CN114657404A - High-density ultrafine-grained molybdenum-lanthanum alloy and preparation method thereof - Google Patents
High-density ultrafine-grained molybdenum-lanthanum alloy and preparation method thereof Download PDFInfo
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Abstract
The invention provides a high-density ultrafine-grained molybdenum lanthanum alloy and a preparation method thereof. According to the preparation method of the high-density ultrafine-grained molybdenum-lanthanum alloy, the thermal activation energy of the molybdenum-lanthanum alloy can be effectively reduced through the non-continuous heating sintering treatment, so that the rapid growth of crystal grains is inhibited, and the prepared molybdenum-lanthanum alloy is high in density and small in size of the crystal grains. The high-density ultrafine-grained molybdenum-lanthanum alloy has high density, very fine crystal grains, excellent performance and wide popularization and application prospects.
Description
Technical Field
The invention belongs to the technical field of metallurgy, relates to molybdenum-lanthanum alloy, and particularly relates to high-density ultrafine-grained molybdenum-lanthanum alloy and a preparation method thereof.
Background
The molybdenum-lanthanum alloy is a high-temperature refractory metal material with excellent comprehensive performance, has excellent performances such as high melting point, high heat conductivity coefficient, better corrosion resistance, wear resistance and the like, is widely applied to various fields such as national defense industry, aerospace, electronic information, energy, chemical industry, metallurgy, nuclear industry and the like, has irreplaceable functions and application requirements, and occupies an important position in rapid development of national economy and science and technology, so that the performance requirements on the molybdenum-lanthanum alloy material are continuously improved.
When the high-density molybdenum-lanthanum alloy is prepared, because the molybdenum-lanthanum alloy powder is very sensitive to the temperature change, crystal grains can grow rapidly when the molybdenum-lanthanum alloy powder meets high temperature in the sintering process, the molybdenum-lanthanum alloy prepared by the traditional sintering process has low density, and the crystal grains have larger size (usually 30-500 microns), so that the molybdenum-lanthanum alloy has poor properties of strength, hardness, corrosion resistance and the like.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a high-density ultrafine-grain molybdenum-lanthanum alloy and a preparation method thereof, and solve the technical problem of poor performance of the molybdenum-lanthanum alloy in the prior art due to low density and large grain size of the molybdenum-lanthanum alloy.
In order to solve the technical problems, the invention adopts the following technical scheme:
a preparation method of high-density ultrafine-grained molybdenum lanthanum alloy is characterized in that a molybdenum lanthanum alloy initial compact is treated by non-continuous heating and sintering to prepare the high-density ultrafine-grained molybdenum lanthanum alloy;
the non-continuous heating sintering treatment comprises the following specific processes:
firstly, heating for the first time, heating the temperature from room temperature to 800 ℃, and then carrying out heat preservation for the first time for 1 h; then, carrying out secondary temperature rise, and carrying out secondary heat preservation for 2 hours after the temperature rises from 800 ℃ to 1200 ℃; heating for the third time, namely heating the temperature from 1200 ℃ to 1300 ℃, and then preserving the heat for the third time for 4-10 hours; and after the third heat preservation is finished, cooling to room temperature, heating for the fourth time, and carrying out fourth heat preservation for 1-4 hours after the temperature is raised to 1600-1800 ℃ from the room temperature.
The invention also has the following technical characteristics:
preferably, the temperature rise time of the first temperature rise is 0.5-3 h; the temperature rise time of the second temperature rise is 1-5 h; the temperature rise time of the third temperature rise is 0.5-3 h; the temperature rise time of the fourth temperature rise is 1-3 h.
Specifically, the density of the high-density ultrafine-grained molybdenum lanthanum alloy is more than or equal to 99%, and the grain size is less than or equal to 3 μm.
The method specifically comprises the following steps:
step one, preparing lanthanum oxide doped molybdenum dioxide powder;
preparing a lanthanum oxide suspension, spraying the prepared lanthanum oxide suspension into molybdenum dioxide powder while uniformly stirring to prepare a mixture A, and heating and drying the prepared mixture A to prepare lanthanum oxide doped molybdenum dioxide powder;
step two, preparing molybdenum-lanthanum alloy powder;
putting the lanthanum oxide doped molybdenum dioxide powder prepared in the step one into a reduction boat, pushing the reduction boat into a reduction furnace, and carrying out reduction reaction in a hydrogen atmosphere to prepare molybdenum-lanthanum alloy powder;
step three, obtaining molybdenum-lanthanum alloy fine powder;
screening the molybdenum-lanthanum alloy powder prepared in the step two to obtain molybdenum-lanthanum alloy fine powder;
step four, preparing molybdenum-lanthanum alloy initial green compacts;
pressing the molybdenum-lanthanum alloy fine powder obtained in the step three to obtain a molybdenum-lanthanum alloy initial compact;
step five, preparing high-density ultrafine-grained molybdenum-lanthanum alloy;
and D, carrying out non-continuous heating sintering treatment on the molybdenum-lanthanum alloy initial compact prepared in the step four to prepare the high-density ultrafine-grained molybdenum-lanthanum alloy.
Specifically, in the first step, the lanthanum oxide doped molybdenum dioxide powder comprises the following raw materials in percentage by mass: 0.1 to 5 percent of lanthanum oxide, 95 to 99.9 percent of molybdenum dioxide, and the sum of the mass percentages of the raw materials is 100 percent.
Specifically, in the second step, the reduction furnace comprises a first temperature zone, a second temperature zone, a third temperature zone, a fourth temperature zone, a fifth temperature zone and a sixth temperature zone, wherein the reduction temperatures of the first temperature zone, the second temperature zone and the third temperature zone are all 50-500 ℃, and the reduction temperatures of the fourth temperature zone, the fifth temperature zone and the sixth temperature zone are all 600-1300 ℃.
Specifically, in the second step, the hydrogen flow rate of the hydrogen atmosphere is 1-8 m3·h-1(ii) a The reaction time of the reduction reaction is 2-18 h.
Specifically, in the third step, the mesh number of the screen mesh adopted for screening is 100-300 meshes.
Specifically, in the fourth step, the pressure adopted by pressing is 150-500 MPa, and the pressure maintaining time is 10-30 min.
The invention also discloses a high-density ultrafine-grained molybdenum lanthanum alloy which is prepared by the preparation method of the high-density ultrafine-grained molybdenum lanthanum alloy.
Compared with the prior art, the invention has the following technical effects:
compared with the traditional continuous heating method, the preparation method of the high-density ultrafine-grained molybdenum-lanthanum alloy disclosed by the invention has the advantages that the thermal activation energy of the molybdenum-lanthanum alloy can be effectively reduced by adopting non-continuous heating sintering treatment, so that the rapid growth of crystal grains is inhibited, and the prepared molybdenum-lanthanum alloy is high in density and small in size of the crystal grains.
According to the preparation method of the high-density ultrafine-grained molybdenum lanthanum alloy, the temperature is raised for the fourth time to 1600-1800 ℃, so that the high-density ultrafine-grained molybdenum lanthanum alloy with the density higher than 99% and the grain size smaller than 3 mu m can be obtained. When the sintering temperature of the traditional continuous heating method is 1500 ℃, the grain size reaches more than 200 mu m, and the density is lower; when the sintering temperature is higher than 1950 ℃, the compactness can reach 97 percent, but simultaneously, the crystal grains are coarser and even reach more than 400 mu m. Therefore, the preparation method of the high-density ultrafine-grained molybdenum lanthanum alloy can effectively improve the sintering efficiency at a relatively proper sintering temperature, further reduce the energy consumption of large-scale production and greatly save the production cost.
According to the preparation method of the high-density ultrafine-grained molybdenum lanthanum alloy, the lanthanum oxide doped molybdenum dioxide powder is prepared by adopting a solid-liquid spray doping technology, so that rare earth lanthanum oxide can be uniformly dispersed in molybdenum dioxide, and the component structure of the finally prepared high-density ultrafine-grained molybdenum lanthanum alloy is uniform.
(IV) the preparation method of the high-density ultrafine-grained molybdenum lanthanum alloy has simple process, can prepare the high-density ultrafine-grained molybdenum lanthanum alloy by sintering with the traditional intermediate frequency sintering furnace, has low price in the intermediate frequency sintering furnace compared with sintering equipment such as a discharge plasma sintering furnace and the like, and greatly saves the cost for large-scale production.
(V) the high-density ultrafine-grained molybdenum-lanthanum alloy has high density, very fine crystal grains, excellent performance and wide popularization and application prospects.
Drawings
Fig. 1 is an EBSD structure diagram of the high-density ultra-fine grain molybdenum-lanthanum alloy of example 1.
The present invention will be explained in further detail with reference to examples.
Detailed Description
The invention comprises the following steps:
the room temperature is 18-25 ℃.
The temperature rise time refers to the time taken to raise the temperature from the initial temperature to the desired temperature.
EBSD refers to Electron Back-scattering diffraction (Electron Back-scattering Patterns).
It is to be noted that all the materials and apparatuses in the present invention, unless otherwise specified, are those known in the art. For example:
the reduction boat and reduction furnace used to prepare the molybdenum lanthanum alloy powder are those known in the art.
The rare earth lanthanum oxide powder used to prepare the lanthanum oxide doped molybdenum dioxide powder has a purity of 99.99% and is a rare earth lanthanum oxide powder known in the prior art.
The purity of the molybdenum dioxide powder adopted for preparing the lanthanum oxide doped molybdenum dioxide powder is more than or equal to 99.96 percent, and the average grain diameter of the molybdenum dioxide powder is 0.5-50 mu m, which is the molybdenum dioxide powder known in the prior art.
The present invention is not limited to the following embodiments, and all equivalent changes based on the technical solutions of the present invention fall within the protection scope of the present invention.
Example 1:
this embodiment provides a method for preparing a high-density ultra-fine grain molybdenum-lanthanum alloy, which specifically includes the following steps:
step one, preparing lanthanum oxide doped molybdenum dioxide powder;
preparing a lanthanum oxide suspension: 1.188kg of rare earth lanthanum oxide powder is weighed and added into deionized water, and a magnetic stirrer is adopted to fully stir the mixture to be completely dispersed, so that lanthanum oxide suspension is prepared. And spraying the prepared lanthanum oxide suspension into 150kg of molybdenum dioxide powder by adopting high-pressure air, uniformly stirring while spraying to obtain a mixture A, and heating and drying the prepared mixture A in a vacuum state to obtain the lanthanum oxide doped molybdenum dioxide powder. The lanthanum oxide doped molybdenum dioxide powder comprises the following raw materials in percentage by mass: 0.8 percent of lanthanum oxide and 99.2 percent of molybdenum dioxide.
Step two, preparing molybdenum-lanthanum alloy powder;
putting the lanthanum oxide doped molybdenum dioxide powder prepared in the step one into a reduction boat, and pushing the reduction boat into the reduction boatIn the original furnace, carrying out reduction reaction in a hydrogen atmosphere to prepare molybdenum-lanthanum alloy powder; specifically, the reduction furnace comprises a first temperature zone, a second temperature zone, a third temperature zone, a fourth temperature zone, a fifth temperature zone and a sixth temperature zone, wherein the reduction temperatures of the first temperature zone, the second temperature zone and the third temperature zone are all 300 ℃, and the reduction temperatures of the fourth temperature zone, the fifth temperature zone and the sixth temperature zone are all 950 ℃; the hydrogen flow rate of the hydrogen atmosphere is 4m3·h-1(ii) a The reaction time of the reduction reaction is 10 hours; the boat pushing speed of the reduction boat is 13 mm/min.
Step three, obtaining molybdenum-lanthanum alloy fine powder;
screening the molybdenum-lanthanum alloy powder prepared in the step two to obtain molybdenum-lanthanum alloy fine powder; the mesh number of the screen used for screening is 270 meshes.
Step four, preparing molybdenum-lanthanum alloy initial green compacts;
pressing the molybdenum-lanthanum alloy fine powder obtained in the step three to obtain a molybdenum-lanthanum alloy initial compact; the pressure for pressing is 180MPa, and the pressure maintaining time is 15 min.
Step five, preparing high-density ultrafine-grained molybdenum-lanthanum alloy;
and D, carrying out non-continuous heating sintering treatment on the molybdenum lanthanum alloy initial pressed compact prepared in the step four, and cooling to room temperature to prepare the high-density ultrafine-grained molybdenum lanthanum alloy. The non-continuous heating sintering treatment comprises the following specific processes: firstly, heating for the first time, namely heating the temperature from room temperature to 800 ℃, and then carrying out heat preservation for the first time for 1h, wherein the heating time of the first heating is 2 h; then, carrying out secondary temperature rise, namely, after the temperature rises from 800 ℃ to 1200 ℃, carrying out secondary heat preservation for 2 hours, wherein the temperature rise time of the secondary temperature rise is 2 hours; carrying out third temperature rise, namely, after the temperature is raised from 1200 ℃ to 1300 ℃, carrying out third heat preservation for 5 hours, wherein the temperature rise time of the third temperature rise is 1 hour; and after the third heat preservation is finished, cooling to room temperature, heating for the fourth time, heating the room temperature to 1600 ℃, and carrying out the fourth heat preservation for 3 hours, wherein the heating time of the fourth temperature rise is 2 hours.
By adopting the preparation method of the high-density ultrafine-grained molybdenum lanthanum alloy in the embodiment, as shown in fig. 1, the density of the finally prepared high-density ultrafine-grained molybdenum lanthanum alloy is 99%, and the grain size is about 3 μm.
Example 2:
this embodiment provides a method for preparing a high-density ultra-fine grain molybdenum-lanthanum alloy, which is substantially the same as that in embodiment 1, except that in step five of this embodiment, after the third heat preservation is completed, the molybdenum-lanthanum alloy is cooled to room temperature, and then the temperature is raised for the fourth time, and the temperature is raised from room temperature to 1700 ℃.
By adopting the preparation method of the high-density ultrafine-grained molybdenum lanthanum alloy in the embodiment, the density of the finally prepared high-density ultrafine-grained molybdenum lanthanum alloy is 99.2%, and the grain size is about 3 μm.
Example 3:
this embodiment provides a method for preparing a high-density ultra-fine grain molybdenum-lanthanum alloy, which is substantially the same as that in embodiment 1, except that in step five of this embodiment, after the third heat preservation is finished, the molybdenum-lanthanum alloy is cooled to room temperature, and then the temperature is raised for the fourth time, and the temperature is raised from room temperature to 1800 ℃.
By adopting the preparation method of the high-density ultrafine-grained molybdenum lanthanum alloy in the embodiment, the density of the finally prepared high-density ultrafine-grained molybdenum lanthanum alloy is 99.4%, and the grain size is about 3 μm.
Example 4:
the embodiment provides a preparation method of a high-density ultrafine-grained molybdenum lanthanum alloy, which specifically comprises the following steps:
step one, preparing lanthanum oxide doped molybdenum dioxide powder;
preparing a lanthanum oxide suspension: 7.398kg of rare earth lanthanum oxide powder is weighed and added into deionized water, and a magnetic stirrer is adopted to fully stir the mixture to ensure that the mixture is fully dispersed, thus obtaining lanthanum oxide suspension. Spraying the prepared lanthanum oxide suspension into 150kg of molybdenum dioxide powder by adopting high-pressure air, uniformly stirring while spraying to obtain a mixture A, and heating and drying the prepared mixture A in a vacuum state to obtain the lanthanum oxide doped molybdenum dioxide powder. The lanthanum oxide doped molybdenum dioxide powder comprises the following raw materials in percentage by mass: lanthanum oxide 4.7%, molybdenum dioxide 95.3%.
In this embodiment, the second step is the same as the second step of embodiment 1.
In this example, step three was substantially the same as step three in example 1, except that the mesh number of the screen used for the screening was 160 mesh.
In this example, step four is substantially the same as step four in example 1, except that the pressure used is 220 MPa.
In this embodiment, step five is the same as step five of embodiment 1.
By adopting the preparation method of the high-density ultrafine-grained molybdenum lanthanum alloy in the embodiment, the density of the finally prepared high-density ultrafine-grained molybdenum lanthanum alloy is 99.1%, and the grain size is about 3 μm.
Example 5:
this embodiment provides a method for preparing a high-density ultra-fine grain molybdenum-lanthanum alloy, which specifically includes the following steps:
step one, preparing lanthanum oxide doped molybdenum dioxide powder;
preparing a lanthanum oxide suspension: 7.398kg of rare earth lanthanum oxide powder is weighed and added into deionized water, and a magnetic stirrer is adopted to fully stir the mixture to ensure that the mixture is fully dispersed, thus obtaining lanthanum oxide suspension. And spraying the prepared lanthanum oxide suspension into 150kg of molybdenum dioxide powder by adopting high-pressure air, uniformly stirring while spraying to obtain a mixture A, and heating and drying the prepared mixture A in a vacuum state to obtain the lanthanum oxide doped molybdenum dioxide powder. The lanthanum oxide doped molybdenum dioxide powder comprises the following raw materials in percentage by mass: lanthanum oxide 4.7%, molybdenum dioxide 95.3%.
In this embodiment, the second step is the same as the second step of embodiment 1.
In this example, step three is the same as step three in example 1.
In this example, the fourth step is substantially the same as that of example 1 except that the pressure used is 220 MPa.
In this example, step five is substantially the same as step five in example 1, except that the fourth temperature increase is performed to increase the temperature from room temperature to 1700 ℃.
By adopting the preparation method of the high-density ultrafine-grained molybdenum lanthanum alloy in the embodiment, the density of the finally prepared high-density ultrafine-grained molybdenum lanthanum alloy is 99.4%, and the grain size is about 3 μm.
Example 6:
the embodiment provides a preparation method of a high-density ultrafine-grained molybdenum lanthanum alloy, which specifically comprises the following steps:
step one, preparing lanthanum oxide doped molybdenum dioxide powder;
preparing a lanthanum oxide suspension: 7.398kg of rare earth lanthanum oxide powder is weighed and added into deionized water, and a magnetic stirrer is adopted to fully stir the mixture to ensure that the mixture is fully dispersed, thus obtaining lanthanum oxide suspension. And spraying the prepared lanthanum oxide suspension into 150kg of molybdenum dioxide powder by adopting high-pressure air, uniformly stirring while spraying to obtain a mixture A, and heating and drying the prepared mixture A in a vacuum state to obtain the lanthanum oxide doped molybdenum dioxide powder. The lanthanum oxide doped molybdenum dioxide powder comprises the following raw materials in percentage by mass: lanthanum oxide 4.7%, molybdenum dioxide 95.3%.
In this embodiment, the second step is the same as the second step of embodiment 1.
In this example, step three is the same as step three in example 1.
In this example, step four is the same as step four in example 1.
In this example, step five is substantially the same as step five in example 1, except that the fourth temperature increase is performed to increase the temperature from room temperature to 1800 ℃.
By adopting the preparation method of the high-density ultrafine-grained molybdenum lanthanum alloy in the embodiment, the density of the finally prepared high-density ultrafine-grained molybdenum lanthanum alloy is 99.2%, and the grain size is about 3 μm.
Comparative example 1:
the comparative example provides a preparation method of molybdenum-lanthanum alloy, which specifically comprises the following steps:
in this comparative example, step one was the same as step one of example 6.
In this example, the second step is the same as the second step of example 6.
In this comparative example, step three was the same as step three of example 6.
In this comparative example, step four was the same as step four of example 6.
In this comparative example, step five specifically was:
and D, continuously heating and sintering the molybdenum-lanthanum alloy initial compact prepared in the step four, and cooling to room temperature to obtain the molybdenum-lanthanum alloy. The specific process of the continuous heating sintering treatment is basically the same as the non-continuous heating sintering treatment in step five of the example 6, and the differences are as follows: and after the third heat preservation is finished, carrying out fourth heat preservation for 7 hours by raising the temperature from 1600 ℃ to 1800 ℃, wherein the temperature raising time of the fourth heat preservation is 4 hours.
By adopting the preparation method of the molybdenum-lanthanum alloy in the comparative example, the density of the finally prepared molybdenum-lanthanum alloy is 97%, and the grain size is about 460 μm.
Comparative example 2:
the comparative example provides a preparation method of molybdenum-lanthanum alloy, which specifically comprises the following steps:
in this comparative example, step one was the same as step one of example 6.
In this example, the second step is the same as the second step of example 6.
In this comparative example, step three was the same as step three of example 6.
In this comparative example, step four was the same as step four of example 6.
In this comparative example, step five is substantially the same as step five of example 6, except that: after the third heat preservation is finished, cooling to room temperature, and then heating for the fourth time, wherein the temperature is increased from the room temperature to 1900 ℃.
By adopting the preparation method of the molybdenum-lanthanum alloy in the comparative example, the density of the finally prepared molybdenum-lanthanum alloy is 99%, and the grain size is about 270 mu m.
From the above examples 1 to 6 and comparative examples 1 to 2, it can be seen that:
(A) in comparative example 1, the molybdenum lanthanum alloy has a density of 97%, and the grain size of the molybdenum lanthanum alloy is about 460 μm; in examples 1 to 6, the densities of the high-density ultra-fine grain molybdenum lanthanum alloy were 99%, 99.2%, 99.4%, 99.1%, 99.4% and 99.2%, respectively, and the grain sizes of the high-density ultra-fine grain molybdenum lanthanum alloy were all about 3 μm. From the above data, the compactness of examples 1 to 6 is higher than that of comparative example 1, and the grain size of examples 1 to 6 is much smaller than that of comparative example 1.
The main difference between comparative example 1 and examples 1 to 6 is that comparative example 1 was subjected to four times of continuous heating during the sintering treatment, whereas examples 1 to 6 were subjected to three times of continuous heating during the sintering treatment, and then to a fourth time of continuous heating after cooling to room temperature.
According to the analysis, the preparation method of the high-density ultrafine-grained molybdenum lanthanum alloy can prepare the high-density ultrafine-grained molybdenum lanthanum alloy with high density and small grain size by adopting the non-continuous heating sintering treatment of the molybdenum lanthanum alloy initial compact.
(B) In comparative example 2, the grain size of the molybdenum lanthanum alloy was 270 μm; in each of examples 1 to 6, the grain size of the high-density ultra-fine grain molybdenum-lanthanum alloy was about 3 μm. From the above data, it can be seen that the grain size of examples 1 to 6 is much smaller than comparative example 2. Comparative example 2 the main difference in the preparation method compared to examples 1 to 6 is that the fourth temperature rise raises the temperature to 1900 c, i.e. the temperature of the fourth temperature rise is greater than 1800 c.
According to the analysis, the preparation method of the high-density ultrafine-grained molybdenum lanthanum alloy can prepare the high-density ultrafine-grained molybdenum lanthanum alloy with high density and small grain size by controlling the temperature of the fourth heating to 1600-1800 ℃.
Claims (10)
1. A preparation method of high-density ultrafine-grained molybdenum lanthanum alloy is characterized in that a molybdenum lanthanum alloy initial compact is treated by non-continuous heating sintering to prepare the high-density ultrafine-grained molybdenum lanthanum alloy;
the non-continuous heating sintering treatment comprises the following specific processes:
firstly, heating for the first time, namely heating the temperature from room temperature to 800 ℃, and then carrying out heat preservation for 1 hour for the first time; then, carrying out secondary temperature rise, and carrying out secondary heat preservation for 2 hours after the temperature rises from 800 ℃ to 1200 ℃; heating for the third time, heating the temperature from 1200 ℃ to 1300 ℃, and then carrying out heat preservation for the third time for 4-10 hours; and after the third heat preservation is finished, cooling to room temperature, heating for the fourth time, and carrying out fourth heat preservation for 1-4 hours after the temperature is raised to 1600-1800 ℃ from the room temperature.
2. The method for preparing the high-density ultrafine grained molybdenum lanthanum alloy according to claim 1, wherein the temperature rise time of the first temperature rise is 0.5-3 h; the temperature rise time of the second temperature rise is 1-5 h; the temperature rise time of the third temperature rise is 0.5-3 h; the temperature rise time of the fourth temperature rise is 1-3 h.
3. The method for preparing high-density ultra-fine grain molybdenum lanthanum alloy of claim 1, wherein the density of the high-density ultra-fine grain molybdenum lanthanum alloy is greater than or equal to 99%, and the grain size is less than or equal to 3 μm.
4. The method for preparing the high-density ultra-fine grain molybdenum lanthanum alloy according to claim 1, which comprises the following steps:
step one, preparing lanthanum oxide doped molybdenum dioxide powder;
preparing a lanthanum oxide suspension, spraying the prepared lanthanum oxide suspension into molybdenum dioxide powder while uniformly stirring to prepare a mixture A, and heating and drying the prepared mixture A to prepare lanthanum oxide doped molybdenum dioxide powder;
step two, preparing molybdenum-lanthanum alloy powder;
putting the lanthanum oxide doped molybdenum dioxide powder prepared in the step one into a reduction boat, pushing the reduction boat into a reduction furnace, and carrying out reduction reaction in a hydrogen atmosphere to prepare molybdenum-lanthanum alloy powder;
step three, obtaining molybdenum-lanthanum alloy fine powder;
screening the molybdenum-lanthanum alloy powder prepared in the step two to obtain molybdenum-lanthanum alloy fine powder;
step four, preparing molybdenum-lanthanum alloy initial green compacts;
pressing the molybdenum-lanthanum alloy fine powder obtained in the step three to obtain a molybdenum-lanthanum alloy initial compact;
step five, preparing high-density ultra-fine grain molybdenum lanthanum alloy;
and D, carrying out non-continuous heating sintering treatment on the molybdenum-lanthanum alloy initial compact prepared in the step four to prepare the high-density ultrafine-grained molybdenum-lanthanum alloy.
5. The method for preparing the high-density ultra-fine grain molybdenum lanthanum alloy according to claim 4, wherein in the first step, the lanthanum oxide doped molybdenum dioxide powder comprises the following raw materials in percentage by mass: 0.1 to 5 percent of lanthanum oxide, 95 to 99.9 percent of molybdenum dioxide, and the sum of the mass percent of the raw materials is 100 percent.
6. The method for preparing the high-density ultra-fine grain molybdenum lanthanum alloy according to claim 4, wherein in the second step, the reducing furnace comprises a first temperature zone, a second temperature zone, a third temperature zone, a fourth temperature zone, a fifth temperature zone and a sixth temperature zone, wherein the reducing temperatures of the first temperature zone, the second temperature zone and the third temperature zone are 50-500 ℃, and the reducing temperatures of the fourth temperature zone, the fifth temperature zone and the sixth temperature zone are 600-1300 ℃.
7. The method for preparing the high-density ultrafine-grained molybdenum lanthanum alloy according to claim 4, wherein in the second step, the hydrogen flow rate of the hydrogen atmosphere is 1-8 m3·h-1(ii) a The reaction time of the reduction reaction is 2-18 h.
8. The method for preparing the high-density ultrafine-grained molybdenum lanthanum alloy according to claim 4, wherein in the third step, the mesh number of the screen mesh adopted by the screening is 100-300 meshes.
9. The method for preparing the high-density ultrafine-grained molybdenum lanthanum alloy according to claim 4, wherein in the fourth step, the pressure used for pressing is 150-500 MPa, and the pressure holding time is 10-30 min.
10. A high-density ultra-fine grain molybdenum lanthanum alloy, which is characterized by being prepared by the preparation method of the high-density ultra-fine grain molybdenum lanthanum alloy of any one of claims 1 to 9.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102534333A (en) * | 2012-01-05 | 2012-07-04 | 西安建筑科技大学 | Method for preparing fine-grain high-density TZM (Titanium-Zirconium-Molybdenum Allo) alloy |
| JP2013023732A (en) * | 2011-07-21 | 2013-02-04 | Fukuda Metal Foil & Powder Co Ltd | Al BRONZE SINTERED ALLOY-SLIDING MATERIAL AND METHOD FOR PRODUCING THE SAME |
| CN102990054A (en) * | 2012-04-01 | 2013-03-27 | 鹤山市沃得钨钼实业有限公司 | Rare earth molybdenum crucible blank and method for manufacturing rare earth molybdenum crucible with same |
| CN104439266A (en) * | 2014-12-12 | 2015-03-25 | 金堆城钼业股份有限公司 | Preparation method of molybdenum powder large in particle size |
| CN109848431A (en) * | 2019-02-27 | 2019-06-07 | 金堆城钼业股份有限公司 | A kind of preparation method of thin molybdenum powder |
| CN113399662A (en) * | 2021-06-21 | 2021-09-17 | 中南大学 | Preparation method of molybdenum-lanthanum alloy sintered blank and product thereof |
-
2022
- 2022-03-24 CN CN202210297963.7A patent/CN114657404B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013023732A (en) * | 2011-07-21 | 2013-02-04 | Fukuda Metal Foil & Powder Co Ltd | Al BRONZE SINTERED ALLOY-SLIDING MATERIAL AND METHOD FOR PRODUCING THE SAME |
| CN102534333A (en) * | 2012-01-05 | 2012-07-04 | 西安建筑科技大学 | Method for preparing fine-grain high-density TZM (Titanium-Zirconium-Molybdenum Allo) alloy |
| CN102990054A (en) * | 2012-04-01 | 2013-03-27 | 鹤山市沃得钨钼实业有限公司 | Rare earth molybdenum crucible blank and method for manufacturing rare earth molybdenum crucible with same |
| CN104439266A (en) * | 2014-12-12 | 2015-03-25 | 金堆城钼业股份有限公司 | Preparation method of molybdenum powder large in particle size |
| CN109848431A (en) * | 2019-02-27 | 2019-06-07 | 金堆城钼业股份有限公司 | A kind of preparation method of thin molybdenum powder |
| CN113399662A (en) * | 2021-06-21 | 2021-09-17 | 中南大学 | Preparation method of molybdenum-lanthanum alloy sintered blank and product thereof |
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