Alloy material high-throughput preparation method based on centrifugal supergravity solidification

Abstract

The invention discloses a high-throughput preparation method of an alloy material based on centrifugal supergravity solidification. The method comprises the steps that alloy raw materials are put into a smelting furnace to be subjected to vacuum smelting and pouring, and a cast ingot is obtained; the cast ingot is sequentially subjected to linear cutting, mechanical grinding, ultrasonic cleaning and constant-temperature drying, and an alloy original material of the super-gravity prepared alloy is prepared; processing the original alloy material into a block cast ingot and putting the block cast ingot into a crucible; placing the crucible in a centrifugal supergravity casting furnace; carrying out supergravity solidification on the block cast ingot in the crucible by utilizing a centrifugal machine and a centrifugal supergravity casting furnace; and finally taking out the block cast ingot to obtain a solidified alloy sample. The device is simple in structure, easy to operate and high in safety coefficient, and alloy samples with alloy components and microstructures in gradient distribution in the supergravity direction can be obtained.

Description

Technical Field

[0001] The invention belongs to a sample preparation method in the field of solidification, and in particular relates to a high-throughput preparation method of alloy materials based on centrifugal ultra-gravity solidification. Background Art

[0002] Key materials are the foundation of high-end manufacturing, but the traditional material research and development model has a long cycle and high investment, and due to the nonlinear relationship between material composition, structure and performance, it is difficult to achieve material design for actual performance requirements. In order to continue to maintain its own scientific and technological advantages, the United States took the lead in launching the "Materials Genome Project" in 2011 to establish a new material research and development model based on high-throughput material calculation, high-throughput material preparation and dedicated database technology, realizing the transformation of material research and development from "experience-guided experiments" to "theoretical prediction and experimental verification", shortening the time from discovery to application of new materials from 10-20 years to 5-10 years, and reducing research and development costs by more than half.

[0003] High-throughput material preparation technology is the basis for the smooth implementation of the "Material Genome Project". In the patent CN105903919A, a device and method for preparing samples with a wide cooling rate range by high-throughput centrifugal casting are proposed. In the patent CN112964538A, a high-throughput preparation method of materials is disclosed. Both methods are based on the gradient cooling rate formed to obtain a microstructure with a gradient distribution, thereby realizing the high-throughput preparation of materials. Obviously, these two methods cannot achieve dynamic regulation of the composition during solidification. In the patent CN115142060A, a high-throughput preparation method for alloy samples suitable for solidification dynamics research is disclosed, that is, two or more metal powders are transported by coaxial powder feeding technology, and the powder ratio along the deposition direction is changed during 3D printing. A wide-composition block alloy sample with alloy composition changing along the deposition direction is formed on the substrate. Compared with the first two methods, although this method can dynamically change the alloy composition, it cannot dynamically change the solidification rate. Summary of the invention

[0004] In order to solve the problems existing in the background technology, the purpose of the present invention is to provide a high-throughput preparation method of alloy materials based on centrifugal ultragravity solidification.

[0005] The technical solution adopted by the present invention comprises the following steps:

[0006] Step S1, placing alloy raw materials into a smelting furnace for vacuum smelting and pouring to obtain an ingot;

[0007] Step S2, sequentially subjecting the ingot obtained in step S1 to wire cutting, mechanical grinding, ultrasonic cleaning and constant temperature drying to obtain an alloy raw material for preparing the alloy by ultra-gravity;

[0008] Step S3: The alloy raw material obtained in step S2 is then processed by wire cutting into a volume of approximately 1 cm 3 Several block ingots are cast and all the block ingots are placed in the crucible, and then a round cover is installed on the top of the crucible to prevent heat loss and element volatilization during the ultra-gravity solidification process;

[0009] Step S4, then, two hanging cups are symmetrically fixed on the horizontal rotor of the centrifuge, and the horizontal rotor is connected to a high-speed electric slip ring, and a speed sensor and a vibration sensor are equipped on the centrifuge, the speed sensor is used to measure the speed of the centrifuge, and the vibration sensor is used to monitor the vibration of the centrifuge; a centrifugal ultra-gravity melting and casting furnace is installed in one of the hanging cups, and a counterweight block for balancing the centrifuge is installed in the other hanging cup, or a centrifugal ultra-gravity melting and casting furnace is installed in one of the hanging cups, and a centrifugal ultra-gravity melting and casting furnace is also installed in the other hanging cup for parallel experiments, wherein the electric wires of the centrifugal ultra-gravity melting and casting furnace are connected to the ground power supply system;

[0010] Step S5, placing the crucible in step S3 in a centrifugal ultra-gravity melting furnace in a centrifuge hanging cup;

[0011] Step S6: without heating, adjusting the dynamic rotation balance of the horizontal rotor to control the dynamic imbalance of the centrifuge;

[0012] Step S7, then using a centrifuge and a centrifugal ultra-gravity melting furnace to perform ultra-gravity solidification on the block ingot in the crucible;

[0013] Step S8: After the ultragravity solidification is completed, the centrifuge and the centrifugal ultragravity melting furnace are turned off, and after the crucible is completely cooled to room temperature, the block ingot is taken out to obtain the solidified alloy sample finally obtained.

[0014] Step S8 is specifically as follows: when the temperature of the centrifugal ultragravity melting furnace drops to 50°C below the alloy solidus temperature, the heating system and the centrifuge of the centrifugal ultragravity melting furnace are turned off; when the furnace temperature drops to below 200°C, the vacuum system is turned off; when the furnace temperature drops to room temperature, the centrifuge is completely stopped, and the sample is taken out from the crucible of the centrifugal ultragravity melting furnace, which is the solidified alloy sample.

[0015] The solidified alloy samples obtained in step S8 were sampled at different heights, and then the microstructure was analyzed using a scanning electron microscope; secondly, the samples at different heights were ground to 2000# with diamond sandpaper, and the mechanical properties of the samples at different heights under ultra-gravity solidification conditions were tested using a universal testing machine. To ensure the reliability of the experimental data, each group of samples was tested at least 3 times.

[0016] The type of crucible in step S3 is determined according to the type of alloy raw materials in step S1 and the centrifugal acceleration during the ultra-gravity solidification process:

[0017] If the liquidus temperature of the alloy raw material is lower than 1200°C and the centrifugal acceleration is not higher than 1500g, the crucible type is graphite crucible;

[0018] If the liquidus temperature of the alloy raw material is lower than 1200°C and the centrifugal acceleration is higher than 1500g, the crucible should be a hot isostatically pressed isotropic high-strength graphite crucible.

[0019] If the liquidus temperature of the alloy raw material is not less than 1200°C and the centrifugal acceleration is higher than 1500g, the crucible type is a molybdenum alloy crucible;

[0020] If the liquidus temperature of the alloy raw material is not lower than 1200°C and the centrifugal acceleration is not higher than 1500g, the crucible type is an ordinary graphite crucible.

[0021] The step S7 is specifically as follows:

[0022] Step S7.1: First, start the vacuum system in the centrifuge (corresponding to Figure 6 When the vacuum degree of the experimental chamber in the vacuum system is less than 1Pa, the heating system in the centrifugal ultragravity melting furnace is started to heat the crucible (corresponding to Figure 6 Point B in the figure, the time period from B to C is the heating time); wherein the centrifugal ultra-gravity melting furnace is placed in the experimental chamber, and during the heating process, the heating rate can be adjusted according to the heating temperature and the type of crucible;

[0023] Step S7.2: When the heating temperature of the crucible reaches the preset temperature (corresponding to Figure 6 After that, the crucible is kept warm for a while by using the heating system, and then the centrifuge is started (corresponding to point C in the figure). Figure 6 Point D in the figure, the time period from D to E is the centrifuge acceleration stage), the centrifugal acceleration of the centrifuge reaches the set centrifugal acceleration Ng (corresponding to Figure 6 After the preset time (the time period from E to F is the holding time when the melt reaches the heating temperature and the centrifugal acceleration at the bottom of the crucible reaches the preset value), the heating system in the centrifugal ultra-gravity melting furnace is controlled to make the block ingot in the crucible solidify at a preset cooling rate until the temperature of the centrifugal ultra-gravity melting furnace drops to 50°C below the solidus temperature of the alloy raw materials (corresponding to Figure 6 At this point, the bulk ingot completes supergravity solidification.

[0024] In the step S7.2, the supergravity solidification of the bulk ingot includes two cooling and solidification methods, namely the first cooling and solidification method and the second cooling and solidification method. The first cooling and solidification method is specifically: by controlling the upper / lower heating power of the heating system in the centrifugal supergravity melting furnace, the supergravity solidification with controllable cooling rate of the bulk ingot can be realized. In specific implementation, according to the thermal conductivity, cooling rate, heating temperature, etc. of the alloy raw materials themselves, by adjusting the upper / lower heating power, the supergravity solidification experiment with different cooling rates can be realized under the same centrifugal acceleration; or it can be realized under different centrifugal acceleration conditions. Ultragravity solidification experiment with the same cooling rate; the second cooling and solidification method is specifically: by controlling the upper / lower heating power of the heating system in the centrifugal ultragravity melting furnace, and at the same time introducing cooling gas (such as argon) into the bottom of the crucible, so as to achieve ultragravity solidification with controllable cooling rate of the bulk ingot. In specific implementation, according to the thermal conductivity, cooling rate, heating temperature, etc. of the alloy raw materials themselves, by adjusting the upper / lower heating power and ventilation flow rate, ultragravity solidification experiments with different cooling rates can be achieved under the same centrifugal acceleration conditions; or ultragravity solidification experiments with the same cooling rate can be achieved under different centrifugal acceleration conditions.

[0025] In step S6, the dynamic unbalance of the centrifuge is less than 2 g·mm.

[0026] In the step S7.2, when the heating temperature of the crucible reaches the preset temperature, the crucible is kept warm by the heating system for 30-60 minutes.

[0027] In the step S7.2, the cooling rate of the block ingot in the crucible during ultra-gravity solidification is 2-8°C / min.

[0028] The present invention intends to use a high-speed rotating centrifuge to form a centrifugal supergravity field in the melting furnace, and use the buoyancy convection effect caused by the supergravity-enhanced density difference to regulate the nucleation and growth behavior and the solidification structure formation sequence through factors such as temperature, cooling rate, and supergravity parameters, so as to achieve dynamic controllable and adjustable composition and solidification rate during the material solidification process, thereby obtaining materials with composition and structure gradients, thereby realizing high-throughput material preparation.

[0029] Centrifugal supergravity strengthens the buoyancy convection intensity in the melt. The greater the centrifugal acceleration, the greater the dynamic factor of the liquid-solid contact process, that is, the buoyancy factor Δρg (Δρ is the density difference between the liquid and solid phases, g = 9.8m / s 2 ), the greater the relative sliding speed of the melt. The huge shear stress overcomes the surface tension of the melt, increases the interphase contact interface in the melt, and greatly strengthens the mass transfer process at the liquid-solid interface. According to Newton's law, the centrifuge rotates at a high speed at a distance R from the rotating axis. i The centrifugal acceleration g generated by the position i for:

[0030]

[0031] Among them, R i is the rotation radius, in meters; ω is the angular velocity, in radians per second; N is the rotation speed, in rpm. When the temperature of the melt (ingot) drops below the liquidus-solidus temperature, crystal nuclei precipitate from the melt. Since the density of the crystal nuclei is greater than that of the melt, the precipitated crystal nuclei gradually sink in the melt under the action of centrifugal supergravity. The sinking speed v depends on the crystal nucleus gravity F1, the melt viscosity resistance F2 and the buoyancy F3 of the crystal nuclei.

[0032] The equation of motion of the crystal nucleus can be expressed as:

[0033]

[0034] Where m is the mass of the nucleus and t is the time. Assume that the precipitated nucleus is spherical, the nucleus radius is r, and the density is ρ s , F1=mg i , F2=6πηrv,F3=4πr 3 ρ l (R i ) i / 3, η is the dynamic viscosity of the melt, and the melt density ρ l (R i ) is the radius of rotation R i Function. Solving the above equation, we can get the nucleus sinking velocity v:

[0035]

[0036] Where A = 6πηr / m, e represents a natural number, π represents the ratio of circumference to circumference, and g i Substitute the expression into:

[0037]

[0038] When the time is long enough, the nucleus tends to sink at a uniform speed, and the limit sinking speed v cr for

[0039]

[0040] If the speed N = 670 rpm, the shaft radius R = 3.49 m, the density of the Al aluminum nucleus ρ s =2.702*10 3 kg / m 3 , the density of Al aluminum melt ρ l =2.38*10 3 kg / m 3 , the relationship between the crystal nucleus radius and its limiting sinking velocity can be obtained.

[0041] The present invention uses centrifugal supergravity solidification equipment with in-situ heating, heat preservation, and controllable and adjustable cooling rate functions. During the solidification process, the centrifugal acceleration during the solidification process is changed by dynamically adjusting the rotation speed, the solution viscosity is changed by adjusting the heating temperature, the crystal nucleus movement time is changed by adjusting the heat preservation time, and the microstructure distribution, composition and morphology are changed by adjusting the cooling rate, so as to realize the controllable and adjustable alloy composition and microstructure during the supergravity solidification process.

[0042] The beneficial effects of the present invention are:

[0043] 1. The present invention uses a centrifugal ultra-gravity melting and casting furnace to change the distribution and growth process of crystal nuclei during the solidification process of the melt through controllable and adjustable centrifugal ultra-gravity, cooling rate, heating temperature, holding time, etc., and obtains alloy samples with alloy components and microstructures gradiently distributed along the ultra-gravity direction through the movement of crystal nuclei under the action of ultra-gravity, thereby realizing high-throughput preparation of materials based on ultra-gravity solidification technology, and solving the key problem of high-throughput sample preparation of large-size blocks.

[0044] 2. The present invention has the function of realizing ultra-gravity directional solidification by using the power reduction method, which solves the key problem of difficult control of temperature gradient in the process of ultra-gravity directional solidification. It is suitable for 1500g-50000g ultra-gravity environment, the furnace temperature ranges from room temperature to 1700°C, the cooling rate and temperature gradient are adjustable and controllable, and it has the advantages of simple structure, operation scheme and high safety factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a schematic diagram of the force analysis of the crystal nucleus under supergravity environment;

[0046] Figure 2 is a graph of the nucleus radius and the limiting sinking velocity;

[0047] Figure 3 is a graph showing the change of the force on the crystal core with centrifugal acceleration at different crystal core radii; (a) is the crystal core radius of 5*10 -6 m, the force on the crystal core changes with centrifugal acceleration; (b) is the crystal core radius of 6*10 -5 m, and (c) is a graph showing the change of the force on the crystal core with centrifugal acceleration; (d) is a graph showing the change of the force on the crystal core with a radius of 10 -4 The graph of the change of the force on the crystal core with the centrifugal acceleration at m;

[0048] Figure 4 It is the relationship between melt viscosity and the limiting velocity of crystal nucleus sinking;

[0049] Figure 5 This is a schematic diagram of the principle of high-throughput preparation of materials in a hypergravity environment;

[0050] Figure 6 It is the flow chart of ultra-gravity solidification;

[0051] Figure 7 Schematic diagram of high-throughput sample in Example 1, wherein (a) is a schematic diagram of the sampling position and eutectic phase analysis position of the high-throughput sample; (b) is a microstructure diagram of the cross section of high-throughput sample A; (c) is a microstructure diagram of the cross section of high-throughput sample B; (d) is a microstructure diagram of the cross section of high-throughput sample C; (e) is a diagram showing the variation of the eutectic phase area fraction of the high-throughput sample along the sample height;

[0052] Figure 8 It is a schematic diagram of the high-throughput sample of Example 2, wherein (a) is a schematic diagram of the sampling position and eutectic phase analysis position of the high-throughput sample; (b) is a microstructure diagram of the cross section of the high-throughput sample A; (c) is a microstructure diagram of the cross section of the high-throughput sample B; (d) is a microstructure diagram of the cross section of the high-throughput sample C; (e) is a diagram showing the changes in the area fraction and average size of the Ni7Zr2 phase in the cross sections of the high-throughput samples A, B and C along the sample height; (f) is a diagram showing the changes in the mechanical properties of the cross sections of the high-throughput samples A, B and C along the sample height. DETAILED DESCRIPTION

[0053] The present invention is described in detail below in conjunction with specific implementation cases. The following implementation cases will help those skilled in the art to further understand the present invention, but will not limit the present invention in any form.

[0054] Example 1: Chemical composition of Cu-72Ag alloy by mass percentage: 72% Ag and the balance Cu; 1037g (g = 9.8 m / s 2 ) The supergravity preparation method comprises the following steps:

[0055] Step S1, obtaining an ingot using alloy raw materials;

[0056] Step S1.1: First, determine the heating temperature, centrifugal acceleration and holding time according to the alloy type:

[0057] Alloy type: Cu-72Ag; heating temperature: 1230℃, centrifugal acceleration: 1037g, holding time: 60min;

[0058] Step S1.2: Then determine the crucible type according to the alloy type, heating temperature, and centrifugal acceleration:

[0059] Alloy type: Cu-72Ag; the liquidus temperature of the alloy raw material Cu-72Ag is lower than 1200°C; heating temperature: 1230°C, centrifugal acceleration: 1037g, and a graphite crucible is selected.

[0060] Step S1.3, placing alloy raw materials Cu and Ag into a smelting furnace for vacuum smelting and pouring to obtain an ingot;

[0061] Step S2, sequentially subjecting the ingot obtained in step S1 to wire cutting, mechanical grinding, ultrasonic cleaning and constant temperature drying to obtain the alloy raw material Cu-72Ag for preparing the alloy by ultra-gravity;

[0062] Step S3: The alloy raw material Cu-72Ag obtained in step S2 is then processed by wire cutting into a volume of approximately 1 cm 3 Several block ingots are cast and all the block ingots are placed in the crucible, and then a round cover is installed on the top of the crucible to prevent heat loss and element volatilization during the ultra-gravity solidification process;

[0063] Step S4, then, two hanging cups are symmetrically fixed on the horizontal rotor of the centrifuge, and the horizontal rotor is connected to a high-speed electric slip ring, and a speed sensor and a vibration sensor are equipped on the centrifuge, the speed sensor is used to measure the speed of the centrifuge, and the vibration sensor is used to monitor the vibration of the centrifuge; a centrifugal ultra-gravity melting furnace is installed in one of the hanging cups, and a counterweight block for balancing the centrifuge is installed in the other hanging cup, wherein the electric wires of the centrifugal ultra-gravity melting furnace are connected to the ground power supply system;

[0064] Step S5, placing the crucible of step S3 in a centrifugal ultra-gravity melting furnace in a centrifuge hanging cup;

[0065] Step S6: without heating, adjusting the dynamic rotation balance of the horizontal rotor to control the dynamic unbalance of the centrifuge to be less than 2 g·mm;

[0066] Step S7: Then, a centrifuge and a centrifugal ultra-gravity melting furnace are used to perform ultra-gravity solidification on the block ingot in the crucible. The specific steps are as follows: Figure 6 As shown:

[0067] Step S7.1, first start the vacuum system in the centrifuge, and when the vacuum degree of the experimental chamber in the vacuum system is 0.5 Pa, start the heating system in the centrifugal ultra-gravity melting furnace to heat the crucible; wherein the centrifugal ultra-gravity melting furnace is placed in the experimental chamber, and during the heating process, the heating rate can be adjusted according to the heating temperature and the type of crucible;

[0068] Step S7.2, when the crucible temperature is heated to 1230°C at a rate of 10°C / min, the crucible is kept warm for 60 minutes by the heating system, and then the centrifuge is started. The centrifugal acceleration of the centrifuge reaches the set centrifugal acceleration of 1037g at an increase rate of 5rpm / s and continues for 60 minutes. Then, the block ingot in the crucible is cooled to below 5°C / min by controlling the up / down heating power of the heating system in the centrifugal ultragravity melting furnace, and ultragravity solidification is performed until the temperature of the centrifugal ultragravity melting furnace drops below 550°C, at which time the block ingot completes ultragravity solidification.

[0069] Step S8: After the ultragravity solidification is completed, the centrifuge and the centrifugal ultragravity melting furnace are turned off. When the furnace temperature drops below 200°C, the vacuum system is turned off. After the crucible is completely cooled to room temperature, the centrifuge is completely stopped, and the taken out block ingot is the final solidified alloy sample.

[0070] Step S9: Take samples of the solidified alloy sample obtained in step S8 at 10 mm, 20 mm, and 30 mm from the bottom of the sample, and then use a scanning electron microscope to perform microstructure analysis to obtain the microstructure distribution of the high-throughput sample along with its height. Figure 7 . Figure 7 (a)- Figure 7 (e) shows that the amount of eutectic phase in the Cu-72wt%Ag alloy gradually increases along the centrifugal supergravity direction, showing an obvious gradient distribution. The statistical results of the area fraction of the precipitated phase show that under centrifugal supergravity, buoyancy convection can be used to prepare high-throughput samples of Cu-Ag alloy with a gradient distribution of organization.

[0071] Example 2

[0072] Cu-5Zr-3Ni alloy chemical composition by mass percentage: 5% Zr, 3% Ni and the balance of Cu; Cu-5Zr-3Ni alloy 1512g (g = 9.8m / s 2 ) The supergravity preparation method comprises the following steps:

[0073] Step S1, obtaining an ingot using alloy raw materials;

[0074] Step S1.1: First, determine the heating temperature, centrifugal acceleration and holding time according to the alloy type:

[0075] Alloy type: Cu-5Zr-3Ni; heating temperature: 1230℃, centrifugal acceleration: 1512g, holding time: 30min;

[0076] Step S1.2: Then determine the crucible type according to the alloy type, heating temperature, and centrifugal acceleration:

[0077] Alloy type: Cu-5Zr-3Ni; the liquidus temperature of the alloy raw material Cu-5Zr-3Ni is lower than 1200°C, the heating temperature is 1230°C, the centrifugal acceleration is 1512g, and a hot isostatically pressed isotropic high-strength graphite crucible is selected.

[0078] Step S1.3, placing alloy raw materials Cu, Cu-Zr and Ni into a smelting furnace for vacuum smelting and pouring to obtain an ingot;

[0079] Step S2, sequentially subjecting the ingot obtained in step S1 to wire cutting, mechanical grinding, ultrasonic cleaning and constant temperature drying to obtain the alloy raw material Cu-5Zr-3Ni for preparing the alloy by ultra-gravity;

[0080] Step S3: The original alloy material Cu-5Zr-3Ni obtained in step S2 is then processed by wire cutting into a volume of approximately 1 cm 3 Several block ingots are cast and all the block ingots are placed in the crucible, and then a round cover is installed on the top of the crucible to prevent heat loss and element volatilization during the ultra-gravity solidification process;

[0081] Step S4, then symmetrically fix two hanging cups on the horizontal rotor of the centrifuge, connect the horizontal rotor with a high-speed electric slip ring, and equip the centrifuge with a speed sensor and a vibration sensor, the speed sensor is used to measure the speed of the centrifuge, and the vibration sensor is used to monitor the vibration of the centrifuge; install a centrifugal ultra-gravity melting furnace in one of the hanging cups, and install a counterweight for balancing the centrifuge in the other hanging cup, wherein the electric wires of the centrifugal ultra-gravity melting furnace are connected to the ground power supply system;

[0082] Step S5, placing the crucible of step S3 in a centrifugal ultra-gravity melting furnace in a centrifuge hanging cup;

[0083] Step S6: without heating, adjusting the dynamic rotation balance of the horizontal rotor to control the dynamic unbalance of the centrifuge to be less than 2 g·mm;

[0084] Step S7: Then, a centrifuge and a centrifugal ultra-gravity melting furnace are used to perform ultra-gravity solidification on the block ingot in the crucible:

[0085] Step S7.1, first start the vacuum system in the centrifuge, and when the vacuum degree of the experimental chamber in the vacuum system is 0.5 Pa, start the heating system in the centrifugal ultra-gravity melting furnace to heat the crucible; wherein the centrifugal ultra-gravity melting furnace is placed in the experimental chamber, and during the heating process, the heating rate can be adjusted according to the heating temperature and the type of crucible;

[0086] Step S7.2, when the crucible temperature is heated to 1230°C at a rate of 10°C / min, the crucible is kept warm for 30 minutes by the heating system, and then the centrifuge is started. The centrifugal acceleration of the centrifuge reaches the set centrifugal acceleration of 1512g at an increase rate of 5rpm / s and continues for 30 minutes. Then, the heating power of the heating system in the centrifugal ultragravity melting furnace is controlled, and 30L / min of argon is introduced at the same time, so that the block ingot in the crucible is ultragravity solidified at a cooling rate of 2°C / min until the temperature of the centrifugal ultragravity melting furnace drops below 550°C, at which time the block ingot completes ultragravity solidification.

[0087] Step S8: After the ultragravity solidification is completed, the centrifuge and the centrifugal ultragravity melting furnace are turned off. When the furnace temperature drops below 200°C, the vacuum system is turned off. After the crucible is completely cooled to room temperature, the centrifuge is completely stopped, and the taken out block ingot is the final solidified alloy sample.

[0088] Step S9: Take samples of the solidified alloy sample obtained in step S8 at 10 mm, 20 mm, and 30 mm from the bottom of the sample, and then use a scanning electron microscope to perform microstructure analysis to obtain the microstructure distribution of the high-throughput sample along with its height. Figure 8 . Figure 8 (a)- Figure 8 (f) shows that the amount of eutectic phase in the Cu-5Zr-3Ni alloy gradually increases along the centrifugal supergravity direction, showing an obvious gradient distribution. The statistical results of the area fraction of the precipitated phase show that under centrifugal supergravity, a high-throughput sample of Cu-5Zr-3Ni alloy with a gradient distribution of organization can be prepared by buoyancy convection.

[0089] Figure 1 This is a schematic diagram of the force analysis of the crystal nucleus under a high-gravity environment. The present invention aims to solve the key problem that the composition and solidification structure cannot be dynamically controlled simultaneously in the high-throughput preparation process of existing materials. Based on a centrifugal high-gravity solidification device with in-situ heating, heat preservation, and controllable and adjustable cooling rate, a high-throughput preparation method for alloy materials is proposed. The relationship between the crystal nucleus radius and its limit sinking speed is shown in Figure 2 . Figure 2 It shows that as the crystal core radius increases, its limit sinking speed increases. -6 m (region 1), the influence of the crystal core radius on the sinking limit velocity is small; 5ⅹ10 -6 m<nucleus radius<6×10 -5 m (region 2), the nucleus radius is approximately proportional to its limit sinking velocity; the nucleus radius is greater than 6 x 10 -5 m (region 3), the nucleus sinking speed increases rapidly. Since the slope of the nucleus radius-limit sinking speed curve is 4πr 2 g iΔρ-6πη, so when the crystal core radius r is small, the slope of the curve is more affected by -6πη, that is, the slope of the curve is smaller; as the crystal core radius r increases, the viscous resistance plays a dominant role. Figure 3 (a)- Figure 3 (c) shows the relationship between the force on the crystal core and the centrifugal acceleration under different crystal core radii r. It can be seen that as the crystal core radius increases, the viscous drag is much smaller than the combined force of its gravity and buoyancy. When the crystal core radius is the same, as the centrifugal acceleration increases, the difference between gravity and buoyancy increases, but the viscous drag remains basically unchanged, so the sinking speed of the crystal core increases. Figure 4 The effect of melt viscosity on the crystal nucleus sinking speed. It can be seen that as the melt viscosity increases, the crystal nucleus sinking speed decreases.

[0090] according to Figure 5 In order to achieve high-throughput preparation of materials under ultra-gravity environment, first, the alloy composition is selected based on: the temperature difference between liquidus and solidus is as large as possible, and the density difference between the crystal nucleus and the melt is as large as possible; second, the solidification speed is as slow as possible, so that the crystal nucleus has enough time to sink or float; third, the alloy melt is superheated as high as possible to reduce the melt viscosity and increase the movement speed of the crystal nucleus; fourth, the force condition of the crystal nucleus is changed by centrifugal acceleration, so that the composition and organization are distributed in a gradient along the direction of centrifugal acceleration.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-throughput preparation method of alloy materials based on centrifugal ultra-gravity solidification, characterized in that: The following steps are involved: Step S1, firstly, placing alloy raw materials into a smelting furnace for vacuum smelting and pouring to obtain an ingot; Step S2, sequentially subjecting the ingot obtained in step S1 to wire cutting, mechanical grinding, ultrasonic cleaning and constant temperature drying to obtain an alloy raw material for preparing the alloy under ultra-gravity conditions; Step S3, then the alloy raw material obtained in step S2 is processed into a plurality of block ingots by wire cutting, and all the block ingots are placed in a crucible, and then a round cover is installed on the top of the crucible; Step S4, symmetrically fixing two hanging cups on the horizontal rotor of the centrifuge, and installing a centrifugal ultra-gravity melting and casting furnace in the hanging cups; Step S5, placing the crucible in step S3 in a centrifugal ultra-gravity melting furnace in a hanging cup; Step S6, adjusting the dynamic rotation balance of the horizontal rotor when not heated to control the dynamic unbalance amount of the centrifuge to reach a set value; Step S7, then using a centrifuge and a centrifugal ultra-gravity melting furnace to perform ultra-gravity solidification on the block ingot in the crucible; Step S8: After the ultragravity solidification is completed, the centrifuge and the centrifugal ultragravity melting furnace are turned off, and after the crucible is completely cooled to room temperature, the block ingot is taken out to obtain the solidified alloy sample finally obtained.

2. The high-throughput preparation method of alloy materials based on centrifugal ultragravity solidification according to claim 1, characterized in that: The type of crucible in step S3 is determined according to the type of alloy raw materials in step S1 and the centrifugal acceleration during the ultra-gravity solidification process: If the liquidus temperature of the alloy raw material is lower than 1200°C and the centrifugal acceleration is not higher than 1500g, the crucible type is graphite crucible; If the liquidus temperature of the alloy raw material is lower than 1200°C and the centrifugal acceleration is higher than 1500g, the crucible is an isostatically pressed isotropic graphite crucible. If the liquidus temperature of the alloy raw material is not less than 1200°C and the centrifugal acceleration is higher than 1500g, the crucible type is a molybdenum alloy crucible; If the liquidus temperature of the alloy raw material is not lower than 1200°C and the centrifugal acceleration is not higher than 1500g, the crucible type is a graphite crucible.

3. The high-throughput preparation method of alloy materials based on centrifugal ultragravity solidification according to claim 1, characterized in that: The step S7 is specifically as follows: Step S7.1, first start the vacuum system in the centrifuge, and when the vacuum degree of the experimental chamber in the vacuum system is less than 1 Pa, start the heating system in the centrifugal ultragravity melting furnace to heat the crucible; Step S7.2, when the heating temperature of the crucible reaches the preset temperature, the crucible is kept warm for a period of time by using the heating system, and then the centrifuge is started. After the centrifugal acceleration of the centrifuge reaches the set centrifugal acceleration Ng and continues for a preset time, the heating system in the centrifugal ultragravity melting and casting furnace is controlled to make the block ingot in the crucible undergo ultragravity solidification at a preset cooling rate until the temperature of the centrifugal ultragravity melting and casting furnace drops to 50°C below the solidus temperature of the alloy raw material, at which time the block ingot completes ultragravity solidification.

4. The high-throughput preparation method of alloy materials based on centrifugal ultra-gravity solidification according to claim 3, characterized in that: In the step S7.2, the supergravity solidification of the bulk ingot includes two cooling and solidification methods, namely a first cooling and solidification method and a second cooling and solidification method. The first cooling and solidification method is specifically: by controlling the heating power of the heating system in the centrifugal supergravity melting and casting furnace, to achieve supergravity solidification with a controllable cooling rate of the bulk ingot; the second cooling and solidification method is specifically: by controlling the heating power of the heating system in the centrifugal supergravity melting and casting furnace, and at the same time introducing cooling gas at the bottom of the crucible, to achieve supergravity solidification with a controllable cooling rate of the bulk ingot.

5. The high-throughput preparation method of alloy materials based on centrifugal ultra-gravity solidification according to claim 1, characterized in that: In step S6, the dynamic unbalance of the centrifuge is less than 2 g·mm.

6. The high-throughput preparation method of alloy material based on centrifugal ultra-gravity solidification according to claim 3, characterized in that: In the step S7.2, when the heating temperature of the crucible reaches the preset temperature, the crucible is kept warm by the heating system for 30-60 minutes.

7. The high-throughput preparation method of alloy materials based on centrifugal ultra-gravity solidification according to claim 3, characterized in that: In the step S7.2, the cooling rate of the block ingot in the crucible during ultra-gravity solidification is 2-8°C / min.

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