Aluminum matrix composite casting and casting method and casting device thereof

Abstract

The invention belongs to the technical field of composite material casting, and particularly relates to an aluminum-based composite material casting and a casting method and device thereof. Molding equipment in the casting device of the aluminum matrix composite casting comprises a mold and a sand core arranged in a mold cavity of the mold, the sand core divides the mold cavity into a first cavity and a second cavity, and at least one pouring gate communicating with the first cavity and the second cavity is arranged on the sand core; the pouring gate is configured to be used for cooling the aluminum-based composite material melt into semi-solid slurry; the smelting equipment is communicated with the first cavity through a liquid rising pipe, and the pressure regulation and control system is used for regulating and controlling the internal pressure of the forming equipment and the smelting equipment, so that an aluminum-based composite material melt in the smelting equipment is injected into the first cavity through the liquid rising pipe and passes through the pouring gate to form semi-solid slurry, and the semi-solid slurry is rapidly filled into the second cavity. By means of the casting device, casting of the aluminum-based composite material casting which is full in mold filling, high in compactness, fine in working face structure and uniform in reinforced phase distribution is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material casting, and in particular relates to an aluminum-based composite material casting and a casting method and a casting device thereof. Background Art

[0002] Particle-reinforced aluminum-based composites have many advantages such as high specific strength, high specific stiffness, high wear resistance, and high vibration damping. Reinforced particles can significantly improve the elastic modulus, yield strength, wear resistance, and high-temperature creep of the matrix while maintaining a low content, and thus are gradually gaining attention. Compared with liquid metal casting, aluminum-based composites contain reinforcing phases in the melt, and the filling conditions are similar to semi-solid casting. They have the advantages of stable filling, dense internal structure of the casting, few internal defects such as pores and segregation, small solidification shrinkage, and high dimensional accuracy of the formed parts. However, due to the presence of reinforcing phases, the fluidity of the composite melt is poor and the filling capacity is weak.

[0003] To improve this problem, some existing technologies use an integrated casting and forging method, but this method is difficult to improve complex structural parts; some existing technologies use a combination of ultrasonic vibration and hydraulics to control the filling of the slurry, but this method is expensive and difficult to implement.

[0004] Therefore, how to successfully prepare aluminum-based composite parts with excellent performance is a current problem. Summary of the invention

[0005] The main purpose of the present invention is to provide an aluminum-based composite material casting, a casting method and a casting device thereof, through which the casting device of the present invention can realize the casting of aluminum-based composite material castings with full mold filling, high density, fine working surface structure and uniform distribution of reinforcing phase.

[0006] In order to achieve the above objectives, the present invention provides the following technical solutions.

[0007] In one aspect, the present invention provides a casting device for aluminum-based composite material castings, which includes a molding device, a smelting device, and a pressure control system;

[0008] The molding device comprises a mold and a sand core placed in the mold cavity thereof, wherein the sand core divides the mold cavity into a first cavity and a second cavity, and the sand core is provided with at least one runner connecting the first cavity and the second cavity; the runner is configured to cool the aluminum-based composite material melt into a semi-solid slurry;

[0009] The smelting equipment is connected to the first chamber through a riser pipe, and the pressure control system is used to control the internal pressure of the molding equipment and the smelting equipment, so that the aluminum-based composite material melt in the smelting equipment is injected into the first chamber through the riser pipe, and forms a semi-solid slurry after passing through the runner to quickly fill the second chamber.

[0010] In some embodiments of the present invention, the sand core is configured to have a temperature lower than a temperature of the aluminum-based composite material melt.

[0011] In some embodiments of the present invention, the temperature of the sand core is 0°C to 300°C.

[0012] In some embodiments of the present invention, the contact surfaces of the sand core and the aluminum-based composite material melt are coated with a sealing coating.

[0013] In some embodiments of the present invention, a chilling layer is provided on the cavity wall of the mold cavity.

[0014] In some embodiments of the present invention, at least one exhaust groove is provided on the mold, and at least one exhaust channel is provided on the sand core. The exhaust channel is connected to the exhaust groove correspondingly, and the exhaust channel is not connected to the runner.

[0015] In some embodiments of the present invention, the mold is also provided with a circulating cooling system for regulating the temperature field gradient in the mold cavity.

[0016] In some embodiments of the present invention, the mold includes an upper mold and a lower mold, and grooves are respectively formed on the parting surfaces of the upper mold and the lower mold, and the two together form the exhaust groove.

[0017] In some embodiments of the present invention, the mold comprises a metal mold.

[0018] In some embodiments of the present invention, the molding equipment includes a molding equipment body having a first containing chamber, and the pressure regulation system is used to control the pressure in the first containing chamber; the mold is placed in the first containing chamber, and the exhaust groove is connected to the first containing chamber.

[0019] In some embodiments of the present invention, the smelting equipment includes a smelting equipment body and a smelting container, the smelting equipment body has a second holding chamber inside, and the pressure control system is used to control the pressure in the second holding chamber; the smelting container is placed in the second holding chamber and reciprocates along the height direction of the smelting equipment body; the smelting container is used to hold the aluminum-based composite material melt.

[0020] In some embodiments of the present invention, the smelting equipment further includes a lifting mechanism, which is disposed below the smelting container and is used to drive the smelting container to reciprocate.

[0021] In some embodiments of the present invention, the smelting equipment further comprises an electromagnetic stirring mechanism arranged around the circumference of the smelting container.

[0022] In some embodiments of the present invention, the pressure regulation system includes a vacuum regulation component and a pressure regulation component, the vacuum regulation component is used to regulate the first containment chamber and the second containment chamber to be a vacuum environment; the pressure regulation component is used to transport inert gas to the second containment chamber to regulate the internal pressure difference between the second containment chamber and the first containment chamber.

[0023] In some embodiments of the present invention, the pressure regulating component includes a gas tank connected to the second containing chamber, and a first control valve for controlling the connection and disconnection between the gas tank and the second containing chamber.

[0024] In some embodiments of the present invention, the vacuum regulating assembly includes a vacuum tank connected to the first containing chamber and the second containing chamber respectively, and a second control valve and a third control valve for controlling the connection and disconnection of the vacuum tank with the first containing chamber and the second containing chamber respectively.

[0025] In another aspect of the present invention, a casting method for an aluminum-based composite material casting is provided, and the casting method is based on the casting device for the aluminum-based composite material casting mentioned above; the casting method comprises the following steps: smelting the aluminum-based composite material through a smelting device to obtain an aluminum-based composite material melt; using a pressure control system to control the internal pressure of the molding device and the smelting device to form a pressure difference; under the action of the pressure difference, the aluminum-based composite material melt is injected into the first chamber through a riser pipe, and after passing through a sand core runner, a semi-solid slurry is formed to quickly fill the second chamber to obtain an aluminum-based composite material casting.

[0026] In some embodiments of the present invention, the smelting process includes: evacuating the interior of the smelting equipment and the molding equipment to the same vacuum degree, which is 1Pa to 10Pa; heating the smelting container to 10°C to 80°C above the liquidus; and electromagnetically stirring the obtained aluminum-based composite material melt.

[0027] In some embodiments of the present invention, the melt injection process includes: preheating the riser tube to 300°C to 500°C; regulating the internal pressure of the smelting equipment to 1000Pa to 300000Pa, so as to inject the aluminum-based composite material melt into the first chamber through the riser tube, and quickly fill it into the second chamber; and during the melt injection process, maintaining the circulating cooling system on; the coolant temperature in the circulating cooling system is preferably 0°C to 40°C.

[0028] In another aspect of the present invention, there is provided an aluminum-based composite material casting, which is produced by the above-mentioned casting method.

[0029] Compared with the prior art, the present invention achieves the following technical effects:

[0030] The present invention realizes the preparation of aluminum-based composite material castings with full mold filling, fine working surface structure and uniform distribution of reinforcing phase, thereby improving the structural uniformity of large aluminum-based composite material components.

[0031] The present invention solves the problem of poor structural uniformity of composite material castings due to different temperature fields in different regions during the filling and solidification process of aluminum-based composite materials. In particular, for large components such as shaft-mounted brake discs, the consistency of structural performance of double working surfaces will be significantly improved.

[0032] The present invention arranges a sand core in the mold and circulates cooling liquid inside the mold to accurately control the temperature field during the molding of the aluminum-based composite material. The temperature of different parts of the mold is adjusted by setting a quenching layer to achieve the goal of controlling the temperature gradient of the aluminum-based composite material filling.

[0033] In the present invention, an air channel is arranged inside the sand core and an exhaust groove is opened at the assembly position with the mold, and the gas is exhausted along the groove during the filling process and the solidification process, thereby improving the shrinkage compensation effect of the casting.

[0034] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference numerals are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0036] Figure 1 A schematic diagram of the structure of a casting device according to some embodiments of the present invention;

[0037] Figure 2 This is the microstructure diagram of the aluminum-based composite shaft-mounted brake disc casting prepared in Example 1.

[0038] Description of reference numerals:

[0039] 100, mold; 101, upper mold; 102, lower mold; 103, mold cavity; 104, exhaust groove; 105, chilling layer; 106, cooling pipe;

[0040] 200, sand core; 201, pouring channel;

[0041] 300, liquid riser;

[0042] 1. Molding equipment;

[0043] 2. Melting equipment; 21. Melting container; 211. Crucible; 212. Induction heating furnace; 22. Lifting mechanism; 221. Hydraulic rod; 222. Dynamic sealing ring; 223. Motor; 23. Electromagnetic stirring mechanism;

[0044] 3. Pressure control system; 31. Pressure control assembly; 311. Gas tank; 312. First control valve; 32. Vacuum control assembly; 321. Vacuum tank; 322. Second control valve; 323. Third control valve. DETAILED DESCRIPTION

[0045] The exemplary embodiments of the present invention will be described in more detail below with reference to specific embodiments. It should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0046] At present, aluminum-based composite materials often have problems such as poor fluidity, poor uniformity of structure, and incomplete filling during the casting process. To solve the above problems, the prior art has proposed a variety of solutions, such as patent number CN210755091U proposes to adopt a casting and forging integration method, but this method is difficult to improve the complex structural parts with thin walls. For example, patent number CN209288228U proposes to use a combination of ultrasonic vibration and hydraulic pressure to control the filling of the slurry, but this method is expensive and difficult to implement. Therefore, how to produce aluminum-based composite castings with excellent performance has become a current problem.

[0047] To this end, the present invention provides, on the one hand, a casting device for preparing aluminum-based composite material castings, and on the other hand, provides a casting method for preparing high-quality aluminum-based composite material castings based on the casting device.

[0048] like Figure 1 As shown, the casting device of the aluminum-based composite material casting proposed in the present invention includes a molding device 1, a smelting device 2 and a pressure control system 3; wherein,

[0049] The molding device 1 includes a mold 100 and a sand core 200 placed in a mold cavity 103 thereof, wherein the sand core 200 divides the mold cavity 103 into a first chamber and a second chamber, and the sand core 200 is provided with at least one runner 201 connecting the first chamber and the second chamber; the runner 201 is configured to cool the aluminum-based composite material melt to a semi-solid slurry;

[0050] The smelting equipment 2 is connected to the first chamber through the riser pipe 300, and the pressure control system 3 is used to control the internal pressure of the molding equipment 1 and the smelting equipment 2, so as to inject the aluminum-based composite material melt in the smelting equipment 2 into the first chamber through the riser pipe 300, and form a semi-solid slurry after passing through the runner 201 to quickly fill the second chamber.

[0051] In an embodiment of the present invention, a sand core 200 for composite material melt suction casting is arranged inside the mold cavity 103 of the mold 100, and the sand core 200 is configured to cool the aluminum-based composite material melt into a semi-solid slurry, so that the slurry can be quickly punched into the second cavity and quickly solidified, thereby obtaining an aluminum-based composite material casting with full filling, high density, fine working surface structure and uniform distribution of reinforcing phase.

[0052] In some embodiments of the present invention, the mold 100 is further provided with a circulating cooling system for regulating the temperature field gradient in the mold cavity 103. In the present invention, the circulating cooling system can be provided to achieve rapid solidification of the composite material melt and improve the structural consistency of the upper and lower working surfaces of the composite material casting.

[0053] like Figure 1 As shown, the circulating cooling system in the present invention specifically includes cooling pipes 106 arranged inside the upper mold 101 and the lower mold 102 for circulating and transporting cooling liquid.

[0054] In the present invention, a cooling liquid, such as water, circulates inside the mold 100 to accurately control the temperature field during the molding of the aluminum-based composite material, adjust the material and size of the quench layer, and adjust the temperature of different parts of the mold 100 to achieve the temperature gradient of the aluminum-based composite material filling.

[0055] In some embodiments of the present invention, a chill layer 105 is coated on the cavity wall of the mold cavity 103, thereby accelerating the cooling of the melt.

[0056] In some embodiments of the present invention, the thickness of the quenching layer 105 may be 100 μm to 500 μm. For example, the thickness of the quenching layer 105 may be one of 100 μm, 200 μm, 300 μm, 400 μm, 500 μm or any value satisfying the above range.

[0057] In some embodiments of the present invention, the raw material of the chill layer 105 is a mixture of graphite powder, aluminum powder and alcohol.

[0058] In some embodiments of the present invention, the mold 100 may be a metal mold, for example, a brass material with good thermal conductivity. A cooling liquid is circulated inside the metal mold to accurately control the temperature field during the molding of the aluminum-based composite material, adjust the material and size of the quenching layer, adjust the temperature of different parts of the mold, and realize the control of the temperature gradient of the aluminum-based composite material filling.

[0059] In some embodiments of the present invention, the sand core 200 is configured to have a temperature lower than that of the aluminum-based composite material melt. For example, the temperature of the sand core 200 may be 0°C to 300°C.

[0060] Exemplarily, the temperature of the sand core 200 may be one of 0°C, 20°C, 50°C, 80°C, 100°C, 150°C, 200°C, 250°C, 300°C or any value satisfying the above range.

[0061] In some embodiments of the present invention, the contact surface between the sand core 200 and the aluminum-based composite material melt is coated with a sealing coating (not shown in the figure), thereby improving the impact resistance of the sand core 200 and preventing the internal gas of the sand core 200 from being discharged into the mold cavity 103, thereby improving the density of the casting.

[0062] In some embodiments of the present invention, at least one exhaust groove 104 is provided on the mold 100, and at least one exhaust channel (not marked in the figure) is also provided on the sand core 200, and the exhaust channel is not connected to the runner 201; the exhaust channel is connected to the exhaust groove 104 accordingly, thereby realizing gas discharge during the filling process and the solidification process, thereby improving the shrinkage compensation effect of the casting.

[0063] In the embodiment of the present invention, the combined design of the vacuum environment and the exhaust groove 104 can eliminate a large amount of gas generated by sand casting, and casting defects are significantly reduced.

[0064] In some embodiments of the present invention, the sand core 200 is provided in a disc-shaped structure, the exhaust channel is distributed along its radial direction, and the runner 201 is distributed along its axial direction, and the two are not connected to each other.

[0065] In some embodiments of the present invention, the mold 100 is formed by combining an upper mold 101 and a lower mold 102. The upper mold 101 and the lower mold 102 are respectively provided with an upper groove and a lower groove on the parting surface. When the upper mold 101 and the lower mold 102 are combined, the upper and lower grooves are combined to form an exhaust groove 104; the sand core 200 is placed in the mold cavity 103 and is arranged close to the parting surface of the upper mold 101 and the lower mold 102. An exhaust duct is provided on the outer surface of the sand core 200 facing the parting surface, that is, on the side surface matching the parting surface. The exhaust duct is connected to the exhaust groove 104 to improve the shrinkage compensation effect of the casting.

[0066] In some embodiments of the present invention, in order to further improve the shrinkage compensation effect of the casting, an exhaust hole (not marked in the figure) is further provided on the matching connection surface between the mold 100 and the sand core 200 .

[0067] In some embodiments of the present invention, the diameter of the exhaust hole is 10 mm to 30 mm, for example, the diameter is one of 10 mm, 20 mm, 30 mm or any value within the above range.

[0068] like Figure 1 As shown, the molding device 1 includes a molding device body having a first receiving chamber, the mold 100 is placed in the first receiving chamber, and the exhaust groove 104 is connected to the first receiving chamber; the pressure control system 3 is used to control the pressure in the first receiving chamber, that is, to control the pressure in the mold cavity 103.

[0069] like Figure 1 As shown, the smelting equipment 2 includes a smelting equipment body having a second holding chamber, and a smelting container 21 placed in the second holding chamber, the smelting container 21 is used to smelt to obtain an aluminum-based composite material melt, and the smelting container 21 is configured to reciprocate along the height direction of the smelting equipment body to achieve flexible adjustment of its position height, so as to facilitate cooperation with the riser 300; the pressure control system 3 is used to control the pressure in the second holding chamber, for example, to control the pressure difference between the second holding chamber and the inside of the first holding chamber, so that the aluminum-based composite material melt is injected into the first chamber through the riser 300.

[0070] In some embodiments of the present invention, the smelting equipment 2 further includes a lifting mechanism 22 , which is disposed below the smelting container 21 and is used to drive the smelting container 21 to reciprocate.

[0071] In some embodiments of the present invention, the lifting mechanism 22 includes a hydraulic rod 221, a dynamic sealing ring 222 and a motor 223. One end of the hydraulic rod 221 is connected to the smelting equipment 2, and the other end extends out of the smelting equipment body and is connected to the motor 223. The hydraulic rod 221 is sealed with the smelting equipment body through the dynamic sealing ring 222 to realize the up and down reciprocating motion of the smelting container 21.

[0072] In some embodiments of the present invention, the smelting container 21 includes a crucible 211 and an induction heating furnace 212 surrounding the outside of the crucible, which is used for melting the composite material.

[0073] In some embodiments of the present invention, the smelting equipment 2 also includes an electromagnetic stirring mechanism 23 arranged around the circumference of the smelting container 21. Specifically, the electromagnetic stirring mechanism 23 is arranged around the outside of the induction heating furnace 212 to achieve continuous stirring of the composite material during the melting and filling process to avoid sedimentation and agglomeration of the reinforcement phase.

[0074] Exemplarily, the electromagnetic stirring mechanism 23 may be an electromagnetic stirring coil, which has a simple and practical structure.

[0075] like Figure 1 As shown, the pressure control system 3 includes a pressure control component 31 and a vacuum control component 32. The vacuum control component 32 is used to control the first holding chamber and the second holding chamber to be a vacuum environment; the pressure control component 31 is used to transport inert gas to the second holding chamber to control the internal pressure difference between the second holding chamber and the first holding chamber to realize the melt injection into the mold cavity 103.

[0076] In some embodiments of the present invention, the pressure regulating component 31 includes a gas tank 311 connected to the second containing chamber, and a first control valve 312 for controlling the connection and disconnection between the gas tank 311 and the second containing chamber. By controlling the first control valve 312, the inert gas pressure in the second containing chamber can be regulated, thereby realizing melt filling and pressure-maintaining solidification in the first chamber and the second chamber.

[0077] In some embodiments of the present invention, the vacuum control component 32 includes a vacuum tank 321 respectively connected to the first holding chamber and the second holding chamber, and a second control valve 322 and a third control valve 323 respectively controlling the opening and closing of the vacuum tank 321 and the first holding chamber and the second holding chamber. By controlling the second control valve 322 and the third control valve 323, the mold cavity 103 and the second holding chamber can be in a vacuum environment to keep the melt pure.

[0078] The casting method of the aluminum-based composite material casting provided by the present invention is based on the casting device of the aluminum-based composite material casting mentioned above.

[0079] The casting method of the present invention is carried out according to the following steps.

[0080] (1) Mold preparation

[0081] According to the casting requirements, the thickness of the chilled layer 105 and the position of the exhaust holes on the inner wall of the metal mold 100 are adjusted.

[0082] The molding sand and the water glass solvent are uniformly mixed in proportion, loaded into a sand box, and placed in a temperature environment of 0°C to 300°C. After the molding sand is solidified and trimmed, a sand core 200 is obtained.

[0083] The sand core 200 is assembled and combined with the metal mold 100 , and the sand core 200 is placed in the mold cavity 103 .

[0084] (2) Composite material melting.

[0085] The aluminum-based composite material is placed in the crucible 211, the vacuum control component 32 is turned on, and the second control valve 322 and the third control valve 323 are opened to simultaneously evacuate the inside of the smelting equipment 2 and the inside of the mold cavity 103 to the same vacuum degree, which may be 1Pa to 10Pa.

[0086] The induction heating furnace 212 is turned on to heat the aluminum-based composite material to 10° C. to 80° C. above the liquidus line of the aluminum-based composite material melt. After melting, the electromagnetic stirring mechanism 23 is turned on to stir the aluminum-based composite material melt.

[0087] (3) Melt is injected into the mold.

[0088] The riser tube 300 is preheated to 300° C. to 500° C., and the motor 223 is driven to raise the position of the smelting container 21 until the riser tube 300 is immersed in the bottom of the aluminum-based composite material melt and is 30 mm to 100 mm away from the bottom of the smelting container 21 .

[0089] Open the first control valve 312, and adjust the internal air pressure of the smelting equipment 2 to reach 1000Pa~300000Pa within 1s~20s. The melt enters the first chamber through the riser 300. At the same time, start the circulating cooling system, the coolant is 0℃~40℃, the melt first flows through the first chamber, and then through the runner 201 in the sand core 200. The temperature in this area is low, and the melt is highly supercooled. It is quickly cooled to the semi-solid range to form a semi-solid slurry and then filled into the second chamber for rapid solidification. After the filling is completed, the pressure is continuously maintained to finally obtain an aluminum-based composite material casting with consistent microstructure and properties in the upper and lower regions.

[0090] The chemical reagents used in the specification and examples of the present invention include any conventional models or types in the art, and the present invention does not impose any special limiting requirements.

[0091] Example 1

[0092] Provides a Figure 1 The casting method of the aluminum-based composite material shaft-mounted brake disc casting of the casting device shown in the figure has the following steps:

[0093] (1) Mold preparation

[0094] According to the casting requirements, the thickness of the chill layer 105 on the inner wall of the metal mold is adjusted to 300 μm and the position of the exhaust hole is adjusted; the molding sand and water glass are evenly mixed in proportion, loaded into the sand box, and placed at 20°C for curing and shaping to obtain the sand core 200. The sand core 200 is assembled with the metal mold 100, and the sand core 200 is placed in the mold cavity 103.

[0095] (2) Composite material melting.

[0096] (2.1) 80 kg of SiCp / A357 composite material was placed in the crucible 211, the vacuum control assembly 32 was turned on, and the second control valve 322 and the third control valve 323 were opened to simultaneously evacuate the interior of the smelting equipment 2 and the interior of the mold cavity 103 to the same vacuum degree of 5 Pa.

[0097] (2.2) Turn on the induction heating furnace 212 to heat the material to 610° C. to obtain a composite material melt.

[0098] (2.3) Turn on the electromagnetic stirring mechanism 23 to stir the melt.

[0099] (3) Filling of composite materials.

[0100] (3.1) The riser tube 300 is preheated to 500° C. The motor 223 is driven to raise the smelting container 21 until the riser tube 300 is immersed in the bottom of the melt and is 50 mm away from the bottom of the smelting container 21 .

[0101] (3.2) The inert gas valve is opened, and the internal pressure of the smelting equipment 2 is adjusted to 0.2 MPa. The melt enters the mold cavity 103 through the riser pipe 300, and the pressure is maintained after the filling is completed.

[0102] At the same time, the cooling liquid (2°C) inside the mold 100 is always on, and the composite material melt first flows through the first cavity and then through the runner 201 in the sand core 200. The melt in this area is subjected to a high degree of supercooling. The melt is quickly cooled to the semi-solid range and then filled into the second cavity for rapid solidification, finally obtaining a SiCp / A357 composite material aluminum-based casting with consistent microstructure and properties in the upper and lower regions.

[0103] In Example 1, a high-quality aluminum-based composite shaft-mounted brake disc casting is obtained according to the above process, and the microstructure is as follows: Figure 2 As shown, SiC particles are uniformly dispersed in the matrix alloy.

[0104] At the same time, the mechanical properties of the castings after heat treatment were tested. The tensile strength of the composite material casting reached 260MPa at room temperature, and the friction coefficient remained at 0.3.

[0105] The double working surfaces of the shaft-mounted brake disc manufactured by the casting device and the casting method of the present invention have uniform structural properties and can maintain a stable friction coefficient.

[0106] The invention can also be used for manufacturing other large and complex metal-based composite material products.

[0107] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A casting device for aluminum-based composite material castings, characterized in that: Including molding equipment, smelting equipment and pressure control system; The molding device comprises a mold and a sand core placed in the mold cavity thereof, wherein the sand core divides the mold cavity into a first cavity and a second cavity, and the sand core is provided with at least one runner connecting the first cavity and the second cavity; the runner is configured to cool the aluminum-based composite material melt into a semi-solid slurry; The smelting equipment is connected to the first chamber through a riser pipe, and the pressure control system is used to control the internal pressure of the molding equipment and the smelting equipment, so that the aluminum-based composite material melt in the smelting equipment is injected into the first chamber through the riser pipe, and forms a semi-solid slurry after passing through the runner to quickly fill the second chamber.

2. The casting device for aluminum-based composite material casting according to claim 1, characterized in that: The sand core is configured to have a temperature lower than the temperature of the aluminum-based composite material melt, preferably 0° C. to 300° C.; Preferably, the contact surface between the sand core and the aluminum-based composite material melt is coated with a sealing coating; Preferably, a chilling layer is provided on the cavity wall of the mold cavity.

3. The casting device for aluminum-based composite material casting according to claim 1, characterized in that: The mold is provided with at least one exhaust groove, and the sand core is also provided with at least one exhaust channel, the exhaust channel is correspondingly connected with the exhaust groove, and the exhaust channel is not connected with the runner; Preferably, the mold is also provided with a circulating cooling system for regulating the temperature field gradient in the mold cavity.

4. The casting device for aluminum-based composite material casting according to claim 3, characterized in that: The mold comprises an upper mold and a lower mold, and grooves are respectively provided on the parting surfaces of the upper mold and the lower mold, and the two are combined to form the exhaust groove; Preferably, the mould comprises a metal type mould.

5. The casting device for aluminum-based composite material casting according to claim 1, characterized in that: The molding device comprises a molding device body having a first containing chamber, and the pressure regulating system is used to control the pressure in the first containing chamber; The mold is placed in the first accommodation chamber, and the exhaust groove is connected to the first accommodation chamber.

6. The casting device for aluminum-based composite material casting according to claim 1, characterized in that: The smelting equipment comprises a smelting equipment body and a smelting container, the smelting equipment body has a second containing chamber inside, and the pressure regulating system is used to control the pressure in the second containing chamber; The smelting container is placed in the second containing chamber and reciprocates along the height direction of the smelting equipment body; the smelting container is used to contain the aluminum-based composite material melt; Preferably, the smelting equipment further comprises a lifting mechanism, which is disposed below the smelting container and is used to drive the smelting container to reciprocate; Preferably, the smelting equipment further comprises an electromagnetic stirring mechanism arranged around the circumference of the smelting container.

7. The casting device for aluminum-based composite material casting according to claim 1, characterized in that: The pressure control system includes a vacuum control component and a pressure control component, wherein the vacuum control component is used to control the first receiving chamber and the second receiving chamber to be a vacuum environment; and the pressure control component is used to transport an inert gas to the second receiving chamber to control the internal pressure difference between the second receiving chamber and the first receiving chamber; Preferably, the pressure regulating assembly comprises a gas tank connected to the second containing chamber, and a first control valve for controlling the connection and disconnection between the gas tank and the second containing chamber; Preferably, the vacuum regulating assembly includes a vacuum tank connected to the first containing chamber and the second containing chamber respectively, and a second control valve and a third control valve for controlling the connection and disconnection of the vacuum tank with the first containing chamber and the second containing chamber respectively.

8. A method for casting an aluminum-based composite material casting, characterized in that: The casting method is based on the casting device of the aluminum-based composite material casting according to any one of claims 1 to 7; the casting method comprises the following steps: Melting the aluminum-based composite material through a melting device to obtain an aluminum-based composite material melt; The internal pressure of the molding equipment and the smelting equipment is regulated by the pressure regulating system to form a pressure difference; Under the action of pressure difference, the aluminum-based composite material melt is injected into the first chamber through the riser pipe, and forms a semi-solid slurry after passing through the sand core runner to quickly fill the second chamber to obtain an aluminum-based composite material casting.

9. The casting method of aluminum-based composite material casting according to claim 8, characterized in that: The smelting process comprises: Evacuate the inside of the melting equipment and the molding equipment to the same vacuum degree, which is 1Pa to 10Pa; Raising the temperature of the smelting vessel to 10°C to 80°C above the liquidus; and Electromagnetic stirring is performed on the obtained aluminum-based composite material melt; Preferably, the melt injection process comprises: Preheat the riser tube to 300℃~500℃; Regulating the internal pressure of the smelting equipment to be 1000Pa to 300000Pa, so as to inject the aluminum-based composite material melt into the first chamber through the riser pipe, and quickly fill the second chamber; and During the melt injection process, the circulating cooling system is kept open; the temperature of the coolant in the circulating cooling system is preferably 0°C to 40°C.

10. An aluminum-based composite casting, characterized in that: It is made by the casting method described in any one of claims 8 to 9.

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