Continuous casting device and continuous casting method for preparing metal-based composite material based on melt dispersion in-situ reaction

Abstract

The invention discloses a continuous casting device and method for preparing a metal-based composite material based on melt dispersion in-situ reaction, and the method comprises the steps: starting a mechanical stirring-melt dispersion device in a composite reaction crucible containing a melt A, enabling the mechanical stirring-melt dispersion device to rotate, and enabling a melt B in a crucible II to flow into a dispersion part through a discharge pipe II, dispersing the melt B into liquid drops through a dispersing piece under rotation, dripping the liquid drops into the melt A, carrying out in-situ reaction with the melt A under the synergistic effect of mechanical stirring to obtain a composite melt containing in-situ reinforced particles, and after the in-situ reaction is completed, continuing to carry out mechanical stirring to disperse the melt to obtain the in-situ reinforced particles. Finally, the temperature is increased, the rotating speed of mechanical stirring-melt dispersion is adjusted, continuous casting melt is obtained, and continuous casting is carried out. According to the method, the mechanical stirring technology and the melt dispersion technology are ingeniously combined, the problem that a reinforcing phase is evenly dispersed in a matrix can be effectively solved, and the particle size of the reinforcing phase is effectively refined.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material preparation, and in particular to a continuous casting device and a continuous casting method for preparing metal-based composite materials based on melt dispersion in-situ reaction. Background Art

[0002] With the rapid development of modern industry, Metal Matrix Composites (MMCs) have become indispensable materials in fields such as aerospace, automotive manufacturing, and the electronics industry due to their excellent mechanical properties, wear resistance, heat resistance, and corrosion resistance. However, when preparing MMCs using traditional continuous casting technology, the introduction and dispersion of reinforcement phases have long restricted material performance and process efficiency. This is specifically manifested in the following technical bottlenecks: First, the mechanical mixing method has inherent defects. The traditional process uses mechanical stirring to mix prefabricated reinforcement phases (such as SiC and Al2O3 particles) into the melt, but the particles have poor wettability with the melt (prone to agglomeration when the contact angle is >90°), resulting in uneven distribution of the reinforcement phase. Studies have shown that the strength of the agglomerated region of the particles is only 30%-50% of that of the matrix, and high-melting-point particles (such as B4C, melting point 2450°C) easily settle to form a segregation layer. In addition, the vortex generated by too fast mechanical stirring will entrain gas (porosity>2%), reduce the density of the material, and require subsequent heat treatment to improve, which increases the cost. Secondly, there are control difficulties in the in-situ reaction method. Although the conventional in-situ reaction method (such as the generation of Al2O3 by the Al-TiO2 system) can improve the interfacial bonding strength, the reaction kinetics is significantly affected by the temperature field and concentration field of the melt, and it is difficult to ensure a uniform reaction. For example, the Al-TiO2 reaction on the surface of the melt is prone to form a coarse reinforcing phase (>5μm) due to rapid heat dissipation, while the reaction in the center of the melt is insufficient (residual unreacted TiO2), resulting in a large span of the reinforcing phase size distribution, affecting fatigue performance. Third, the compatibility of the composite continuous casting process is insufficient. Although electromagnetic stirring or ultrasonic assistance can improve particle dispersion, the equipment is complex, energy consumption is high, and it is difficult to synchronize with the continuous casting billet speed (usually 0.5-2m / min), resulting in limited industrial application. Furthermore, existing continuous casting equipment lacks dynamic temperature compensation for reaction exotherm and suffers from poor melt mixing, making localized melt undercooling or overheating prone to causing cracks in the cast strand. Clearly, current technological approaches focus on the independent optimization of either "enhanced phase premixing" or "single in-situ reaction," but neither addresses the synergistic challenges of achieving uniform dispersion, controllable reaction, and process continuity. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the first purpose of the present invention is to provide a continuous casting method for preparing metal-based composite materials based on in-situ reaction of melt dispersion. The method of the present invention can effectively solve the problem of uniform dispersion of the reinforcing phase in the matrix by cleverly combining the two processes of mechanical stirring and melt dispersion, effectively refine the size of the reinforcing phase particles, and achieve uniform and stable distribution of the reinforcing phase particles in the matrix in the range of nanometer to micrometer scale, avoiding agglomeration and segregation, and comprehensively improving the performance of the composite material.

[0004] The second object of the present invention is to provide a continuous casting device for preparing metal-based composite materials based on melt dispersion in-situ reaction.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention discloses a continuous casting method for preparing a metal-based composite material based on an in-situ melt dispersion reaction. The method comprises the following steps: starting a mechanical stirring-melt dispersion device in a composite reaction crucible containing melt A to rotate the melt B; then flowing melt B in crucible No. II into a dispersion member through a discharge pipe No. 2; the dispersion member disperses melt B into droplets under rotation and drips them into melt A; and under the synergistic effect of mechanical stirring, the droplets react in situ with melt A to obtain a composite melt containing in-situ strengthening particles; and after the in-situ reaction is completed, heating the melt and continuing mechanical stirring to obtain a continuously cast melt. The continuously cast melt is then continuously cast to obtain the composite material.

[0007] The viscosity of melt A is higher than the viscosity of melt B;

[0008] The mechanical stirring-melt dispersion device comprises a stirring rod, a stirring paddle fixed to the bottom of the stirring rod, and a dispersing member fixed to the stirring rod and located above the stirring paddle, wherein the dispersing member is a porous structure;

[0009] During the continuous casting, the superheat of the continuous casting melt is controlled to be 150-300° C., and the apparent viscosity is ≤8 mPa·s.

[0010] In the preparation method of the present invention, a mechanical stirring-melt dispersion device is used. First, melt B is passed through a dispersion element. Under the dynamic action of rotating centrifugal force, melt B passes through the through-hole of the dispersion element at high speed and high pressure. The melt is dispersed into fine droplets or streams and drips into melt A in a dispersed manner. Under the synergistic action of mechanical stirring, an in-situ reaction occurs with melt A, which greatly increases the specific surface area of the reaction, thereby effectively increasing the in-situ reaction interface and refining the in-situ reinforcing phase particles. In addition, the melt dispersion is combined with the three-dimensional flow field effect formed by mechanical stirring, so that the melt and the refined in-situ reinforcing phase particles can be more evenly distributed throughout the internal area of the crucible. After the in-situ reaction is completed, mechanical stirring is continued to further evenly disperse the in-situ reinforcing particles in the matrix. The superheat and apparent viscosity of the composite melt are controlled within the range of the present invention by heating and continuous casting is performed, thereby obtaining a matrix with mainly columnar crystals, fine grains, and reinforcing phase particles uniformly and stably distributed in the matrix in the nanometer to micrometer scale range, thereby obtaining a composite material with excellent performance.

[0011] In the present invention, it is necessary to control the low-viscosity melt B to pass through the dispersion piece. If the placement order of melt B and melt A is reversed, the melt dispersion effect will be poor, the maximum in-situ reaction interface cannot be obtained, and the reinforced particles will be coarsened. In addition, the superheat of the composite melt needs to be controlled to ensure that the melt has excellent fluidity during continuous casting. If the superheat of the composite melt is too high, it is easy to cause coarse columnar crystals and central segregation. If the superheat is too low, the proportion of equiaxed crystals increases. In addition, through the coordination of the superheat of the melt and the stirring, the apparent viscosity of the composite melt is made ≤8mPa·s, so that the composite melt has excellent fluidity, ensuring the continuity of the continuous casting process and product quality.

[0012] A preferred solution is to prepare corresponding raw materials according to the composition of alloy A, place all the raw materials of alloy A in crucible No. 1 and heat to obtain melt A, and then flow melt A into a preheated and insulated composite reaction crucible through discharge pipe No. 1, or place a portion of the raw materials of alloy A in crucible No. 1 and heat to obtain melt A1, and place another portion of the raw materials of alloy A in a composite reaction crucible and heat to obtain melt A2, and then flow melt A1 into the composite reaction crucible through discharge pipe No. 1 and mix with melt A2 to form melt A, and prepare corresponding raw materials according to the composition of alloy B, place them in crucible No. 2 and heat to obtain melt B.

[0013] In actual operation, when the raw materials of melt A contain powder raw materials that are very easy to float on the surface of the melt (such as Cu2O, graphite powder), it is necessary to place this part of the powder raw materials in the composite reaction crucible to ensure that the in-situ reaction in the composite reaction crucible proceeds according to the designed proportion. If there are no powder raw materials that are easy to float, placing all of alloy A in crucible No. 1 and heating and melting it will help the continuous production of the material.

[0014] In the present invention, alloy A and alloy B are systems that can form high-temperature stable second-phase strengthened particles through in-situ liquid phase reaction. For example, the in-situ reaction system combinations of alloy A and alloy B include: Cu-Cu2O and Cu-Al (generating Al2O3 particles), Cu-Cu2O and Cu-Cr (generating Cr2O3 particles), Cu-Cu2O and Cu-Ti (generating TiO2 particles), Cu-Cu2O and Cu-Zr (generating ZrO2 particles), Cu-Hf and Cu-B (generating HfB2 particles), Cu-Zr and Cu-B (generating ZrB2 particles), Al-Ti and Al-B (generating TiB2 particles), and Cu-Ti and Cu-B (generating TiB2 particles). In the actual operation process, according to the viscosity of the alloy melt, the one with high viscosity is used as alloy A and the one with low viscosity is used as alloy B. The melt B formed after melting alloy B passes through a dispersion piece, such as Cu-Ti melt and Cu-B melt. The viscosity of Cu-B melt is relatively lower. In order to obtain a better melt dispersion effect, the Cu-B melt is placed in melting crucible No. Ⅱ.

[0015] In a preferred embodiment, the in-situ strengthening particles are selected from at least one of Al2O3, Cr2O3, TiO2, ZrO2, HfB2, ZrB2, and TiB2.

[0016] The preferred solution is to flow melt B through the No. 2 discharge pipe into the dispersion unit at a flow rate of 5-10 cm 3 By controlling the flow rate within this range, it is possible to achieve higher efficiency while avoiding the situation where the melt droplets merge due to excessive flow, resulting in poor melt dispersion.

[0017] In a preferred embodiment, the height distance between the No. 2 discharge pipe and the top of the disperser is controlled to be 8-25 mm, and the horizontal distance between the outlet end of the No. 2 discharge pipe and the center of the disperser is controlled to be 15-25 mm. By controlling the distance between the No. 2 discharge pipe and the disperser within this range, the melt passes through the disperser near the center of the disperser, achieving optimal melt dispersion and ultimately forming the finest second-phase particles. The center of the disperser refers to the vertical centerline of the disperser.

[0018] Preferably, during the in-situ reaction, the temperature difference between the upper and lower layers of melt A and melt B is controlled to be ≤15°C.

[0019] In a preferred embodiment, during the in-situ reaction, the temperature of the composite reaction crucible is controlled to be the melting point of the composite melt + 50 to 100°C, and the temperature of melt B is the melting point of alloy B + 50 to 300°C.

[0020] In the present invention, during the in-situ reaction, the temperatures of melt B and the composite reaction crucible are controlled within the above-mentioned ranges, resulting in the finest reinforcement phase. If both temperatures are too high, the resulting in-situ particles will be coarse. If the temperature of melt B is too low, the melt viscosity will be too high, resulting in insufficient shear force during dispersion and increased droplet size, which will also reduce the refinement effect.

[0021] In a preferred embodiment, the distance between the dispersing element and the stirring paddle in the mechanical stirring-melt dispersion device is 40-60 mm. During the in-situ reaction, the depth of the stirring paddle inserted into the melt is controlled to 40-50% of the total melt depth by the up-and-down movement of the mechanical stirring-melt dispersion device, and the distance between the bottom end of the dispersing element and the liquid surface is controlled to 25-40 mm. By controlling the distance between the dispersing element and the stirring paddle, as well as the insertion depth of the stirring paddle within these ranges, optimal stirring effect can be achieved, and the synergistic effect between the dispersing element and the stirring paddle is maximized, ultimately resulting in a composite material with optimal performance.

[0022] In a preferred embodiment, the dispersing member is selected from a conical dispersing member or a circular dispersing member, wherein the conical dispersing member comprises a conical dispersing disk, wherein a circumferential array of holes of the conical dispersing disk is arranged, and each row comprises a plurality of through holes spaced apart along a generatrix direction; wherein the circular dispersing member comprises a circular dispersing disk, wherein a circumferential array of holes of the circular dispersing disk is arranged, and each row comprises a plurality of through holes spaced apart along a radial direction;

[0023] A chute is provided between any two rows of holes on the outer side wall of the conical dispersing disk; or a convex strip is provided between any two rows of holes on the inner side wall of the conical dispersing disk; a convex strip is provided between two rows of holes on the upper surface of the circular dispersing disk;

[0024] In the conical or circular dispersion disk, the diameter of any through hole is 2-3 mm, and the distribution density of the through holes is 0.5-1.5 / cm 2 ;

[0025] The thickness of the conical dispersion disk or the circular dispersion disk is 2-9 mm.

[0026] The dispersion element provided by the present invention has a plurality of through holes arranged in an array periodically in the dispersion disk, which effectively ensures the uniformity of the size of the melt dispersion droplets, and the aperture and distribution of the through holes are controlled within the scope of the present invention to achieve the best final refinement effect. If the aperture is too large, it will cause the droplets to coarsen and the reaction interface is insufficient; and if the aperture is too small, it will also affect the dispersion effect due to the increase in melt flow resistance. At the same time, controlling the thickness of the dispersion disk within the scope of the present invention can ensure that the melt flows out continuously through the dispersion element. If the disk is too thick, it will affect the continuity of melt dispersion. In addition, the present invention In the dispersion element, chutes or ridges are arranged at intervals between the two rows of holes. The chutes and ridges can, on the one hand, exert a stronger shearing effect on the melt, disperse and fragment the melt, and prevent the droplets from merging; on the other hand, they drive the melt to rotate, so that the melt obtains a stronger centrifugal effect and a greater centrifugal force. This enhanced centrifugal effect promotes the rapid dynamic balance of the melt in the dispersion element, which not only ensures the stable outflow of the melt through the circular holes and edges of the dispersion element, but also avoids the retention and accumulation of the melt in the dispersion cavity, thereby achieving a uniform dispersion effect of the melt with excellent continuity and stability.

[0027] In a preferred embodiment, the conical dispersing member is selected from one of conical dispersing member No. 1, conical dispersing member No. 2, and conical dispersing member No. 3, wherein the conical dispersing member No. 1 comprises a conical dispersing disk No. 1, wherein the conical dispersing disk No. 1 has a plurality of rows of holes arranged in a circumferential array, each row comprising a plurality of through holes evenly spaced along a generatrix; the spacing between adjacent through holes in each row is 3-6 mm, and a chute is provided on the outer wall between any two rows of holes; the chute has a depth of 3-5 mm and a width of 2-8 mm, and the angle between the generatrix of the conical dispersing disk No. 1 and the horizontal plane is 5-60°, preferably 15-45°;

[0028] The conical dispersing element No. 2 comprises a conical dispersing disc No. 2, which is in an inverted cone shape. The conical dispersing disc No. 2 has a plurality of rows of holes arranged in a circumferential array, each row comprising a plurality of through holes evenly spaced along a generatrix. The spacing between adjacent through holes in each row is 8-15 mm, and a ridge is provided on the inner sidewall between any two rows of holes. The ridge has a height of 3-5 mm and a width of 2-4 mm. The angle between the generatrix of the conical dispersing disc and the horizontal plane is 30-45°.

[0029] The No. 3 conical dispersion element includes a No. 3 conical dispersion disk, which is an inverted cone. The No. 3 conical dispersion disk has multiple rows of holes arranged in a circumferential array, each row including multiple through holes evenly spaced along the busbar direction, the spacing between adjacent through holes in each row is 4-12 mm, and a convex strip is provided between any two rows of holes on its inner side wall; the height of the convex strip is 1.5-2.5 mm, and the width is 3-6 mm; the angle between the busbar of the conical dispersion disk and the horizontal plane is 10-30°.

[0030] The conical dispersion disks provided in the present invention all refer to the side faces of truncated cones, i.e., frustums. The conical dispersion disk of conical dispersion element No. 1 is the side face of a frustum with a small upper base and a large lower base. Conical dispersion elements No. 2 and No. 3 are inverted cones, and their conical dispersion disks are the side faces of a frustum with a small lower base and a large upper base.

[0031] In a preferred embodiment, the circular dispersion disk has a circumferential array of multiple rows of holes, each row including multiple through holes evenly spaced along the radial direction, the spacing between adjacent through holes in each row is 5-10 mm, and above the disk surface, a convex strip is provided between any two rows of holes, the height of the convex strip is 3-5 mm, and the width is 3-8 mm.

[0032] In the present invention, conical disperser No. 1, conical disperser No. 2, conical disperser No. 3 and circular disperser are provided. All four dispersers are made of graphite material to better match different melts and obtain better refining effect.

[0033] Further preferably, the material of the disperser is graphite. When the melt viscosity of melt B is less than 10 mPa·s and the wetting angle between melt B and graphite is less than 120°, the disperser is selected from conical disperser No. 2. When the melt viscosity of melt B is greater than 10 mPa·s and the wetting angle between melt B and graphite is less than 120°, the disperser is selected from conical disperser No. 1. When the melt viscosity of melt B is less than 10 mPa·s and the wetting angle between melt B and graphite is greater than 120°, the disperser is selected from conical disperser No. 3. When the melt viscosity of melt B is greater than 10 mPa·s and the wetting angle between melt B and graphite is greater than 120°, the disperser is selected from circular disperser.

[0034] In a preferred embodiment, the stirring paddle is selected from one of stirring paddle A, stirring paddle B, and stirring paddle C, wherein the stirring paddle A is a straight-blade stirring paddle, the stirring paddle B is a pitch-blade stirring paddle, and the blade thereof is at 30°C with the horizontal plane, and the stirring paddle C is a pitch-blade stirring paddle, and the blade thereof is at -30°C with the horizontal plane.

[0035] Further preferably, when the density of the composite melt differs from the density of the in-situ strengthened particles by no more than 0.3 g / cm 3 When the density of the composite melt differs from the density of the in-situ strengthened particles by more than 0.3 g / cm 3 , and the density of the composite melt is greater than the density of the in-situ strengthened particles, the stirring blade is selected from stirring blade B, when the density of the composite melt differs from the density of the in-situ strengthened particles by more than 0.3 g / cm 3 , and when the density of the composite melt is less than the density of the in-situ strengthened particles, the stirring paddle is selected from stirring paddle C.

[0036] In the present invention, suitable dispersing parts are selected to ensure good dispersion of the alloy melt B, and suitable stirring paddles are selected to ensure good dispersion of the in-situ particles in the composite melt. By matching the type of dispersing parts with the type of stirring paddles, the in-situ strengthened particles are fully refined and evenly distributed.

[0037] In a preferred embodiment, during the in-situ reaction, the rotational speed of the mechanical stirring-melt dispersion device is 100-150 r / min. Throughout the in-situ reaction, the rotational speed of the mechanical stirring-melt dispersion device must be maintained constant to ensure the continuity of the melt dispersion process. A rotational speed that is too low at this stage will result in poor melt dispersion, while a rotational speed that is too high will cause the dispersed melt to splash onto the inner wall of the crucible, affecting the progress of the in-situ reaction.

[0038] The preferred solution is to continue adding other alloy raw materials to the composite melt after the in-situ reaction is completed. There are two main purposes: one is to introduce other alloy elements into the matrix to facilitate the introduction of other strengthening phases (such as precipitation strengthening) in the later heat treatment of the material; the other is to improve the wettability of the composite melt and the in-situ strengthening particles, and promote the dispersion and distribution of the in-situ strengthening particles. Continuous casting production requires a composition fluctuation of ≤0.5wt%, and has higher requirements for the uniformity of the composition. It is necessary to detect the composition of the composite melt in real time through the detection hole, take samples every 30-90 seconds for detection, and replenish raw materials in real time according to the test results.

[0039] In a preferred embodiment, after the in-situ reaction is completed, the temperature is increased and mechanical stirring is continued for 1-10 minutes to obtain a continuous casting melt, and the continuous casting melt is continuously cast; mechanical stirring is continued to obtain a continuous casting melt and during the continuous casting process, the speed of the mechanical stirring-melt dispersion device is adjusted to 20-80r / min, and electromagnetic stirring is performed at the same time, and the frequency of the electromagnetic stirring is controlled to 20-35Hz and the current is 30-50A.

[0040] During the continuous casting process, by controlling the superheat of the melt and coordinating mechanical stirring and electromagnetic stirring, the apparent viscosity of the melt can be reduced and the melt fluidity can be increased, thereby ensuring the continuity of the continuous casting process and product quality.

[0041] Further preferably, mechanical stirring is continued to obtain the continuous casting melt and during the continuous casting process, the speed of the mechanical stirring-melt dispersion device is controlled to fluctuate cyclically at 20-40r / min, 40-60r / min, and 60-80r / min, and the fluctuation period is 3-5s. Take three speeds as an example, 20r / min, 40r / min, and 60r / min. Specifically, 20r / min→40r / min→60r / min→20r / min→40r / min→60r / min, so periodically fluctuate, and each speed maintains 3-5s. By adopting periodic variable speed stirring, the fluidity of the melt is the best, and the agglomeration of the reinforcing particles can be better avoided, and the performance of the composite material obtained by continuous casting is optimal.

[0042] Preferably, during the continuous casting process, the cooling water flow rate of the crystallizer is 100-2000 L / h.

[0043] Further preferably, during the continuous casting process, when the superheat of the continuous casting melt is ≤200°C, the cooling water flow rate of the crystallizer is 200-600L / min, and when the superheat of the continuous casting melt is >200°C, the cooling water flow rate of the crystallizer is 700-1500L / min.

[0044] Preferably, during the continuous casting process, the crystallizer vibrates at a frequency of 20-50 Hz, an amplitude of 0.5-2 mm, and an angle of 15-30° with the casting direction. Vibration during continuous casting further improves melt fluidity and enhances particle dispersion.

[0045] In a preferred embodiment, the continuous casting method is downward-drawing continuous casting, wherein the pull rod moves downward at a speed of 0.1-3 mm / s. The melt is rapidly cooled and solidified in a cold mold (water-cooled crystallizer) and continuously pulled out by the pull rod, thereby continuously producing the metal matrix composite material.

[0046] Further preferably, during the down-draw continuous casting, the liquid level of the continuous casting melt is controlled at 50-120mm. Experiments have found that it is optimal to control the liquid level of the continuous casting melt within this range. If the melt is insufficient to feed the solidified shell when it is lower than 50mm, and the flow field intensity at the bottom of the melt is insufficient when it is higher than 120mm, the stirring effect is poor, resulting in an increase in melt viscosity, and particles are prone to agglomeration. In the actual production process, on the one hand, when the liquid level of the continuous casting melt drops to 50-60mm, the down-draw can be suspended, and melt A and melt B are supplemented to react in situ, and then dispersed, the temperature is raised to obtain a height of 100-120mm of the continuous casting melt, and then the down-draw continuous casting is continued to realize intermittent continuous production. On the other hand, a continuous casting melt crucible can be added between the composite reaction crucible and the continuous casting mold so that the composite melt in the composite reaction crucible is continuously supplemented to the continuous casting melt crucible to realize complete continuous production.

[0047] The present invention also provides a continuous casting device for preparing metal-based composite materials based on melt dispersion in-situ reaction, the continuous casting device comprising: No. I crucible, No. II crucible, composite reaction crucible, mechanical stirring-melt dispersion device, continuous casting mold, crystallizer, and traction rod;

[0048] The No. Ⅰ crucible is connected to the composite reaction crucible through the No. 1 discharge pipe, and the No. Ⅱ crucible is connected to the composite reaction crucible through the No. 2 discharge pipe;

[0049] The mechanical stirring-melt dispersion device passes through the top center of the composite reaction crucible and extends into the interior of the composite reaction crucible; the mechanical stirring-melt dispersion device comprises a stirring rod, a stirring paddle fixed to the bottom of the stirring rod, and a dispersion member fixed to the stirring rod above the stirring paddle; the dispersion member is a porous structure and is used to disperse the melt into droplets;

[0050] A crystallizer is provided outside the continuous casting mold, and the crystallizer is used to cool the continuous casting mold;

[0051] The continuous casting mold is located below the composite reaction crucible, with its upper end connected to the lower liquid outlet of the composite reaction crucible and its lower end close to the traction rod, and the continuously cast metal matrix composite material is pulled out by the traction of the traction rod.

[0052] In a preferred embodiment, crucible No. 1 is provided with stopper rod No. 1, and crucible No. 2 is provided with stopper rod No. 2. Stopper rods No. 1 and No. 2 are respectively connected to vertical transmission devices. The vertical transmission devices control the vertical movement of stopper rods No. 1 and No. 2, thereby controlling the opening and closing of the liquid outlets of crucibles No. 1 and No. 2, and the melt flow rate at the liquid outlets.

[0053] In a preferred embodiment, the composite reaction crucible is provided with an upper liquid outlet and a lower liquid outlet, between which a stopper rod No. 3 is provided perpendicular thereto, and the stopper rod No. 3 is connected to a horizontal transmission device by a bolt, and the opening and closing of the liquid outlet is controlled by controlling the horizontal movement distance.

[0054] In a preferred embodiment, the composite reaction crucible is surrounded by an electromagnetic induction coil. This utilizes the principle of electromagnetic induction to rapidly raise the temperature. Furthermore, the electromagnetic induction coil provides electromagnetic stirring, generating shear forces and circulation within the melt through mechanical stirring. This synergistic effect, combined with the electromagnetic stirring provided by the electromagnetic induction coil, creates a complex flow state within the melt. This promotes thorough mixing of melts of varying composition and temperature, facilitating the full in-situ reaction, effectively reducing residual reactive elements, and ensuring the precise composition of the final product. Furthermore, the high-intensity stirring can break down coarse grains, agglomerates, or other inhomogeneous phases within the melt, making it finer and more dispersed.

[0055] In a preferred embodiment, the mechanical stirring-melt dispersion device further comprises a servo motor and a planetary gear reducer. The servo motor is located outside the composite reaction crucible and is used to drive the stirring paddle and the dispersion element to rotate at a speed range of 0-1000 r / min. The high-precision servo motor is used as the driving source, and the planetary gear reducer is equipped to drive the transmission shaft, stirring paddle and other components to rotate, achieving stepless speed change of the stirring paddle within the range of 0-1000 r / min.

[0056] In a preferred embodiment, the stirring rod in the mechanical stirring-melt dispersion device is composed of a long rod and a short rod connected by threads from top to bottom.

[0057] In a preferred embodiment, in the mechanical stirring-melt dispersion device, the distance between the dispersion element and the stirring paddle is 40-60 mm.

[0058] In a preferred embodiment, the dispersing member is selected from a conical dispersing member or a circular dispersing member, wherein the conical dispersing member comprises a conical dispersing disk, wherein a circumferential array of holes of the conical dispersing disk is arranged, and each row comprises a plurality of through holes spaced apart along a generatrix direction; wherein the circular dispersing member comprises a circular dispersing disk, wherein a circumferential array of holes of the circular dispersing disk is arranged, and each row comprises a plurality of through holes spaced apart along a radial direction;

[0059] A chute is provided between any two rows of holes on the outer side wall of the conical dispersing disk; or a convex strip is provided between any two rows of holes on the inner side wall of the conical dispersing disk; a convex strip is provided between two rows of holes on the upper surface of the circular dispersing disk;

[0060] In the conical or circular dispersion disk, the diameter of any through hole is 2-3 mm, and the distribution density of the through holes is 0.5-1.5 / cm 2 ;

[0061] The thickness of the conical dispersion disk or the circular dispersion disk is 2-9 mm.

[0062] Further preferably, the conical dispersing member further includes a fixing ring A fixed above the conical dispersing disk and coaxial with the conical dispersing disk, and the circular dispersing member further includes a fixing ring B fixed above the circular dispersing disk and coaxial with the circular dispersing disk, the outer diameters of the fixing ring A and the fixing ring B are both 15-20 mm, and the interiors of the fixing ring A and the fixing ring B are both threaded for connecting to the stirring rod.

[0063] Further preferably, the conical dispersing member is selected from one of conical dispersing member No. 1, conical dispersing member No. 2, and conical dispersing member No. 3, wherein the conical dispersing member No. 1 comprises a conical dispersing disk No. 1, wherein the conical dispersing disk No. 1 has a plurality of rows of holes arranged in a circumferential array, each row comprising a plurality of through holes evenly spaced along a generatrix direction; the spacing between adjacent through holes in each row is 3-6 mm, and a chute is provided on the outer wall thereof between any two rows of holes; the chute has a depth of 3-5 mm and a width of 2-8 mm, and the angle between the generatrix of the conical dispersing disk No. 1 and the horizontal plane is 5-60°, preferably 15-45°;

[0064] The conical dispersing element No. 2 comprises a conical dispersing disc No. 2, which is in an inverted cone shape. The conical dispersing disc No. 2 has a plurality of rows of holes arranged in a circumferential array, each row comprising a plurality of through holes evenly spaced along a generatrix. The spacing between adjacent through holes in each row is 8-15 mm, and a ridge is provided on the inner sidewall between any two rows of holes. The ridge has a height of 3-5 mm and a width of 2-4 mm. The angle between the generatrix of the conical dispersing disc and the horizontal plane is 30-45°.

[0065] The No. 3 conical dispersion element includes a No. 3 conical dispersion disk, which is an inverted cone. The No. 3 conical dispersion disk has multiple rows of holes arranged in a circumferential array, each row including multiple through holes evenly spaced along the busbar direction, the spacing between adjacent through holes in each row is 4-12 mm, and a convex strip is provided between any two rows of holes on its inner side wall; the height of the convex strip is 1.5-2.5 mm, and the width is 3-6 mm; the angle between the busbar of the conical dispersion disk and the horizontal plane is 10-30°.

[0066] In a preferred embodiment, the circular dispersion disk has a circumferential array of multiple rows of holes, each row including multiple through holes evenly spaced along the radial direction, the spacing between adjacent through holes in each row is 5-10 mm, and above the disk surface, a convex strip is provided between any two rows of holes, the height of the convex strip is 3-5 mm, and the width is 3-8 mm.

[0067] In a preferred embodiment, the stirring paddle is selected from one of stirring paddle A, stirring paddle B, and stirring paddle C, wherein the stirring paddle A is a straight-blade stirring paddle, the stirring paddle B is a pitch-blade stirring paddle, and the blade thereof is at 30°C with the horizontal plane, and the stirring paddle C is a pitch-blade stirring paddle, and the blade thereof is at -30°C with the horizontal plane.

[0068] In a preferred embodiment, the distance between the top of the drawbar and the No. 3 stopper rod in the composite reactor crucible is 15-30 mm. Experimental results show that maintaining the distance between the top of the drawbar and the stopper rod within this range results in optimal ingot performance. Excessive distance can lead to poor product quality at the ingot head, such as internal porosity and surface defects. Excessive distance can hinder melt solidification, hindering effective formation of a solid-liquid interface, and impairing the ability of the solidification interface to capture strengthening particles.

[0069] In a preferred solution, the crystallizer is connected to a vibration device, and the vibration device realizes the vibration of the crystallizer.

[0070] Principles and advantages

[0071] 1. The reinforcement phase is evenly dispersed and refined in size. The provided mechanical stirring-melt dispersion device rotates at high speed to disperse the reaction melt B into the interior of another reaction melt A for in-situ reaction, breaking through the eddy agglomeration limitation of traditional mechanical stirring. It effectively combines dispersion, in-situ reaction and mechanical stirring, and improves the interface of the in-situ reaction by 2-3 orders of magnitude. The average particle size of the in-situ reaction reinforcement phase (such as Al2O3, TiB2) is refined to below 100nm. The nucleation rate of the in-situ reaction reinforcement phase is regulated in combination with the thermal / dynamic conditions of the melt to achieve significant refinement and dispersed distribution of the reinforcement phase.

[0072] 2. Interface bonding strengthening and defect suppression. Combined with this device, various types of in-situ reinforcing phases (such as HfB2, TiB2, ZrB2, Al2O3, Cr2O3, TiO2, etc.) can be generated through in-situ reactions, and the reinforcing phases and the matrix form a coherent / semi-coherent interface (compared with the incoherent interface, its bonding strength is increased by 30%-50%), while avoiding the pore defects (porosity <0.5%) and impurity elements introduced by prefabricated particles.

[0073] 3. For the mechanical stirring-melt dispersion device, the present invention provides a variety of dispersing parts and stirring paddles. Suitable dispersing parts are selected to ensure good dispersion of the melt, and suitable stirring paddles are selected to ensure good dispersion of in-situ particles in the composite melt. The type of dispersing parts and the type of stirring paddle can be selected according to different physical properties such as the viscosity of the raw material melt and the density difference between the composite melt and the in-situ strengthening particles. It is suitable for a variety of combinations of base metals (such as aluminum alloys, magnesium alloys, copper alloys, etc.) and reinforcing phases (such as hafnium boride, titanium boride, aluminum oxide, etc.).

[0074] 4. The process continuity is compatible with industrialization, integrating dispersion, in-situ reaction, mechanical stirring and continuous casting forming modules to realize the integrated continuous production of "melting-reaction-solidification" of composite materials (bill drawing speed 0.5-3m / min adjustable), solving the problem of low efficiency of traditional multi-process intermittent production (such as premixing-casting-hot pressing). The single continuous operation time is ≥8 hours, which is suitable for large-scale, efficient and continuous preparation of aluminum, magnesium and copper-based composite materials.

[0075] 5. Energy consumption and cost optimization: This process organically combines the in-situ dispersion reaction to generate the in-situ reinforcement phase, the smelting of the metal matrix, and the continuous casting of the composite material, achieving integrated continuous production from raw materials to finished product. Compared with stir casting and powder metallurgy methods, this process not only significantly simplifies the production process (eliminating the need for premixing, prefabricating reinforcement particles, and sintering), but also significantly reduces overall production costs by 20%-30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 It is a schematic diagram of the overall structure of the preparation device of the present invention.

[0077] Figure 2 A three-dimensional schematic diagram of a dispersion element provided by the present invention, wherein Figure 2 (a) is a No. 1 cone-shaped disperser; Figure 2 (b) is a No. 2 cone-shaped disperser; Figure 2 (c) is a No. 3 cone disperser; Figure 2 (d) is a circular dispersion piece.

[0078] Figure 3 A three-dimensional schematic diagram of a stirring paddle provided by the present invention, wherein Figure 3 (a) is stirring paddle A; Figure 3 (b) is a stirring paddle B; Figure 3 (c) is a stirring paddle C.

[0079] Figure 4 The microstructure of the Al3Ti / TiB2 / 7050 aluminum-based composite material prepared in Example 1 at different magnifications is shown in FIG. Figure 4 (a) is the lower multiple, Figure 4 (b) is a higher magnification.

[0080] Figure 5 This is the microstructure diagram of the Mg-Zn-Zr-Cr2O3-Al2O3 composite material prepared in Example 2.

[0081] Figure 6 This is the microstructure diagram of the Mg-Zn-Zr-Cr2O3-Al2O3 composite material prepared in Example 3.

[0082] Figure 7This is the microstructure diagram of the Cu-Fe-P-TiB2 composite material prepared in Example 4. DETAILED DESCRIPTION

[0083] The following is a clear and complete description of the implementation of the present invention in conjunction with the accompanying drawings. First, the device details are described in detail.

[0084] See also Figure 1 A continuous casting device for preparing metal-based composite materials based on melt dispersion in-situ reaction includes: No. 1 crucible 23, No. 2 crucible, composite reaction crucible 6, mechanical stirring-melt dispersion device, continuous casting mold, crystallizer 28, and traction rod 27.

[0085] The composite reaction crucible 6 is located in the center of the apparatus. Its left end is connected to the liquid outlet 22 of crucible No. 1 23 via discharge pipe No. 1 21, and its right end is connected to crucible No. 2 21-1. When discharging melt A, discharge pipe No. 1 21 should prevent melt A from entering the dispersing element 3, and therefore its horizontal surface should be located below the dispersing element 3. The opening of discharge pipe No. 1 21 maintains a safe distance of 5-10 mm from the dispersing element 3, while the horizontal surface of discharge pipe No. 2 21-1 should be located above the dispersing element 3. When discharging melt B, discharge pipe No. 2 21-1 should ensure that melt B fully enters the rotating dispersing element 3. The height distance between discharge pipe No. 2 and the top of dispersing element 3 is controlled to be 8-25 mm to prevent collision with the rotating dispersing element 3 during the preparation process. Horizontally, the distance between the outlet end of discharge pipe No. 2 and the center of dispersing element 3 is controlled to be 15-25 mm.

[0086] The bottom of the composite reaction crucible 6 is at an angle of 15° to the horizontal plane to ensure that the composite melt can be completely transported to the upper liquid outlet 8. A stopper rod No. 3 is provided at the bottom of the composite reaction crucible 6. After the composite melt is stirred, the stopper rod No. 3 is pulled out, and the composite melt flows into the lower liquid outlet 10, and then flows into the continuous casting mold from the lower liquid outlet 10.

[0087] Crucible No. 1 23 is provided with a stopper rod 15, and crucible No. 2 is provided with a stopper rod. The two have the same structure. Taking crucible No. 1 23 as an example, stopper rod No. 15 is connected to a vertical transmission device, which includes a threaded tube 13 and a holder 14. The vertical transmission device controls the lifting and lowering of stopper rod No. 1 by the up and down movement of holder 14, thereby realizing the opening and closing of liquid outlet No. 1 22 in crucible No. 1 23 and the control of melt flow.

[0088] The composite reaction crucible 6, crucible No. 1 23, and crucible No. 2 are all provided with insulation devices, atmosphere protection devices, and gas channels. Taking the insulation device of crucible No. 1 23 as an example, it includes, from the inside to the outside, an insulating air gap 20, a quartz sleeve 24, and an electromagnetic induction coil insulation layer 18, wherein the electromagnetic induction coil insulation layer 18 is composed of an electromagnetic induction coil 19 and asbestos filled in the gap between the electromagnetic induction coil 19, which effectively reduces heat loss. Taking the atmosphere protection device of crucible No. 1 23 as an example, it is composed of a crucible outer layer and a first quartz cover 17, wherein the first quartz cover 17 has a through hole for replenishing raw materials, installing No. 1 stopper rod 15, and serving as a protective gas exhaust port 16, while the through hole of the second quartz cover 12 in the composite reaction crucible 6 is used for replenishing raw materials, discharging protective gas, installing the second vent pipe 11, and installing the long rod 2 of the stirring rod. In addition, a through hole is also provided in the upper crucible wall of crucible No. 1 23, and the through hole is installed with a first vent pipe 26.

[0089] In order to accurately control the melt temperature in crucible No. 1 23, crucible No. 2 and the composite reaction crucible 6, temperature measuring holes are provided on crucible No. 1 23, crucible No. 2 and the composite reaction crucible 6 for installing temperature sensors, such as the first temperature sensor 25 in crucible No. 1 and the second temperature sensor 9 in the composite reaction crucible 6; the first temperature sensor 25 and the second temperature sensor 9 are both connected to the heating system through wires, and the heating system is controlled by a PID program. The temperature sensor feeds back the measured temperature signal to the heating system, thereby controlling the heat generation of the heating system to achieve precise adjustment of the melt temperature.

[0090] The continuous casting mold is located below the composite reaction crucible 6. The prepared metal-based composite material can be made into rods, plates, strips, wires, pipes, and special-shaped materials through different continuous casting molds.

[0091] A crystallizer 28 is provided outside the continuous casting mold. The crystallizer 28 is a water-cooled crystallizer for cooling the continuous casting mold.

[0092] Furthermore, the crystallizer 28 is connected to a vibration device, which is used to achieve vibration of the crystallizer 28 .

[0093] The upper end of the continuous casting mold is connected to the lower liquid outlet 10 of the composite reaction crucible 6, and the lower end is close to the traction rod 27. The continuously cast metal-based composite material is pulled out by the traction of the traction rod 27. The traction rod 27 is controlled by a pneumatic valve and is pulled by an electric mechanical traction device 29.

[0094] By modifying the continuous casting mold and the composite reaction crucible, the continuous casting method can be any of the top-draw, bottom-draw or horizontal types.

[0095] The specific structures of the stopper rod, vertical transmission device, vibration device and traction rod are all prior art and will not be described in detail here. The crucible, discharge pipe, stirring paddle, atmosphere protection device and stopper rod are all made of graphite or refractory material.

[0096] The mechanical stirring-melt dispersion device is composed of: a servo motor 1, a long rod 2 of a stirring rod, a dispersing element 3, a short rod 4 of a stirring rod, and a stirring paddle 5, which are connected by threads. In the mechanical stirring-melt dispersion device, the distance between the dispersing element 3 and the stirring paddle 5 is 40-60 mm.

[0097] The dispersing element 3 is selected from a conical dispersing element or a circular dispersing element. The conical dispersing element includes a conical dispersing disk, and the conical dispersing disk has a plurality of rows of holes arranged in a circumferential array, and each row includes a plurality of through holes spaced apart along the generatrix direction. The circular dispersing element includes a circular dispersing disk, and the circular dispersing disk has a plurality of rows of holes arranged in a circumferential array, and each row includes a plurality of through holes spaced apart along the radial direction.

[0098] A chute is provided between any two rows of holes on the outer side wall of the conical dispersing disk; or a convex strip is provided between any two rows of holes on the inner side wall of the conical dispersing disk; a convex strip is provided between two rows of holes on the upper surface of the circular dispersing disk;

[0099] In the conical or circular dispersion disk, the diameter of any through hole is 2-3 mm, and the distribution density of the through holes is 0.5-1.5 / cm 2 ;

[0100] The thickness of the conical dispersion disk or the circular dispersion disk is 2-9 mm;

[0101] The conical dispersing member also includes a fixing ring A fixed above the conical dispersing disk and coaxial with the conical dispersing disk. The circular dispersing member also includes a fixing ring B fixed above the circular dispersing disk and coaxial with the circular dispersing disk. The outer diameter of the fixing ring is 15 to 20 mm, and the interior of the fixing ring A and the fixing ring B are both threaded for connecting to the stirring rod.

[0102] Further preference, such as Figure 2 As shown, the dispersion element 3 is divided into four types, namely, cone dispersion element No. 1 as shown in FIG. Figure 2 As shown in (a), the conical disperser No. 2 is as follows Figure 2 As shown in (b), the No. 3 conical dispersion piece is as follows Figure 2 (c) shows that the circular dispersion element is as follows Figure 2(d), wherein the conical dispersing element No. 1 comprises a conical dispersing disc No. 1, and the conical dispersing disc No. 1 has a plurality of rows of holes arranged in a circumferential array, each row comprising a plurality of through holes evenly spaced along a generatrix; the spacing between adjacent through holes in each row is 3-6 mm, and a chute is provided on the outer wall between any two rows of holes; the chute has a depth of 3-5 mm and a width of 2-8 mm, and the angle between the generatrix of the conical dispersing disc No. 1 and the horizontal plane is 5-60°, preferably 15-45°;

[0103] The conical dispersing element No. 2 includes a conical dispersing disc No. 2, which is in an inverted cone shape. The conical dispersing disc No. 2 has multiple rows of holes arranged in a circumferential array, each row including multiple through holes evenly spaced along the generatrix. The spacing between adjacent through holes in each row is 8-15 mm, and a ridge is provided on the inner sidewall between any two rows of holes. The ridge has a height of 3-5 mm and a width of 2-4 mm. The angle between the generatrix of the conical dispersing disc and the horizontal plane is 30-45°.

[0104] The No. 3 conical dispersing element comprises a No. 3 conical dispersing disc, which is in the shape of an inverted cone. The No. 3 conical dispersing disc has multiple rows of holes arranged in a circumferential array, each row comprising multiple through holes evenly spaced along the generatrix direction. The spacing between adjacent through holes in each row is 4-12 mm, and a ridge is provided on the inner sidewall between any two rows of holes; the ridge has a height of 1.5-2.5 mm and a width of 3-6 mm. The angle between the generatrix of the conical dispersing disc and the horizontal plane is 10-30°.

[0105] The circular dispersion disk has a circumferential array of multiple rows of holes, each row including multiple through holes evenly spaced along the radial direction, the spacing between adjacent through holes in each row is 5-10 mm, and a convex strip is provided between any two rows of holes above the disk surface, the height of the convex strip is 3-5 mm, and the width is 3-8 mm.

[0106] See also Figure 3 , the stirring paddle 5 is divided into three types, stirring paddle A is as Figure 3 As shown in (a), the stirring blade B is as Figure 3 As shown in (b), the stirring blade C is as Figure 3 (c), wherein impeller A is a straight-blade impeller, impeller B is a pitch-blade impeller, the blades of which are at 30° with the horizontal plane, and impeller C is a pitch-blade impeller, the blades of which are at -30° with the horizontal plane.

[0107] The present invention will be further described below with reference to specific embodiments.

[0108] Example 1:

[0109] Preparation of an Al3Ti / TiB2 / 7050 aluminum-based composite. Mass fractions: 0.5% Al3Ti, 0.5% TiB2, 6% Zn, 2% Mg, 2% Cu, 0.1% Zr, 0.05% Si, 0.05% Fe, with the balance being aluminum. A stirring paddle C and a circular disperser were used.

[0110] In this embodiment, the density of Al3Ti is about 3.5g / cm 3 , the density of TiB2 is about 4.5g / cm 3 , the density of Al-based melt is about 2.7g / cm 3 The density of Al-based melt is less than that of Al3Ti and TiB2 particles, and the density difference exceeds 0.3g / cm 3 Therefore, stirring blade C is selected. At a temperature above 700°C, the viscosity of melt B (i.e., Al-B melt) is greater than 10mPa·s, and the wetting angle between the viscosity of melt B (i.e., Al-B melt) and graphite is greater than 120°. Therefore, a circular dispersing element is selected. In the circular dispersing element, the diameter of the through holes is 3mm, and the distribution density of the through holes is 0.8 / cm 2 The spacing between adjacent through holes in each row is 6 mm, and a convex strip is set between any two rows of holes above the disc surface. The height of the convex strip is 3.5 mm and the width is 5 mm. The maximum diameter of the dispersion disc is 58 mm.

[0111] In the mechanical stirring-melt dispersion device, the distance between the stirring paddle C and the lowest point of the circular dispersion element is 50 mm;

[0112] The specific preparation process is as follows:

[0113] 1. Preparation of melt raw materials:

[0114] Place Al-Ti and Al-B raw materials in crucibles I and II, respectively, ensuring a Ti:B mass ratio of 5:1. Turn on the heating device and argon atmosphere protection (full atmosphere protection, gas flow rate of 35L / h). Heat crucible I to 760°C (Al-Ti melt melting point approximately 680°C) and hold it for 15 minutes; heat crucible II to 760°C (Al-Ti melt melting point approximately 670°C) and hold it for 15 minutes.

[0115] 2. Mechanical stirring-melt dispersion liquid phase in situ reaction:

[0116] While the raw materials are being heated and melted, the composite reaction crucible is heated to 760°C and held at this temperature for 15 minutes. Subsequently, the servo motor is turned on to drive the mechanical stirring-melt dispersion device to rotate at a speed of 150 r / min. The stopper rod in crucible No. 1 is raised by the lifting mechanism to transfer the Al-Ti melt in crucible No. 1 to the composite reaction crucible. Subsequently, the Al-B melt in crucible No. 2 is transferred to the composite reaction crucible in the same manner at a speed of 10 cm. 3 / s is injected into the dispersion piece.

[0117] The height distance between discharge pipe No. 1 and the top of the disperser was controlled at 15 mm, and the horizontal distance between the outlet end of discharge pipe No. 2 and the center of the disperser was controlled at 18 mm. The Al-B melt was dispersed into fine droplets and thoroughly mixed with the Al-Ti melt under stirring, undergoing an in-situ reaction to generate Al3Ti and TiB2 strengthening particles, forming a composite melt. During this in-situ reaction, the mechanical stirring-melt dispersion device was moved up and down to control the depth of the stirring paddle inserted into the melt to 45% of the total melt depth, and the distance between the lowest end of the disperser and the liquid surface was controlled at 25 mm.

[0118] After the Al-B melt was dispersed, the two melts continued to react in situ for about 1.5 minutes; then the temperature of the composite reaction crucible was raised to 800°C, and the stirring speed was adjusted to a periodic fluctuation mode (speed: 30r / min→50r / min→70r / min→30r / min→50r / min→70r / min, fluctuation period: 3s); during the in situ reaction process and the completion of the in situ reaction, electromagnetic stirring was continued during the mechanical stirring process, and the parameters of the electromagnetic stirring were: frequency 30Hz, current 40A.

[0119] 3. Supplementation of other elements:

[0120] After the temperature of the composite reaction crucible is raised to 800°C and kept warm for 5 minutes, raw materials are added to the composite melt through the through hole of the quartz cover 12 and melted, and aluminum-zinc, aluminum-magnesium, aluminum-copper, aluminum-zirconium, aluminum-iron, aluminum-silicon and other intermediate alloy raw materials are added in proportion. The composite reaction crucible is kept warm at 800°C for 5 minutes (the melting point of the composite melt is 640°C); the composite melt is sampled through the through hole of the quartz cover 12, and the composition is detected using a spectrometer. The corresponding elements are supplemented according to the composition results, and then kept warm for another 5 minutes after supplementation; if no supplementation is required, the next step can be directly performed.

[0121] 4. Downward continuous casting

[0122] Mechanical stirring was maintained in a periodic fluctuation mode (speed: 30 rpm → 50 rpm → 70 rpm → 30 rpm → 50 rpm → 70 rpm, fluctuation period: 3 s). Electromagnetic stirring parameters were maintained at a frequency of 30 Hz and a current of 40 A. The composite reaction crucible temperature was controlled at 800°C (superheat 160°C). Under these control conditions, the apparent viscosity of the composite melt was approximately 5 mPa·s. The cooling water flow rate of the crystallizer was 500 L / min. The crystallizer vibrated at a frequency of 30 Hz, an amplitude of 0.7 mm, and a 20° angle with the casting direction. The drawbar should be properly positioned before heating, with its tip maintaining a distance of 20 mm from the stopper rod.

[0123] A horizontal drive system pulls the stopper rod, allowing the composite melt to flow into the lower outlet of the continuous casting device. The traction device is activated, driving the pull rod downward at a speed of 0.5 mm / s. The melt cools and solidifies through the cold mold, and is continuously pulled out by the pull rod, achieving continuous production of cast billets.

[0124] 5. Liquid level control of continuous casting melt

[0125] When the liquid level of the composite melt drops to 50 mm, the traction device is turned off and the composite melt is replenished according to the above steps 1-3 to ensure that the height of the composite melt reaches 110 mm; then the traction device is turned on and the downward continuous casting is continued (step 4) to realize intermittent continuous production.

[0126] Using the above method, an Al3Ti / TiB2 / 7070 aluminum-based composite material billet with a density exceeding 99% and a uniform structure was produced. Specifically, the mass percentages were: 0.5% Al3Ti, 0.5% TiB2, 6% Zn, 2% Mg, 2% Cu, 0.1% Zr, 0.05% Si, and 0.05% Fe.

[0127] like Figure 4 The ingots are finely dispersed, with an average TiB2 particle size of ~145nm and an average Al3Ti particle size of ~138nm. After a series of processing and heat treatments, including homogenization at 470°C for 2 hours, drawing with a 60% deformation, and aging at 120°C for 12 hours, the ingots exhibit excellent performance, with a hardness of 235HV, a yield strength of ~715MPa, a tensile strength of ~765MPa, and an elongation of ~12%.

[0128] Comparative Example 1

[0129] Other preparation processes and parameters were identical to those in Example 1, except that the dispersion element was not installed. The TiB2 and Al3Ti particles in the ingot were coarse, with an average particle size of ~268 nm. The ingot underwent a series of processing and heat treatments, including homogenization at 470°C for 2 hours, drawing with a 60% deformation, and aging at 120°C for 12 hours. However, its performance was inferior to that of Example 1, with a hardness of 200 HV, a yield strength of ~610 MPa, a tensile strength of ~650 MPa, and an elongation of ~8%.

[0130] Example 2:

[0131] Preparation of Mg-Zn-Zr-Cr2O3-Al2O3 composite material. Mass fraction: 0.5% Cr2O3, 1% Al2O3, 4% Zn, 0.8% Zr, and the balance Mg. This embodiment uses stirring blade C and No. 3 conical dispersion element.

[0132] In this embodiment, the density of Al2O3 particles is about 3.95g / cm 3 , the density of Cr2O3 particles is about 5.21g / cm 3 , the density of Mg-based melt is about 1.58 g / cm 3 The density of Mg-based melt is less than that of Al2O3 and Cr2O3 particles, and the density difference exceeds 0.3g / cm 3 , so the stirring paddle C is selected. At temperatures above 650℃, the viscosity of the Mg-Zn melt is less than 10mPa·s, and the wetting angle between the Mg-Zn melt and graphite is greater than 120°, so the No. 3 melt dispersion piece is selected.

[0133] The diameter of the through holes in the No. 3 conical disperser is 3 mm, and the distribution density of the through holes is 0.8 / cm 2 The spacing between adjacent through-holes in each row is 5 mm, the height of the ridges is 2.5 mm, and the width is 5 mm. The angle between the generatrix of the conical dispersion disc and the horizontal plane is 20°. The maximum diameter of the dispersion disc is 60 mm. In the mechanical stirring-melt dispersion device, the distance between the stirring paddle C and the melt dispersion element No. 3 is 50 mm.

[0134] The specific preparation process is as follows:

[0135] 1. Preparation of melt raw materials:

[0136] Place the Mg raw material and the Mg-Cr-Al raw material in crucibles I and II, respectively. Place the Cu2O raw material in the composite reaction crucible, ensuring a mass ratio of (Al+Cr):Cu2O of 1:5. Turn on the heating device and argon atmosphere protection (full atmosphere protection, gas flow rate of 30L / h). Heat crucible I to 720°C (Mg melt melting point approximately 650°C) and hold it for 15 minutes; heat crucible II to 730°C (Mg-Cr-Al melt melting point approximately 630°C) and hold it for 15 minutes.

[0137] 2. Mechanical stirring-melt dispersion liquid phase in situ reaction:

[0138] During the heating and melting of the raw materials, the composite reaction crucible is heated to 720°C and kept warm for 15 minutes. Subsequently, the servo motor is turned on to drive the mechanical stirring-melt dispersion device to rotate, and the speed is adjusted to 130r / min. The stopper rod in crucible No. 1 is raised by the lifting mechanism, and all the Mg melt in crucible No. 1 is transported to the composite reaction crucible to mix with Cu2O to obtain Mg-Cu2O melt; then, the Mg-Cr-Al melt in crucible No. 2 is mixed with Cu2O in the same way. 3 / s is injected into the dispersion piece.

[0139] The height distance between discharge pipe No. 1 and the top of the dispersing element is controlled at 20 mm, and the horizontal distance between the outlet end of discharge pipe No. 2 and the center of the dispersing element is controlled at 15 mm. The Mg-Cr-Al melt is dispersed into fine droplets and thoroughly mixed with the Mg-Cu2O melt under stirring, undergoing an in-situ reaction to generate Cr2O3 and Al2O3 strengthening particles, thereby obtaining a composite melt. During the in-situ reaction, the mechanical stirring-melt dispersing device is moved up and down to control the depth of the stirring paddle inserted into the melt to 40% of the total melt depth, and the distance between the lowest end of the dispersing element and the liquid surface is controlled at 25 mm.

[0140] After the dispersion of the Mg-Cr-Al melt was completed, the two melts continued to react in situ for about 30 seconds; then the temperature of the composite reaction crucible was raised to 780°C, and the stirring speed was adjusted to a periodic fluctuation mode (speed: 35 r / min→55 r / min→75 r / min→35 r / min→55 r / min→75 r / min, fluctuation period: 4 seconds); during the in situ reaction process and after the in situ reaction was completed, electromagnetic stirring was continued during the mechanical stirring process, and the electromagnetic stirring parameters were: frequency 25 Hz, current 35 A.

[0141] 3. Downward continuous casting

[0142] After the temperature of the composite reaction crucible was raised to 780°C (150°C superheat) and held for 5 minutes, mechanical stirring was maintained in a periodic fluctuation mode (speed: 35 rpm → 55 rpm → 75 rpm → 35 rpm → 55 rpm → 75 rpm, fluctuation period: 4 seconds). The electromagnetic stirring parameters were maintained at a frequency of 25 Hz and a current of 35 A. Under these control conditions, the apparent viscosity of the composite melt was approximately 7 mPa·s. The cooling water flow rate of the crystallizer was 600 L / min. The crystallizer vibrated at a frequency of 40 Hz, an amplitude of 0.8 mm, and a 25° angle with the casting direction. The drawbar should be properly assembled before heating, with its head 25 mm away from the stopper rod.

[0143] A horizontal drive system pulls the stopper rod, allowing the composite melt to flow into the lower outlet of the continuous casting unit. The traction device is activated, driving the pull rod downward at a speed of 1.2 mm / s. The melt cools and solidifies through the cold mold, and is continuously pulled out by the pull rod, achieving continuous production of cast billets.

[0144] 4. Liquid level control of continuous casting melt

[0145] When the liquid level of the composite melt drops to 60 mm, the traction device is turned off, and the composite melt is replenished according to the above steps 1 and 2 to ensure that the height of the composite melt reaches 120 mm; then the traction device is turned on and the downward continuous casting is continued (step 3) to realize intermittent continuous production.

[0146] Using the above method, a Mg-Zn-Zr-Cr2O3-Al2O3 magnesium-based composite material sheet with a density exceeding 99.9% and a uniform structure was prepared. The specific mass percentages were: 0.5% Cr2O3, 1% Al2O3, 4% Zn, 0.8% Zr, and the balance Mg.

[0147] like Figure 5 The ingots are finely dispersed, with an average Al2O3 particle size of ~123nm and an average Cr2O3 particle size of ~159nm. The ingots undergo a series of processing and heat treatments, including homogenization at 400℃ for 4 hours, hot rolling at 350℃ for 50%, solutionizing at 400℃ for 1 hour, cold rolling to 60% deformation, and aging at 150℃ for 10 hours, resulting in excellent performance with a hardness of 210HV, a yield strength of ~640MPa, a tensile strength of ~685MPa, and an elongation of ~14%.

[0148] Example 3:

[0149] The other preparation processes and parameters were the same as in Example 2, except that agitator C and conical disperser No. 2 were used. Using this method, a Mg-Zn-Zr-Cr2O3-Al2O3 magnesium-based composite material with a density of 99.8% and a uniform structure was prepared. Specifically, the mass percentages were: 0.6% Cr2O3, 0.9% Al2O3, 4% Zn, 0.7% Zr, and the balance Mg.

[0150] The average particle size of the Al2O3 particles in the ingot was 154 nm, and the average particle size of the Cr2O3 particles was 181 nm, both larger than the particle sizes in Example 2. The ingot underwent a series of processing and heat treatments, including homogenization at 400°C for 4 h, hot rolling at 350°C for 50%, solutionizing at 400°C for 1 h, cold rolling to 60% deformation, and aging at 150°C for 10 h. However, the performance was inferior to that of Example 2, with a hardness of 205 HV, a yield strength of 620 MPa, a tensile strength of 660 MPa, and an elongation of 10%.

[0151] Example 4:

[0152] Preparation of a Cu-Fe-P-TiB2 composite material. Mass fraction: 0.5% TiB2, 0.3% Fe, 0.03% P, and the balance Cu. Use stirring paddle B and cone-shaped disperser No. 2.

[0153] In this embodiment, the density of the Cu-based melt is about 8.96 g / cm 3 , the density of TiB2 particles is about 4.51g / cm 3 The density of Cu-based melt is much greater than that of TiB2 particles, with a density difference of 4.45 g / cm 3 (far exceeding 0.3g / cm 3 Threshold), so the stirring blade B is selected. At temperatures above 1200°C, the melt viscosity of Cu-Fe-PB is less than 10mPa·s, and the wetting angle between the Cu-Fe-PB melt and graphite is less than 120°, so the No. 2 conical dispersion piece is selected.

[0154] The through-hole diameter of the No. 2 conical disperser used is 3 mm, and the distribution density of the through-holes is 1 / cm 2 The spacing between adjacent through-holes in each row is 10 mm, and a raised strip is provided on the inner wall between any two rows of holes; the raised strip is 4 mm high and 3 mm wide. The angle between the generatrix of the conical dispersing disc and the horizontal plane is 40°, and the maximum diameter of the dispersing disc is 60 mm. In the mechanical stirring-melt dispersion device, the distance between the stirring paddle B and the lowest point of the conical dispersing element No. 2 is 45 mm.

[0155] The specific preparation process is as follows:

[0156] 1. Preparation of melt raw materials:

[0157] Place the Cu-Ti raw material and the Cu-Fe-PB raw material in crucibles No. 1 and No. 2, respectively, ensuring a Ti:B mass ratio of 2:1. Turn on the heating device and argon atmosphere protection (full atmosphere protection, gas flow rate of 40L / h). Heat crucible No. 1 to 1200°C (Cu-Ti melt melting point approximately 1100°C) and hold it for 15 minutes; heat crucible No. 2 to 1200°C (Cu-Fe-PB melt melting point approximately 1120°C) and hold it for 15 minutes.

[0158] 2. Mechanical stirring-melt dispersion liquid phase in situ reaction:

[0159] While the raw materials are being heated and melted, the composite reaction crucible is heated to 1150°C and held for 15 minutes. Subsequently, the servo motor is turned on to drive the mechanical stirring-melt dispersion device to rotate at a speed of 120 r / min. The stopper rod in crucible No. 1 is raised by the lifting mechanism to transfer all the Cu-Ti melt in crucible No. 1 to the composite reaction crucible. Subsequently, the Cu-Fe-PB melt in crucible No. 2 is transferred to the composite reaction crucible in the same manner at a speed of 10 cm. 3 / s is injected into the dispersion piece.

[0160] The height distance between discharge pipe No. 1 and the top of the dispersing element is controlled at 20 mm, and the horizontal distance between the outlet end of discharge pipe No. 2 and the center of the dispersing element is controlled at 18 mm. The Cu-Fe-PB melt is dispersed into fine droplets and thoroughly mixed with the Cu-Ti melt under stirring, undergoing an in-situ reaction to generate TiB2-reinforced particles, resulting in a composite melt (melting point approximately 1100°C). During the in-situ reaction, the mechanical stirring-melt dispersing device is moved up and down to control the depth of the stirring paddle inserted into the melt to 45% of the total melt depth, and the distance from the lowest end of the dispersing element to the liquid surface is controlled at 25 mm.

[0161] After the dispersion of the Cu-Fe-PB melt was completed, the two melts continued to react in situ for about 30 seconds; then the temperature of the composite reaction crucible was raised to 1320°C, and the stirring speed was adjusted to a periodic fluctuation mode (speed: 35r / min→55r / min→75r / min→35r / min→55r / min→75r / min, fluctuation period: 5s); during the in situ reaction process and after the in situ reaction was completed, electromagnetic stirring was continued during the mechanical stirring process, and the parameters of the electromagnetic stirring were: frequency 35Hz, current 50A.

[0162] 3. Downward continuous casting

[0163] The temperature of the composite reaction crucible was raised to 1320°C (superheat 220°C) and held for 5 minutes. Mechanical stirring was then maintained in a periodic fluctuation mode (speed: 35 rpm → 55 rpm → 75 rpm → 35 rpm → 55 rpm → 75 rpm, fluctuation period: 5 seconds). The electromagnetic stirring parameters were maintained at a frequency of 35 Hz and a current of 50 A. The cooling water flow rate of the crystallizer was 800 L / min. The crystallizer vibrated at a frequency of 40 Hz, an amplitude of 1 mm, and a 30° angle with the direction of casting. The drawbar should be properly positioned before heating, with its head 20 mm away from the stopper rod.

[0164] A horizontal drive system pulls the stopper rod, allowing the composite melt to flow into the lower outlet of the continuous casting unit. The traction device is activated, driving the pull rod downward at a speed of 1 mm / s. The melt cools and solidifies through the cold mold, and is continuously pulled out by the pull rod, achieving continuous production of cast billets.

[0165] 4. Liquid level control of continuous casting melt

[0166] When the liquid level of the composite melt drops to 60 mm, the traction device is turned off, and the composite melt is replenished according to the above steps 1 and 2 to ensure that the height of the composite melt reaches 120 mm; then the traction device is turned on and the downward continuous casting is continued (step 3) to realize intermittent continuous production.

[0167] Using the above method, a Cu-Fe-P-TiB2 composite material sheet with a density of over 99.8% and uniform structure was prepared. The specific mass percentages were: TiB2 was 0.5%, containing 0.3% Fe, 0.03% P, and the balance being Cu.

[0168] like Figure 7 The particles in the ingot are finely dispersed, with an average TiB2 particle size of ~109nm. The ingot undergoes a series of processing and heat treatments, including homogenization at 950℃ for 4h, hot rolling at 900℃ for 50%, solutionizing at 950℃ for 2h, cold rolling for 90% deformation, and aging at 450℃ for 2h, resulting in excellent performance with a hardness of 225HV, a yield strength of ~685MPa, a tensile strength of ~755MPa, an elongation of ~15%, and a conductivity of 85% IACS.

[0169] Example 5:

[0170] All other conditions were the same as in Example 4, except that after the in-situ reaction was completed, the mechanical stirring and melt dispersion device was controlled to rotate at a constant speed of 75 rpm during the mechanical stirring and downcasting process. In this example, a Cu-Fe-P-TiB2 composite material sheet with a density exceeding 99.7% and a uniform structure was produced. Specifically, the mass percentages were: 0.5% TiB2, 0.31% Fe, 0.03% P, and the balance Cu.

[0171] Compared to Example 4, the ingot of Example 5 had poor particle distribution uniformity, with an average TiB2 particle size of ~135 nm. The ingot underwent a series of processing and heat treatments, including homogenization at 950°C for 4 h, hot rolling at 900°C for 50% of the original mass, solutionizing at 950°C for 2 h, cold rolling to 90% of the original mass, and aging at 450°C for 2 h. However, the ingot's performance was inferior to that of Example 4, with a hardness of 215 HV, a yield strength of ~655 MPa, a tensile strength of ~720 MPa, an elongation of ~12%, and a conductivity of 84% IACS.

[0172] Example 6:

[0173] Preparation of a Cu-Ni-Si-HfB2 composite material. Mass fraction: 1% HfB2, 1.5% Ni, 0.3% Si, and the balance Cu. Agitator C and a No. 3 cone disperser were used.

[0174] In this embodiment, the density of the Cu-based melt is about 8.96 g / cm 3 The density of HfB2 particles is about 10.5g / cm 3 The density of Cu-based melt is less than that of HfB2 particles, and the density difference is 1.54 g / cm 3 (over 0.3g / cm 3 threshold), so stirring paddle C is selected. At temperatures above 1200°C, the melt viscosity of Cu-Ni-Si-B is less than 10 mPa·s, and the wetting angle between the Cu-Ni-Si-B melt and graphite is greater than 120°, so the No. 3 conical dispersing element is selected.

[0175] The through-hole diameter of the No. 3 conical disperser used is 3 mm, and the distribution density of the through-holes is 0.8 / cm 2 The spacing between adjacent through-holes in each row is 8 mm, and a raised strip is provided on the inner wall between any two rows of holes; the raised strip is 2 mm high and 5 mm wide. The angle between the generatrix of the conical dispersing disc and the horizontal plane is 20°, and the maximum diameter of the dispersing disc is 60 mm. In the mechanical stirring-melt dispersion device, the distance between the stirring paddle C and the lowest point of the conical dispersing element No. 3 is 50 mm.

[0176] The specific preparation process is as follows:

[0177] 1. Preparation of melt raw materials:

[0178] Place the Cu-Hf raw material and the Cu-Ni-Si-B raw material in crucibles I and II, respectively, ensuring a Hf:B mass ratio of 4:1. Turn on the heating device and argon atmosphere protection (full atmosphere protection, gas flow rate of 30L / h). Heat crucible I to 1220°C (Cu-Hf melt melting point approximately 1120°C) and hold it for 15 minutes; heat crucible II to 1220°C (Cu-Ni-Si-B melt melting point approximately 1120°C) and hold it for 15 minutes.

[0179] 2. Mechanical stirring-melt dispersion liquid phase in situ reaction:

[0180] While the raw materials are being heated and melted, the composite reaction crucible is heated to 1200°C and kept warm for 15 minutes. Subsequently, the servo motor is turned on to drive the mechanical stirring-melt dispersion device to rotate at a speed of 100 r / min. The stopper rod in crucible No. 1 is raised by the lifting mechanism to transfer all the Cu-Hf melt in crucible No. 1 to the composite reaction crucible; then, in the same way, the Cu-Ni-Si-B melt in crucible No. 2 is transferred to the composite reaction crucible at 8 cm 3 / s is injected into the dispersion piece.

[0181] The height distance between discharge pipe No. 1 and the top of the dispersing element is controlled at 20 mm. The horizontal distance between the outlet end of discharge pipe No. 2 and the center of the dispersing element is controlled at 20 mm. The Cu-Ni-Si-B melt is dispersed into fine droplets and thoroughly mixed with the Cu-Hf melt under stirring, undergoing an in-situ reaction to generate HfB2-reinforced particles, resulting in a composite melt (melting point approximately 1120°C). During the in-situ reaction, the mechanical stirring-melt dispersing device is moved up and down to control the depth of the stirring paddle inserted into the melt to 40% of the total melt depth. The distance between the lowest end of the dispersing element and the liquid surface is controlled at 25 mm.

[0182] After the Cu-Ni-Si-B melt was dispersed, the two melts continued to react in situ for about 30 seconds. The temperature of the composite reaction crucible was then raised to 1320°C, and the stirring speed was adjusted to a periodic fluctuation mode (speed: 35 r / min→55 r / min→75 r / min→35 r / min→55 r / min→75 r / min, fluctuation period: 3 seconds). During the in-situ reaction process and after the in-situ reaction was completed, electromagnetic stirring was continued during the mechanical stirring process. The parameters of the electromagnetic stirring were: frequency 30 Hz, current 45 A.

[0183] 3. Downward continuous casting

[0184] After the temperature of the composite reaction crucible is raised to 1350°C (superheat 230°C) and maintained for 5 minutes, mechanical stirring is maintained in a periodic fluctuation mode (speed: 35r / min → 55r / min → 75r / min → 35r / min → 55r / min → 75r / min, fluctuation period: 3s). The parameters for maintaining electromagnetic stirring are a frequency of 30Hz, a current of 45A, and a cooling water flow rate of 1000L / min for the crystallizer. The crystallizer vibration frequency is 30Hz, the amplitude is 0.8mm, and the vibration direction forms a 20° angle with the casting direction. Before heating, the traction rod 27 should be assembled in the appropriate position, with the distance between its head and the stopper rod guaranteed to be 20mm. The stopper rod is pulled by a horizontal transmission device, allowing the composite melt to flow into the lower liquid outlet 10 of the continuous casting device. The traction device is activated, driving the traction rod downward at a traction speed of 1.5mm / s. The melt is cooled and solidified by the cold mold and continuously pulled out under the traction of the traction rod, achieving continuous production of cast billets.

[0185] 4. Liquid level control of continuous casting melt

[0186] When the liquid level of the composite melt drops to 60 mm, the traction device is turned off, and the composite melt is replenished according to the above steps 1 and 2 to ensure that the height of the composite melt reaches 120 mm; then the traction device is turned on and the downward continuous casting is continued (step 3) to realize intermittent continuous production.

[0187] Using the above method, a Cu-Ni-Si-HfB2 composite material sheet with a density exceeding 99.9% and uniform structure was prepared. The specific mass percentages were: HfB2 was 1%, containing 1.5% Ni, 0.3% Si, and the balance Cu.

[0188] like Figure 7 The particles in the ingot are finely dispersed, and the average particle size of the HfB2 particles in the ingot is ~103nm. The ingot undergoes a series of processing and heat treatments, including homogenization at 960℃ / 2h, hot rolling at 900℃ for 50%, solutionizing at 960℃ / 1h, cold rolling for 90% deformation, and aging (450℃, 1.5h), resulting in excellent performance with a hardness of 295HV, a yield strength of ~920MPa, a tensile strength of ~980MPa, an elongation of ~13%, and a conductivity of 62%IACS.

[0189] Comparative Example 2:

[0190] The other preparation processes and parameters were identical to those in Example 6, except that the mechanical stirring-melt dispersion device was not used. Using this method, a Cu-Ni-Si-HfB2 composite sheet with a density of 99.8% was produced. Specifically, the mass percentages were: HfB2 at 0.9%, Ni at 1.6%, Si at 0.3%, and Cu as the balance.

[0191] Compared to Example 6, the HfB2 particles in the ingot were coarse and extremely unevenly distributed, with severe agglomeration, and an average particle size of ~386 nm. The ingot underwent a series of processing and heat treatments, including homogenization at 960°C for 2 h, hot rolling at 900°C for 50% of the original weight, solutionizing at 960°C for 1 h, cold rolling to 90% of the original weight, and aging at 450°C for 1.5 h. The ingot exhibited excellent performance, with a hardness of 220 HV, a yield strength of ~670 MPa, a tensile strength of ~715 MPa, an elongation of ~4%, and a conductivity of 55% IACS, far inferior to that of Example 6.

Claims

1. A continuous casting method for preparing metal matrix composite materials based on melt dispersion in-situ reaction, characterized by: The mechanical stirring-melt dispersion device in the composite reaction crucible containing melt A is turned on to rotate, and then melt B in crucible No. 2 is flowed into the dispersion member through the discharge pipe No.

2. Under the rotation, melt B is dispersed into liquid droplets by the dispersion member and dripped into melt A. Under the synergistic effect of mechanical stirring, the melt B reacts in situ with melt A to obtain a composite melt containing in-situ strengthened particles. After the in-situ reaction is completed, the temperature is increased and mechanical stirring is continued to obtain a continuous casting melt, and the continuous casting melt is continuously cast to obtain the composite melt. The viscosity of melt A is higher than the viscosity of melt B; The mechanical stirring-melt dispersion device comprises a stirring rod, a stirring paddle fixed to the bottom of the stirring rod, and a dispersing member fixed to the stirring rod and located above the stirring paddle, wherein the dispersing member is a porous structure; During the continuous casting, the superheat of the continuous casting melt is controlled to be 150-300° C., and the apparent viscosity is ≤8 mPa·s.

2. The continuous casting method for preparing metal matrix composite materials based on melt dispersion in-situ reaction according to claim 1, characterized in that: According to the composition of alloy A, corresponding raw materials are prepared, all of the raw materials of alloy A are placed in crucible No. 1 and heated to obtain melt A, and melt A is then discharged into a preheated composite reaction crucible through discharge pipe No. 1, or a portion of the raw materials of alloy A are placed in crucible No. 1 and heated to obtain melt A1, and another portion of the raw materials of alloy A are placed in the composite reaction crucible and heated to obtain melt A2, and melt A1 is then discharged into the composite reaction crucible through discharge pipe No. 1 to be mixed with melt A2 to form melt A, and corresponding raw materials are prepared according to the composition of alloy B, placed in crucible No. 2 and heated to obtain melt B; The melt B flows into the dispersion part through the No. 2 discharge pipe at a flow rate of 5-10 cm 3 / s; The height distance between the No. 2 discharge pipe and the top of the disperser is controlled to be 8-25 mm, and the horizontal distance between the outlet end of the No. 2 discharge pipe and the center of the disperser is controlled to be 15-25 mm; During the in-situ reaction, the temperature difference between the upper and lower layers of melt A and melt B is controlled to be ≤15°C; During the in-situ reaction, the temperature of the composite reaction crucible is controlled to be the melting point of the composite melt + 50-100°C, and the temperature of melt B is the melting point of alloy B + 50-300°C.

3. A continuous casting method for preparing a metal matrix composite material based on melt dispersion in-situ reaction according to claim 1 or 2, characterized in that: In the mechanical stirring-melt dispersion device, the distance between the dispersing element and the stirring paddle is 40-60 mm; during the in-situ reaction, the depth of the stirring paddle extending into the melt is controlled to be 40-50% of the total depth of the melt by moving the mechanical stirring-melt dispersion device up and down, and the distance between the bottom end of the dispersing element and the liquid surface is controlled to be 25-40 mm; The dispersing member is selected from a conical dispersing member or a circular dispersing member, wherein the conical dispersing member comprises a conical dispersing disk, wherein a circumferential array of holes of the conical dispersing disk is arranged, and each row comprises a plurality of through holes spaced apart along a generatrix direction; wherein the circular dispersing member comprises a circular dispersing disk, wherein a circumferential array of holes of the circular dispersing disk is arranged, and each row comprises a plurality of through holes spaced apart along a radial direction; A chute is provided between any two rows of holes on the outer side wall of the conical dispersing disk; or a convex strip is provided between any two rows of holes on the inner side wall of the conical dispersing disk; a convex strip is provided between two rows of holes on the upper surface of the circular dispersing disk; In the conical or circular dispersion disk, the diameter of any through hole is 2-3 mm, and the distribution density of the through holes is 0.5-1.5 / cm 2 ; The thickness of the conical dispersion disk or the circular dispersion disk is 2-9 mm.

4. The continuous casting method for preparing metal matrix composite materials based on melt dispersion in-situ reaction according to claim 3, characterized in that: The conical dispersing member is selected from one of conical dispersing member No. 1, conical dispersing member No. 2, and conical dispersing member No. 3, wherein the conical dispersing member No. 1 comprises a conical dispersing disk No. 1, wherein the conical dispersing disk No. 1 has a plurality of rows of holes arranged in a circumferential array, each row comprising a plurality of through holes evenly spaced along a generatrix; the spacing between adjacent through holes in each row is 3-6 mm, and a chute is provided on the outer wall between any two rows of holes; the chute has a depth of 3-5 mm and a width of 2-8 mm, and the angle between the generatrix of the conical dispersing disk No. 1 and the horizontal plane is 5-60°; The conical dispersing element No. 2 comprises a conical dispersing disc No. 2, which is in an inverted cone shape. The conical dispersing disc No. 2 has multiple rows of holes arranged in a circumferential array, each row comprising multiple through holes evenly spaced along a generatrix. The spacing between adjacent through holes in each row is 8-15 mm, and a convex strip is provided on the inner side wall between any two rows of holes. The height of the convex strip is 3-5 mm and the width is 2-4 mm. The angle between the generatrix of the conical dispersing disc and the horizontal plane is 30-45°. The conical dispersing element No. 3 comprises a conical dispersing disc No. 3, which is in an inverted cone shape. The conical dispersing disc No. 3 has a plurality of rows of holes arranged in a circumferential array, each row comprising a plurality of through holes evenly spaced along a generatrix direction, the spacing between adjacent through holes in each row being 4-12 mm, and a convex strip being provided on the inner side wall between any two rows of holes; the convex strip having a height of 1.5-2.5 mm and a width of 3-6 mm; the angle between the generatrix of the conical dispersing disc and the horizontal plane being 10-30°; The circular dispersion disk has a plurality of rows of holes arranged in a circumferential array on its disk surface, each row including a plurality of through holes evenly spaced along the radial direction, the spacing between adjacent through holes in each row being 5-10 mm, and a convex strip is provided between any two rows of holes on the upper side of the disk surface, the height of the convex strip being 3-5 mm and the width being 3-8 mm; The material of the dispersing member is graphite. When the melt viscosity of melt B is less than 10 mPa·s and the wetting angle between melt B and graphite is less than 120°, the dispersing member is selected from conical dispersing member No.

2. When the melt viscosity of melt B is greater than 10 mPa·s and the wetting angle between melt B and graphite is less than 120°, the dispersing member is selected from conical dispersing member No.

1. When the melt viscosity of melt B is less than 10 mPa·s and the wetting angle between melt B and graphite is greater than 120°, the dispersing member is selected from conical dispersing member No.

3. When the melt viscosity of melt B is greater than 10 mPa·s and the wetting angle between melt B and graphite is greater than 120°, the dispersing member is selected from circular dispersing member.

5. The continuous casting method for preparing metal matrix composite materials based on melt dispersion in-situ reaction according to claim 1 or 2, characterized in that: The stirring paddle is selected from one of stirring paddle A, stirring paddle B, and stirring paddle C, wherein the stirring paddle A is a straight-blade stirring paddle, the stirring paddle B is a pitch-blade stirring paddle, the blade of which is 30° with the horizontal plane, and the stirring paddle C is a pitch-blade stirring paddle, the blade of which is -30° with the horizontal plane; When the density of the composite melt differs from that of the in-situ strengthened particles by no more than 0.3 g / cm 3 When the density of the composite melt differs from the density of the in-situ strengthened particles by more than 0.3 g / cm 3 , and the density of the composite melt is greater than the density of the in-situ strengthened particles, the stirring blade is selected from stirring blade B, when the density of the composite melt differs from the density of the in-situ strengthened particles by more than 0.3 g / cm 3 , and when the density of the composite melt is less than the density of the in-situ strengthened particles, the stirring paddle is selected from stirring paddle C; During the in-situ reaction, the rotation speed of the mechanical stirring-melt dispersion device is 100-150 r / min; After the in-situ reaction is completed, other alloy raw materials are added to the composite melt; After the in-situ reaction is completed, the temperature is increased and mechanical stirring is continued for 1-10 minutes to obtain a continuous casting melt, and the continuous casting melt is continuously cast; the mechanical stirring is continued to obtain the continuous casting melt and during the continuous casting process, the speed of the mechanical stirring-melt dispersion device is adjusted to 20-80 r / min, and electromagnetic stirring is simultaneously performed, and the frequency of the electromagnetic stirring is controlled to be 20-35 Hz and the current is controlled to be 30-50 A; During the continuous casting process, the cooling water flow rate of the crystallizer is 100-2000 L / h; During the continuous casting process, the vibration frequency of the crystallizer is 20-50 Hz, the amplitude is 0.5-2 mm, and the vibration direction forms an angle of 15-30° with the casting direction.

6. The continuous casting method for preparing metal matrix composite materials based on melt dispersion in-situ reaction according to claim 5, characterized in that: Continue to perform mechanical stirring to obtain the continuous casting melt and during the continuous casting process, control the speed of the mechanical stirring-melt dispersion device to cycle and fluctuate at 20-40 r / min, 40-60 r / min, and 60-80 r / min, with a fluctuation period of 3-5 s; During the continuous casting process, when the superheat of the continuous casting melt is ≤200°C, the cooling water flow rate of the crystallizer is 200-600 L / min; when the superheat of the continuous casting melt is greater than 200°C, the cooling water flow rate of the crystallizer is 700-1500 L / min; The continuous casting method is downward continuous casting, and during the downward continuous casting, the pulling speed of the pulling rod moving downward is 0.1-3 mm / s; During the downward continuous casting, the liquid level of the continuous casting melt is controlled at 50-120 mm.

7. A continuous casting device for preparing metal matrix composite materials based on melt dispersion in-situ reaction, characterized by: The continuous casting device includes: crucible No. I, crucible No. II, composite reaction crucible, mechanical stirring-melt dispersion device, continuous casting mold, crystallizer, and traction rod; The No. Ⅰ crucible is connected to the composite reaction crucible through the No. 1 discharge pipe, and the No. Ⅱ crucible is connected to the composite reaction crucible through the No. 2 discharge pipe; The mechanical stirring-melt dispersion device passes through the top center of the composite reaction crucible and extends into the interior of the composite reaction crucible; the mechanical stirring-melt dispersion device comprises a stirring rod, a stirring paddle fixed to the bottom of the stirring rod, and a dispersion member fixed to the stirring rod above the stirring paddle; the dispersion member is a porous structure and is used to disperse the melt into droplets; A crystallizer is provided outside the continuous casting mold, and the crystallizer is used to cool the continuous casting mold; The continuous casting mold is located below the composite reaction crucible, with its upper end connected to the lower liquid outlet of the composite reaction crucible and its lower end close to the traction rod, and the continuously cast metal matrix composite material is pulled out by the traction of the traction rod.

8. The continuous casting device for preparing metal matrix composite materials based on melt dispersion in-situ reaction according to claim 7, characterized in that: The crucible No. 1 is provided with a stopper rod No. 1, and the crucible No. 2 is provided with a stopper rod No. 2, and the stopper rod No. 1 and the stopper rod No. 2 are respectively connected to a vertical transmission device; The composite reaction crucible is provided with an upper liquid outlet and a lower liquid outlet, between which a stopper rod No. 3 is provided perpendicular thereto, and the stopper rod No. 3 is connected to the horizontal transmission device by a bolt; The composite reaction crucible is surrounded by an electromagnetic induction coil; The mechanical stirring-melt dispersion device further comprises a servo motor and a planetary gear reducer. The servo motor is located outside the composite reaction crucible and is used to drive the stirring paddle and the dispersion element to rotate. The speed range is 0-1000 r / min. The stirring rod in the mechanical stirring-melt dispersion device is composed of a long rod and a short rod connected by threads from top to bottom; In the mechanical stirring-melt dispersion device, the distance between the dispersion element and the stirring paddle is 40-60 mm; The dispersing member is selected from a conical dispersing member or a circular dispersing member, wherein the conical dispersing member comprises a conical dispersing disk, wherein a circumferential array of holes of the conical dispersing disk is arranged, and each row comprises a plurality of through holes spaced apart along a generatrix direction; wherein the circular dispersing member comprises a circular dispersing disk, wherein a circumferential array of holes of the circular dispersing disk is arranged, and each row comprises a plurality of through holes spaced apart along a radial direction; A chute is provided between any two rows of holes on the outer side wall of the conical dispersing disk; or a convex strip is provided between any two rows of holes on the inner side wall of the conical dispersing disk; a convex strip is provided between two rows of holes on the upper surface of the circular dispersing disk; In the conical or circular dispersion disk, the diameter of any through hole is 2-3 mm, and the distribution density of the through holes is 0.5-1.5 / cm 2 ; The thickness of the conical dispersion disk or the circular dispersion disk is 2-9 mm; The conical dispersing member further includes a fixing ring A fixed above the conical dispersing disk and coaxial with the conical dispersing disk, and the circular dispersing member further includes a fixing ring B fixed above the circular dispersing disk and coaxial with the circular dispersing disk. The outer diameters of the fixing ring A and the fixing ring B are both 15~20 mm, and the interiors of the fixing ring A and the fixing ring B are both threaded for connecting to the stirring rod.

9. The continuous casting device for preparing metal matrix composite materials based on melt dispersion in-situ reaction according to claim 8, characterized in that: The conical dispersing member is selected from one of conical dispersing member No. 1, conical dispersing member No. 2, and conical dispersing member No. 3, wherein the conical dispersing member No. 1 comprises a conical dispersing disk No. 1, wherein the conical dispersing disk No. 1 has a plurality of rows of holes arranged in a circumferential array, each row comprising a plurality of through holes evenly spaced along a generatrix; the spacing between adjacent through holes in each row is 3-6 mm, and a chute is provided on the outer wall between any two rows of holes; the chute has a depth of 3-5 mm and a width of 2-8 mm, and the angle between the generatrix of the conical dispersing disk No. 1 and the horizontal plane is 5-60°; The conical dispersing element No. 2 comprises a conical dispersing disc No. 2, which is in an inverted cone shape. The conical dispersing disc No. 2 has multiple rows of holes arranged in a circumferential array, each row comprising multiple through holes evenly spaced along a generatrix. The spacing between adjacent through holes in each row is 8-15 mm, and a convex strip is provided on the inner side wall between any two rows of holes. The height of the convex strip is 3-5 mm and the width is 2-4 mm. The angle between the generatrix of the conical dispersing disc and the horizontal plane is 30-45°. The conical dispersing element No. 3 comprises a conical dispersing disc No. 3, which is in an inverted cone shape. The conical dispersing disc No. 3 has a plurality of rows of holes arranged in a circumferential array, each row comprising a plurality of through holes evenly spaced along a generatrix direction, the spacing between adjacent through holes in each row being 4-12 mm, and a convex strip being provided on the inner side wall between any two rows of holes; the convex strip having a height of 1.5-2.5 mm and a width of 3-6 mm; the angle between the generatrix of the conical dispersing disc and the horizontal plane being 10-30°; The circular dispersion disk has a plurality of rows of holes arranged in a circumferential array on its disk surface, each row including a plurality of through holes evenly spaced along the radial direction, the spacing between adjacent through holes in each row being 5-10 mm, and a convex strip is provided between any two rows of holes on the upper side of the disk surface, the height of the convex strip being 3-5 mm and the width being 3-8 mm; The stirring paddle is selected from one of stirring paddle A, stirring paddle B, and stirring paddle C. The stirring paddle A is a straight-blade stirring paddle, the stirring paddle B is a pitch-blade stirring paddle, and the blade thereof is at 30°C with the horizontal plane. The stirring paddle C is a pitch-blade stirring paddle, and the blade thereof is at -30°C with the horizontal plane.

10. The continuous casting device for preparing metal matrix composite materials based on melt dispersion in-situ reaction according to claim 7, characterized in that: The distance between the top of the drawbar and the No. 3 stopper rod in the composite reaction crucible is 15-30 mm; The crystallizer is connected to a vibration device, and the vibration device realizes the vibration of the crystallizer.

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