阅读说明：本技术 一种深过冷处理gh605高温合金及其制备方法 (GH605 high-temperature alloy subjected to deep supercooling treatment and preparation method thereof ) 是由 贺一轩 刘栩东 卜凡 李金山 王军 于 2021-08-27 设计创作，主要内容包括：本发明公开了一种深过冷处理GH605高温合金及其制备方法,该合金制备方法包括如下过程：将原始态GH605合金样品置入石英试管并放入净化剂；将石英试管置于感应炉腔室的高频感应加热线圈内,将腔室内抽真空并充入Ar气体；调节加热温度与红外测温仪位置,使实时测量温度与合金样品温度保持一致,待净化剂充分熔化并包覆合金样品后,将合金样品过热至高于合金样品的液相线温度100K–250K并保温,实时观测合金熔体状态；待发生再辉现象后,判断合金样品的过冷度是否达到过冷度50K以上的要求,若满足要求则让合金样品自然冷却至室温。本发明采用熔体过冷处理,调控凝固及后续相的析出,获得大过冷度且显微硬度相比原始态提升60.4％-66.7％的合金。(The invention discloses a GH605 high-temperature alloy subjected to deep supercooling treatment and a preparation method thereof, wherein the preparation method of the alloy comprises the following steps: placing an original GH605 alloy sample into a quartz test tube and placing a purifying agent; placing a quartz test tube in a high-frequency induction heating coil of a cavity of an induction furnace, vacuumizing the cavity and filling Ar gas into the cavity; adjusting the heating temperature and the position of an infrared thermometer to keep the real-time measurement temperature consistent with the temperature of the alloy sample, overheating the alloy sample to be 100-250K higher than the liquidus temperature of the alloy sample after the purifying agent is fully melted and coats the alloy sample, preserving the heat, and observing the state of the alloy melt in real time; and after the recalescence phenomenon occurs, judging whether the supercooling degree of the alloy sample reaches the requirement of the supercooling degree of more than 50K, and if the supercooling degree of the alloy sample meets the requirement, naturally cooling the alloy sample to the room temperature. The invention adopts melt supercooling treatment, regulates solidification and subsequent phase precipitation, and obtains the alloy with high supercooling degree and microhardness improved by 60.4-66.7% compared with the original state.)

1. The GH605 high-temperature alloy subjected to deep undercooling treatment is characterized by being an alloy with a smooth surface and microhardness which is improved by 60.4% -66.7% compared with that of the original state.

2. The deep undercooling-treated GH605 superalloy of claim 1, wherein the reticulated second phase of the deep undercooling-treated GH605 superalloy is a Co (W, Cr) -Laves phase with a face-centered cubic crystal structure.

3. The preparation method of the GH605 high-temperature alloy subjected to deep undercooling treatment of claim 1 or 2, which is characterized by comprising the following steps:

step 1: placing an original GH605 alloy sample into a quartz test tube, and placing a certain amount of purifying agent above the sample;

step 2: placing a quartz test tube filled with a sample in a high-frequency induction heating coil of an induction furnace chamber, vacuumizing the induction furnace chamber and filling high-purity Ar gas;

and step 3: starting a high-frequency induction heating power supply, firstly slowly adjusting the power heating temperature to be higher than the melting point of the purifying agent but lower than the melting point or liquidus temperature of the alloy sample, and discharging water and bubbles existing in the purifying agent; starting an infrared thermometer to detect the temperature of the alloy sample in real time, and transmitting the change curve of the temperature along with time to a computer end for analysis of a supercooling curve;

and 4, step 4: keeping the temperature at the temperature of the step 3 for 5-20min, continuing to heat until the alloy sample is melted after bubbles are fully discharged, continuing to overheat the alloy sample to a temperature 100K-250K higher than the liquidus temperature of the alloy sample, keeping the temperature for a period of time, and observing the state of the alloy melt in real time in the heat preservation process;

and 5: and (4) after the heat preservation is finished, turning off the heating power supply, starting to cool the alloy sample, continuously observing the change curve of the temperature along with the time at the computer end, quickly judging whether the supercooling degree of the alloy sample meets the requirement of the supercooling degree of more than 50K after the resurgence phenomenon occurs, naturally cooling the alloy sample to the room temperature if the supercooling degree meets the requirement, and continuing to perform the step 4 if the supercooling degree does not meet the requirement to finally realize the supercooling degree meeting the requirement.

4. The method for preparing the GH605 superalloy through deep undercooling treatment according to claim 3, wherein the method further comprises the steps of placing a quartz test tube and a raw GH605 alloy sample which is cut from a GH605 master alloy ingot and weighs about 4g into an alcohol solution for shaking washing by an ultrasonic washing machine before the step 1, and drying after the washing is finished.

5. The method for preparing GH605 high-temperature alloy through deep undercooling treatment according to claim 3, wherein the method is characterized in thatThe purifying agent is prepared from the following components in percentage by weight: 5% -15% of NaSiO₃Powder of 75-95% Na₂B₄O₇And B₂O₃A powder mixture; wherein, Na₂B₄O₇And B₂O₃In a ratio of 1: 4.

6. The method for preparing the GH605 superalloy through deep undercooling treatment according to claim 3, wherein the step 2 of vacuumizing and filling the chamber with high-purity Ar gas specifically comprises the following steps:

the vacuum degree in the induction furnace chamber is pumped to 5 multiplied by 10 by utilizing a mechanical pump and a molecular pump in sequence^-3Pa, then filling high-purity Ar gas to 5X 10^-2MPa; and repeating the vacuumizing and inflating operations to ensure the vacuum degree in the induction furnace chamber.

7. The method for preparing the GH605 superalloy through deep undercooling treatment according to claim 3, wherein the step 3 of starting an infrared thermometer to detect the temperature of the alloy sample in real time specifically comprises the following steps:

and opening the infrared thermometer, and adjusting the position of the probe to enable the probe to be aligned to the position of the melt in the quartz test tube so as to detect the temperature of the alloy sample in real time.

8. The preparation method of the GH605 superalloy with deep undercooling treatment according to claim 3, wherein the holding time of the alloy sample after being overheated to 100K-250K higher than the liquidus temperature of the alloy sample in the step 4 is preferably 5 min.

9. The method for preparing the GH605 superalloy with deep undercooling treatment according to claim 3, wherein the quartz test tube is a transparent glass tube which can stably endure 1700 ℃.

Technical Field

The invention belongs to the technical field of alloys, and particularly relates to a GH605 high-temperature alloy subjected to deep supercooling treatment and a preparation method thereof.

Background

The high-temperature alloy is a metal material which can be at a temperature of more than 600 ℃, has oxidation resistance and corrosion resistance and can work for a long time under the action of certain stress. The high-temperature alloy is not only used material for aviation and aerospace engines and key hot end parts, but also high-temperature corrosion-resistant material required by industrial departments of petroleum, chemical engineering and the like. At the present stage, the high-temperature alloys are various in types, and common high-temperature alloys are divided into the following components according to main elements: nickel-based, iron-based, and cobalt-based superalloys. Compared with nickel-based and iron-based high-temperature alloys, the cobalt-based high-temperature alloy has good shear resistance, strong thermal fatigue and creep property and good hot corrosion resistance, so that the cobalt-based high-temperature alloy is widely applied to key parts such as fasteners, combustion chambers and even turbochargers with high requirements on creep and fatigue. In recent years, by analyzing the damage of the cobalt-based high-temperature alloy key parts in the aircraft engine, the micro-crack nucleation and cracking caused by abrasion are found to be main failure factors. Therefore, the improvement of the wear resistance of the cobalt-based high-temperature alloy is a key factor for improving the service life of an aeroengine.

The key means for improving abrasion resistance can be started from two aspects, one of which is: the method is characterized in that a lubricant is injected into a wear contact surface, and undoubtedly, the method puts higher requirements on the combination and packaging of parts; secondly, the surface hardness of parts is increased, and the method starts from raw materials, increases the abrasion resistance of the alloy and is undoubtedly more universal. At present, common methods for increasing the surface hardness of the GH605 high-temperature alloy mainly comprise shot blasting, hard coating plating and the like, but the treatment effect cannot be expected, and the GH605 high-temperature alloy with the required hardness cannot be obtained.

Disclosure of Invention

The invention provides a GH605 high-temperature alloy subjected to deep undercooling treatment and a preparation method thereof, and the method for the deep undercooling treatment is characterized by being simple to operate and capable of obviously improving the hardness of the GH605 high-temperature alloy. The chemical composition of GH605 alloy is shown in the following table:

TABLE 1 GH605 alloy chemical composition table (GB/T14992-

The invention is realized by the following technical scheme:

the invention provides a GH605 high-temperature alloy subjected to deep undercooling treatment, which is an alloy with a smooth surface and microhardness improved by 60.4% -66.7% compared with that of the original state.

As a further illustration of the invention, the reticular second phase of the GH605 high-temperature alloy subjected to deep undercooling treatment is a Co (W, Cr) -Laves phase and has a face-centered cubic crystal structure.

The second aspect of the invention provides a preparation method of the GH605 high-temperature alloy subjected to deep undercooling treatment, which comprises the following steps:

step 1: placing an original GH605 alloy sample into a quartz test tube, and placing a certain amount of purifying agent above the sample;

step 2: placing a quartz test tube filled with a sample in a high-frequency induction heating coil of an induction furnace chamber, vacuumizing the induction furnace chamber and filling high-purity Ar gas;

and step 3: starting a high-frequency induction heating power supply, firstly slowly adjusting the power heating temperature to be higher than the melting point of the purifying agent but lower than the melting point or liquidus temperature of the alloy sample, and discharging water and bubbles existing in the purifying agent; starting an infrared thermometer to detect the temperature of the alloy sample in real time, and transmitting the change curve of the temperature along with time to a computer end for analysis of a supercooling curve;

and 4, step 4: keeping the temperature at the temperature of the step 3 for 5-20min, continuing to heat until the alloy sample is melted after bubbles are fully discharged, continuing to overheat the alloy sample to a temperature 100K-250K higher than the liquidus temperature of the alloy sample, keeping the temperature for a period of time, and observing the state of the alloy melt in real time in the heat preservation process;

and 5: and (4) after the heat preservation is finished, turning off the heating power supply, starting to cool the alloy sample, continuously observing the change curve of the temperature along with the time at the computer end, quickly judging whether the supercooling degree of the alloy sample meets the requirement of the supercooling degree of more than 50K after the resurgence phenomenon occurs, naturally cooling the alloy sample to the room temperature if the supercooling degree meets the requirement, and continuing to perform the step 4 if the supercooling degree does not meet the requirement to finally realize the supercooling degree meeting the requirement.

As a further illustration of the invention, the preparation method further comprises the steps of placing a quartz test tube and a GH605 alloy sample in an original state which is cut from the GH605 master alloy ingot and weighs about 4g into an alcohol solution for shaking and washing by an ultrasonic cleaning machine before the step 1, and drying after the washing is finished.

As a further explanation of the invention, the purifying agent comprises the following components in percentage by weight: 5% -15% of NaSiO₃Powder of 75-95% Na₂B₄O₇And B₂O₃A powder mixture; wherein, Na₂B₄O₇And B₂O₃In a ratio of 1: 4.

As a further explanation of the present invention, the step 2 of evacuating the chamber and filling high purity Ar gas includes:

the vacuum degree in the induction furnace chamber is pumped to 5 multiplied by 10 by utilizing a mechanical pump and a molecular pump in sequence^-3Pa, then filling high-purity Ar gas to 5X 10^-2MPa; and repeating the vacuumizing and inflating operations to ensure the vacuum degree in the induction furnace chamber.

As a further explanation of the present invention, the step 3 of starting the infrared thermometer to detect the temperature of the alloy sample in real time specifically comprises:

and opening the infrared thermometer, and adjusting the position of the probe to enable the probe to be aligned to the position of the melt in the quartz test tube so as to detect the temperature of the alloy sample in real time.

As a further illustration of the invention, the holding time after the alloy sample is overheated to 100K-250K higher than the liquidus temperature of the alloy sample in the step 4 is preferably 5 min.

As a further illustration of the present invention, the quartz test tube is a clear glass tube that can stably withstand 1700 ℃.

As a further explanation of the invention, in order to obtain nucleation supercooling degrees of different degrees, the state of the alloy melt can be adjusted by changing parameters such as heat preservation time, overheating temperature and the like of the alloy melt in the cyclic experiment process from step 4 to step 5, and then GH605 alloy samples in different required supercooling degree states can be obtained.

Compared with the prior art, the invention has the following beneficial technical effects:

aiming at GH605 high-temperature alloy, the invention only adopts simple melt supercooling treatment, regulates and controls the solidification process and the precipitation of subsequent phases, and can obtain the alloy with large supercooling degree (delta T is 166.7-347.5 ℃), smooth surface and microhardness which is improved by about 60.4-66.7% compared with the original state. The treatment method provided by the invention can reduce energy consumption and simultaneously improve properties such as microhardness of the high-temperature alloy.

Drawings

FIG. 1 is a photograph of a deep undercooled solidification curve and a raw GH605 alloy of a sample prepared in example 1 of the present invention;

in FIG. 2, (a) is an original GH605 alloy structure, and (b) is the GH605 alloy structure after deep undercooling treatment of example 1;

FIG. 3 is a schematic diagram of a focused ion beam cutting region of a TEM sample prepared by Fib technology (a) and a sectional view of the region thinned layer by layer (b);

FIG. 4 (a) is a TEM picture of a reticular second phase of a GH605 alloy structure after deep undercooling treatment of example 2; (b) and (c) the GH605 alloy structure reticular second phase after the deep undercooling treatment of the embodiment 2 is respectively inAnd [012 ]]Selecting an area under the crystal axis for electron diffraction spots; (d) and (e) a composition energy spectrum and an element composition table of a reticular second phase of the GH605 alloy structure after the deep undercooling treatment in example 2；

FIG. 5 is a nano indentation test curve of GH605 alloy after deep undercooling treatment and original GH605 alloy of example 1;

FIG. 6 is a photograph of a deep undercooled solidification curve and an original GH605 alloy of a sample prepared in example 2 of the present invention;

in FIG. 7, (a) is an original GH605 alloy structure, and (b) is the GH605 alloy structure after deep undercooling treatment of example 2;

FIG. 8 is a schematic diagram of a focused ion beam cutting region of a TEM sample prepared by Fib technology (a) and a sectional view of the region thinned layer by layer (b);

FIG. 9 (a) is a TEM picture of a reticular second phase of a GH605 alloy structure after deep undercooling treatment of example 2; (b) and (c) the GH605 alloy structure reticular second phase after the deep undercooling treatment of the embodiment 2 is respectively inAnd [012 ]]Selecting an area under the crystal axis for electron diffraction spots; (d) and (e) is a component energy spectrum and an element composition table of a reticular second phase of the GH605 alloy structure after the deep super-cooling treatment in the embodiment 2;

fig. 10 is nano indentation test curves of GH605 alloy after deep undercooling treatment of example 2 and original GH605 alloy.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, a detailed description of the present invention will be given below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and features of the embodiments may be combined with each other without conflict.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Example 1

A preparation method of a GH605 high-temperature alloy subjected to deep undercooling treatment comprises the following steps:

firstly, cutting a quartz test tube and a mother alloy ingot into samples with the weight of about 4g, placing the samples into an alcohol solution, washing the samples by oscillation by using an ultrasonic cleaning machine, drying the samples by using a blower after the washing is finished, then placing the samples into the bottom of the quartz test tube, and placing about 0.3g of purifying agent above the samples, wherein the proportion of the purifying agent is 10 percent NaSiO₃Powder, 90% Na₂B₄O₇And B₂O₃A powder mixture. Wherein, Na₂B₄O₇And B₂O₃The ratio was 1: 4. The purifying agent can avoid pure B₂O₃The powder can react with part of the sample at high temperature, and can prevent the high-temperature sample from being oxidized and improve the surface smoothness of the sample.

Secondly, placing the quartz test tube in a high-frequency induction heating coil of a cavity of an induction furnace, and pumping the vacuum degree of the cavity to 5 multiplied by 10 by utilizing a mechanical pump and a molecular pump in sequence^-3Pa, then filling high-purity Ar gas to 5X 10^-2MPa. The vacuum and gas filling operations are repeated to ensure the degree of vacuum in the chamber.

And thirdly, starting a high-frequency induction heating power supply, firstly slowly adjusting the power heating temperature to be higher than the melting point of the purifying agent but lower than the melting point or liquidus temperature of the alloy, such as 900 ℃, and removing water and bubbles in the purifying agent. At the moment, the infrared thermometer is opened, and the position of the probe is adjusted to be aligned with the position of the melt in the test tube so as to detect the alloy temperature in real time, and the change curve of the temperature along with the time can be transmitted to a computer for analysis of the supercooling curve.

And fourthly, preserving the temperature at 900 ℃ for 5min, continuing heating power until the alloy block is melted after bubbles are fully discharged, overheating the alloy sample coated by the molten glass to a temperature higher than 130K (about 1530 ℃ as shown in figure 1) of the alloy liquid phase temperature, preserving the temperature for 5min, and observing the state of the alloy melt in real time in the heat preservation process.

And fifthly, closing the heating power supply after the heat preservation is finished, starting to cool the alloy sample, continuously observing the change curve of the temperature of the computer end along with the time, and as shown in figure 1, when the recalescence phenomenon occurs, ensuring that the supercooling degree of the alloy is about 166.7 ℃ (the liquidus temperature T of the alloy_m1411.0 ℃ and nucleation temperature T_N1244.3 deg.C difference), a large supercooling was achieved, and the sample was allowed to cool naturally to room temperature.

The original GH605 alloy and GH605 alloy samples obtained after deep undercooling treatment in example 1 are subjected to SEM and TEM tissue characterization and microhardness and nanoindentation performance tests, and the results are as follows:

as shown in fig. 2, the pristine GH605 alloy consists of a single phase of γ -Co with small amounts of spherical carbides distributed within the grains and at the grain boundaries. In the GH605 alloy after the deep undercooling treatment of example 1, the grain size of the gamma-Co matrix is obviously reduced, and a large number of reticular second phases are arranged in a cross way.

As shown in fig. 3, TEM sample preparation was performed on the reticulated second phase using FIB techniques for characterization of crystal structure and elemental composition. The TEM representation results are shown in FIG. 4, from which it is known that the obtained second reticular phase is Co (W, Cr) -Laves phase with face-centered cubic crystal structure after deep supercooling.

As shown in Table 2, the original GH605 alloy was tested for Vickers hardness at room temperature at 10 points with an average value of 308HV, whereas the average hardness of GH605 alloy increased to 494HV after the deep undercooling treatment of example 1.

TABLE 2

As shown in fig. 5, the nano indentation test was performed on the GH605 alloy sample in the original state and the GH605 alloy sample after the deep undercooling treatment of example 1, wherein when the load is 10000 μ N, the displacement of the alloy matrix in the original state is 260nm, and after the deep undercooling treatment, the displacement of the alloy matrix is 233nm and the Laves phase displacement is 218 nm. This further demonstrates the hardness magnitude order: the Laves phase after deep supercooling treatment is larger than the alloy matrix after deep supercooling treatment is larger than the original alloy matrix. Therefore, the high-hardness Laves phase and the high-hardness alloy matrix are obtained through deep undercooling treatment, and under the combined action of the Laves phase and the high-hardness alloy matrix, the overall hardness of the alloy after the deep undercooling treatment is higher than that of the original alloy.

Example 2

A preparation method of a GH605 high-temperature alloy subjected to deep undercooling treatment comprises the following steps:

firstly, cutting a quartz test tube and a mother alloy ingot into samples with the weight of about 4g, placing the samples into an alcohol solution, washing the samples by oscillation by using an ultrasonic cleaning machine, drying the samples by using a blower after the washing is finished, then placing the samples into the bottom of the quartz test tube, and placing about 0.3g of purifying agent above the samples, wherein the proportion of the purifying agent is 8 percent NaSiO₃Powder, 92% Na₂B₄O₇And B₂O₃A powder mixture. Wherein, Na₂B₄O₇And B₂O₃The ratio was 1: 4. The purifying agent can avoid pure B₂O₃The powder can react with part of the sample at high temperature, and can prevent the high-temperature sample from being oxidized and improve the surface smoothness of the sample.

Secondly, placing the quartz test tube in a high-frequency induction heating coil of a cavity of an induction furnace, and pumping the vacuum degree of the cavity to 5 multiplied by 10 by utilizing a mechanical pump and a molecular pump in sequence^-3Pa, then filling high-purity Ar gas to 5X 10^-2MPa. The vacuum and gas filling operations are repeated to ensure the degree of vacuum in the chamber.

And thirdly, starting a high-frequency induction heating power supply, firstly slowly adjusting the power heating temperature to be higher than the melting point of the purifying agent but lower than the melting point or liquidus temperature of the alloy, such as 850 ℃, and removing water and bubbles in the purifying agent. At the moment, the infrared thermometer is opened, and the position of the probe is adjusted to be aligned with the position of the melt in the test tube so as to detect the alloy temperature in real time, and the change curve of the temperature along with the time can be transmitted to a computer for analysis of the supercooling curve.

And fourthly, preserving the temperature at 850 ℃ for 15min, continuing heating power until the alloy block is melted after bubbles are fully discharged, overheating the alloy sample coated by the molten glass to be higher than the alloy liquid phase temperature by 150K (shown in figure 6, about 1550 ℃) and preserving the temperature for 15min, and observing the state of the alloy melt in real time in the heat preservation process.

And fifthly, turning off the heating power supply after the heat preservation is finished, starting to cool the alloy sample, continuously observing the change curve of the temperature of the computer end along with the time, and as shown in figure 6, when the recalescence phenomenon occurs, the supercooling degree of the alloy is about 347.5 ℃ (the liquidus temperature T of the alloy_m1437.7 ℃ and nucleation temperature T_N1090.2 deg.C difference), a large supercooling was achieved, and the sample was allowed to cool naturally to room temperature.

The original GH605 alloy and GH605 alloy samples obtained after deep undercooling treatment in example 2 are subjected to SEM and TEM tissue characterization and microhardness and nanoindentation performance tests, and the results are as follows:

as shown in fig. 7, the pristine GH605 alloy consists of a single phase of γ -Co with small amounts of spherical carbides distributed within the grains and at the grain boundaries. In the GH605 alloy after the deep undercooling treatment of example 2, the grain size of the gamma-Co matrix is significantly reduced, and a large number of second phases are formed in a network shape and arranged to cross each other.

As shown in fig. 8, TEM sample preparation was performed on the reticulated second phase using FIB technology for characterization of crystal structure and elemental composition. The TEM representation result is shown in FIG. 9, from which it is known that the second reticular phase obtained by deep supercooling in example 2 is a Co (W, Cr) -Laves phase and has a face-centered cubic crystal structure.

As shown in Table 3, the original GH605 alloy was subjected to Vickers hardness test at room temperature at 10 points with an average value of 308HV, whereas after deep undercooling treatment of example 2, the average hardness value increased to 513.5 HV.

TABLE 3

As shown in fig. 10, the nano indentation test was performed on the GH605 alloy sample in the raw state and the GH605 alloy sample after the deep undercooling treatment of example 2, and when the load was the same as 10000 μ N, the displacement of the alloy matrix in the raw state was 260nm, and after the deep undercooling treatment, the displacement of the alloy matrix was 230nm and the Laves phase displacement was 218 nm. This further demonstrates the hardness magnitude order: the Laves phase after deep supercooling treatment is larger than the alloy matrix after deep supercooling treatment is larger than the original alloy matrix. Therefore, the high-hardness Laves phase and the high-hardness alloy matrix are obtained through deep undercooling treatment, and under the combined action of the Laves phase and the high-hardness alloy matrix, the overall hardness of the alloy after the deep undercooling treatment is higher than that of the original alloy.

Example 3

A preparation method of a GH605 high-temperature alloy subjected to deep undercooling treatment comprises the following steps:

firstly, cutting a quartz test tube and a mother alloy ingot into samples with the weight of about 4g, placing the samples into an alcohol solution, washing the samples by oscillation by using an ultrasonic cleaning machine, drying the samples by using a blower after the washing is finished, then placing the samples into the bottom of the quartz test tube, and placing about 0.3g of purifying agent above the samples, wherein the proportion of the purifying agent is 5 percent NaSiO₃Powder, 95% Na₂B₄O₇And B₂O₃A powder mixture. Wherein, Na₂B₄O₇And B₂O₃The ratio was 1: 4. The purifying agent can avoid pure B₂O₃The powder can react with part of the sample at high temperature, and can prevent the high-temperature sample from being oxidized and improve the surface smoothness of the sample.

Secondly, placing the quartz test tube in a high-frequency induction heating coil of a cavity of an induction furnace, and pumping the vacuum degree of the cavity to 5 multiplied by 10 by utilizing a mechanical pump and a molecular pump in sequence^-3Pa, then filling high-purity Ar gas to 5X 10^-2MPa. The vacuum and gas filling operations are repeated to ensure the degree of vacuum in the chamber.

And thirdly, starting a high-frequency induction heating power supply, firstly slowly adjusting the power heating temperature to be higher than the melting point of the purifying agent but lower than the melting point or liquidus temperature of the alloy, such as 800 ℃, and removing water and bubbles in the purifying agent. At the moment, the infrared thermometer is opened, and the position of the probe is adjusted to be aligned with the position of the melt in the test tube so as to detect the alloy temperature in real time, and the change curve of the temperature along with the time can be transmitted to a computer for analysis of the supercooling curve.

And fourthly, preserving heat at 800 ℃ for 20min, continuing heating power until the alloy block is melted after bubbles are fully discharged, overheating the alloy sample coated by the molten glass to be higher than the alloy liquid phase temperature by 100K, preserving heat for 5min, and observing the state of the alloy melt in real time in the heat preservation process.

And fifthly, closing the heating power supply after the heat preservation is finished, starting to cool the alloy sample, continuously observing the change curve of the temperature of the computer end along with the time, and ensuring that the supercooling degree of the alloy is about 166.7 ℃ (the liquidus temperature T of the alloy) when the recalescence phenomenon occurs_m1411.0 ℃ and nucleation temperature T_N1244.3 deg.C difference), a large supercooling was achieved, and the sample was allowed to cool naturally to room temperature.

Example 4

A preparation method of a GH605 high-temperature alloy subjected to deep undercooling treatment comprises the following steps:

firstly, cutting a quartz test tube and a mother alloy ingot into samples with the weight of about 4g, placing the samples into an alcohol solution, washing the samples by oscillation by using an ultrasonic cleaning machine, drying the samples by using a blower after the washing is finished, then placing the samples into the bottom of the quartz test tube, and placing about 0.3g of purifying agent above the samples, wherein the proportion of the purifying agent is 15 percent NaSiO₃Powder, 85% Na₂B₄O₇And B₂O₃A powder mixture. Wherein, Na₂B₄O₇And B₂O₃The ratio was 1: 4. The purifying agent can avoid pure B₂O₃The powder can react with part of the sample at high temperature, and can prevent the high-temperature sample from being oxidized and improve the surface smoothness of the sample.

Secondly, placing the quartz test tube in a high-frequency induction heating coil of a cavity of an induction furnace, and pumping the vacuum degree of the cavity to 5 multiplied by 10 by utilizing a mechanical pump and a molecular pump in sequence^-3Pa, then filling high-purity Ar gas to 5X 10^-2MPa. The vacuum and gas filling operations are repeated to ensure the degree of vacuum in the chamber.

And thirdly, starting a high-frequency induction heating power supply, firstly slowly adjusting the power heating temperature to be higher than the melting point of the purifying agent but lower than the melting point or liquidus temperature of the alloy, such as 1000 ℃, and removing water and bubbles in the purifying agent. At the moment, the infrared thermometer is opened, and the position of the probe is adjusted to be aligned with the position of the melt in the test tube so as to detect the alloy temperature in real time, and the change curve of the temperature along with the time can be transmitted to a computer for analysis of the supercooling curve.

And fourthly, preserving heat at 1000 ℃ for 5min, continuing heating power until the alloy block is melted after bubbles are fully discharged, overheating the alloy sample coated by the molten glass to be higher than the alloy liquid phase temperature by 250K, preserving heat for 5min, and observing the state of the alloy melt in real time in the heat preservation process.

And fifthly, turning off the heating power supply after heat preservation is finished, starting to cool the alloy sample, continuously observing the change curve of the temperature of the computer end along with time, and ensuring that the supercooling degree of the alloy is about 347.5 ℃ (the liquidus temperature T of the alloy) when the recalescence phenomenon occurs_m1437.7 ℃ and nucleation temperature T_N1090.2 deg.C difference), a large supercooling was achieved, and the sample was allowed to cool naturally to room temperature.

Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.