high-temperature alloy smelting processes, lanthanum is typically added directly to the furnace in elemental form. However, lanthanum is highly reactive, has a low melting point (920℃), and low density (6.162 g / cm³), leading to several problems in high-temperature alloy smelting: severe oxidation and volatilization. Firstly, after addition, lanthanum floats on the surface of the molten alloy and undergoes oxidation, forming oxide inclusions. Secondly, in the later stages of refining, the high temperature of the molten alloy causes significant lanthanum loss. Thirdly, lanthanum exhibits severe density segregation, floating during smelting and casting. Fourthly, it readily reacts with refractory materials, contaminating the alloy and corroding the crucible. These problems prevent lanthanum from fully dissolving into the alloy melt, resulting in a yield of less than 30%, unstable content control, and uneven distribution of lanthanum within the ingot. Consequently, product quality fails to meet specifications, leading to substantial economic losses. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the existing defects and provide a preparation process for improving the yield and uniformity of lanthanum in high-temperature alloys, thereby solving the problems of low lanthanum yield and uneven distribution in lanthanum-containing high-temperature alloys.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A preparation process for improving the lanthanum yield and uniformity in high-temperature alloys includes the following steps:

[0007] (1) Preparation of lanthanum-containing master alloy: Select master alloying elements according to the high-temperature alloy composition, place the metal raw materials other than lanthanum in a vacuum induction furnace, evacuate to ≤1Pa for melting and refining, the refining temperature is 1600℃~1700℃, the refining time is 10min~30min; lower the refining temperature to 1500℃~1550℃, fill the furnace with ultrapure argon gas with a volume fraction of 99.999% to make the furnace pressure reach 10000Pa~20000Pa; add elemental lanthanum to the melt, raise the refining temperature to 1600℃~1700℃ and stir continuously, and pour immediately; after cooling to form an alloy ingot, crush it.

[0008] (2) High-temperature alloy ingredients: According to the requirements of high-temperature alloy composition, calculate the amount of each element raw material by mass percentage. All raw materials must be clean and free of oil.

[0009] (3) Smelting: Place the raw materials other than Al and Ti in a magnesium oxide or aluminum oxide crucible, and evacuate to ≤1Pa for smelting and refining. The refining temperature is 1500℃~1650℃ and the refining time is 30min~60min. Lower the refining temperature to 1450℃~1500℃, add Al and Ti and continue refining for 5min~15min, with continuous stirring.

[0010] (4) Argon filling: Close the vacuum valve and fill the vacuum induction furnace with 99.999% ultrapure argon gas by volume to make the pressure inside the furnace reach 10000Pa~20000Pa;

[0011] (5) Adding lanthanum: At the end of the refining process, add the lanthanum-containing intermediate alloy prepared in step (1) into the furnace, raise the refining temperature to 1500℃~1600℃, and stir for 0.5min~5min;

[0012] (6) Pouring: Pouring is carried out at a temperature of 1460℃~1480℃.

[0013] As a preferred technical solution of the present invention, when the mass fraction of lanthanum in the target high-temperature alloy is a, the amount of lanthanum added is 110%×a~125%×a (mass fraction), and the amount of lanthanum added (mass fraction) in the lanthanum-containing master alloy is: the amount of lanthanum added / the mass fraction of lanthanum in the master alloy.

[0014] As a preferred technical solution of the present invention, in step (1), when preparing the lanthanum-containing master alloy, the metal raw materials other than lanthanum are one or more combinations of nickel, cobalt, and tungsten.

[0015] As a preferred technical solution of the present invention, the lanthanum-containing intermediate alloy prepared in step (1) is any one of nickel-lanthanum, cobalt-lanthanum, nickel-cobalt-lanthanum, and nickel-tungsten-lanthanum alloy.

[0016] As a preferred technical solution of the present invention, in step (1), after the lanthanum-containing intermediate alloy is cooled to form an alloy ingot, it is crushed into particles with a size of 12mm to 20mm.

[0017] As a preferred technical solution of the present invention, the lanthanum-containing intermediate alloy prepared in step (1) has a specific gravity ≥8g / cm³, and the mass fraction of lanthanum in the intermediate alloy is 10%~20%.

[0018] As a preferred technical solution of the present invention, when melting raw materials other than Al and Ti in step (3), the crucible used is a magnesium oxide crucible or an aluminum oxide crucible, and the inner wall of the crucible is cleaned and free of impurities.

[0019] As a preferred technical solution of the present invention, in the refining process after adding Al and Ti in step (3), the stirring rate is 50r / min~100r / min, and the stirring method is electromagnetic induction stirring.

[0020] As a preferred technical solution of the present invention, the stirring time after adding the lanthanum-containing intermediate alloy in step (5) is 1 min to 3 min, and the casting is completed within 3 min after the stirring is finished.

[0021] As a preferred embodiment of the present invention, the high-temperature alloy is a nickel-based high-temperature alloy, a cobalt-based high-temperature alloy, or an iron-based high-temperature alloy, and the mass fraction of lanthanum in the target high-temperature alloy is 0.01% to 0.1%.

[0022] Compared with the prior art, the beneficial effects of the present invention are: in the smelting process, a lanthanum-containing master alloy is used to replace elemental lanthanum. By limiting the elemental composition of the master alloy, the physical properties of the master alloy, such as melting point and density, are closer to those of high-temperature alloys. This can effectively overcome the metallurgical problems of easy oxidation, easy volatilization, and easy burn-off of elemental lanthanum in high-temperature alloy smelting, and also solve the problem of uneven composition distribution caused by elemental lanthanum floating on the surface of the high-temperature alloy melt.

[0023] The timing of adding the lanthanum-containing master alloy is at the end of the refining process. Immediate casting after refining and stirring can effectively shorten the time for lanthanum oxidation and burn-off. Furthermore, by controlling the furnace atmosphere and pressure, refining temperature, and casting temperature, and by using magnesium oxide or aluminum oxide crucibles, the oxidation and burn-off of lanthanum can be reduced, effectively improving the lanthanum yield.

[0024] The process of this invention significantly reduces the loss of lanthanum during casting, lowers the cost of raw materials, and maintains a stable lanthanum yield of 75%-90% in the high-temperature alloy. Simultaneously, the lanthanum content in the ingot is uniform, effectively improving the product quality of lanthanum-containing high-temperature alloys and resulting in significant economic benefits. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] This invention provides a technical solution:

[0027] A preparation process for improving the lanthanum yield and uniformity in high-temperature alloys includes the following steps:

[0028] (1) Preparation of lanthanum-containing master alloy: Select master alloying elements according to the high-temperature alloy composition. Place the metal raw materials other than lanthanum in a vacuum induction furnace, evacuate to ≤1 Pa for melting and refining. The refining temperature is 1600℃~1700℃, and the refining time is 10min~30min. Lower the refining temperature to 1500℃~1550℃, and fill the furnace with ultrapure argon gas with a volume fraction of 99.999% and nitrogen pressure of 10000Pa~20000Pa. Add elemental lanthanum to the melt, raise the refining temperature to 1600℃~1700℃ and stir continuously, and pour immediately. After cooling to form an alloy ingot, crush it.

[0029] (2) High-temperature alloy ingredients: According to the requirements of high-temperature alloy composition, calculate the amount of each element raw material according to the mass percentage. All raw materials must be clean and free of oil.

[0030] (3) Melting: Place the raw materials other than Al and Ti in a magnesium oxide or aluminum oxide crucible, and evacuate to ≤1 Pa for melting and refining. The refining temperature is 1500℃~1650℃ and the refining time is 30min~60min. Lower the refining temperature to 1450℃~1500℃, add Al and Ti and continue refining for 5min~15min, with continuous stirring.

[0031] (4) Argon filling: Close the vacuum valve and fill the vacuum induction furnace with 99.999% ultrapure argon gas by volume to make the pressure inside the furnace reach 10000Pa~20000Pa.

[0032] (5) Adding lanthanum: Lanthanum is added at the end of the refining process. Add the lanthanum-containing master alloy into the furnace, raise the refining temperature to 1500℃~1600℃, and stir for 0.5min~5min.

[0033] (6) Pouring: The pouring temperature is 1460℃~1480℃.

[0034] If the mass fraction of lanthanum in the target high-temperature alloy is a, then the amount of lanthanum added is 110%×a~125%×a (mass fraction). The amount of lanthanum added (mass fraction) in the lanthanum-containing master alloy is: the amount of lanthanum added / the mass fraction of lanthanum in the master alloy.

[0035] The lanthanum-containing master alloy prepared in step (1) is any one of nickel-lanthanum, cobalt-lanthanum, nickel-cobalt-lanthanum, or nickel-tungsten-lanthanum alloy. The master alloy has a size of 12 mm to 20 mm, a specific gravity of ≥8 g / cm3, and a lanthanum mass fraction of 10% to 20%.

[0036] Example 1

[0037] Based on the target high-temperature alloy composition, a nickel-lanthanum alloy was selected as the intermediate alloy.

[0038] Step 1: Place metallic nickel in a vacuum induction furnace and evacuate to 1 Pa for melting and refining. The refining temperature is 1650℃, and the refining time is 20 minutes. Lower the refining temperature to 1550℃ and introduce 99.999% pure argon gas into the furnace, with a nitrogen pressure of 20000 Pa. Add elemental lanthanum to the melt, raise the refining temperature to 1650℃, and continue stirring. Pour immediately. After cooling to form an alloy ingot, break it to 12mm~20mm. The measured mass fraction of lanthanum in the intermediate alloy is 14.15%.

[0039] Step 2: The target high-temperature alloy contains 0.02% lanthanum by mass, 0.025% lanthanum by mass, and the intermediate alloy contains 0.18% lanthanum by mass.

[0040] All raw materials except the master alloy, Al, and Ti were placed in an alumina crucible and smelted and refined under vacuum at 1 Pa for 60 minutes at a refining temperature of 1580°C. The refining temperature was then lowered to 1500°C, and Al and Ti were added, with refining continuing for 5 minutes while stirring continuously. The vacuum valve was closed, and 99.999% pure argon gas was introduced into the vacuum induction furnace until the furnace pressure reached 20000 Pa. The nickel-lanthanum master alloy was added to the furnace, the refining temperature was raised to 1580°C, and stirring was carried out for 1 minute. The mixture was then immediately poured at a pouring temperature of 1460°C.

[0041] Samples were taken from three different locations along the axial direction of the ingot from top to bottom. The mass fractions of lanthanum were 0.023%, 0.023%, and 0.021%, respectively. The element distribution was uniform, and the average yield was 89.3%.

[0042] Example 2

[0043] Based on the target high-temperature alloy composition, a cobalt-lanthanum alloy was selected as the intermediate alloy.

[0044] Step 1: Place metallic nickel in a vacuum induction furnace and evacuate to 1 Pa for melting and refining. The refining temperature is 1650℃, and the refining time is 20 minutes. Lower the refining temperature to 1530℃, and introduce ultra-pure argon gas with a volume fraction of 99.999% into the furnace. The nitrogen pressure is 20000 Pa. Add elemental lanthanum to the melt, raise the refining temperature to 1650℃, and stir continuously. Pour immediately. After cooling to form an alloy ingot, break it to 12mm~20mm. The mass fraction of lanthanum in the intermediate alloy is 9.98%.

[0045] Step 2: The target high-temperature alloy contains 0.05% lanthanum by mass, the amount of lanthanum added is 0.0625%, and the amount of lanthanum added to the master alloy is 0.63% by mass.

[0046] All raw materials except the master alloy, Al, and Ti were placed in an alumina crucible and smelted and refined under vacuum at 1 Pa for 60 minutes at a refining temperature of 1600°C. The refining temperature was then lowered to 1500°C, and Al and Ti were added, with refining continuing for 15 minutes while stirring continuously. The vacuum valve was then closed, and 99.999% pure argon gas was introduced into the vacuum induction furnace until the furnace pressure reached 20000 Pa. The cobalt-lanthanum master alloy was added to the furnace, the refining temperature was raised to 1600°C, and the furnace was stirred for 1 minute. The furnace was then immediately poured at a pouring temperature of 1480°C.

[0047] Samples were taken from three different locations along the axial direction of the ingot from top to bottom. The mass fractions of lanthanum were 0.053%, 0.052%, and 0.050%, respectively. The element distribution was uniform, and the average yield was 82.7%.

[0048] Example 3

[0049] Based on the target high-temperature alloy composition, a nickel-lanthanum alloy was selected as the intermediate alloy.

[0050] Step 1: Place metallic nickel in a vacuum induction furnace and evacuate to 1 Pa for melting and refining. The refining temperature is 1650℃, and the refining time is 20 minutes. Lower the refining temperature to 1550℃ and introduce 99.999% pure argon gas into the furnace, with a nitrogen pressure of 20000 Pa. Add elemental lanthanum to the melt, raise the refining temperature to 1650℃, and continue stirring. Immediately pour the mixture. After cooling to form an alloy ingot, break it to 12mm~20mm. The mass fraction of lanthanum in the master alloy is 20.03%.

[0051] Step 2: The target alloy contains 0.02% lanthanum by mass, the amount of lanthanum added is 0.025%, and the master alloy contains 0.125% lanthanum by mass.

[0052] All raw materials except the master alloy, Al, and Ti were placed in an alumina crucible and smelted and refined under vacuum at 1 Pa for 60 minutes at a refining temperature of 1580°C. The refining temperature was then lowered to 1500°C, and Al and Ti were added, with refining continuing for 5 minutes while stirring continuously. The vacuum valve was closed, and 99.999% pure argon gas was introduced into the vacuum induction furnace until the furnace pressure reached 20000 Pa. The nickel-lanthanum master alloy was added to the furnace, the refining temperature was raised to 1580°C, and stirring was carried out for 1 minute. The mixture was then immediately poured at a pouring temperature of 1460°C.

[0053] Samples were taken from three different locations along the axial direction of the ingot from top to bottom. The mass fractions of lanthanum were 0.021%, 0.021%, and 0.022%, respectively. The element distribution was uniform, and the average yield was 85.3%.

[0054] Example 4

[0055] Based on the target high-temperature alloy composition, a nickel-tungsten-lanthanum alloy was selected as the intermediate alloy.

[0056] Step 1: Place metallic nickel and metallic tungsten in a vacuum induction furnace, evacuate to 1 Pa, and melt and refine them at 1700℃ for 30 minutes. Lower the refining temperature to 1550℃, and introduce 99.999% pure argon gas into the furnace, with a nitrogen pressure of 20000 Pa. Add elemental lanthanum to the melt, raise the refining temperature to 1700℃, and continue stirring before immediately pouring. After cooling to form an alloy ingot, break it to 12mm-20mm. The measured mass fraction of lanthanum in the intermediate alloy is 10.96%.

[0057] Step 2: The target alloy contains 0.02% lanthanum by mass, the amount of lanthanum added is 0.025%, and the master alloy contains 0.228% lanthanum by mass.

[0058] All raw materials except the master alloy, Al, and Ti were placed in an alumina crucible and smelted and refined under vacuum at 1 Pa for 60 minutes at a refining temperature of 1600°C. The refining temperature was then lowered to 1500°C, and Al and Ti were added, with refining continuing for 5 minutes while stirring continuously. The vacuum valve was then closed, and 99.999% pure argon gas was introduced into the vacuum induction furnace until the furnace pressure reached 20000 Pa. The nickel-tungsten-lanthanum master alloy was added to the furnace, the refining temperature was raised to 1600°C, and stirring was carried out for 1 minute. The mixture was then immediately poured at a pouring temperature of 1480°C.

[0059] Samples were taken from three different locations along the axial direction of the ingot from top to bottom. The mass fractions of lanthanum were 0.020%, 0.023%, and 0.022%, respectively. The element distribution was uniform, and the average yield was 86.7%.

[0060] Example 5

[0061] Based on the target high-temperature alloy composition, a nickel-tungsten-lanthanum alloy was selected as the intermediate alloy.

[0062] Step 1: Place metallic nickel and metallic tungsten in a vacuum induction furnace, evacuate to 1 Pa, and melt and refine them at 1700℃ for 30 minutes. Lower the refining temperature to 1550℃, and introduce 99.999% pure argon gas into the furnace, with a nitrogen pressure of 20000 Pa. Add elemental lanthanum to the melt, raise the refining temperature to 1700℃, and continue stirring before immediately pouring. After cooling to form an alloy ingot, break it to 12mm-20mm. The measured mass fraction of lanthanum in the intermediate alloy is 20.15%.

[0063] Step 2: The mass fraction of lanthanum in the target alloy is 0.02%, the amount of lanthanum added is 0.022%, and the mass fraction of lanthanum added to the intermediate alloy is 0.109%.

[0064] All raw materials except the master alloy, Al, and Ti were placed in an alumina crucible and smelted and refined under vacuum at 1 Pa for 60 minutes at a refining temperature of 1600°C. The refining temperature was then lowered to 1500°C, and Al and Ti were added, with refining continuing for 5 minutes while stirring continuously. The vacuum valve was then closed, and 99.999% pure argon gas was introduced into the vacuum induction furnace until the furnace pressure reached 20000 Pa. The nickel-tungsten-lanthanum master alloy was added to the furnace, the refining temperature was raised to 1600°C, and stirring was carried out for 1 minute. The mixture was then immediately poured at a pouring temperature of 1480°C.

[0065] Samples were taken from three different locations along the axial direction of the ingot from top to bottom. The mass fractions of lanthanum were 0.020%, 0.018%, and 0.018%, respectively. The element distribution was uniform, and the average yield was 84.8%.

[0066] Example 6

[0067] Based on the target high-temperature alloy composition, a nickel-cobalt-lanthanum alloy was selected as the intermediate alloy.

[0068] Step 1: Place metallic nickel and metallic cobalt in a vacuum induction furnace, evacuate to 1 Pa, and melt and refine them at 1650℃ for 20 minutes. Lower the refining temperature to 1550℃, and introduce 99.999% pure argon gas into the furnace, with a nitrogen pressure of 20000 Pa. Add elemental lanthanum to the melt, raise the refining temperature to 1650℃, and continue stirring before immediately pouring. After cooling to form an alloy ingot, break it to 12mm-20mm. The measured mass fraction of lanthanum in the intermediate alloy is 15.07%.

[0069] Step 2: The target alloy contains 0.05% lanthanum by mass, the amount of lanthanum added is 0.0625%, and the amount of lanthanum added to the master alloy is 0.41% by mass.

[0070] All raw materials except the master alloy, Al, and Ti were placed in an alumina crucible and smelted and refined under vacuum at 1 Pa for 60 minutes at a refining temperature of 1600°C. The refining temperature was then lowered to 1500°C, and Al and Ti were added, with refining continuing for 15 minutes while stirring continuously. The vacuum valve was then closed, and 99.999% pure argon gas was introduced into the vacuum induction furnace until the furnace pressure reached 20000 Pa. The cobalt-lanthanum master alloy was added to the furnace, the refining temperature was raised to 1600°C, and stirring was continued for 1 minute. The furnace was then immediately poured at a pouring temperature of 1480°C.

[0071] Samples were taken from three different locations along the axial direction of the ingot from top to bottom. The mass fractions of lanthanum were 0.058%, 0.053%, and 0.050%, respectively. The element distribution was uniform, and the average yield was 85.9%.

[0072] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A preparation process for improving the yield and uniformity of lanthanum in high-temperature alloys, characterized in that, Includes the following steps: (1) Preparation of lanthanum-containing master alloy: Select master alloying elements according to the high-temperature alloy composition, place the metal raw materials other than lanthanum in a vacuum induction furnace, evacuate to ≤1Pa for melting and refining, the refining temperature is 1600℃~1700℃, the refining time is 10min~30min; lower the refining temperature to 1500℃~1550℃, fill the furnace with ultrapure argon gas with a volume fraction of 99.999% to make the furnace pressure reach 10000Pa~20000Pa; add elemental lanthanum to the melt, raise the refining temperature to 1600℃~1700℃ and stir continuously, and pour immediately; after cooling to form an alloy ingot, crush it. (2) High-temperature alloy ingredients: According to the requirements of high-temperature alloy composition, calculate the amount of each element raw material by mass percentage. All raw materials must be clean and free of oil. (3) Smelting: Place the raw materials other than Al and Ti in a magnesium oxide or aluminum oxide crucible, and evacuate to ≤1Pa for smelting and refining. The refining temperature is 1500℃~1650℃ and the refining time is 30min~60min. Lower the refining temperature to 1450℃~1500℃, add Al and Ti and continue refining for 5min~15min, with continuous stirring. (4) Argon filling: Close the vacuum valve and fill the vacuum induction furnace with 99.999% ultrapure argon gas by volume to make the pressure inside the furnace reach 10000Pa~20000Pa; (5) Adding lanthanum: At the end of the refining process, add the lanthanum-containing intermediate alloy prepared in step (1) into the furnace, raise the refining temperature to 1500℃~1600℃, and stir for 0.5min~5min; (6) Pouring: Pouring is carried out at a temperature of 1460℃~1480℃.

2. The preparation process for improving the lanthanum yield and uniformity in high-temperature alloys according to claim 1, characterized in that: When the mass fraction of lanthanum in the target high-temperature alloy is a, the amount of lanthanum added is 110%×a~125%×a. The amount of lanthanum added to the lanthanum-containing master alloy is: the amount of lanthanum added / the mass fraction of lanthanum in the master alloy.

3. The preparation process for improving the lanthanum yield and uniformity in high-temperature alloys according to claim 1, characterized in that: In step (1), when preparing the lanthanum-containing master alloy, the metal raw materials other than lanthanum are one or more combinations of nickel, cobalt, and tungsten.

4. A preparation process for improving the lanthanum yield and uniformity in high-temperature alloys according to claim 1 or 3, characterized in that: The lanthanum-containing master alloy prepared in step (1) is any one of nickel-lanthanum, cobalt-lanthanum, nickel-cobalt-lanthanum, or nickel-tungsten-lanthanum alloy.

5. The preparation process for improving the lanthanum yield and uniformity in high-temperature alloys according to claim 1, characterized in that: In step (1), the lanthanum-containing master alloy is cooled to form an alloy ingot, which is then crushed into particles with a size of 12mm to 20mm.

6. A preparation process for improving the lanthanum yield and uniformity in high-temperature alloys according to claim 1 or 5, characterized in that: The lanthanum-containing master alloy prepared in step (1) has a specific gravity ≥8 g / cm³, and the mass fraction of lanthanum in the master alloy is 10%~20%.

7. The preparation process for improving the lanthanum yield and uniformity in high-temperature alloys according to claim 1, characterized in that: In step (3), when smelting raw materials other than Al and Ti, the crucible used is a magnesium oxide crucible or an aluminum oxide crucible, and the inner wall of the crucible is cleaned and free of impurities.

8. The preparation process for improving the lanthanum yield and uniformity in high-temperature alloys according to claim 1, characterized in that: In step (3), during the refining process after adding Al and Ti, the stirring rate is 50 r / min to 100 r / min, and the stirring method is electromagnetic induction stirring.

9. The preparation process for improving the lanthanum yield and uniformity in high-temperature alloys according to claim 1, characterized in that: In step (5), the stirring time after adding the lanthanum-containing intermediate alloy is 1 min to 3 min, and the casting is completed within 3 min after the stirring is finished.

10. The preparation process for improving the lanthanum yield and uniformity in high-temperature alloys according to claim 1, characterized in that: The high-temperature alloy is a nickel-based high-temperature alloy, a cobalt-based high-temperature alloy, or an iron-based high-temperature alloy, and the mass fraction of lanthanum in the target high-temperature alloy is 0.01% to 0.1%.