Wave type semi-solid slurry preparation device and preparation method of high-strength and high-toughness light-weight die-casting aluminum-silicon alloy structural part

Abstract

The application discloses a wave-shaped semi-solid slurry preparation device and a preparation method of high-strength and high-toughness light-weight die-casting aluminum-silicon alloy structural member, relates to the technical field of aluminum alloy, and solves the problems of poor plasticity and low strength of existing aluminum-silicon alloy castings; the wave-shaped semi-solid slurry preparation device can realize forced cooling of metal liquid, rapidly supercool the metal liquid, and induce burst nucleation, so that the cooling speed of the metal liquid reaches 200-300 DEG C / s; then, the device is used to prepare semi-solid slurry, the semi-solid slurry is die-cast into an aluminum-silicon alloy casting, and the aluminum-silicon alloy casting is subjected to isothermal hot extrusion to obtain an aluminum-silicon alloy extruded part; the aluminum-silicon alloy extruded part is subjected to T6 heat treatment to obtain a high-strength and high-toughness die-casting aluminum alloy structural member; the method can significantly improve the microstructure of the aluminum-silicon alloy, improve mechanical properties, make the aluminum-silicon alloy have high strength and good plasticity, and realize the balance between high strength and high plasticity of the aluminum-silicon alloy.

Description

Technical Field

[0001] This invention relates to the field of die-cast aluminum alloy technology, specifically to a wave-shaped semi-solid slurry preparation device and a method for preparing high-strength, tough, and lightweight die-cast aluminum-silicon alloy structural parts. Background Technology

[0002] Al-Si alloy structural parts are widely used in major national economic and defense construction fields such as aerospace, automobiles, high-speed rail, and shipbuilding due to their high specific strength, high hardness, low coefficient of linear expansion, good thermal stability, and excellent castability. They are especially used in the transportation sector for manufacturing and processing components such as engine blocks, steering knuckles, and pistons.

[0003] A356 alloy is a typical hypoeutectic Al-Si alloy, composed of α-Al and eutectic Si phases. On one hand, the rough and irregular intermetallic compounds and the needle-like eutectic Si phase exhibit high brittleness and cannot adapt to the plastic deformation of the surrounding soft and tough α-Al matrix, thus reducing the alloy's resistance to stress cracking. On the other hand, A356 alloy lacks elements that provide significant solid solution strengthening or can combine with the α-Al matrix to form high-hardness intermetallic compound precipitates. This results in poor plasticity, low strength, and extremely low toughness in A356 alloy, severely limiting its application in scenarios requiring high strength, toughness, and lightweight properties.

[0004] A356 alloy can be processed using semi-solid processing technology. This involves solidifying molten metal into a semi-solid alloy slurry, which is then die-cast, combining the advantages of traditional forging and casting methods. The semi-solid slurry exhibits good fluidity, a lower filling temperature, stable filling, and a fine microstructure. Its viscosity is higher than that of the fully liquid state, resulting in less gas entrainment. While this method can improve the properties of Al-Si alloys, certain drawbacks remain.

[0005] 1. When molten aluminum-silicon alloy is rapidly cooled to a certain degree, the supercooling reaches a critical value, and atoms or molecules in the liquid phase rapidly aggregate to form a large number of crystal nuclei, a phenomenon known as explosive nucleation. The cooling rate plays a crucial role; the faster the cooling rate, the greater the supercooling of the molten metal, and the higher the nucleation rate. This can significantly refine the grains, reduce structural defects, and improve the strength and toughness of the material. However, in existing technologies, the liquid phase content of semi-solid slurry filling the mold cavity is 40%-80%, sometimes even approaching 90%. The remaining liquid phase undergoes secondary solidification after filling the cavity, experiencing a new solidification process, namely, the precipitation of secondary primary phases and eutectic reactions, resulting in solidification shrinkage and compositional segregation, thus producing defects such as shrinkage porosity and thermal cracking, affecting the mechanical properties of the formed parts.

[0006] 2. Iron (Fe) is a common impurity in A356 alloy, which directly impairs the mechanical and processing properties of the product. Due to the limited solubility of iron in aluminum, iron-rich intermetallic compounds, such as β-Al5FeSi phase and π-Al8FeMg3Si6 phase, are easily formed during the solidification of molten metal to form a semi-solid alloy slurry. At low cooling rates, Fe-rich intermetallic compounds tend to form needle-like β-Al5FeSi phase, which, together with needle-like eutectic Si phase, increases the brittleness of the alloy and seriously affects its toughness, negatively impacting the improvement of the alloy's strength.

[0007] 3. The eutectic Si phase is mainly needle-shaped, rod-shaped, or strip-shaped, and is unevenly distributed with sharp edges, which severely cuts the alloy matrix. At the same time, the sharp edges are prone to stress concentration, thus affecting the strength and plasticity of the alloy. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a wave-shaped semi-solid slurry preparation device and a method for preparing high-strength, high-toughness, and lightweight die-cast aluminum-silicon alloy structural parts. By using the wave-shaped semi-solid slurry preparation device to forcibly cool the aluminum-silicon alloy molten metal, a semi-solid slurry is first prepared. Then, a horizontal die-casting method is used to obtain die-cast aluminum-silicon alloy structural parts with moderate strength and moderate plasticity. Combined with isothermal hot extrusion and T6 heat treatment, the microstructure of the die-cast aluminum-silicon alloy is significantly improved, achieving stable preparation of high-strength, high-toughness, and lightweight structural parts made of die-cast aluminum alloy. This ensures a balance between high strength and high plasticity and significantly improves mechanical properties.

[0009] The present invention is achieved through the following technical solution.

[0010] The first objective of this invention is to provide a wave-type semi-solid slurry preparation apparatus, comprising:

[0011] A wave-shaped water-cooled ramp is used to force-cool molten metal to form a semi-solid slurry. The surface of the wave-shaped water-cooled ramp has grooves and protrusions, and a water-cooling system is provided on the back of the protrusions.

[0012] A pouring device is located above a wavy water-cooled slope and is used to pour molten metal onto the slope surface of the wavy water-cooled slope.

[0013] A collection device is installed at the outlet of the wave-shaped water-cooled slope to collect semi-solid slurry.

[0014] The molten metal is collected in the groove of the wave-shaped water-cooling slope and then flows through the protrusion of the wave-shaped water-cooling slope for strong heat exchange, so that the cooling rate of the molten metal reaches 200-300℃ / s.

[0015] This invention provides a wave-shaped semi-solid slurry preparation device capable of forced cooling of molten metal, inducing explosive nucleation through rapid supercooling. This device allows the aluminum-silicon alloy molten metal to experience intense and rapid cooling under the combined action of circulating water cooling and a wave-shaped cooling ramp. The grooves of the wave-shaped water cooling ramp can gather, stabilize, and constrain the flow of the molten metal, ensuring that subsequent flow of molten metal over the protrusions is more concentrated and stable in contact with the protruding surfaces, thereby improving heat exchange efficiency and achieving a cooling rate of 200-300℃ / s.

[0016] When the high-temperature molten metal flows over the wavy ramp, the grooves in the wavy structure act to gather, stabilize, and constrain the flow of the molten metal. It then flows over the protrusions in the wavy structure, where circulating cooling water is introduced into the water-cooling system on the back side of the protrusions. Under the forced cooling effect of the circulating cooling water, strong heat transfer is generated, forcing the Al-Si alloy to nucleate explosively, forming a special semi-solid slurry consisting of spherical or near-spherical α-Al phases and the remaining high-solute liquid phase. This effectively refines and homogenizes the microstructure of the aluminum-silicon alloy, while also inhibiting the formation of Fe-rich intermetallic compounds to a certain extent and preventing the eutectic Si from growing into coarse dendrites. Furthermore, real-time measurements by two temperature sensors at the pouring cup and the collection device show a cooling rate of 200-300℃ / s.

[0017] Furthermore, the wavy water-cooling ramp includes at least two protrusions and two grooves, with an overall length of not less than 400 mm. That is, it is configured as a double-wavy water-cooling ramp, consisting of two wavy protrusions of different sizes and two grooves of different sizes, with the second section being larger than the first. In one specific embodiment, the length, radius of curvature, and depth of the first groove are 46 mm, 40 mm, and 8 mm, respectively; the length, radius of curvature, and height of the first wavy protrusion are 115 mm, 100 mm, and 12 mm, respectively; the length, radius of curvature, and depth of the second groove are 65 mm, 75 mm, and 10 mm, respectively; and the length, radius of curvature, and height of the second wavy protrusion are 120 mm, 150 mm, and 12 mm, respectively. Long-term experimental research has shown that to ensure cooling performance, the overall length of the wavy water-cooling ramp should be not less than 400 mm. In one specific embodiment, the overall length of the double-wavy water-cooling ramp is 440 mm.

[0018] When the molten metal flows through the first wavy ramp, the first groove first acts to gather, stabilize, and constrain the flow of the high-temperature alloy molten metal. Then, it flows through the first protrusion, where the forced cooling effect of the circulating cooling water on the back side generates an initial strong cooling effect. Next, the molten metal with a low solids content flows through the second wavy ramp, where it further gathers and stabilizes with the second groove, and then flows through the second protrusion, generating strong heat exchange. Simultaneously, the back side of the second protrusion is equipped with circulating cooling water, and the combined effect of these two factors generates a second forced cooling. Through these two forced cooling heat exchanges, the alloy is forced to nucleate explosively, forming a special semi-solid slurry consisting of spherical or near-spherical α-Al phases and the remaining high-solute liquid phase. This effectively refines and homogenizes the microstructure of the A356 alloy, while also inhibiting the formation of Fe-rich intermetallic compounds to a certain extent.

[0019] Furthermore, the water-cooling system is a circulating cooling water pipe, and the back of the protrusions of the wavy water-cooling ramp is provided with an installation groove, in which the circulating cooling water pipe is fixed. The number of cooling water pipes installed must match the protrusions of the wavy structure. By providing recessed installation grooves on the back of the protrusions, the installation stability of the cooling water pipes is ensured, and the contact between the cooling water pipes and the protrusions is made tighter, thereby achieving better forced heat exchange. In one specific embodiment, for a double-wavy water-cooling ramp, two sets of cooling water pipes are provided, namely an upper circulating cooling water pipe and a lower circulating cooling water pipe.

[0020] Furthermore, the pouring device includes a pouring cup and a fixing plate. The fixing plate is positioned above the corrugated water-cooled slope, and the pouring cup is mounted on the fixing plate via an elbow clamp. The pouring cup is a steel preheating pouring cup with a rectangular opening frame on its side. After preheating, the pouring cup is first positioned correctly by engaging with a guide block through the rectangular opening frame on its side, and then fixed to the fixing plate by the elbow clamp, thus completing the installation of the pouring cup.

[0021] Furthermore, it also includes a guide post, a guide sleeve, and a horizontally moving guide plate. The bottom of the guide post is mounted on a fixed base, and the upper part of the guide post is fitted with a guide sleeve to drive the pouring cup to move up and down. The horizontally moving guide plate is mounted below the fixed plate, and its side is slidably connected to the guide sleeve through a sliding groove to drive the pouring cup to move horizontally. The guide sleeve is bolted into the sliding groove on the side of the horizontally moving guide plate. Adjusting the bolt allows for the horizontal movement of the pouring cup, the fixed plate, and the horizontally moving guide plate as a whole. The guide post and guide sleeve are bolted together, and adjusting the bolt allows for the vertical movement of the pouring cup, the fixed plate, and the horizontally moving guide plate as a whole. This design provides adjustability to the pouring cup, thereby ensuring the relative position between the pouring cup and the wavy water-cooled ramp, making it suitable for various application requirements.

[0022] Furthermore, the collecting device includes a collecting crucible, a high-temperature resistant pad, a handle, and a linear guide rail. The high-temperature resistant pad is connected to the linear guide rail at both ends for linear movement. The collecting crucible is placed on the high-temperature resistant pad, and the handle is connected to the high-temperature resistant pad for pulling the pad and the crucible. The collecting crucible is used to collect semi-solid slurry and is placed on the high-temperature resistant pad, aligned with the wavy water-cooled inclined discharge port. The handle is fixed to the side of the high-temperature resistant pad with bolts, and the linear guide rail is bolted to the fixed base. The collecting device of this invention can be pulled, facilitating material retrieval after collection.

[0023] Furthermore, the device of the present invention also includes an angle adjustment device for adjusting the inclination angle of the wave-shaped water-cooling ramp. The angle adjustment device includes multiple hinge seats, a self-locking cylinder, and a push rod. The self-locking cylinder is mounted on a fixed base one via the hinge seats. The upper end of the wave-shaped water-cooling ramp is connected to the push rod of the self-locking cylinder via the hinge seat one. The lower end of the wave-shaped water-cooling ramp is mounted on a support platform via a hinge seat three. The support platform is located on the fixed base one. In use, by adjusting the air intake and exhaust volume of the self-locking cylinder, the push rod is moved, thereby pushing the wave-shaped water-cooling ramp to rotate around the bottom hinge seat three, thereby adjusting the angle between the wave-shaped water-cooling ramp and the horizontal plane, and thus controlling the cooling time of the molten metal flowing through the wave-shaped water-cooling ramp.

[0024] The second objective of this invention is to provide a method for preparing high-strength, high-toughness, and lightweight die-cast aluminum-silicon alloy structural components, comprising the following steps:

[0025] A semi-solid slurry of aluminum-silicon alloy was obtained by rapidly supercooling the molten aluminum-silicon alloy to induce explosive nucleation, with a cooling rate of 200-300℃ / s.

[0026] Aluminum-silicon alloy semi-solid slurry is die-cast to obtain die-cast aluminum-silicon alloy castings with moderate strength and moderate plasticity.

[0027] Isothermal hot extrusion is performed on die-cast aluminum-silicon alloy castings to obtain die-cast aluminum-silicon alloy structural parts with a high strength and moderate plasticity.

[0028] T6 heat treatment was performed on die-cast aluminum-silicon alloy structural parts to obtain high-strength, high-toughness, and lightweight die-cast aluminum-silicon alloy structural parts.

[0029] The method for preparing die-cast aluminum-silicon alloy provided by this invention firstly uses a wave-type semi-solid slurry preparation device to control the forced cooling rate of the aluminum-silicon alloy molten metal at 200-300℃ / s. This forced heat exchange in the molten metal, with its rapid cooling rate, forces the alloy to undergo explosive nucleation, forming a special semi-solid slurry consisting of spherical or near-spherical α-Al phases coexisting with the remaining high-solute liquid phase. This effectively refines and homogenizes the microstructure of the Al-Si alloy, while simultaneously inhibiting the formation of Fe-rich intermetallic compounds to a certain extent and preventing the eutectic Si from growing into a coarse dendritic structure, thus avoiding the eutectic Si from being combined with Fe-rich intermetallic compounds. The process of adding a compound increases the brittleness of the alloy; then, combined with isothermal hot extrusion and T6 heat treatment, the micro-defects generated during the rheological die casting process are further eliminated, and the sharp-angled lath-shaped eutectic Si particles in the microstructure of the semi-solid casting are broken and refined, so that the eutectic Si phase is spherically or nearly spherically dispersed around the α-Al phase and the distribution is uniform; finally, a high-strength and high-plasticity aluminum-silicon alloy with a uniform microstructure composed of primary α-Al phase and spherical or nearly spherical fine Si phase is prepared, achieving a balance between high strength and high plasticity of aluminum-silicon alloy, so that the obtained alloy has a tensile strength >260MPa and an elongation >15%.

[0030] Therefore, the method of the present invention can significantly improve the microstructure of aluminum-silicon alloys, enhance their mechanical properties, and give them high strength and good plasticity, enabling them to be more widely used in fields requiring high strength and high plasticity. Moreover, the preparation method is simple, has stable composition, and is suitable for industrial production.

[0031] Furthermore, the process parameters for the isothermal hot extrusion are as follows: hot extrusion pressure is 50-200 MPa, extrusion speed is 1-5 mm / s, extrusion time is 5-15 min, holding time is 5-120 min, and isothermal temperature is 200-400℃.

[0032] Furthermore, the T6 heat treatment includes solution treatment and artificial aging treatment; wherein, the solution treatment is carried out at a temperature of 400-600℃ for 1.5-3 hours; and the artificial aging treatment is carried out at a temperature of 100-200℃ for 1.5-4 hours. This invention employs a short-time T6 heat treatment, with a solution treatment time ≤3 hours and an artificial aging treatment time ≤4 hours. Compared to existing technologies, this shortens the processing time. Furthermore, combined with the subsequent isothermal hot extrusion process, it reduces energy consumption while improving the mechanical properties of the casting.

[0033] In one specific embodiment, a method for preparing a high-performance aluminum-silicon alloy includes the following steps:

[0034] S1. Melt the aluminum-silicon alloy, hold it at the temperature for 1-5 minutes, then lower the melt temperature to 685-705℃ for purification treatment, and then air cool it naturally to 660-675℃ to obtain silicon alloy molten metal; wherein, the melting temperature is 715-745℃, the alloy melting and holding are carried out in a medium frequency induction heating furnace, and the purification treatment uses hexachloroethane, including degassing treatment and slag removal treatment.

[0035] S2. Using a wave-type semi-solid slurry preparation device, aluminum-silicon alloy liquid is rapidly supercooled to induce explosive nucleation, and aluminum-silicon alloy semi-solid slurry is obtained. The cooling rate is 200-300℃ / s.

[0036] S3. The semi-solid slurry of aluminum-silicon alloy is die-cast to obtain die-cast aluminum-silicon alloy castings with medium strength and medium plasticity. The process parameters for die casting are: injection pressure of 105-155 MPa, filling speed of 10-25 mm / s, die casting mold temperature of 185-450℃, and holding time of die casting mold of 2-4 min.

[0037] S4. Isothermal hot extrusion is applied to die-cast aluminum-silicon alloy castings to obtain die-cast aluminum-silicon alloy structural parts with high strength and moderate plasticity. The process parameters for isothermal hot extrusion are as follows: hot extrusion pressure is 50-200 MPa, extrusion speed is 1-5 mm / s, extrusion time is 5-15 min, holding time is 5-120 min, and isothermal temperature is 200-400℃.

[0038] S5. Perform T6 heat treatment on the die-cast aluminum-silicon alloy structural parts. The T6 heat treatment includes solution treatment and artificial aging treatment. The solution treatment is carried out at a temperature of 400-600℃ for 1.5-3 hours. The artificial aging treatment is carried out at a temperature of 100-200℃ for 1.5-4 hours to obtain high-strength, tough, and lightweight die-cast aluminum-silicon alloy structural parts.

[0039] A third objective of this invention is to provide a die-cast aluminum-silicon alloy prepared by the aforementioned method.

[0040] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0041] 1. This invention provides a wave-shaped semi-solid slurry preparation device capable of forced cooling of molten metal, inducing explosive nucleation through rapid supercooling. The molten metal experiences intense and rapid cooling under the combined action of circulating water cooling and the wave-shaped cooling ramp. The grooves of the wave-shaped water cooling ramp can gather, stabilize, and constrain the flow of the molten metal, allowing subsequent flow of molten metal to make more concentrated and stable contact with the raised surface, thereby improving heat exchange efficiency and achieving a cooling rate of 200-300℃ / s.

[0042] 2. The method for preparing high-strength, high-toughness, and lightweight die-cast aluminum-silicon alloy structural parts provided by this invention firstly uses a wave-type semi-solid slurry preparation device to control the forced cooling rate of the aluminum-silicon alloy molten metal at 200-300℃ / s. This forced heat exchange in the molten metal, with its rapid cooling rate, forces the alloy to undergo explosive nucleation, forming a special semi-solid slurry consisting of spherical or near-spherical α-Al phases coexisting with the remaining high-solute liquid phase. This effectively refines and homogenizes the microstructure of the Al-Si alloy, while simultaneously inhibiting the formation of Fe-rich intermetallic compounds to a certain extent and preventing the eutectic Si from growing into a coarse dendritic structure, thus preventing the eutectic Si from being mixed with Fe-rich metals. Intercalation compounds increase the brittleness of the alloy; then, combined with isothermal hot extrusion and T6 heat treatment, micro-defects generated during semi-solid rheological die casting are further eliminated, and the sharp-angled lath-shaped eutectic Si particles in the microstructure of the semi-solid casting are broken and refined, so that the eutectic Si phase is spherically or nearly spherically dispersed around the α-Al phase and uniformly distributed; finally, a high-strength, high-toughness, lightweight die-cast aluminum alloy structural part with uniform microstructure composed of primary α-Al phase and spherical or nearly spherical fine Si phase is prepared, achieving a balance between high strength and high plasticity of aluminum-silicon alloy, resulting in a structural part with tensile strength >260MPa and elongation >15%. Attached Figure Description

[0043] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0044] Figure 1 This is a schematic diagram of the structure of the wave-shaped semi-solid slurry preparation device of the present invention;

[0045] Figure 2 This is a half-sectional view of the wave-shaped semi-solid slurry preparation device of the present invention;

[0046] Figure 3 This is a schematic diagram of the structure of a wave-shaped water-cooled ramp;

[0047] Figure 4 This is a schematic diagram of the upper and lower circulating cooling water pipes.

[0048] Figure 5 The image shows the microstructure of the A356 alloy ingot obtained in Comparative Example 1.

[0049] Figure 6 Microstructure of the A356 alloy semi-solid casting prepared in Example 2;

[0050] Figure 7 Microstructure of the A356 alloy semi-solid casting prepared in Example 3;

[0051] Figure 8 The image shows the microstructure of the high-strength, tough, lightweight die-cast aluminum-silicon alloy structural component prepared in Example 4.

[0052] Figure 9 The image shows the microstructure of the high-strength, tough, lightweight die-cast aluminum-silicon alloy structural component prepared in Example 5.

[0053] Figure 10 The image shows the microstructure of the A356 alloy casting prepared in Comparative Example 2.

[0054] Figure 11 The image shows the microstructure of the A356 alloy casting prepared in Comparative Example 3.

[0055] Figure 12 The image shows the microstructure of the A356 alloy casting prepared in Comparative Example 4.

[0056] Figure 13 The image shows the microstructure of the A356 alloy casting prepared in Comparative Example 5.

[0057] Figure 14 Comparison of stress-strain curves of die-cast A356 alloys prepared in Examples 4 and 5 and Comparative Examples 2-5.

[0058] The attached diagram shows the markings and corresponding component names:

[0059] 1-Elbow clamp, 2-Fixing plate, 3-Guide block, 4-Cup, 5-Guide sleeve, 6-Horizontal moving guide plate, 7-Hinge seat one, 8-Guide post, 9-Push rod, 10-Cylinder with self-locking, 11-Fixing seat one, 12-Hinge seat two, 13-Support platform, 14-Upper circulating cooling water pipe, 15-Fixing seat two, 16-Handle, 17-High temperature resistant pad, 18-Linear guide rail, 19-Collection crucible, 20-Lower circulating cooling water pipe, 21-Wave-shaped water-cooled ramp. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0061] The following detailed description, with appropriate reference to the accompanying drawings, outlines embodiments of a wave-shaped semi-solid slurry preparation apparatus, a die-cast aluminum-silicon alloy, and a preparation method according to the present invention. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art.

[0062] In the description of this invention, the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this application is usually placed in when in use, or the orientation or positional relationship that is commonly understood by those skilled in the art. It is only for the convenience of describing this application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application.

[0063] Meanwhile, the terms "set up," "assemble," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0064] The "scope" disclosed in this invention is defined in the form of a lower limit and an upper limit. A given scope is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific scope. The scope defined in this way can include or exclude end values, and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a scope.

[0065] Unless otherwise specified, the terms "comprising" and "including" as used in this invention can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other substances not listed may also be included, or that only the listed substances may be included.

[0066] Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, but are preferably performed sequentially.

[0067] The technical solution of the present invention will be further described in detail below with reference to the embodiments.

[0068] It should be noted that the following embodiments use A356 alloy as an example, and the wave-shaped water-cooled slope in the wave-shaped semi-solid slurry preparation device adopts a double-wave-shaped water-cooled slope. Unless otherwise specified, the experimental methods used in the embodiments are conventional methods. Unless otherwise specified, the materials, reagents, methods, and instruments used are all conventional materials, reagents, methods, and instruments in the art, and can be obtained commercially by those skilled in the art.

[0069] Example 1

[0070] This embodiment provides a wave-shaped semi-solid slurry preparation device, such as... Figure 1-4 As shown, it includes:

[0071] A wave-shaped water-cooled ramp 21 is used to force-cool molten metal to form a semi-solid slurry. The ramp surface of the wave-shaped water-cooled ramp 21 has grooves and protrusions, and a water-cooling system is provided on the back of the protrusions.

[0072] A pouring device is located above the corrugated water-cooled slope 21 and is used to pour molten metal onto the slope surface of the corrugated water-cooled slope 21.

[0073] A collection device is installed at the outlet of the wave-shaped water-cooled slope 21 to collect semi-solid slurry.

[0074] The molten metal flows through the groove of the wave-shaped water-cooling slope 21 and accumulates thereafter, and then flows through the protrusion of the wave-shaped water-cooling slope 21 for strong heat exchange, so that the cooling rate of the molten metal reaches 200-300℃ / s.

[0075] This invention provides a wave-shaped semi-solid slurry preparation device capable of forced cooling of molten metal, inducing explosive nucleation through rapid supercooling. This device allows Al-Si molten metal to experience intense and rapid cooling under the combined action of circulating water cooling and the wave-shaped cooling ramp. Specifically, the grooves of the wave-shaped water cooling ramp 21 can gather, stabilize, and constrain the flow of the molten metal, ensuring that subsequent flow of molten metal over the protrusions is more concentrated and stable in contact with the protruding surface, thereby improving heat exchange efficiency and achieving a cooling rate of 200-300℃ / s.

[0076] When the high-temperature molten metal flows over the wavy ramp, the grooves in the wavy structure act to gather, stabilize, and constrain the flow of the molten metal. It then flows over the protrusions in the wavy structure, where circulating cooling water is introduced into the water-cooling system on the back side of the protrusions. Under the forced cooling effect of the circulating water, strong heat transfer is generated, forcing the Al-Si alloy to nucleate explosively, forming a special semi-solid slurry consisting of spherical or near-spherical α-Al phases and the remaining high-solute liquid phase. This effectively refines and homogenizes the microstructure of the Al-Si alloy, while also inhibiting the formation of Fe-rich intermetallic compounds to some extent. Real-time measurements using two temperature sensors at position 4 of the pouring cup and at the collection device show a cooling rate of 200-300℃ / s.

[0077] As a preferred option, such as Figure 3 As shown, the wave-shaped water-cooling ramp 21 includes at least two protrusions and two grooves, with an overall length of not less than 400 mm, i.e., it is configured as a double-wave-shaped water-cooling ramp 21, consisting of two wave-shaped protrusions of different sizes and two grooves of different sizes, with the second segment being larger than the first segment. In one specific embodiment, the length, radius of curvature, and depth of the first groove are 46 mm, 40 mm, and 8 mm, respectively; the length, radius of curvature, and height of the first wave-shaped protrusion are 115 mm, 100 mm, and 12 mm, respectively; the length, radius of curvature, and depth of the second groove are 65 mm, 75 mm, and 10 mm, respectively; and the length, radius of curvature, and height of the second wave-shaped protrusion are 120 mm, 150 mm, and 12 mm, respectively. Furthermore, long-term experimental research has shown that to ensure cooling performance, the overall length of the wave-shaped water-cooling ramp 21 should be not less than 400 mm. In one specific embodiment, the overall length of the double-wave-shaped water-cooling ramp 21 is 440 mm.

[0078] When the high-temperature molten metal flows through the first wavy ramp, the first groove first acts to gather, stabilize, and constrain the flow of the molten metal. Then, as it flows through the first protrusion, the forced cooling effect of the circulating cooling water on the back side generates an initial strong cooling effect. Next, when the molten metal with a low solids fraction flows through the second wavy ramp, it further gathers and stabilizes the flow with the second groove. Then, it flows through the second protrusion, generating strong heat exchange. At the same time, the back side of the second protrusion is equipped with circulating cooling water, and the combined effect of the two generates a second forced cooling. Through two forced cooling heat exchanges, the alloy is forced to nucleate explosively, forming a special semi-solid slurry in which spherical or near-spherical α-Al phases coexist with the remaining high-solute liquid phase. This effectively refines and homogenizes the microstructure of the Al-Si alloy, while also inhibiting the formation of Fe-rich intermetallic compounds to a certain extent.

[0079] like Figure 1As shown in Figure 2, the water-cooling system of the present invention is a circulating cooling water pipe. An installation groove is provided on the back of the protrusion of the corrugated water-cooling ramp 21, and the circulating cooling water pipe is fixed in the installation groove. The number of cooling water pipes installed needs to match the protrusion of the corrugated structure. By providing a recessed installation groove on the back of the protrusion, the installation stability of the cooling water pipe is ensured, and the contact between the cooling water pipe and the protrusion is made tighter, thereby better achieving forced heat exchange. In one specific embodiment, as... Figure 4 As shown, for the double-wave water-cooled slope 21, two sets of cooling water pipes are provided, namely the upper circulating cooling water pipe 14 and the lower circulating cooling water pipe 20.

[0080] like Figure 1 As shown, the pouring device includes a pouring cup 4 and a fixing plate 2. The fixing plate 2 is located above the corrugated water-cooled ramp 21, and the pouring cup 4 is mounted on the fixing plate 2 via an elbow clamp 1. The pouring cup 4 is a steel preheating pouring cup 4, with a rectangular opening frame on its side. After preheating, the pouring cup 4 is first positioned correctly by cooperating with the guide block 3 through the rectangular opening frame on its side, and then fixed to the fixing plate 2 by the elbow clamp 1, thus realizing the installation of the pouring cup 4.

[0081] As a preferred option, such as Figure 1 As shown, the device of the present invention also includes a guide post 8, a guide sleeve 5, and a horizontally moving guide plate 6. The bottom of the guide post 8 is mounted on the fixed base 11, and the guide sleeve 5 is sleeved on the upper part of the guide post 8 to drive the pouring cup 4 to move up and down. The horizontally moving guide plate 6 is mounted below the fixed plate 2, and the side of the horizontally moving guide plate 6 is slidably connected to the guide sleeve 5 through a sliding groove to drive the pouring cup 4 to move horizontally. The guide sleeve 5 is bolted to the sliding groove on the side of the horizontally moving guide plate 6. By adjusting the bolt, the pouring cup 4, the fixed plate 2, and the horizontally moving guide plate 6 can be moved horizontally as a whole. The guide post 8 and the guide sleeve 5 are bolted together, and by adjusting the bolt, the pouring cup 4, the fixed plate 2, and the horizontally moving guide plate 6 can be moved up and down as a whole. This design gives the pouring cup 4 adjustability, thereby ensuring the relative position between the pouring cup 4 and the wave-shaped water-cooled ramp 21, suitable for various application requirements.

[0082] As a preferred option, such as Figure 1 and 2As shown, the collection device includes a collection crucible 19, a high-temperature resistant pad 17, a handle 16, and a linear guide rail 18. The high-temperature resistant pad 17 is connected to the linear guide rail 18 at both ends for linear movement. The collection crucible 19 is placed on the high-temperature resistant pad 17, and the handle 16 is connected to the high-temperature resistant pad 17 for pulling the high-temperature resistant pad 17 and the collection crucible 19. The collection crucible 19 is used to collect semi-solid slurry and is placed on the high-temperature resistant pad 17 aligned with the outlet of the wavy water-cooled slope 21. The handle 16 is fixed to the side of the high-temperature resistant pad 17 by bolts, and the linear guide rail 18 is bolted to the fixing base 15. The collection device of this invention can be pulled, facilitating material retrieval after collection.

[0083] As a preferred option, such as Figure 1 and 2 As shown, the device of the present invention also includes an angle adjustment device for adjusting the tilt angle of the wave-shaped water-cooled ramp 21. The angle adjustment device includes multiple hinge seats, a self-locking cylinder 10, and a push rod 9. The self-locking cylinder 10 is mounted on a fixed base 11 via the hinge seats. The upper end of the wave-shaped water-cooled ramp 21 is connected to the push rod 9 of the self-locking cylinder 10 via a hinge seat 7. The lower end of the wave-shaped water-cooled ramp 21 is mounted on a support platform 13 via a hinge seat 3. The support platform 13 is located on the fixed base 11. In use, by adjusting the air intake and exhaust volume of the self-locking cylinder 10, the push rod 9 is moved, thereby pushing the wave-shaped water-cooled ramp 21 to rotate around the bottom hinge seat 3, thereby adjusting the angle between the wave-shaped water-cooled ramp 21 and the horizontal plane, thus controlling the cooling time of the molten metal flowing through the wave-shaped water-cooled ramp 21.

[0084] Comparative Example 1.

[0085] The conventional as-cast A356 alloy, without using the wave-shaped semi-solid slurry preparation device of this invention, is prepared as follows:

[0086] (1) Weigh 5 kg of A356 billet raw material and place it in a medium frequency induction heating furnace for melting. The melting temperature is 715℃. After melting, keep it in the furnace for 2 minutes. When the temperature of the molten metal drops to 700℃, degas and remove slag. Then cool it to 675℃ with air to obtain molten metal.

[0087] (2) After a clear solidified shell appears on the surface of the A356 molten metal in the crucible to be collected, water quenching is performed.

[0088] Example 2

[0089] A356 alloy semi-solid ingots are prepared using the wave-shaped semi-solid slurry preparation device of this invention, and the preparation method is as follows:

[0090] (1) Weigh 5 kg of A356 billet raw material and place it in a medium frequency induction heating furnace for melting. The melting temperature is 715℃. After melting, keep it in the furnace for 2 minutes. When the temperature of the molten metal drops to 700℃, degas and remove slag. Then cool it to 675℃ with air to obtain molten metal.

[0091] (2) Adjust the inclination angle of the wave-shaped water-cooled slope to 35° by using the push rod and the self-locking cylinder. At the same time, adjust the guide sleeve, horizontally move the guide plate and guide column so that the outlet of the pouring cup is aligned with the first buffer groove on the wave-shaped water-cooled slope to ensure that the length of the cooling channel in contact with the molten metal is not less than 400mm. Adjust the flow rate of the circulating cooling water pipes of the upper and lower circulating cooling water pipes to 40ml / s and 35ml / s respectively. The cooling rate of the molten metal after rapid supercooling-induced explosive nucleation treatment is 200℃ / s, and A356 alloy semi-solid slurry is obtained.

[0092] (3) Use a crucible with a preheating temperature of 400℃ to collect the semi-solid slurry of A356 alloy. Then, after a clear solidification shell appears on the surface of the semi-solid slurry of A356 in the crucible to be collected, water quench it.

[0093] Example 3

[0094] The only difference between this embodiment and embodiment 2 is that in step (2), by adjusting the guide sleeve, horizontally moving the guide plate, and the guide column, the outlet of the pouring cup is aligned with the second buffer groove on the wave-shaped water-cooled slope, ensuring that the length of the cooling channel in contact with the molten metal is not less than 200mm.

[0095] Microstructure images of the A356 alloy semi-solid ingots obtained from Comparative Example 1 and Examples 2 and 3 are shown below. Figure 5-7 As shown:

[0096] Figure 5 It exhibits the morphological characteristics of traditional as-cast A356 alloy, with a large number of dendritic structures, and the eutectic Si phase is continuously distributed in a network structure around the primary α-Al phase, which is not conducive to improving the strength and plasticity of the alloy.

[0097] Figure 6 The microstructure of the A356 alloy semi-solid ingot obtained by the wave-shaped semi-solid slurry preparation device of the present invention has the best uniformity. The eutectic Si particles are relatively uniformly distributed around the primary α-Al phase in the α-Al matrix with the characteristics of fine rod-shaped structure.

[0098] Figure 7Although the microstructure shown was prepared using the wave-shaped semi-solid slurry preparation device of the present invention, only one wave-shaped structure was used, which resulted in poor quenching effect on the A356 alloy liquid. The overall distribution of the microstructure was very uneven, the primary α-Al growth was insufficient, and the high-density eutectic structure was distributed very unevenly around the primary α-Al phase in a huge network form, which was not conducive to improving the strength and plasticity of the alloy.

[0099] Example 4

[0100] A method for preparing a high-strength, high-toughness, lightweight die-cast aluminum-silicon alloy structural component is as follows:

[0101] (1) Weigh 5 kg of A356 billet raw material and place it in a medium frequency induction heating furnace for melting. The melting temperature is 715℃. After melting, keep it in the furnace for 2 minutes. When the temperature of the molten metal drops to 700℃, degas and remove slag. Then cool it to 675℃ with air to obtain molten metal.

[0102] (2) Adjust the inclination angle of the double wave-shaped water-cooled slope to 35° by using the push rod and the self-locking cylinder. At the same time, adjust the guide sleeve, horizontally move the guide plate and guide column so that the outlet of the pouring cup is aligned with the first buffer groove on the wave-shaped water-cooled slope to ensure that the length of the cooling channel in contact with the molten metal is not less than 400mm. Adjust the flow rate of the circulating cooling water pipes of the upper and lower circulating cooling water pipes to 40ml / s and 35ml / s respectively. The cooling rate of the molten metal after rapid supercooling-induced explosive nucleation treatment is 200℃ / s, and A356 alloy semi-solid slurry is obtained.

[0103] (3) Use a crucible with a preheating temperature of 400°C to collect the semi-solid slurry of A356 alloy, and then use a ceramic ladle to quickly pour it into the pressure chamber of the horizontal die casting machine;

[0104] (4) Set the forming pressure of the horizontal die casting machine to 125 MPa, the filling speed to 25 mm / s, and the mold temperature to 350℃. After the die casting is completed, keep the part in the forming mold for 1.5 min and then take it out. Quickly quench it with water to cool it to room temperature.

[0105] (5) The casting was subjected to solution treatment at 525℃ for 2.5 hours and then artificial aging treatment at 180℃ for 3 hours.

[0106] (6) The casting is subjected to slow isothermal hot extrusion with an extrusion pressure of 100 MPa, a holding temperature of 300℃, an extrusion time of 15 min, and a holding time of 20 min after extrusion to obtain a high-strength and high-plasticity die-cast A356 alloy.

[0107] Example 5

[0108] A method for preparing a high-strength, high-toughness, lightweight die-cast aluminum-silicon alloy structural component is as follows:

[0109] (1) Weigh 5 kg of A356 billet raw material and place it in a medium frequency induction heating furnace for melting. The melting temperature is 715℃. After melting, keep it in the furnace for 2 minutes. When the temperature of the molten metal drops to 700℃, degas and remove slag. Then cool it to 675℃ with air to obtain molten metal.

[0110] (2) Adjust the inclination angle of the double wave-shaped water-cooled slope to 35° by using the push rod and the self-locking cylinder. At the same time, adjust the guide sleeve, horizontally move the guide plate and guide column so that the outlet of the pouring cup is aligned with the first buffer groove on the wave-shaped water-cooled slope to ensure that the length of the cooling channel in contact with the molten metal is not less than 400mm. Adjust the flow rate of the circulating cooling water pipes of the upper and lower circulating cooling water pipes to 40ml / s and 35ml / s respectively. The cooling rate of the molten metal after rapid supercooling-induced explosive nucleation treatment is 200℃ / s, and A356 alloy semi-solid slurry is obtained.

[0111] (3) Use a crucible with a preheating temperature of 400°C to collect the semi-solid slurry of A356 alloy, and then quickly pour it into the pressure chamber of the horizontal die casting machine;

[0112] (4) Set the injection pressure of the horizontal die casting machine to 125 MPa, the filling speed to 25 mm / s, and the mold temperature to 350℃. After the die casting is completed, keep the part in the mold for 1.5 min and then take it out. Quickly quench it with water to cool it to room temperature.

[0113] (5) The casting is subjected to slow isothermal hot extrusion with an extrusion pressure of 100 MPa, a holding temperature of 300℃, an extrusion time of 15 min, and a holding time of 20 min after extrusion to obtain an A356 alloy extruded part.

[0114] (6) The hot-extruded castings were subjected to solution treatment at 525°C for 2.5 hours and then artificial aging treatment at 180°C for 3 hours to obtain high-strength and high-plasticity die-cast A356 alloy.

[0115] The microstructure images of the high-strength, high-plasticity die-cast A356 alloys obtained in Examples 4 and 5 are as follows: Figure 8 and Figure 9 :

[0116] from Figure 8 It can be seen that after T6 heat treatment followed by isothermal hot extrusion, the eutectic Si phase is distributed in the form of particles around the α-Al matrix in the material, but the distribution is not uniform. At the same time, there are large and numerous rod-shaped eutectic Si phases.

[0117] from Figure 9It can be seen that the material obtained by first isothermal hot extrusion and then T6 heat treatment has eutectic Si particles dispersed around the α-Al matrix, with a more uniform distribution, and the eutectic Si particles are spherical or nearly spherical, compared to... Figure 8 In contrast, it has a better spheroidization effect and smaller size, which is more conducive to improving the tensile strength and plasticity of the alloy.

[0118] Comparative Example 2.

[0119] The only difference between this comparative example and Example 4 is that step (6) is not performed after step (5), that is, isothermal hot extrusion is not performed, and metallographic sampling and mechanical property testing are performed directly.

[0120] Comparative Example 3.

[0121] The only difference between this comparative example and Example 4 is that steps (5) and (6) are not performed after step (4), that is, isothermal hot extrusion and T6 heat treatment are not performed, and metallographic sampling and mechanical property testing are performed directly.

[0122] Comparative Example 4.

[0123] A method for preparing die-cast A356 alloy is as follows:

[0124] (1) Weigh 5 kg of A356 billet raw material and place it in a medium frequency induction heating furnace for melting. The melting temperature is 715℃. After melting, keep it in the furnace for 2 minutes. When the temperature of the molten metal drops to 700℃, degas and remove slag. Then cool it to 675℃ with air to obtain molten metal.

[0125] (2) Collect the A356 alloy molten metal using a crucible preheated to 400°C, and then quickly pour it into the pressure chamber of a horizontal die-casting machine;

[0126] (3) Set the injection pressure of the horizontal die casting machine to 125 MPa, the filling speed to 25 mm / s, and the mold temperature to 350℃. After the die casting is completed, keep the part in the mold for 1.5 min and then take it out. Quickly quench it in water to cool it to room temperature.

[0127] (4) The hot-extruded castings were subjected to solution treatment at 525°C for 2.5 hours and then artificial aging treatment at 180°C for 3 hours to obtain high-strength and high-plasticity A356 alloy.

[0128] Comparative Example 5.

[0129] A method for preparing die-cast aluminum-silicon alloy castings is as follows:

[0130] (1) Weigh 5 kg of A356 billet raw material and place it in a medium frequency induction heating furnace for melting. The melting temperature is 715℃. After melting, keep it in the furnace for 2 minutes. When the temperature of the molten metal drops to 700℃, degas and remove slag. Then cool it to 675℃ with air to obtain molten metal.

[0131] (2) Collect the A356 alloy molten metal using a crucible with a preheating temperature of 400°C, and then quickly pour it into the pressure chamber of a horizontal die-casting machine;

[0132] (3) Set the injection pressure of the horizontal die casting machine to 125 MPa, the filling speed to 25 mm / s, and the mold temperature to 350℃. After the die casting is completed, keep the part in the mold for 1.5 min and then take it out. Quickly quench it in water to cool it to room temperature.

[0133] (5) The casting is subjected to slow isothermal hot extrusion with an extrusion pressure of 100 MPa, a holding temperature of 300℃, an extrusion time of 15 min, and a holding time of 20 min after extrusion to obtain an A356 alloy extruded part.

[0134] (6) The hot-extruded castings were subjected to solution treatment at 525°C for 2.5 hours and then artificial aging treatment at 180°C for 3 hours to obtain high-strength and high-plasticity A356 alloy.

[0135] The microstructure images of the die-cast aluminum-silicon alloy samples prepared in Comparative Examples 2-5 are shown below. Figure 10-13 As shown:

[0136] from Figure 10 It can be seen that the product obtained by semi-solid rheo-die casting + T6 heat treatment without isothermal hot extrusion has obvious spheroidization effect of α-Al phase, and the eutectic Si phase exhibits rod-shaped morphology distribution with obvious blunting of edges and corners, and is relatively uniformly distributed around the primary α-Al.

[0137] from Figure 11 It can be seen that the products obtained by using only semi-solid rheo-die casting without T6 heat treatment and isothermal hot extrusion have uneven distribution of phases in the microstructure, insufficient growth of some α-Al, which is rose-shaped, and a large number of needle-like eutectic Si phases aggregate and are randomly distributed around the α-Al phase, separating the matrix, which is not conducive to improving the alloy's high strength and good plasticity.

[0138] from Figure 12 It can be seen that the microstructure of the product obtained by traditional liquid die casting + T6 is as follows: the α-Al phase exhibits a relatively coarse dendritic morphology, while the eutectic Si phase in the microstructure is still a slender needle-like structure with sharp edges, which severely cuts the alloy matrix. Furthermore, the sharp edges easily cause stress concentration and reduce the mechanical properties of the alloy.

[0139] from Figure 13 It can be seen that the microstructure of the product obtained by traditional liquid die casting + hot pressing + T6 is similar to that of Comparative Example 4. The α-Al phase exhibits coarse columnar dendritic crystals, while the eutectic Si phase surrounding the α-Al phase is relatively... Figure 12 The spheroidization effect is good, and the whole shape is round rod-shaped.

[0140] The tensile strength and elongation of the die-cast aluminum-silicon alloy samples prepared in Examples 4 and 5, and Comparative Examples 2-5, were tested. The test results are shown in Table 1, and the stress-strain curves are compared as follows: Figure 14 As shown.

[0141] Table 1. Test data of aluminum-silicon alloy die castings prepared in the examples and comparative examples.

[0142] .

[0143] As can be seen from the data in Table 1:

[0144] This invention, through the control of semi-solid rheological die casting, isothermal hot extrusion, and short-time T6 heat treatment processes, yields aluminum-silicon alloy die-cast structural parts with a tensile strength greater than 260 MPa and an elongation greater than 15%. Furthermore, it was found that after semi-solid rheological die casting, isothermal hot extrusion followed by short-time T6 heat treatment slightly reduces the tensile strength of the aluminum-silicon alloy die-cast structural parts from 289.7 MPa to 260.1 MPa compared to short-time T6 heat treatment followed by isothermal hot extrusion, but significantly increases the elongation from 15.2% to 21.4%, thus achieving a better balance between the tensile strength and elongation of the die-cast aluminum-silicon alloy.

[0145] Comparative Example 1 did not undergo isothermal hot extrusion, and Comparative Example 2 did not undergo isothermal hot extrusion and T6 heat treatment, resulting in products with lower elongation.

[0146] Comparative Examples 4 and 5 were prepared under conventional liquid die casting conditions, and the resulting tensile strength was significantly reduced, and the product elongation was low.

[0147] Finally, it should be noted that the above specific embodiments are only used to describe the purpose, technical solution, and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation of the present invention and is not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the foregoing specific embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions or improvements can be made to some or all of the technical features. These modifications, equivalent substitutions, and improvements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A wave type semi-solid slurry preparation device characterized by, The application relates to a device for rapidly supercooling and inducing burst nucleation of aluminum-silicon alloy liquid, and belongs to the technical field of aluminum-silicon alloy semi-solid processing. The device comprises the following parts: a wave-shaped water-cooled slope (21) for forcibly cooling the metal liquid to form a semi-solid slurry, the slope surface of the wave-shaped water-cooled slope (21) is provided with grooves and protrusions, and the back surface of the protrusions is provided with a water-cooling system; a pouring device arranged above the wave-shaped water-cooled slope (21) and used for pouring the metal liquid on the slope surface of the wave-shaped water-cooled slope (21); a collecting device arranged at the discharge port of the wave-shaped water-cooled slope (21) and used for collecting the semi-solid slurry; 2. A wave type semi-solid slurry preparation device according to claim 1, characterized in that, wherein the metal liquid flows through the grooves of the wave-shaped water-cooled slope (21) to be gathered, and then flows through the protrusions of the wave-shaped water-cooled slope (21) to be subjected to strong heat exchange, so that the cooling speed of the metal liquid reaches 200-300 DEG C / s.

3. A wave type semi-solid slurry preparation device according to claim 1, characterized in that, The wave-shaped water-cooled slope (21) comprises at least two protrusions and two grooves, and the overall length is not less than 400 mm.

4. A wave type semi-solid slurry preparation device according to claim 1, characterized in that, The water-cooling system is a circulating cooling water pipe, the back surface of the protrusion of the wave-shaped water-cooled slope (21) is provided with a mounting groove, and the circulating cooling water pipe is fixed in the mounting groove.

5. A wave type semi-solid slurry preparation device according to claim 4, characterized in that, The pouring device comprises a pouring cup (4) and a fixed plate (2), the fixed plate (2) is arranged above the wave-shaped water-cooled slope (21), and the pouring cup (4) is mounted on the fixed plate (2) through an elbow clamp (1).

6. A wave type semi-solid slurry preparation apparatus according to any one of claims 1 to 5, characterized in that, Further, a guide column (8), a guide sleeve (5) and a horizontal moving guide plate (6) are arranged, the bottom of the guide column (8) is mounted on a fixed base (11), the upper portion of the guide column (8) is sleeved with the guide sleeve (5) for driving the pouring cup (4) to move up and down, the horizontal moving guide plate (6) is arranged below the fixed plate (2), and the side surface of the horizontal moving guide plate (6) is slidably connected with the guide sleeve (5) through a sliding groove for driving the pouring cup (4) to move horizontally.

7. A method for preparing a high-strength, high-toughness, lightweight die-cast aluminum-silicon alloy structural component, characterized in that, Further, an angle adjusting device is arranged for adjusting the inclination angle of the wave-shaped water-cooled slope (21), the angle adjusting device comprises a plurality of hinge seats, a self-locking cylinder (10) and a push rod (9), the self-locking cylinder (10) is mounted on the fixed base (11) through the hinge seats, the upper end of the wave-shaped water-cooled slope (21) is connected with the push rod (9) of the self-locking cylinder (10) through a hinge seat (7), the lower end of the wave-shaped water-cooled slope (21) is mounted on a supporting table (13) through a hinge seat (3), and the supporting table (13) is arranged on the fixed base (11). The device comprises the following steps: The device is used for rapidly supercooling and inducing burst nucleation of aluminum-silicon alloy liquid to obtain aluminum-silicon alloy semi-solid slurry, and the cooling speed is 200-300 DEG C / s. The aluminum-silicon alloy semi-solid slurry is pressure cast to form a pressure cast aluminum-silicon alloy casting with medium strength and medium plasticity matched; The pressure cast aluminum-silicon alloy casting is subjected to isothermal hot extrusion to obtain a pressure cast aluminum-silicon alloy structural member with high strength and medium plasticity matched; The pressure cast aluminum-silicon alloy structural member is subjected to T6 heat treatment to obtain a high-strength and high-toughness light-weight pressure cast aluminum-silicon alloy structural member.

8. The method according to claim 7, wherein the method is characterized by, The process parameters of the isothermal hot extrusion are as follows: hot extrusion pressure is 50-200 MPa, extrusion speed is 1-5 mm / s, extrusion time is 5-15 min, holding time is 5-120 min, and isothermal temperature is 200-400 DEG C.

9. The method according to claim 8, wherein the method is characterized by, The T6 heat treatment comprises solution treatment and artificial aging treatment; wherein the solution treatment has a temperature of 400-600 DEG C and a time of 1.5-3 hours; and the artificial aging treatment has a temperature of 100-200 DEG C and a time of 1.5-4 hours. 10.A high-strength and high-toughness light-weighted die-cast aluminum-silicon alloy structural member, which is prepared by the method of any one of claims 7-9.

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