High-entropy rare earth iron alloy and preparation method thereof

Abstract

The application relates to the field of material preparation, and particularly discloses a preparation method of a high-entropy rare earth iron alloy, which comprises the following steps: (1) adding La-Ce-Fe, Sm-Fe, Y-Fe alloys and Fe into a crucible, and melting and compounding the La-Ce-Fe, Sm-Fe, Y-Fe alloys and Fe into a liquid-state Ce-Y-La-Sm-Fe master alloy; (2) blowing dehydrated CaF2-MgF2-BaF2 powder into the master alloy in step (1) in a pulse mode in an argon carrier, and then constant-temperature heating under the protection of argon; inserting a vibration rod into the melted alloy, loading the vibration rod into ultrasonic oscillation, and finally blowing N2 / Ar mixed gas into the alloy and standing still; and (3) casting and cooling the Ce-Y-La-Sm-Fe alloy obtained in step (2), and the purity of the alloy is not lower than 99.65%. The Ce-Y-La-Sm-Fe alloy obtained by the method has high purity, no toxic and harmful gas is generated in the production process, the alloy composition is uniform, and the production cost and energy consumption are low.

Description

Technical Field

[0001] This invention relates to the field of high-entropy rare earth iron alloy preparation technology, specifically disclosing a Ce-Y-La-Sm-Fe alloy and its preparation method. Background Technology

[0002] High-entropy rare-earth ferroalloys are a novel material combining the properties of high-entropy alloys (HEAs) and rare-earth elements. They possess excellent mechanical properties, corrosion resistance, high-temperature resistance, and functionality, showing broad application prospects in various fields. Currently, vacuum arc melting is the main method for preparing high-entropy rare-earth alloys. However, the main problems include difficulty in controlling the furnace temperature and the occurrence of various physicochemical reactions within the furnace, including reduction, oxidation, and pyrolysis reactions. These reactions generate large amounts of gas and slag, easily polluting the environment. Furthermore, the dynamic characteristics of these reactions are difficult to predict and control, further affecting the quality and production efficiency of steel. Summary of the Invention

[0003] This invention addresses the problem of impurity control during the preparation of rare earth high-entropy ferroalloys by proposing a new technology for the simultaneous removal of impurities and gases to prepare high-quality rare earth multi-element alloys.

[0004] The technical solution of the present invention is as follows:

[0005] A method for preparing a high-entropy rare-earth iron alloy includes the following steps:

[0006] (1) Pre-melting of master alloy

[0007] La-Ce-Fe, Sm-Fe, and Y-Fe alloys with a purity of not less than 99.25% and Fe with a purity of not less than 99.95% are added to a tungsten crucible and melted according to the composition ratio to form a liquid Ce-Y-La-Sm-Fe master alloy.

[0008] (2) Pulse synchronous degassing and impurity removal

[0009] In an argon carrier with a purity of not less than 99.99%, dehydrated CaF2-MgF2-BaF2 powder is blown into the liquid Ce-Y-La-Sm-Fe master alloy of step (1) in a pulse manner, and then kept at a constant temperature for 30-50 minutes under argon protection.

[0010] Insert a Y-Ni-Fe vibratory rod into the molten alloy and load the vibratory rod into ultrasonic vibration for 12-20 minutes, and match it with electromagnetic stirring at 8-12 KJ / (kg·s).

[0011] Finally, N2 / Ar mixed gas is blown into the alloy and allowed to stand for 15-25 minutes;

[0012] (3) Collection of alloy products

[0013] The Ce-Y-La-Sm-Fe alloy obtained in step (2) is cast into ingots in an argon-protected casting system and cooled to room temperature. It is then stored in a vacuum-sealed storage tank with an alloy purity of not less than 99.65%.

[0014] Preferably, in step (1), Ce, Y, and La each account for 20% by mass in the Ce-Y-La-Sm-Fe master alloy, Sm accounts for 10%, and Fe accounts for 30%.

[0015] Preferably, the melting and mixing process in step (1) is carried out under nitrogen protection with a purity of not less than 99.99%, the melting temperature is 950-1050℃, and the constant temperature time is 50-90min.

[0016] Preferably, the pulse in step (2) is 5-10Hz. When the blowing pulse is below 5Hz, large slag inclusions are likely to appear in the alloy; when the blowing pulse is above 10Hz, splashing and fine slag inclusions are likely to appear in the alloy; when the blowing pulse is 7-8Hz, the melt absorption is stable, the slag-gold separation is smooth, and the alloy purity is optimal.

[0017] Preferably, the molar ratio of CaF2-MgF2-BaF2 powder in step (2) is 6:5:2, and it needs to be dehydrated at 280°C for 15 hours under argon protection.

[0018] Preferably, the frequency of the ultrasound in step (2) is 25-35 Hz, and the sound intensity is 2.2-3.9 W / cm². 2 .

[0019] Preferably, the molar ratio of the N2 / Ar mixed gas in step (2) is 70:30.

[0020] The present invention also provides a Ce-Y-La-Sm-Fe alloy prepared by any of the above methods.

[0021] The Ce-Y-La-Sm-Fe alloy product obtained by this invention has impurities of no more than 0.5%, and no toxic or harmful gases are generated during the production process, which meets environmental protection requirements; moreover, the alloy composition is uniform, and the production cost and energy consumption are low. Detailed Implementation

[0022] The present invention will be described in detail with reference to the following embodiments.

[0023] In all examples, the CaF2-MgF2-BaF2 powder with a molar ratio of 6:5:2 was dried at 280°C for 15 hours.

[0024] Example 1:

[0025] A Ce-Y-La-Sm-Fe master alloy mixture was prepared by weighing La-Ce-Fe, Sm-Fe, and Y-Fe alloys with a purity of not less than 99.25% and pure Fe (purity not less than 99.95%) according to the composition ratio (Ce, Y, and La each account for 20% by mass, Sm accounts for 10%, and Fe accounts for 30%) and adding it to a tungsten crucible. Under nitrogen protection (purity not less than 99.99%), the melting temperature was 950℃, and the holding time was 50 min. Dehydrated CaF2-MgF2-BaF2 powder was then pulsed (5Hz) into the molten alloy in an argon carrier with a purity of not less than 99.99%, and the temperature was held for 30 min. Ultrasonic waves (frequency 25Hz, sound intensity 2.2 W / cm²) were then applied using Y-Ni-Fe as the vibration carrier. 2 The mixture was agitated for 12 minutes with an electromagnetic stirring power of 8 kJ / (kg·s). Finally, a N2 / Ar mixed gas with a molar ratio of 70:30 was blown into the alloy and allowed to stand for 15 minutes. The resulting Ce-Y-La-Sm-Fe alloy was cast into ingots in an argon-protected casting system and cooled to room temperature. It was then stored in a vacuum-sealed storage tank. The purity of the Ce-Y-La-Sm-Fe alloy was not less than 99.65%.

[0026] Example 2:

[0027] A Ce-Y-La-Sm-Fe master alloy mixture was prepared by weighing La-Ce-Fe, Sm-Fe, and Y-Fe alloys with a purity of not less than 99.25% and pure Fe (purity not less than 99.95%) according to the composition ratio (Ce, Y, and La each account for 20% by mass, Sm accounts for 10%, and Fe accounts for 30%) and adding it to a tungsten crucible. Under nitrogen protection (purity not less than 99.99%), the melting temperature was 1050℃, and the holding time was 90 min. Dehydrated CaF2-MgF2-BaF2 powder was then pulsed (10 Hz) into the molten alloy in an argon carrier with a purity of not less than 99.99% and held at the temperature for 50 min. Finally, ultrasound (frequency 35 Hz, sound intensity 3.9 W / cm²) was applied using Y-Ni-Fe as the vibration carrier. 2 The mixture was agitated for 20 minutes with an electromagnetic stirring power of 12 kJ / (kg·s). Finally, a N2 / Ar mixed gas with a molar ratio of 70:30 was blown into the alloy and allowed to stand for 25 minutes. The resulting Ce-Y-La-Sm-Fe alloy was cast into ingots in an argon-protected casting system and cooled to room temperature. It was then stored in a vacuum-sealed storage tank. The purity of the Ce-Y-La-Sm-Fe alloy was not less than 99.70%.

[0028] Example 3:

[0029] A Ce-Y-La-Sm-Fe master alloy mixture, consisting of La-Ce-Fe, Sm-Fe, and Y-Fe alloys with a purity of not less than 99.25%, and pure Fe (purity not less than 99.95%), was prepared by metering and mixing according to the following proportions (Ce, Y, and La each accounted for 20% by mass, Sm accounted for 10%, and Fe accounted for 30%). This mixture was then added to a tungsten crucible and melted at 1000℃ for 70 min under nitrogen protection (purity not less than 99.99%). Dehydrated CaF2-MgF2-BaF2 powder was then pulsed (7 Hz) into the molten alloy in an argon gas carrier with a purity of not less than 99.99%, and held at this temperature for 40 min. Finally, ultrasound (frequency 30 Hz, sound intensity 3.0 W / cm²) was applied using Y-Ni-Fe as the vibration carrier. 2 The mixture was agitated for 16 minutes with an electromagnetic stirring power of 10 kJ / (kg·s). Finally, a N2 / Ar mixed gas with a molar ratio of 70:30 was blown into the alloy and allowed to stand for 20 minutes. The resulting Ce-Y-La-Sm-Fe alloy was cast into ingots in an argon-protected casting system and cooled to room temperature. It was then stored in a vacuum-sealed storage tank. The purity of the Ce-Y-La-Sm-Fe alloy was not less than 99.75%.

[0030] Example 4:

[0031] A Ce-Y-La-Sm-Fe master alloy mixture was prepared by weighing La-Ce-Fe, Sm-Fe, and Y-Fe alloys with a purity of not less than 99.25% and pure Fe (purity not less than 99.95%) according to the composition ratio (Ce, Y, and La each account for 20% by mass, Sm accounts for 10%, and Fe accounts for 30%) and adding it to a tungsten crucible. Under nitrogen protection (purity not less than 99.99%), the melting temperature was 975℃, and the holding time was 60 min. Dehydrated CaF2-MgF2-BaF2 powder was then pulsed (6Hz) into the molten alloy in an argon carrier with a purity of not less than 99.99%, and the temperature was held for 35 min. Ultrasonic waves (frequency 28Hz, sound intensity 2.6 W / cm²) were then applied using Y-Ni-Fe as the vibration carrier. 2 The mixture was agitated for 14 minutes with an electromagnetic stirring power of 9 kJ / (kg·s). Finally, a N2 / Ar mixed gas with a molar ratio of 70:30 was blown into the alloy and allowed to stand for 17 minutes. The resulting Ce-Y-La-Sm-Fe alloy was cast into ingots in an argon-protected casting system and cooled to room temperature. It was then stored in a vacuum-sealed storage tank. The purity of the Ce-Y-La-Sm-Fe alloy was not less than 99.70%.

[0032] Example 5:

[0033] A Ce-Y-La-Sm-Fe master alloy mixture was prepared by weighing La-Ce-Fe, Sm-Fe, and Y-Fe alloys with a purity of not less than 99.25% and pure Fe (purity not less than 99.95%) according to the composition ratio (Ce, Y, and La each account for 20% by mass, Sm accounts for 10%, and Fe accounts for 30%) and adding it to a tungsten crucible. Under nitrogen protection (purity not less than 99.99%), the melting temperature was 1025℃, and the holding time was 80 min. Dehydrated CaF2-MgF2-BaF2 powder was then pulsed (9Hz) into the molten alloy in an argon carrier with a purity of not less than 99.99%, and the temperature was held for 45 min. Ultrasonic waves (frequency 32Hz, sound intensity 3.5 W / cm²) were then applied using Y-Ni-Fe as the vibration carrier. 2 The mixture was agitated for 18 minutes with an electromagnetic stirring power of 11 kJ / (kg·s). Finally, a N2 / Ar mixed gas with a molar ratio of 70:30 was blown into the alloy and allowed to stand for 22 minutes. The resulting Ce-Y-La-Sm-Fe alloy was cast into ingots in an argon-protected casting system and cooled to room temperature. It was then stored in a vacuum-sealed storage tank. The purity of the Ce-Y-La-Sm-Fe alloy was not less than 99.65%.

[0034] Example 6:

[0035] A Ce-Y-La-Sm-Fe master alloy mixture was prepared by weighing La-Ce-Fe, Sm-Fe, and Y-Fe alloys with a purity of not less than 99.25% and pure Fe (purity not less than 99.95%) according to the composition ratio (Ce, Y, and La each account for 20% by mass, Sm accounts for 10%, and Fe accounts for 30%) and adding it to a tungsten crucible. Under nitrogen protection (purity not less than 99.99%), the melting temperature was 975℃, and the holding time was 85 min. Dehydrated CaF2-MgF2-BaF2 powder was then pulsed (9Hz) into the molten alloy in an argon carrier with a purity of not less than 99.99%, and held at this temperature for 35 min. Ultrasonic waves (frequency 30Hz, sound intensity 3.5 W / cm²) were then applied using Y-Ni-Fe as the vibration carrier. 2 The mixture was agitated for 15 minutes with an electromagnetic stirring power of 10 kJ / (kg·s). Finally, a N2 / Ar mixed gas with a molar ratio of 70:30 was blown into the alloy and allowed to stand for 20 minutes. The resulting Ce-Y-La-Sm-Fe alloy was cast into ingots in an argon-protected casting system and cooled to room temperature. It was then stored in a vacuum-sealed storage tank. The purity of the Ce-Y-La-Sm-Fe alloy was not less than 99.70%.

Claims

1. A method for preparing a high-entropy rare-earth iron alloy, characterized in that, Includes the following steps: (1) Pre-melting of master alloy La-Ce-Fe, Sm-Fe, and Y-Fe alloys with a purity of not less than 99.25% and Fe with a purity of not less than 99.95% are added to a tungsten crucible and melted according to the composition ratio to form a liquid Ce-Y-La-Sm-Fe master alloy. In step (1), Ce, Y, and La each account for 20% of the mass of the Ce-Y-La-Sm-Fe master alloy, Sm accounts for 10%, and Fe accounts for 30%. (2) Pulse synchronous degassing and impurity removal In an argon carrier with a purity of not less than 99.99%, dehydrated CaF2-MgF2-BaF2 powder is blown into the liquid Ce-Y-La-Sm-Fe master alloy of step (1) in a pulse manner, and then kept at a constant temperature for 30-50 minutes under argon protection. Insert a Y-Ni-Fe vibratory rod into the molten alloy and load the vibratory rod into ultrasonic vibration for 12-20 minutes, and match it with electromagnetic stirring at 8-12 KJ / (kg·s). Finally, N2 / Ar mixed gas is blown into the alloy and allowed to stand for 15-25 minutes; (3) Collection of alloy products The Ce-Y-La-Sm-Fe alloy obtained in step (2) is cast into ingots in an argon-protected casting system and cooled to room temperature. It is then stored in a vacuum-sealed storage tank with an alloy purity of not less than 99.65%.

2. The preparation method according to claim 1, characterized in that, In step (1), the melting and preparation process is carried out under nitrogen protection with a purity of not less than 99.99%, the melting temperature is 950-1050℃, and the holding time is 50-90min.

3. The preparation method according to claim 1, characterized in that, The pulse in step (2) is 5-10Hz.

4. The preparation method according to claim 1, characterized in that, In step (2), the molar ratio of CaF2-MgF2-BaF2 powder is 6:5:2, and it needs to be dehydrated at 280℃ for 15 hours under argon protection.

5. The preparation method according to claim 1, characterized in that, In step (2), the frequency of the ultrasound is 25-35 Hz, and the sound intensity is 2.2-3.9 W / cm². 2 .

6. The preparation method according to claim 1, characterized in that, In step (2), the molar ratio of the N2 / Ar mixed gas is 70:

30.

7. A Ce-Y-La-Sm-Fe alloy prepared by any one of claims 1-6.