Method and system for preparing bimetallic composite material based on metal droplet size regulation and control

Abstract

The invention discloses a bimetallic composite material preparation method and system based on metal droplet size regulation and control, and belongs to the technical field of centrifugal casting. According to the method, aiming at a bimetal system with a liquid-liquid mixing and dissolving gap, an alloy melt is smelted according to a preset proportion, and then precise control over the size of second metal phase liquid drops is achieved in a casting ladle by regulating and controlling the standing time in combination with a high-temperature and high-speed camera shooting system. Then relevant casting parameters are input into an autonomously derived liquid drop movement speed and trajectory prediction model, the liquid drop position is predicted, and finally the centrifugal rotating speed or the heating power is adjusted through feedback control according to the deviation between a prediction result and a preset trajectory, so that directional preparation of different structures of the bimetal composite material is achieved. The corresponding system comprises a monitoring module, a calculation module and an execution module which cooperatively complete parameter monitoring, calculation analysis and precise regulation and control in the material preparation process. The casting inclusion defect can be reduced, the product quality instability is reduced, and directional preparation of different structures of the bimetal composite material is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of centrifugal casting, and relates to a double-metal composite material preparation method and system based on metal droplet size regulation, which is particularly suitable for double-metal composite materials (such as Cu-Fe and Cu-Co) with liquid-liquid mixed melting gaps, and solves the problems of uncontrollable product structure and large quality fluctuation of the existing centrifugal casting method for preparing composite materials. BACKGROUND

[0002] Double-metal composite materials are prepared by metallurgical bonding of two alloys with different physical, chemical or mechanical properties, and the performance thereof is superior to that of single metal materials. For example, the inner layer of copper-iron double-metal composite material is iron or low-carbon steel, and the outer layer is red copper or copper alloy. The copper-iron double-metal composite material has excellent electrical conductivity, thermal conductivity and corrosion resistance of copper, and high strength, wear resistance and low cost characteristics of iron, and has broad application prospects in the fields of automobiles, communications, electronics, chemical industry, power systems, medical equipment, aerospace, machinery manufacturing and the like. According to the state of the pre-bonding material, the preparation methods of double-metal composite materials are mainly divided into three categories: solid-solid bonding method, such as diffusion bonding, explosive welding and friction welding; solid-liquid bonding method, including composite casting and insert forming; and liquid-liquid bonding method, such as centrifugal casting method. The solid-solid bonding method and the solid-liquid bonding method need to be finely treated before bonding, and the process parameters and environmental conditions need to be accurately controlled during bonding, which makes the above methods complex and costly.

[0003] In the metal system, many alloys have a miscibility gap in the liquid state. When the alloy melt cools to the miscibility gap, the alloy melt with uniform composition will spontaneously decompose into two liquid phases with different compositions. This liquid phase separation phenomenon often leads to macrosegregation in the alloy ingot, which is not conducive to traditional alloy manufacturing. However, on the other hand, reasonable use of this phenomenon helps to prepare alloys with special structures. Centrifugal casting is a very promising method for preparing double-metal composite materials with a miscibility gap, because the interface of dissimilar metals is well metallurgically bonded, the cost is low, the process is simple, and the flow is short. However, the structure of the double-metal composite material prepared by the centrifugal casting method is uncontrollable, the product structure and quality fluctuate greatly, and it is completely dependent on experience and trial and error. Therefore, there is an urgent need for a method that can accurately control the structure and quality of the centrifugal casting double-metal composite material.

[0004] In general, the structure of the bimetallic composite prepared by centrifugal casting is uncontrollable, the product structure and quality fluctuate greatly, and the experience and trial and error are completely relied on. Moreover, the experience only focuses on the influence of the rotating speed on the surface quality, shrinkage and the like of the centrifugal casting sample. However, the product structure and quality of the centrifugal casting bimetallic composite are related to the temperature gradient, the metal liquid droplet radius, the density, the viscosity, the interface energy and the like in addition to the rotating speed. Since the existing technology and experience lack the influence of the temperature gradient, the metal liquid droplet radius, the density, the viscosity, the interface energy and the like on the product structure and quality of the centrifugal casting bimetallic composite, the existing technology is difficult to realize the accurate control of the product structure and quality of the bimetallic composite. SUMMARY

[0005] In view of the problems that the size of the second metal phase liquid droplet is uncontrollable, the multi-parameter synergistic effect is absent and the structure and quality stability are poor in the preparation of the bimetallic composite with a liquid-liquid miscibility gap by the existing centrifugal casting, the present application provides a bimetallic composite preparation method and system based on metal liquid droplet size regulation, which realizes the directional preparation and quality stability of the composite material complex structure by accurately regulating the liquid droplet size, establishing a multi-parameter correlation model and closed-loop control.

[0006] The present application is realized by the following technical scheme. A bimetallic composite preparation method based on metal liquid droplet size regulation comprises the following steps: (a) Alloy melting: an alloy containing bimetallic A and B with a liquid-liquid miscibility gap is prepared according to a preset mass percentage, and the prepared alloy raw material is placed in a melting furnace for melting to obtain an alloy melt with uniform composition; (b) Metal liquid droplet size regulation in ladle: the alloy melt obtained in step (a) is poured from the melting furnace into a ladle, and the alloy melt is allowed to stand in the ladle (0-60 seconds), during which the non-metallic inclusions float to the surface of the melt, the melt temperature is stabilized and the melt turbulence is reduced, the size of the second metal phase liquid droplet is regulated by controlling the standing time, the longer the standing time, the larger the size of the second metal phase liquid droplet, and the size of the second metal phase liquid droplet is monitored in real time by using a high-temperature high-speed camera system; (c) Metal liquid droplet trajectory prediction: obtain casting parameters, the casting parameters include the second phase metal liquid droplet radius, the second phase metal liquid droplet density, the second phase metal liquid droplet viscosity, the interface energy, the radial temperature gradient, the centrifugal radius, the initial position of the liquid droplet, the rotating speed and the temperature gradient of the centrifugal casting, input the above-mentioned casting parameters into the liquid droplet motion velocity model and the liquid droplet motion trajectory prediction model to obtain the position of the second phase metal liquid droplet at time t, change the alloy melt solidification speed by controlling the mold preheating temperature, utilize the mutual competition between the second metal phase liquid droplet motion speed and the alloy melt solidification speed (the moving speed of the solid-liquid interface) to obtain bimetallic composites with different structures; (d) Feedback control: based on the trajectory prediction model of the droplet movement in step (c), the real-time position of the second phase metal droplet is calculated, the real-time position is compared with the preset trajectory, and the rotation speed of the centrifugal casting or the heating power is adjusted to ensure that the final double-metal composite material meets the preset structural requirements.

[0007] The structure of the double-metal composite material includes complete separation of the A-rich phase and the B-rich phase, the presence of spherical B phase in the A-rich phase, the presence of spherical A phase in the B-rich phase, and a multi-layer composite structure.

[0008] Specifically, the double-metal A and B are selected from any one of Cu-Fe, Cu-Co, Cu-Cr, Al-Pb, Al-Bi, Al-In, Ag-Ni, Ag-Cr, Pb-Fe, Zn-Pb, and Ga-Pb.

[0009] Specifically, the high-temperature high-speed camera system includes a high-temperature sapphire lens with a temperature resistance of ≥2000℃, a water-cooled protective sleeve, a near-infrared light source with a wavelength of 850-1050nm, and a 1000fps high-speed camera.

[0010] Further, in step (b), the ladle can be subjected to heat preservation treatment when the alloy melt is stationary in the ladle, so as to maintain the stability of the alloy melt temperature and avoid the influence of temperature fluctuation on the formation and growth of the second metal phase droplets.

[0011] Further, in step (c), the mold preheating temperature is adjusted according to the solidification characteristics of the double-metal A and B alloy melts and the structure of the required double-metal composite material. The mold preheating can be achieved by electric heating or flame heating, and the uniformity of the temperature of each part of the mold is controlled during the preheating process.

[0012] Further, in step (d), when adjusting the rotation speed of the centrifugal casting, a frequency converter is used to achieve a rotation speed adjustment range of ±100rpm; when adjusting the heating power, an induction heater is used to achieve a power adjustment range of ±50kW.

[0013] A double-metal composite material preparation system for realizing a double-metal composite material preparation method based on metal droplet size control, comprising a monitoring module, a calculation module and an execution module; The monitoring module comprises a high-temperature camera unit arranged in the ladle and a radial thermocouple array arranged on the mold, the high-temperature camera unit is used to monitor the size of the second phase metal droplets in the ladle in real time, and the radial thermocouple array is used to collect temperature gradient data in the radial direction of the mold in real time. The computing module: for inputting material parameters and process parameters, the material parameters include the second phase metal droplet radius, the second phase metal droplet density, the second phase metal droplet viscosity, the interface energy, the process parameters include the radial temperature gradient, the centrifugal radius, the angular velocity, the droplet initial position, the rotation speed of the centrifugal casting and the temperature gradient, the computing module is built-in the droplet motion speed model and the droplet motion trajectory prediction model in claim 1, the position of the second phase metal droplet at time t can be calculated according to the input parameters, and the deviation of the real-time position and the preset trajectory is compared; The executing module: including a frequency converter and an induction heater, the frequency converter is connected with the centrifugal casting equipment, is used for adjusting the rotation speed of the centrifugal casting according to the deviation signal of the computing module, and the adjustment range is ±100rpm, the induction heater is connected with the mold or the smelting related equipment, is used for adjusting the heating power according to the deviation signal of the computing module, and the adjustment range is ±50kW.

[0014] Further, the high-temperature camera unit in the monitoring module is also equipped with image analysis software, which can automatically analyze the collected second phase metal droplet image, calculate the average size, size distribution and other parameters of the droplet, and transmit these parameters to the computing module in real time.

[0015] Further, the computing module also has a data storage function, which can store the input parameters, calculation process data and final result data, facilitating subsequent process optimization and product quality traceability.

[0016] Further, the frequency converter and the induction heater in the executing module both have automatic control and manual control modes, in the automatic control mode, the parameters are automatically adjusted according to the signal of the computing module, and in the manual control mode, the operator can manually adjust the parameters according to the actual situation.

[0017] The advantages and beneficial effects of the present application are: 1、The present application can significantly reduce the inclusion defects in the castings.

[0018] 2、The present application can reduce the instability of the quality of the bimetallic composite material product with immiscible gap and improve the casting yield.

[0019] 3、The present application can realize precise control of the structure of the bimetallic composite material casting with immiscible gap, through precise control of the droplet size and droplet trajectory prediction, various complex structures such as completely separated type, spherical dispersion type and multi-layer composite (such as Fe / Cu / Fe) can be prepared, different structures have different characteristics, which expands the application range of the bimetallic composite material, and the droplet size and process parameters can be adjusted to meet the requirements of different application scenarios for material performance. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 Schematic diagram of the change of the velocity of the Fe-rich droplet with the droplet radius and the change of the position of the Fe-rich droplet (centrifugal radius) with time in Example 1.

[0021] Figure 2 Schematic diagram of the change of the velocity of the Fe-rich droplet with the droplet radius and the change of the position of the Fe-rich droplet (centrifugal radius) with time in Example 1. Figure 2 Photographs of (a) cross-section and (b) longitudinal section of the Cu / Fe bimetallic composite material.

[0022] Figure 3 Photographs of (a) SEM and (b) EBSD of the Cu / Fe bimetallic composite material in Example 1.

[0023] Figure 4 Schematic diagram of the change of the velocity of the Fe-rich droplet with the droplet radius and the change of the position of the Fe-rich droplet (centrifugal radius) with time in Example 2.

[0024] Figure 5 Macroscopic morphology of the sample prepared in Example 2.

[0025] Figure 6 Photographs of (a) low magnification and (b) high magnification SEM of the sample prepared in Example 2.

[0026] Figure 7 Schematic diagram of the change of the velocity of the Fe-rich droplet with the droplet radius in Example 3.

[0027] Figure 8 Macroscopic morphology photograph of the sample prepared in Example 3.

[0028] Figure 9 EBSD photographs of (a) outer Fe / Cu interface and (b) inner Cu / Fe interface of the sample prepared in Example 3. DETAILED DESCRIPTION

[0029] The present application is further illustrated in detail below.

[0030] A bimetallic composite material preparation method based on metal droplet size control, comprising the following steps: (a) Melting alloy melt: preparing an alloy containing bimetals A and B with liquid-liquid miscibility gap according to a preset mass percentage, placing the prepared alloy raw material in a melting furnace for melting to obtain an alloy melt with uniform composition; the bimetals A and B are selected from any one of Cu - Fe, Cu - Co, Cu - Cr, Al - Pb, Al - Bi, Al - In, Ag - Ni, Ag - Cr, Pb- Fe, Zn - Pb, Ga - Pb; the melting temperature is set according to the characteristics of the bimetals A and B to ensure that the alloy raw material is completely melted and the composition is uniform, and inert gas protection can be used during the melting process to prevent the alloy melt from being oxidized; (b) Size control of molten metal droplets in the ladle: The alloy melt obtained in step (a) is poured from the melting furnace into the ladle and allowed to stand for 0-60 seconds. During this process, non-metallic inclusions float to the surface of the melt, while the melt temperature is stabilized and the melt turbulence is reduced. The size of the second metal phase droplets is controlled by adjusting the standing time. The longer the standing time, the larger the size of the second metal phase droplets. The size of the second metal phase droplets is monitored in real time using a high-temperature high-speed camera system. The high-temperature high-speed camera system includes a high-temperature resistant sapphire lens with a temperature resistance of ≥2000℃, a water-cooled protective sleeve, a near-infrared light source with a wavelength of 850-1050nm, and a 1000fps high-speed camera. In step (b), when the alloy melt is placed in the ladle, the ladle can be kept warm to maintain the temperature stability of the alloy melt and avoid the formation and growth of the second metal phase droplets due to temperature fluctuations. (c) Metal Droplet Trajectory Prediction: Casting parameters are obtained, including the radius, density, viscosity, interfacial energy, radial temperature gradient, centrifugal radius, initial droplet position, centrifugal casting rotation speed, and temperature gradient of the second-phase metal droplet. These casting parameters are input into the droplet velocity model and the droplet trajectory prediction model to obtain the position of the second-phase metal droplet at time t. By controlling the mold preheating temperature to change the solidification rate of the alloy melt, and utilizing the competition between the second-phase metal droplet velocity and the alloy melt solidification rate (the movement speed of the solid-liquid interface), bimetallic composite materials with different structures are obtained. The droplet trajectory prediction model can be found in the literature "A Novel Liquid-Liquid Method for Preparing Bimetallic Composite Materials Using Liquid Phase Separation Phenomenon," which specifically includes: Droplet velocity model: (1); Where v d ρ is the velocity of the second metallic phase droplet in the immiscible alloy melt, r is the radius of the second metallic phase droplet, and ρ is the velocity of the droplet. d and ρ m These are the densities of the second metallic droplet and the liquid matrix, respectively; ω is the angular velocity; R is the centrifugal radius; and μ is the density of the liquid phase droplet and the liquid matrix, respectively. m and μ d Let represent the viscosity of the liquid matrix and the second metal phase droplet, respectively, and σ represent the interfacial energy. This represents the temperature gradient along the radial direction.

[0031] The droplet trajectory prediction model is as follows: (2); Where R(t) is the position (centrifugal radius) of the second metal phase droplet at any time t, and R0 is a parameter related to the initial position of the droplet.

[0032] In step (c), the mold preheating temperature is adjusted according to the solidification characteristics of the bimetallic A and B alloy melts and the required structure of the bimetallic composite material. Mold preheating can be carried out by electric heating or flame heating, and the temperature of each part of the mold is uniformly controlled during the preheating process.

[0033] (d) Feedback Control: Based on the droplet trajectory prediction model in step (c), the real-time position of the second-phase metal droplet is calculated. The real-time position is compared with the preset trajectory, and the centrifugal casting speed or heating power is adjusted to ensure that the final bimetallic composite material meets the preset structural requirements. When adjusting the centrifugal casting speed, a frequency converter is used to achieve a speed adjustment range of ±100 rpm; when adjusting the heating power, an induction heater is used to achieve a power adjustment range of ±50 kW. The structure of the bimetallic composite material includes complete separation of the A-rich phase and the B-rich phase, the presence of spherical B phases in the A-rich phase, the presence of spherical A phases in the B-rich phase, and a multi-layered composite structure.

[0034] The present invention will be further explained in detail below with reference to the embodiments.

[0035] Example 1: Cu / Fe bimetallic composite material with complete separation of Cu-rich and Fe-rich phases 1. Melting and Droplet Control: Melt composition: Cu-30Fe-1.6C (wt%), smelted at 1800K; Static monitoring: The alloy melt is poured from the melting furnace (or crucible) into a ladle. The melt is allowed to stand in the ladle for 30 seconds to allow non-metallic inclusions to float to the surface, while simultaneously stabilizing the temperature and reducing turbulence. The droplet size is controlled by the duration of the static monitoring; longer static times result in larger droplets. A high-temperature imaging system displays the change in Fe-rich droplet size with static time. The results show that the average diameter of the second metallic phase droplets reaches ~50 μm after 30 seconds of static monitoring.

[0036] 2. Centrifugal casting control: Initial parameters: Mold preheating temperature 300℃ o C, rotation speed 1400 rpm, mold centrifugation radius 37.5 mm. Trajectory prediction: Casting parameters, including Fe-rich droplet radius, density, viscosity, interfacial energy, radial temperature gradient, centrifugal radius, initial position of the Fe-rich droplet, centrifugal casting rotation speed, and temperature gradient, are input into the droplet velocity and trajectory prediction model to obtain the position of the A-rich metal droplet at time t. Figure 1 As shown. Calculation results indicate that the velocity of the Fe-rich droplets is 90-115 mm / s, and the mold preheating temperature is 300°C. oAt C, the solidification rate of the alloy melt (i.e., the solid-liquid interface movement rate) is about 10 mm / s. Obviously, the movement speed of the Fe-rich droplets is much greater than the solid-liquid interface movement rate. Therefore, it is predicted that Cu / Fe bimetallic composite materials with complete separation of Cu-rich and Fe-rich phases can be obtained under this process condition.

[0037] 3. Results: Based on the above process conditions, a Cu / Fe bimetallic composite material with completely separated Cu-rich and Fe-rich phases was successfully prepared, such as... Figure 2 As shown, the prepared sample exhibits a metallurgical bonding interface between the copper (Cu) layer and the Fe-rich layer, and is free of cracks. Figure 3 These are SEM and EBSD images of the Cu / Fe bimetallic composite material. In the EBSD image, the red area represents the Cu phase, the blue area represents the Fe phase, and the yellow area represents the Fe3C phase.

[0038] Example 2: A complex Cu / Fe bimetallic composite material with a spherical Fe-rich phase within a Cu-rich phase. Melt composition: Cu-30Fe-1.6C (wt%), smelted at 1800K; Static monitoring: The alloy melt is poured from the melting furnace (or crucible) into a ladle. The melt is allowed to stand in the ladle for 1 second. A 1-second stand yields smaller droplets, with an average second-metal phase droplet size of 10 μm. A high-temperature imaging system displays the change in Fe-rich droplet size over time.

[0039] 2. Centrifugal casting control: Initial parameters: rotation speed 1400 rpm, mold preheating temperature 300℃ o C, the centrifugal radius of the mold is 37.5 mm.

[0040] Trajectory prediction: Casting parameters, including Fe-rich droplet radius, density, viscosity, interfacial energy, radial temperature gradient, centrifugal radius, initial position of the Fe-rich droplet, centrifugal casting rotation speed, and temperature gradient, are input into the droplet trajectory prediction model to obtain the velocity and position of the Fe-rich metal droplet at time t. Figure 4 As shown. Calculation results indicate that the velocity of the Fe-rich droplets is 7-8 mm / s, and the mold preheating temperature is 300°C. o At C, the solidification rate of the alloy melt (i.e., the solid-liquid interface movement speed) is about 10 mm / s. Obviously, the movement speed of Fe-rich droplets is less than the solid-liquid interface movement speed. Therefore, it is predicted that under this process condition, since the movement speed of Fe-rich droplets is less than the solid-liquid interface movement speed, it is impossible to form a Cu / Fe composite material with complete separation of Cu-rich phase and Fe-rich phase. Instead, a composite material containing spherical Fe-rich phase in Cu-rich phase will be obtained.

[0041] 3. Results: Figure 5 These are macroscopic morphological photographs of the prepared samples. It can be seen that the prepared samples did not exhibit complete stratification between Cu-rich and Fe-rich phases. Figure 6 The image shows a SEM image of the prepared sample. It can be seen that many spherical Fe-rich phases are distributed in the Cu-rich matrix, which is consistent with the prediction results of the prediction model.

[0042] Example 3: Fe / Cu / Fe bimetallic composite material with complete separation of Cu-rich and Fe-rich phases 1. Melting and Droplet Control: Melt composition: Cu-30Fe-1.6C (wt%), smelted at 1800K; Static monitoring: The alloy melt is poured from the melting furnace (or crucible) into a ladle. The melt is allowed to stand in the ladle for 60 seconds to allow non-metallic inclusions to float to the surface, while simultaneously stabilizing the temperature and reducing turbulence. The droplet size is controlled by the duration of the static monitoring; the longer the static time, the larger the droplets. A high-temperature imaging system displays the change in Fe-rich droplet size with static time. The results show that after 60 seconds of static monitoring, some Fe-rich droplets fully coalesce and, under the influence of buoyancy, completely separate from the Cu-rich liquid phase matrix, forming an upper Fe-rich liquid phase layer; some Fe-rich droplets exist in the mixing zone between the middle Cu-rich and Fe-rich liquid phases, with an average Fe-rich droplet size of ~100 μm; the lower layer is mainly a Cu-rich liquid phase layer.

[0043] 2. Centrifugal casting control: Initial parameters: Mold preheating temperature 300℃ o C, rotation speed 1400 rpm, mold centrifugation radius 37.5 mm.

[0044] Trajectory Prediction: Before casting, the alloy melt forms an upper Fe-rich liquid phase layer, an intermediate mixed layer, and a lower Cu-rich layer. When the crucible is poured, the uppermost Fe-rich liquid phase flows out first, entering the high-speed rotating centrifugal casting cavity and preferentially begins to cool and solidify; following the Fe-rich liquid phase, the mixture in the intermediate transition zone and the lower Cu-rich layer are poured into the rotating mold. This portion of the post-cast melt covers the partially solidified or still liquid inner layer of Fe-rich melt. Casting parameters, including Fe-rich droplet radius, density, viscosity, interfacial energy, radial temperature gradient, centrifugal radius, initial position of the Fe-rich droplet, centrifugal casting speed, and temperature gradient, are input into the droplet trajectory prediction model to obtain the velocity of the Fe-rich metal droplets, such as... Figure 7As shown, the average size of the Fe-rich droplets in the mixing zone is ~100 μm, and their velocity is 312-413 mm / s, which is much greater than the solid-liquid interface velocity (10 mm / s). Therefore, it is predicted that under these process conditions, the Fe-rich droplets in the post-cast mixture will move towards the center of rotation and solidify in the outer region of the intermediate Cu layer, ultimately forming an Fe / Cu / Fe type bimetallic composite material.

[0045] 3. Results: Based on the above process conditions, a Fe / Cu / Fe bimetallic composite material with complete separation of Cu-rich and Fe-rich phases was successfully prepared, such as... Figure 8 As shown, the results are consistent with the prediction model. The prepared sample shows a metallurgical bonding interface between the copper Cu layer and the Fe-rich layer, and there are no cracks. Figure 9 This is the EBSD image of the Fe / Cu / Fe bimetallic composite material. The red area in the EBSD image represents the Cu phase, the blue area represents the Fe phase, and the yellow area represents the Fe3C phase.

[0046] Example 4 A bimetallic composite material preparation system for realizing a method for preparing bimetallic composite materials based on the size control of metal droplets includes a monitoring module, a calculation module, and an execution module; The monitoring module includes a high-temperature camera unit installed inside the ladle and a radial thermocouple array installed on the mold. The high-temperature camera unit is used to monitor the size of the second-phase metal droplets inside the ladle in real time, and the radial thermocouple array is used to collect the temperature gradient data of the mold radially in real time. The calculation module is used to input material parameters and process parameters. The material parameters include the radius, density, viscosity, and interfacial energy of the second-phase metal droplet. The process parameters include the radial temperature gradient, centrifugal radius, angular velocity, initial droplet position, centrifugal casting rotation speed, and temperature gradient. The calculation module incorporates the droplet motion velocity model and droplet motion trajectory prediction model described in claim 1. It can calculate the position of the second-phase metal droplet at time t based on the input parameters and compare the deviation between the real-time position and the preset trajectory. The execution module includes a frequency converter and an induction heater. The frequency converter is connected to the centrifugal casting equipment and is used to adjust the centrifugal casting speed according to the deviation signal from the calculation module. The adjustment range is ±100 rpm. The induction heater is connected to the mold or smelting-related equipment and is used to adjust the heating power according to the deviation signal from the calculation module. The adjustment range is ±50 kW.

[0047] Furthermore, the high-temperature camera unit in the monitoring module is also equipped with image analysis software, which can automatically analyze the acquired images of the second-phase metal droplets, calculate parameters such as the average size and size distribution of the droplets, and transmit these parameters to the calculation module in real time.

[0048] Furthermore, the calculation module also has a data storage function, which can store input parameters, calculation process data and final result data, facilitating subsequent process optimization and product quality traceability.

[0049] Furthermore, both the frequency converter and the induction heater in the execution module have two modes: automatic control and manual control. In automatic control mode, the parameters are automatically adjusted according to the signal from the calculation module. In manual control mode, the operator can manually adjust the parameters according to the actual situation.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing bimetallic composite materials based on the control of metal droplet size, characterized in that, Includes the following steps: (a) Melting alloy melt: Prepare an alloy containing bimetals A and B with a liquid-liquid miscibility gap according to a preset mass percentage, place the prepared alloy raw materials in a melting furnace for melting, and obtain an alloy melt with uniform composition. (b) Size control of metal droplets in ladle: The alloy melt obtained in step (a) is poured from the melting furnace into the ladle and allowed to stand in the ladle (0-60 seconds). During this process, non-metallic inclusions float to the surface of the melt, and the melt temperature is stabilized and the melt turbulence is reduced. The size of the second metal phase droplets is controlled by controlling the length of the standing time. The longer the standing time, the larger the size of the second metal phase droplets. The size of the second metal phase droplets is monitored in real time using a high-temperature high-speed camera system. (c) Metal droplet trajectory prediction: The casting parameters are obtained, including the radius, density, viscosity, interfacial energy, radial temperature gradient, centrifugal radius, initial position of the droplet, rotational speed and temperature gradient of the centrifugal casting. The casting parameters are input into the droplet motion velocity model and the droplet motion trajectory prediction model to obtain the position of the second phase metal droplet at time t. The solidification rate of the alloy melt is changed by controlling the mold preheating temperature. By utilizing the competition between the second metal phase droplet motion velocity and the alloy melt solidification rate (the movement speed of the solid-liquid interface), bimetallic composite materials with different structures are obtained. (d) Feedback control: Based on the droplet motion trajectory prediction model in step (c), the real-time position of the second phase metal droplet is calculated. The real-time position is compared with the preset trajectory, and the rotation speed or heating power of the centrifugal casting is adjusted to ensure that the bimetallic composite material that meets the preset structural requirements is finally obtained.

2. The method for preparing bimetallic composite materials according to claim 1, characterized in that, The bimetals A and B are selected from any one of Cu-Fe, Cu-Co, Cu-Cr, Al-Pb, Al-Bi, Al-In, Ag-Ni, Ag-Cr, Pb-Fe, Zn-Pb, and Ga-Pb.

3. The method for preparing bimetallic composite materials according to claim 1, characterized in that, The high-temperature high-speed camera system includes a high-temperature resistant sapphire lens with a temperature resistance of ≥2000℃, a water-cooled protective sleeve, a near-infrared light source with a wavelength of 850-1050nm, and a 1000fps high-speed camera.

4. The method for preparing bimetallic composite materials according to claim 1, characterized in that, In step (b), when the alloy melt is placed in the ladle, the ladle can be kept warm to maintain the temperature of the alloy melt and avoid the formation and growth of the second metal phase droplets due to temperature fluctuations.

5. The method for preparing bimetallic composite materials according to claim 1, characterized in that, In step (c), the mold preheating temperature is adjusted according to the solidification characteristics of the bimetallic A and B alloy melts and the required structure of the bimetallic composite material. Mold preheating can be carried out by electric heating or flame heating, and the temperature of each part of the mold is uniformly controlled during the preheating process.

6. The method for preparing bimetallic composite materials according to claim 1, characterized in that, In step (d), when adjusting the centrifugal casting speed, the speed can be adjusted within a range of ±100 rpm using a frequency converter; when adjusting the heating power, the power can be adjusted within a range of ±50 kW using an induction heater.

7. A bimetallic composite material preparation system for implementing the bimetallic composite material preparation method according to any one of claims 1-6, comprising a monitoring module, a calculation module, and an execution module, characterized in that: The monitoring module includes a high-temperature camera unit installed inside the ladle and a radial thermocouple array installed on the mold. The high-temperature camera unit is used to monitor the size of the second-phase metal droplets inside the ladle in real time, and the radial thermocouple array is used to collect the temperature gradient data of the mold radially in real time. The calculation module is used to input material parameters and process parameters. The material parameters include the radius, density, viscosity, and interfacial energy of the second-phase metal droplet. The process parameters include the radial temperature gradient, centrifugal radius, angular velocity, initial droplet position, centrifugal casting rotation speed, and temperature gradient. The calculation module incorporates the droplet motion velocity model and droplet motion trajectory prediction model described in claim 1. It can calculate the position of the second-phase metal droplet at time t based on the input parameters and compare the deviation between the real-time position and the preset trajectory. The execution module includes a frequency converter and an induction heater. The frequency converter is connected to the centrifugal casting equipment and is used to adjust the centrifugal casting speed according to the deviation signal from the calculation module. The induction heater is connected to the mold or smelting-related equipment and is used to adjust the heating power according to the deviation signal from the calculation module.

8. The bimetallic composite material preparation system according to claim 7, characterized in that, The high-temperature camera unit in the monitoring module is also equipped with image analysis software, which can automatically analyze the acquired images of the second-phase metal droplets, calculate the parameters of the droplets, and transmit these parameters to the calculation module in real time.

9. The bimetallic composite material preparation system according to claim 7, characterized in that, The calculation module also has a data storage function, which can store input parameters, calculation process data and final result data, facilitating subsequent process optimization and product quality traceability.

10. The bimetallic composite material preparation system according to claim 7, characterized in that, The frequency converter and induction heater in the execution module both have two control modes: automatic and manual. In automatic control mode, the parameters are automatically adjusted according to the signal from the calculation module. In manual control mode, the operator can manually adjust the parameters according to the actual situation.

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