Light alloy semi-solid melt preparation and injection extrusion casting molding equipment and method

Abstract

The present invention belongs to the technical field of nonferrous metal material preparation, and discloses a light alloy semi-solid melt preparation and injection extrusion casting molding equipment and method. The equipment includes an intelligent melt microstructure prediction module, a melt preparation unit, and an extrusion casting molding unit. The method includes the steps of equipment preheating, semi-solid melt preparation, injection feeding, and extrusion casting molding. The present invention achieves seamless docking between the melt preparation unit and the extrusion casting molding unit, realizing an integrated process from preparation to molding of the semi-solid melt. By coupling a unified phase field model to predict the changes in microstructure morphology under different process parameters during the semi-solid melt preparation process, the optimal process parameters of the semi-solid melt preparation process are determined, and the melt preparation process is optimized. This is of great significance for improving the controllability of the semi-solid melt, the stability of the semi-solid molded castings, and the product quality.

Description

Technical Field

[0001] The present invention belongs to the technical field of nonferrous metal material preparation, and in particular relates to a light alloy semi-solid melt preparation and injection extrusion casting molding device and method. Background Art

[0002] As a new metal material forming process, semi-solid squeeze casting technology has the following advantages over traditional squeeze casting: high melt viscosity and easy control of filling; less air entrainment during filling, reduced oxidation and improved mechanical properties; low deformation temperature, small thermal shock and long mold life; easy to automate and improve processing efficiency, and has extremely broad application prospects in aerospace, transportation, communications and other fields.

[0003] Semi-solid extrusion casting technology is mainly divided into two stages, namely the semi-solid melt preparation stage and the extrusion casting molding stage. However, the current existing semi-solid extrusion casting molding process has an obvious separation between the two stages of melt preparation and molding. First, the metal raw material is heated to prepare a semi-solid melt, and then the semi-solid melt is extruded and cast. The extrusion casting molding process currently generally includes rheological extrusion casting process and thixoforming process. In the rheological extrusion casting process, the prepared semi-solid melt is transferred into the material cylinder through a crucible or a scoop to complete filling and solidification. This leads to the inevitable oxidation of the melt and difficulty in temperature control during transportation. Problems such as; thixoforming can obtain the ingot form of the bulk alloy after cooling forming or large plastic deformation, which has the advantages of convenient transportation and storage, stable quality of formed parts, etc., but it also has the disadvantages of complicated process, high energy consumption, and easy residual deformed structure in the microstructure. Summary of the Invention

[0004] The purpose of the present invention is to provide a light alloy semi-solid melt preparation and injection extrusion casting molding equipment and method in view of the background technology.

[0005] In one aspect of the present invention, a light alloy semi-solid melt preparation and injection extrusion casting molding equipment is provided, including a melt microstructure intelligent prediction module, a melt preparation unit and an extrusion casting molding unit, wherein the melt preparation unit is horizontally arranged and includes an injection cylinder, a piston rod, a cylinder fixing seat, a servo motor, a motor shaft, a motor fixing seat, a motor guide sleeve, a coaxiality adjustment device, a guide column, a feed port guide sleeve, a feed port fixing seat, a feed funnel, a stirring screw, a material pipe, an infrared heater, a material pipe thermocouple, and a nozzle; the extrusion casting molding unit is vertically arranged on a workbench and includes a fixed mold frame, a fixed mold core, a material cylinder, a sprue sleeve, a sprue sleeve fixing plate, a shot head, a shot rod, a movable mold frame, a movable mold core, a diverter cone, a movable mold electric heating plate, a fixed mold electric heating plate, a material cylinder heating sleeve, a mold temperature controller, and an ejection assembly, wherein:

[0006] The melt microstructure intelligent prediction module is used to determine the semi-solid melt preparation process parameters by predicting the microstructure based on a unified phase field model. The semi-solid melt preparation process parameters include melt temperature, stirring speed, and stirring time.

[0007] The servo motor is mounted on the motor fixing seat, the motor shaft is connected to the stirring screw via the coaxiality adjustment device, the cylinder fixing seat is arranged on the outside of the motor fixing seat, the injection cylinder is mounted on the cylinder fixing seat, the guide column is fixed between the workbench and the cylinder fixing seat, the motor guide sleeve is sleeved on the guide column, the motor fixing seat is fixedly connected to the motor guide sleeve, and the piston rod is connected to the motor fixing seat;

[0008] The feed pipe is divided into three parts: the head of the feed pipe, the middle of the feed pipe and the tail of the feed pipe. The feed port fixing seat is arranged between the coaxiality adjustment device and the tail of the feed pipe. The side of the feed port fixing seat is fixedly connected to the tail of the feed pipe. The upper part of the feed port fixing seat is provided with the feed funnel. The lower part of the feed port fixing seat is fixedly connected with the feed port guide sleeve. The feed port guide sleeve is sleeved on the guide column and fixed to the guide column by fixing bolts. The feed end of the stirring screw passes through the feed port fixing seat, and the stirring screw extends out of the feed port fixing seat. The end of the feed port fixing seat is connected to the motor shaft, the feed funnel arranged on the upper part of the feed port fixing seat is connected to the feed end of the stirring screw, the rest of the stirring screw is installed in the material pipe, the discharge end of the stirring screw is equipped with a support ring for supporting and installing the stirring screw, a screw head for pushing the material, and a check ring for preventing reverse backflow, the nozzle is connected to the material pipe head through a flange and bolts, and the material pipe head, the middle part and the material pipe tail of the material pipe are respectively covered with one of the infrared heaters and are correspondingly configured with one of the material pipe thermocouples;

[0009] The bottom of the extrusion casting molding unit is provided with a fixed mold heat insulation plate and a fixed mold fixing plate fixed to the workbench through a pressure plate, the fixed mold frame is installed on the fixed mold fixing plate, the material cylinder is installed in the fixed mold frame, the injection head and the injection rod are installed in the material cylinder, the fixed mold core is cooperatively installed on the top of the material cylinder, and the outside of the material cylinder is covered with the material cylinder heating jacket and is correspondingly configured with a material cylinder thermocouple;

[0010] A gate is provided on the side of the material cylinder facing the nozzle, the gate sleeve is fitted on the gate, the gate sleeve fixing plate is connected between the gate sleeve and the flange, the gate sleeve fixing plate is concentrically mounted with the gate sleeve and internally communicated with the gate sleeve, the nozzle is inserted into the gate sleeve fixing plate and the gate sleeve, and the nozzle cavity of the nozzle is communicated with the gate, and a flange pad is provided on the side of the fixed mold frame facing the nozzle to support and fix the flange;

[0011] The movable mold frame is mounted on the upper part of the fixed mold frame, and the movable mold frame and the fixed mold frame are positioned and aligned with each other through guide rods and matching guide sleeves, the movable mold core is mounted in the movable mold frame, the diverter cone is connected to the movable mold core, and the movable mold core and the fixed mold core jointly form a mold cavity, the ejector assembly is arranged above the movable mold frame, and comprises a push plate, a push fixing plate, a push rod and a reset rod, the upper part of the movable mold frame is provided with mold feet on both sides of the ejector assembly, the push plate and the push fixing plate are fitted between the mold feet on both sides, the ejector rod and the reset rod are mounted on the lower bottom surface of the push fixing plate, and the free ends of the ejector rod and the reset rod both pass through the movable mold frame and the movable mold core, the ejector rod is arranged to face the mold cavity, the reset rod is arranged to deviate from the mold cavity, and the length of the reset rod is greater than the length of the ejector rod;

[0012] The outside of the movable mold frame is covered with the movable mold electric heating plate, the outside of the fixed mold frame is covered with the fixed mold electric heating plate, and the movable mold frame and the fixed mold frame are both opened with oil circuits, and the mold temperature controller is connected to the oil circuits of the movable mold frame and the fixed mold frame via a heating oil pipe.

[0013] Furthermore, in the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting molding equipment, the gate sleeve is covered with a heating device to heat and keep the transported melt warm.

[0014] Furthermore, in the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting molding equipment, a fixed mold core groove is provided on the lower surface of the fixed mold core, and the fixed mold core is mounted on the top of the material cylinder in a snap-fit ​​manner through the fixed mold core groove.

[0015] Furthermore, in the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting molding equipment, the gate is processed with a gate groove, and the gate sleeve is fitted and installed on one side of the gate and is provided with a gate sleeve convex ring. Through the fitting of the gate groove and the gate sleeve convex ring, the gate sleeve is fitted and installed on the gate.

[0016] In another aspect of the present invention, a method for preparing a light alloy semi-solid melt and performing injection extrusion casting is provided. The method is implemented using the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting equipment, and comprises the following steps:

[0017] 1. Equipment preheating

[0018] Preheat the movable mold frame and the fixed mold frame respectively, and preheat the material cylinder;

[0019] Turn on the infrared heaters covering the head, middle and tail of the material pipe to preheat the material pipe;

[0020] 2. Semi-solid melt preparation

[0021] Using the melt microstructure intelligent prediction module based on the unified phase field model to predict the microstructure and determine the semi-solid melt preparation process parameters, wherein the semi-solid melt preparation process parameters include melt temperature, stirring speed, and stirring time;

[0022] The semi-solid melt is prepared according to the determined process parameters, wherein the semi-solid melt is prepared according to the determined process parameters including:

[0023] Pipe heating: Heat the head, middle and tail of the pipe to corresponding temperatures respectively to ensure that the temperature of the melt reaches the determined melt temperature when it reaches the head of the pipe;

[0024] Feeding and stirring: Light alloy particles are fed into the feeding funnel. Based on the determined stirring speed and stirring time, the stirring screw is used to transport the light alloy particles into the material pipe and from the tail end of the material pipe to the middle part of the material pipe to the head end of the material pipe;

[0025] 3. Injection feeding

[0026] Control the movable mold frame to move downward until the guide rod on the movable mold frame enters the guide sleeve on the fixed mold frame to complete the mold closing;

[0027] Start the injection cylinder so that the screw head at the front end of the stirring screw will inject the semi-solid melt stored in the front end of the material pipe head into the nozzle cavity of the nozzle at high speed and then inject it into the preheated material cylinder;

[0028] 4. Squeeze Casting

[0029] The semi-solid melt in the material cylinder is pushed into the mold cavity through the fixed mold core. After the filling is completed, the semi-solid melt is kept under pressure so that the semi-solid melt is solidified under pressure.

[0030] Control the movable mold frame to move upward to complete mold opening;

[0031] The push plate is controlled to move toward the fixed mold frame, and the ejector rod is used to eject the molded casting adhered to the mold cavity.

[0032] Furthermore, in the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting method, the evolution equation of the unified phase field model is expressed as:

[0033] ;

[0034] ;

[0035] ;

[0036] in,

[0037] ;

[0038] ;

[0039] ;

[0040] ;

[0041] ;

[0042] ;

[0043] ;

[0044] Where, is the phase field order parameter, For time, is the number of grains, For the The local order parameter of each grain, is the relaxation time, is the characteristic relaxation time, is the minimum liquid phase solute diffusion coefficient, is the thermal diffusivity, is the number of alloy components including matrix components and solute components, for The first alloy component other than the matrix component Solute components, is the equilibrium distribution coefficient, is the dimensionless supersaturation, is the ratio of the thermocapillary length to the chemical capillary length, is the diffusion coefficient of the liquid solute, is the interface energy anisotropy function, is the diffusion interface width, is the characteristic diffusion interface width, is the coupling coefficient, is the dimensionless temperature, is the solid-phase solute diffusion coefficient, is the anisotropic strength, is the orientation angle, which takes a random value between 0 and 2π. To adjust the parameters, is the time iteration scale, and its value is , is the temperature, is the melting point, is the liquidus slope, is the liquid phase solute concentration, is the latent heat of fusion, is the specific heat, is the solute concentration, is the symbol for partial derivative, represents the partial derivative operation with respect to time, represents the gradient operation, is the Laplace operator symbol, and is an intermediate parameter.

[0045] Furthermore, in the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting molding method, the semi-solid melt preparation process parameters are determined by the following method:

[0046] Determine parameters according to light alloy system 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 ;

[0047] Melt temperature parameter , stirring speed parameters , stirring time parameters , as input parameters, according to the different input parameters, the unified phase field model is used to obtain the microstructure morphology under different input parameter combinations, and according to the degree of grain spheroidization of the microstructure morphology, the optimal melt temperature, stirring speed, and stirring time are screened out as the optimal semi-solid melt preparation process parameters.

[0048] Furthermore, in the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting method, the step of preheating the equipment includes:

[0049] Turn on the mold temperature controller and the movable mold electric heating plate and the fixed mold electric heating plate to preheat the movable mold frame and the fixed mold frame respectively, and start the cylinder heating jacket to preheat the cylinder. The preheating temperature of the mold temperature controller is set to 295-305°C, and the heating temperatures of the movable mold electric heating plate, the fixed mold electric heating plate and the cylinder heating jacket are all set to 595-605°C, until the temperature inside the cylinder reaches 545-555°C as monitored by the cylinder thermocouple and the temperature inside the mold cavity reaches 295-305°C as monitored by the mold thermocouple;

[0050] Turn on the infrared heaters covering the head, middle and tail of the material pipe to preheat the material pipe until the temperature inside the material pipe reaches 295~305℃ as monitored by the material pipe thermocouple.

[0051] Furthermore, in the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting molding method, the step of preparing the semi-solid melt according to the determined process parameters includes:

[0052] Pipe heating: Use corresponding infrared heaters to heat the head, middle and tail of the pipe respectively. The heating temperature of the tail area of ​​the pipe is set to 575~585℃; the heating temperature of the middle area of ​​the pipe is set to 595~605℃; the heating temperature of the head area of ​​the pipe is set to 620℃ to ensure that the temperature of the melt reaches the melt temperature of 620℃ when it reaches the head of the pipe;

[0053] Feeding and stirring: Feed the light alloy particles through the feeding funnel, control the rotation of the stirring screw at a stirring speed of 100r / min and a stirring time of 30s, and use the stirring screw to transport the light alloy particles into the material pipe and from the tail of the material pipe through the middle of the material pipe to the head of the material pipe.

[0054] Furthermore, in the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting molding method, the injection feeding step includes:

[0055] Spray water-based graphite lubricant evenly on the inner wall of the cylinder, spray magnesium oxide release agent evenly on the mold cavity surface inside the fixed mold core and the movable mold core, introduce argon gas into the cylinder in advance, and control the movable mold frame to move downward until the guide rod on the movable mold frame enters the guide sleeve on the fixed mold frame, completing the mold closing;

[0056] Start the injection cylinder so that the screw head at the front end of the stirring screw will inject the semi-solid melt stored in the front end of the material pipe head into the nozzle cavity of the nozzle at high speed and then into the preheated material cylinder.

[0057] Furthermore, in the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting molding method, the extrusion casting molding step includes:

[0058] Control the injection rod and injection head to move upward, pushing the semi-solid melt in the cylinder into the mold cavity through the fixed mold core. After the filling is completed, continue to apply pressure to the injection rod and injection head to maintain the pressure of the semi-solid melt, so that the semi-solid melt is solidified under pressure;

[0059] Control the movable mold frame to move upward to complete mold opening;

[0060] Control the push plate to move toward the fixed mold frame, and use the ejector rod to eject the molded casting adhered to the mold cavity. After the ejection is completed, control the movable mold frame to move downward to complete the mold closing, and reset the ejector rod under the driving action of the reset rod.

[0061] Furthermore, the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting molding method also includes a casting cleaning step: placing the casting on a steel plate, naturally cooling it to room temperature, polishing the casting surface with sandpaper after cooling, and then cleaning it with anhydrous ethanol and drying it.

[0062] Furthermore, in the above-mentioned method for preparing a semi-solid light alloy melt and performing injection extrusion casting, in the feeding and stirring steps, the feeding amount of the light alloy particles is set to 295-305 g each time.

[0063] Furthermore, in the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting molding method, in the injection feeding step, the stirring screw is pushed at a speed of 2.4~2.6m / s.

[0064] Furthermore, in the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting molding method, in the extrusion casting molding step, the injection rod and the injection head are controlled to move upward at a speed of 36~40mm / s. After the filling is completed, a holding pressure of 38~42 tons is continuously applied to the injection rod and the injection head, and the semi-solid melt is kept under pressure for 29~31s.

[0065] Furthermore, in the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting molding method, in the extrusion casting molding step, after the mold opening is completed, the injection cylinder is started and the stirring screw is pulled backward to reset; the injection rod and the injection head are controlled to reset downward.

[0066] Furthermore, in the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting molding method, the light alloy is AZ91D magnesium alloy.

[0067] The light alloy semi-solid melt preparation and injection extrusion casting molding equipment and method of the present invention utilize temperature and speed control mechanical stirring technology to perform semi-solid melt preparation and injection extrusion casting molding. This enables an integrated process from semi-solid melt preparation to molding, eliminating the melt transfer step. While ensuring a simple process flow, it effectively avoids oxidation and temperature runaway problems that may occur during melt transfer. This is of great significance for improving the controllability of the semi-solid melt, the stability of semi-solid molded castings, and product quality. Compared with the prior art, the light alloy semi-solid melt preparation and injection extrusion casting molding equipment and method of the present invention have the following advantages and beneficial effects:

[0068] The intelligent melt microstructure prediction module is coupled with a unified phase field model to predict the microstructure morphology changes under different process parameters during the semi-solid melt preparation process. Based on the prediction results, the optimal process parameters such as melt temperature, stirring speed, and stirring time are determined to prepare a semi-solid melt with stable quality, thereby optimizing the melt preparation process and improving casting performance.

[0069] By designing the material cylinder inside the fixed mold of the extrusion casting molding unit, adding a sprue sleeve to the material cylinder and assembling it with the nozzle of the melt preparation unit, a seamless connection between the melt preparation unit and the extrusion casting molding unit is achieved, and the prepared semi-solid melt is directly injected from the nozzle into the material cylinder for extrusion casting molding;

[0070] The use of electric heating plates, cylinder heating jackets and mold temperature controllers to perform oil-electric internal and external coordinated heating of the mold can accurately control the temperature of the semi-solid melt, improve the stability of semi-solid processing, and enhance the quality of light alloy semi-solid molding castings. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the relevant drawings. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0072] Figure 1 It is a schematic diagram of the overall structure of the light alloy semi-solid melt preparation and injection extrusion casting molding equipment of the present invention;

[0073] Figure 2 It is a structural schematic diagram of the connection portion between the melt preparation unit and the extrusion casting molding unit in the light alloy semi-solid melt preparation and injection extrusion casting molding equipment of the present invention;

[0074] Figure 3It is an exploded schematic diagram of the internal structure of the squeeze casting molding unit in the light alloy semi-solid melt preparation and injection squeeze casting molding equipment of the present invention;

[0075] Figure 4 It is a schematic diagram of the three-dimensional structure of the injection feeding part of the light alloy semi-solid melt preparation and injection extrusion casting molding equipment of the present invention;

[0076] Figure 5 yes Figure 4 AA section view;

[0077] Figure 6 This is a schematic diagram of the principle of intelligently predicting the melt microstructure based on a unified phase field model in the light alloy semi-solid melt preparation and injection extrusion casting molding method of the present invention;

[0078] Figures 7 to 10 This is a schematic structural diagram of the light alloy semi-solid melt preparation and injection extrusion casting molding equipment of the present invention. Figures 7 to 10 A state diagram showing different stages in the process of preparing a light alloy semi-solid melt and performing injection extrusion casting molding according to the present invention;

[0079] Figure 11 A microstructure diagram of a casting produced by the light alloy semi-solid melt preparation and injection extrusion casting molding method of the present invention;

[0080] Figure 12 Another microstructure diagram of a casting produced by the light alloy semi-solid melt preparation and injection extrusion casting molding method of the present invention;

[0081] Figure 13 A microstructure diagram of a casting produced by a prior art squeeze casting process;

[0082] Figure 14 Another microstructure diagram of a casting produced by a prior art squeeze casting process;

[0083] Figure 15 1 is a schematic diagram of mechanical properties test results of castings obtained by squeeze casting;

[0084] Figure 16 This is a schematic diagram of the mechanical properties test results of the casting obtained by extrusion casting after T6 heat treatment.

[0085] Description of reference numerals:

[0086] 1. Movable mold insulation plate, 2. Mold foot fixing plate, 3. Ejector plate, 4. Ejector fixing plate, 5. Mold foot, 6. Ejector rod, 7. Reset rod, 8. Movable mold electric heating plate, 9. Movable mold frame, 10. Mold temperature controller, 11. Mold thermocouple, 12. Heating oil pipe, 13. Cylinder thermocouple, 14. Fixed mold electric heating plate, 15. Fixed mold fixing plate, 16. Fixed mold insulation plate, 17. Workbench, 18. Fixed mold frame, 19. Cylinder, 19.1. Gate, 19.2. Gate groove, 20. Shooting head, 21. Shooting rod, 22. Cylinder heating jacket, 23. Sprue bushing, 23.1 Sprue bushing convex ring, 24. Sprue bushing fixing plate, 25. Flange gasket Plate, 26. Check ring, 27. Support ring, 28. Infrared heater, 29. Guide column, 30. Material pipe, 31. Fixing bolt, 32. Feed inlet guide sleeve, 33. Feed inlet fixing seat, 34. Motor guide sleeve, 35. Motor fixing seat, 36. Cylinder fixing seat, 37. Injection cylinder, 38. Piston rod, 39. Servo motor, 40. Motor shaft, 41. Coaxiality adjustment device, 42. Feed funnel, 43. Stirring screw, 44. Material pipe thermocouple, 45. Screw head, 46. Flange, 47. Nozzle, 47.1. Nozzle cavity, 48. Fixed mold core, 48.1 Fixed mold core groove, 49. Moving mold core, 50. Diverter cone. DETAILED DESCRIPTION

[0087] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0088] First of all, it should be noted that in this article, "light alloy" refers to an alloy formed by fusing two or more metal elements (such as aluminum, magnesium, titanium, etc.) with a density less than or equal to 4.5 g / cubic centimeter.

[0089] like Figures 1 to 5As shown, the light alloy semi-solid melt preparation and injection extrusion casting molding equipment of the present invention mainly includes a melt microstructure intelligent prediction module, a melt preparation unit and an extrusion casting molding unit. The melt preparation unit is arranged horizontally, including an injection cylinder 37, a piston rod 38, a cylinder fixing seat 36, a servo motor 39, a motor shaft 40, a motor fixing seat 35, a motor guide sleeve 34, a coaxiality adjustment device 41, a guide column 29, a feed port guide sleeve 32, a feed port fixing seat 33, a feed funnel 42, a stirring screw 43, a material pipe 30, an infrared heater 28, a material pipe thermocouple 44, and a nozzle 47; the extrusion casting molding unit is arranged vertically on a workbench 17, including a fixed mold frame 18, a fixed mold core 48, a material cylinder 19, a gate sleeve 23, a gate sleeve fixing plate 24, a shot head 20, a shot rod 21, a movable mold frame 9, a movable mold core 49, a diverter cone 50, a movable mold electric heating plate 8, a fixed mold electric heating plate 14, a cylinder heating sleeve 22, a mold temperature controller 10, and an ejection assembly.

[0090] A servo motor 39 is mounted on the motor mount 35. The motor shaft 40 of the servo motor 39 is connected to the stirring screw 43 via a coaxial adjustment device 41. The cylinder mount 36 is located outside the motor mount 35, i.e., farther away from the stirring screw 43 than the motor mount 35. The injection cylinder 37 is mounted on the cylinder mount 36. The guide post 29 is fixed between the workbench 17 and the cylinder mount 36. The motor guide sleeve 34 is mounted on the guide post 29. The motor mount 35 is fixedly connected to the motor guide sleeve 34. The piston rod 38 of the injection cylinder 37 is connected to the motor mount 35.

[0091] The feed pipe 30 is divided into three parts: the feed pipe head, the feed pipe middle and the feed pipe tail. The feed port fixing seat 33 is arranged between the coaxiality adjustment device 41 and the feed pipe tail of the feed pipe 30. The side of the feed port fixing seat 33 is fixedly connected to the feed pipe tail by bolts. A feed funnel 42 is provided on the upper part of the feed port fixing seat 33, and a feed port guide sleeve 32 is fixedly connected to the lower part of the feed port fixing seat 33. The feed port guide sleeve 32 is sleeved on the guide column 29 and fixed to the guide column 29 by fixing bolts 31. The feed end of the stirring screw 43 passes through the feed port fixing base 33. The end of the stirring screw 43 extending from the feed port fixing base 33 is connected to the motor shaft 40 of the servo motor 39. A feed funnel 42, located above the feed port fixing base 33, is connected to the feed end of the stirring screw 43. The rest of the stirring screw 43 is installed in the material pipe 30. The discharge end of the stirring screw 43 is equipped with a support ring 27 for supporting and mounting the stirring screw 43, a screw head 45 for pushing the material, and a check ring 26 for preventing reverse backflow. A nozzle 47 is connected to the material pipe head of the material pipe 30 via a flange 46 and bolts. The head, middle and tail of the material tube 30 are respectively covered with an infrared heater 28 and are correspondingly configured with a material tube thermocouple 44. The infrared heater 28 is used to heat the material tube 30, and the material tube thermocouple 44 is used to monitor the temperature of the head, middle and tail of the material tube in real time and feed back to the infrared heater 28 to accurately control the temperature of the material tube 30.

[0092] The bottom of the extrusion casting molding unit is provided with a fixed mold insulation plate 16 and a fixed mold fixing plate 15 fixed to the workbench 17 by a pressure plate, the fixed mold frame 18 is installed on the fixed mold fixing plate 15, the material cylinder 19 is installed in the fixed mold frame 18, the injection head 20 and the injection rod 21 are installed in the material cylinder 19, and the fixed mold core 48 is installed in cooperation on the top of the material cylinder 19. The outside of the material cylinder 19 is covered with a cylinder heating jacket 22 for heating the material cylinder 19, and the material cylinder 19 is provided with a cylinder thermocouple 13 for real-time monitoring of the temperature in the material cylinder 19 and feeding back to the cylinder heating jacket 22 to accurately control the temperature of the material cylinder 19.

[0093] The material cylinder 19 has a gate 19.1 on the side facing the nozzle 47. A sprue bushing 23, which provides insulation, is fitted over gate 19.1. A sprue bushing fixing plate 24 is screwed between the sprue bushing 23 and a flange 46. The sprue bushing fixing plate 24 and the sprue bushing 23 are mounted concentrically and internally connected. A nozzle 47 is inserted within the sprue bushing fixing plate 24 and the sprue bushing 23, with its nozzle cavity 47.1 connected to the gate 19.1 of the material cylinder 19. As described above, the nozzle 47 is connected to the head of the material pipe 30 via the flange 46. This allows the melt in the material pipe 30 to enter the material cylinder 19 directly through the nozzle 47 for extrusion casting. Furthermore, a flange pad 25 is provided on the side of the fixed mold frame 18 facing the nozzle 47 to support and secure the flange 46. This ensures a reliable connection between the melt preparation unit and the extrusion casting unit, achieving an integrated process for preparing, conveying, and molding the semi-solid melt.

[0094] Preferably, the sprue bushing 23 is covered with a heating device (not shown), thereby fixing the nozzle 47 and simultaneously heating and keeping the melt in the conveying process, so as to ensure the quality of the melt.

[0095] Preferably, a fixed mold core groove 48 . 1 is provided on the lower surface of the fixed mold core 48 , through which the fixed mold core 48 is mounted on the top of the material cylinder 19 in a snap-fit ​​manner.

[0096] Preferably, the gate 19.1 on the side of the material cylinder 19 is processed with a gate groove 19.2, and the gate sleeve 23 is installed on one side of the gate 19.1 and is provided with a gate sleeve convex ring 23.1. Thus, the gate sleeve 23 is installed on the gate 19.1 through the cooperation between the gate groove 19.2 and the gate sleeve convex ring 23.1.

[0097] The movable mold frame 9 is mounted above the fixed mold frame 18. The movable mold frame 9 and the fixed mold frame 18 are positioned and aligned with each other via guide rods (not shown) and matching guide sleeves (not shown). The movable mold core 49 is mounted within the movable mold frame 9. A diverter cone 50 is connected to the movable mold core 49. Together, the movable mold core 49 and the fixed mold core 48 form the mold cavity. The ejector assembly, located above the movable mold frame 9, includes a pusher plate 3, a pusher fixing plate 4, an ejector rod 6, and a reset rod 7. This assembly is used to eject the casting after the casting is completed. The upper part of the movable mold frame 9 is provided with mold feet 5 on both sides of the ejection assembly, and the push plate 3 and the push fixing plate 4 are fitted between the mold feet 5 on both sides to ensure that the movable mold frame 9 is level and thus ensure stable installation. The upper part of the mold foot 5 is installed with a mold foot fixing plate 2, and the upper part of the mold foot fixing plate 2 is installed with a movable mold heat insulation plate 1, the ejector rod 6 and the reset rod 7 are installed on the lower bottom surface of the pusher fixing plate 4 and the free ends of the ejector rod 6 and the reset rod 7 pass through the movable mold frame 9 and the movable mold core 49, the ejector rod 6 and the reset rod 7 are arranged so that the ejector rod 6 is facing the mold cavity and the reset rod 7 is deviated from the mold cavity, and the length of the reset rod 7 is slightly larger than the length of the ejector rod 6.

[0098] The movable mold frame 9 is covered with a movable mold electric heating plate 8 for electrically heating the movable mold frame 9. The fixed mold frame 18 is covered with a fixed mold electric heating plate 14 for electrically heating the fixed mold frame 18. Oil circuits are opened in both the movable mold frame 9 and the fixed mold frame 18. The mold temperature controller 10 is connected to the oil circuits of the movable mold frame 9 and the fixed mold frame 18 via a heating oil pipe 12, thereby heating the movable mold frame 9 and the fixed mold frame 18 with heating oil. A mold thermocouple 11 is configured on the movable mold core 49 for real-time monitoring of the temperature in the mold cavity and feeding back to the movable mold electric heating plate 8, the fixed mold electric heating plate 14, and the mold temperature controller 10 to achieve precise control of the mold cavity temperature.

[0099] The light alloy semi-solid melt preparation and injection extrusion casting apparatus of the present invention includes an intelligent melt microstructure prediction module for determining semi-solid melt preparation process parameters by predicting the microstructure based on a unified phase field model. These parameters may include, for example, melt temperature, stirring speed, and stirring time, thereby optimizing the melt preparation process and improving casting performance. The operating process of the intelligent melt microstructure prediction module is described in detail below regarding the light alloy semi-solid melt preparation and injection extrusion casting method of the present invention.

[0100] The method for preparing a light alloy semi-solid melt and injection extrusion casting of the present invention is implemented using the above-mentioned light alloy semi-solid melt preparation and injection extrusion casting equipment, and includes the following steps:

[0101] 1. Equipment preheating

[0102] Preheat the movable mold frame 9 and the fixed mold frame 18 respectively, and preheat the material cylinder 19;

[0103] Turn on the infrared heaters 28 covering the head, middle and tail of the material tube 30 to preheat the material tube 30;

[0104] 2. Semi-solid melt preparation

[0105] The melt microstructure intelligent prediction module is used to predict the microstructure based on the unified phase field model to determine the semi-solid melt preparation process parameters, including melt temperature, stirring speed, and stirring time.

[0106] Preparing a semi-solid melt according to determined process parameters;

[0107] The preparation of the semi-solid melt according to the determined process parameters specifically includes the following:

[0108] Pipe heating: The head, middle and tail of the pipe 30 are heated to corresponding temperatures respectively to ensure that the temperature of the melt reaches the determined melt temperature when it reaches the head of the pipe;

[0109] Feeding and stirring: Light alloy particles are fed into the feeding funnel. Based on the determined stirring speed and stirring time, the stirring screw 43 is used to transport the light alloy particles into the material pipe 30 and transport them from the tail end of the material pipe to the middle part of the material pipe to the head end of the material pipe.

[0110] 3. Injection feeding

[0111] Control the movable mold frame 9 to move downward until the guide rod on the movable mold frame 9 enters the guide sleeve on the fixed mold frame 18 to complete the mold closing;

[0112] Start the injection cylinder 37 so that the screw head 45 at the front end of the stirring screw 43 injects the semi-solid melt stored in the front end of the head of the material pipe 30 into the nozzle cavity 47.1 of the nozzle 47 at high speed and then into the preheated material cylinder 19;

[0113] 4. Squeeze Casting

[0114] The semi-solid melt in the material cylinder 19 is pushed into the mold cavity through the fixed mold core 48. After the filling is completed, the semi-solid melt is kept under pressure so that the semi-solid melt is solidified under pressure.

[0115] Control the movable mold frame 9 to move upward to complete mold opening;

[0116] The push plate 3 is controlled to move toward the fixed mold frame 18, and the ejector rod 6 is used to eject the molded casting adhered to the mold cavity.

[0117] In the embodiment of the present invention, batch castings can be continuously extruded and cast by repeating the above steps of adding and stirring, injection feeding, and extrusion casting.

[0118] Furthermore, in an embodiment of the present invention, the evolution equation of the unified phase field model is expressed as:

[0119] ;

[0120] ;

[0121] ;

[0122] in,

[0123] ;

[0124] ;

[0125] ;

[0126] ;

[0127] ;

[0128] ;

[0129] ;

[0130] Where, is the phase field order parameter, For time, is the number of grains, For the The local order parameter of each grain, is the relaxation time, is the characteristic relaxation time, is the minimum liquid phase solute diffusion coefficient, is the thermal diffusivity, is the number of alloy components including matrix components and solute components, for The first alloy component other than the matrix component Solute components, is the equilibrium distribution coefficient, is the dimensionless supersaturation, is the ratio of the thermocapillary length to the chemical capillary length, is the diffusion coefficient of the liquid solute, is the interface energy anisotropy function, is the diffusion interface width, is the characteristic diffusion interface width, is the coupling coefficient, is the dimensionless temperature, is the solid-phase solute diffusion coefficient, is the anisotropic strength, is the orientation angle, which takes a random value between 0 and 2π. To adjust the parameters, is the time iteration scale, which takes the value , is the temperature, is the melting point, is the liquidus slope, is the liquid phase solute concentration, is the latent heat of fusion, is the specific heat, is the solute concentration, is the symbol for partial derivative, represents the partial derivative operation with respect to time, represents the gradient operation, is the Laplace operator symbol, and is an intermediate parameter.

[0131] Based on the unified phase field model defined above, the semi-solid melt preparation process parameters are determined in the following way:

[0132] Determine parameters according to light alloy system 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 ;

[0133] Melt temperature parameter , stirring speed parameters , stirring time parameters , as input parameters, according to the different input parameters, the unified phase field model is used to obtain the microstructure morphology under different input parameter combinations, and according to the degree of grain spheroidization of the microstructure morphology, the optimal melt temperature, stirring speed, and stirring time are screened out as the optimal semi-solid melt preparation process parameters.

[0134] In the embodiment of the present invention, for the above-mentioned input parameters, the best melt temperature screened out is 620°C, the best stirring speed is 100r / min, and the best stirring time is 30s. , stirring speed , stirring time As the optimal process parameters for preparing semi-solid melt.

[0135] Furthermore, in an embodiment of the present invention, the device preheating step further includes the following:

[0136] Turn on the mold temperature controller 10, the movable mold electric heating plate 8, and the fixed mold electric heating plate 14 to preheat the movable mold frame 9 and the fixed mold frame 18 respectively, and start the cylinder heating jacket 22 to preheat the cylinder 19. The preheating temperature of the mold temperature controller 10 is set to 295-305°C, and the heating temperatures of the movable mold electric heating plate 8, the fixed mold electric heating plate 14, and the cylinder heating jacket 22 are all set to 595-605°C, until the temperature inside the cylinder 19 reaches 545-555°C as monitored by the cylinder thermocouple 13 and the temperature inside the mold cavity reaches 295-305°C as monitored by the mold thermocouple 11;

[0137] The infrared heaters 28 covering the head, middle and tail of the material pipe 30 are turned on to preheat the material pipe 30 until the temperature inside the material pipe 30 reaches 295-305° C. as monitored by the material pipe thermocouple 44 .

[0138] In an embodiment of the present invention, by simultaneously turning on the mold temperature controller 10, the movable mold electric heating plate 8, the fixed mold electric heating plate 14 and the cylinder heating jacket 22 for heating, the oil-electric internal and external coordinated heating of the equipment can be achieved, thereby improving the heating efficiency and ensuring the uniformity of the equipment preheating.

[0139] Furthermore, in an embodiment of the present invention, based on the above-mentioned specifically determined optimal process parameters for preparing the semi-solid melt, the step of preparing the semi-solid melt according to the determined process parameters further includes the following:

[0140] Pipe heating: The corresponding infrared heaters 28 are used to heat the head, middle and tail of the pipe 30. The heating temperature of the tail area of ​​the pipe is set to 575-585°C; the heating temperature of the middle area of ​​the pipe is set to 595-605°C; and the heating temperature of the head area of ​​the pipe is set to 620°C to ensure that the temperature of the melt reaches the melt temperature of 620°C when it reaches the head of the pipe.

[0141] Feeding and stirring: The light alloy particles are fed into the feeding funnel 42, and the stirring screw 43 is controlled to rotate at a stirring speed of 100 r / min and a stirring time of 30 s. The stirring screw 43 is used to transport the light alloy particles into the material pipe 30 and transport them from the tail of the material pipe through the middle of the material pipe to the head of the material pipe.

[0142] In the embodiment of the present invention, the tail area of ​​the material pipe is used as the heating section, the middle area of ​​the material pipe is used as the insulation section, and the head area of ​​the material pipe is used as the homogenization section. The temperatures of the head, middle and tail of the material pipe can be respectively measured by the material pipe thermocouples 44 corresponding to these three areas. By heating the material pipe 30 in three stages, it can be ensured that the temperature of the melt when it reaches the head of the material pipe can reach the melt temperature of 620°C in the above-mentioned optimal process parameters.

[0143] In an embodiment of the present invention, the rotation of the stirring screw 43 is controlled by the servo motor 39. During the conveying process of the light alloy particles, the rotating stirring screw 43 applies a shear force to the light alloy particles. At the same time, under the heating of the infrared heater 28 outside the material pipe 30, the light alloy particles are heated and begin to melt in the tail area of ​​the material pipe, and are transformed from solid particles to semi-solid melts in the middle area of ​​the material pipe, and the preparation of the semi-solid melt is completed in the head area of ​​the material pipe. When the stirring time reaches 30s, the semi-solid melt is conveyed and stored at the front end of the material pipe head under the action of the stirring screw 43, in preparation for subsequent semi-solid melt injection operations.

[0144] Furthermore, as a preferred implementation of the embodiment of the present invention, in the above-defined feeding and stirring steps, the feeding amount of the light alloy particles each time is set to 295-305 g.

[0145] Furthermore, in an embodiment of the present invention, the injection feeding step further includes the following contents:

[0146] Evenly spray water-based graphite lubricant on the inner wall of the cylinder 19, and evenly spray magnesium oxide release agent on the mold cavity surface inside the fixed mold core 48 and the movable mold core 49. Pre-introduce argon gas into the cylinder 19, and control the movable mold frame 9 to move downward until the guide rod on the movable mold frame 9 enters the guide sleeve on the fixed mold frame 18, completing the mold closing.

[0147] Start the injection cylinder 37 so that the screw head 45 at the front end of the stirring screw 43 will inject the semi-solid melt stored in the front end of the material pipe head into the nozzle cavity 47.1 of the nozzle 47 at high speed and then into the preheated material cylinder 19.

[0148] In an embodiment of the present invention, by evenly spraying a water-based graphite lubricant on the inner wall of the cylinder 19, it can be ensured that the shooting head 20 and the shooting rod 21 will not rub against the inner wall of the cylinder 19 during the upward and downward processes; by evenly spraying a magnesium oxide release agent on the mold cavity surface inside the fixed mold core 48 and the movable mold core 49, it can be ensured that the casting is smoothly demolded; by pre-introducing argon gas into the interior of the cylinder 19, it can be ensured that the argon atmosphere inside the cylinder 19 prevents oxidation and combustion of the semi-solid melt when it is in the cylinder 19.

[0149] In the embodiment of the present invention, the movable mold frame 9 is controlled to move downward by starting the mold opening and closing driving mechanism (not shown).

[0150] In the embodiment of the present invention, when it is necessary to inject the semi-solid melt stored in the front end of the material pipe head into the nozzle cavity 47.1 of the nozzle 47 at high speed and then inject it into the preheated material cylinder 19, the injection cylinder 37 is started, so that the piston rod 38 of the injection cylinder 37 pushes the connected motor fixing seat 35, and the motor guide sleeve 34 fixedly connected to the motor fixing seat 35 moves forward along the guide column 29 (that is, moves toward the material pipe 30). As a result, the servo motor 39 installed on the motor fixing seat 35 moves forward accordingly, and the stirring screw 43 connected to the motor shaft 40 of the servo motor 39 also moves forward accordingly, so that the screw head 45 at the front end of the stirring screw 43 can inject the semi-solid melt stored in the front end of the material pipe head into the nozzle cavity 47.1 of the nozzle 47 at high speed and then inject it into the preheated material cylinder 19, wherein the injection feeding direction of the semi-solid melt is shown in FIG. Figure 5 As shown by arrow A1.

[0151] Furthermore, as a preferred embodiment of the present invention, in the injection feeding step defined above, the stirring screw 43 is pushed at a speed of 2.4~2.6m / s, so that the screw head 45 at the front end of the stirring screw 43 injects the semi-solid melt stored in the front end of the material pipe head into the nozzle cavity 47.1 of the nozzle 47 at high speed and then into the preheated material cylinder 19.

[0152] Furthermore, in an embodiment of the present invention, the extrusion casting step further includes the following:

[0153] Control the injection rod 21 and the injection head 20 to move upward, pushing the semi-solid melt in the cylinder 19 into the mold cavity through the fixed mold core 48. After the filling is completed, continue to apply pressure to the injection rod 21 and the injection head 20 to maintain the pressure on the semi-solid melt, so that the semi-solid melt is solidified under pressure;

[0154] Control the movable mold frame 9 to move upward to complete mold opening;

[0155] Control the push plate 3 to move toward the fixed mold frame 18, and use the ejector rod 6 to eject the molded casting adhered to the mold cavity. After the ejection is completed, control the movable mold frame 9 to move downward to complete the mold closing, and reset the ejector rod 6 under the driving action of the reset rod 7.

[0156] In the embodiment of the present invention, the injection drive mechanism (not shown) is activated to control the injection rod 21 and the injection head 20 to move upward, so as to push the semi-solid melt in the cylinder 19 into the mold cavity through the fixed mold core 48. The feeding direction of the semi-solid melt injection is shown in FIG. Figure 5 As shown by the arrow A2, after the filling is completed, pressure is continuously applied to the injection rod 21 and the injection head 20 to maintain the pressure of the semi-solid melt so that the semi-solid melt is solidified under pressure.

[0157] In the embodiment of the present invention, the mold opening is completed by starting the mold opening and closing driving mechanism to control the movable mold frame 9 to move upward.

[0158] In the embodiment of the present invention, the ejection drive mechanism (not shown) is started to control the push plate 3 to move toward the fixed mold frame 18, so that the ejector rod 6 moves downward with the push plate 3 to eject the molded casting adhered to the mold cavity. After the ejection is completed, the mold opening and closing drive mechanism is started to control the movable mold frame 9 to move downward to complete the mold closing. During the mold closing process, the protruding reset rod 7 that moves downward with the push plate 3 and the ejector rod 6 is pushed back to its original position under the reaction of the fixed mold core 48, thereby driving the push plate 3 and the ejector rod 6 to return to their positions, thereby causing the ejector rod 6 to reset under the driving action of the reset rod 7, and completing the extrusion casting of the light alloy semi-solid melt.

[0159] Furthermore, as a preferred implementation mode of an embodiment of the present invention, in the above-defined extrusion casting step, in order to facilitate the subsequent injection extrusion casting, after the mold opening is completed, the injection cylinder 37 is started and the stirring screw 43 is pulled backward to reset; the injection rod 21 and the injection head 20 are controlled to reset downward.

[0160] Specifically, the injection cylinder 37 is started, so that the piston rod 38 of the injection cylinder 37 pulls the connected motor fixing seat 35 to move backward, thereby pulling the stirring screw 43 backward to reset, and starting the injection drive mechanism to control the injection rod 21 and the injection head 20 to reset downward.

[0161] Furthermore, as a preferred implementation mode of an embodiment of the present invention, in the above-mentioned extrusion casting molding step, the injection rod 21 and the injection head 20 are controlled to move upward at a speed of 36~40mm / s. After the filling is completed, a holding pressure of 38~42 tons is continuously applied to the injection rod 21 and the injection head 20 to maintain the semi-solid melt for 29~31s.

[0162] Furthermore, in an embodiment of the present invention, the light alloy semi-solid melt preparation and injection extrusion casting molding method of the present invention may also include a casting cleaning step: placing the casting on a steel plate, naturally cooling it to room temperature, and after cooling, polishing the casting surface with sandpaper, and then cleaning it with anhydrous ethanol and drying it.

[0163] As a specific embodiment, in the light alloy semi-solid melt preparation and injection extrusion casting molding equipment and method of the present invention, the mold opening and closing drive mechanism and the injection drive mechanism are both hydraulic cylinders, and the ejection drive mechanism is a punching cylinder.

[0164] The following describes in detail the light alloy semi-solid melt preparation and injection extrusion casting method of the present invention, using the production of AZ91D magnesium alloy castings as a specific example. The chemical materials used in this example are: AZ91D magnesium alloy particles, deionized water, anhydrous ethanol, argon gas, water-based graphite lubricant, and magnesium oxide release agent, and the amounts used are as follows:

[0165]

[0166] The light alloy semi-solid melt preparation and injection extrusion casting method according to the embodiment of the present invention comprises the following steps:

[0167] 1. Equipment preheating

[0168] (1) Turn on the mold temperature controller 10 and the movable mold electric heating plate 8 and the fixed mold electric heating plate 14 to preheat the movable mold frame 9 and the fixed mold frame 18 respectively, and start the cylinder heating sleeve 22 to preheat the cylinder 19. Among them, the preheating temperature of the mold temperature controller 10 is set to 300℃, the heating power of the movable mold electric heating plate 8 and the fixed mold electric heating plate 14 is 6000w, and the heating power of the cylinder heating sleeve 22 is 1000w. The heating temperatures of the movable mold electric heating plate 8, the fixed mold electric heating plate 14 and the cylinder heating sleeve 22 are all set to 600℃. The temperature inside the mold cavity and the temperature inside the cylinder 19 are respectively monitored by the mold thermocouple 11 and the cylinder thermocouple 13 to ensure that the temperature inside the cylinder 19 reaches 550℃ and the temperature inside the mold cavity reaches 300℃.

[0169] (2) First, clean the inner wall of the material tube 30 with a metal brush, and then clean the inner surface of the material tube 30 with anhydrous ethanol and deionized water to make the inner surface of the material tube 30 smooth, flat and clean. Turn on the infrared heater 28 covering the material tube head, material tube middle and material tube tail to preheat the material tube 30. Monitor the temperature of the material tube 30 through the material tube thermocouple 44 to ensure that the internal temperature of the material tube 30 reaches 300°C.

[0170] 2. Semi-solid melt preparation

[0171] (1) Using the melt microstructure intelligent prediction module based on the unified phase field model to predict the microstructure, the semi-solid melt preparation process parameters are determined. The semi-solid melt preparation process parameters include melt temperature, stirring speed, and stirring time. The specific implementation process is as follows:

[0172] For AZ91D magnesium alloy, , that is, the number of alloy components of AZ91D magnesium alloy is 3, including matrix component magnesium (Mg), solute components aluminum (Al) and zinc (Zn), , respectively represent aluminum (Al) and zinc (Zn). According to the AZ91D magnesium alloy system input parameters 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 , the input values ​​are shown in Table 1 below:

[0173] Table 1 Thermophysical properties of AZ91D magnesium alloy

[0174]

[0175] Enter melt temperature parameters separately , at each melt temperature Enter the stirring speed parameters , and finally enter the mixing time parameters According to the different input parameters, the microstructure morphology under different parameter combinations is obtained, and the melt temperature is screened according to the degree of grain spheroidization of the microstructure morphology. , stirring speed , stirring time As the best process parameters for semi-solid melt preparation, the purpose of optimizing the melt preparation process and improving casting performance is achieved.

[0176] (2) If Figure 7 As shown in FIG, the semi-solid melt is prepared according to the optimal process parameters determined by the melt microstructure intelligent prediction module based on the unified phase field model, wherein the melt temperature is 620°C, the stirring speed is 100 r / min, and the stirring time is 30 s. The semi-solid melt preparation process specifically includes:

[0177] Pipe heating: Start the infrared heater 28 and adjust the temperature of each part of the pipe 30 according to the feedback signal of the pipe thermocouple 44, so that the heating temperatures of the tail, middle and head of the pipe 30 are 580°C, 600°C and 620°C respectively. By heating the pipe 30 in three stages, it is ensured that the temperature of the melt reaches the melt temperature of 620°C in the above-mentioned optimal process parameters when it reaches the head of the pipe.

[0178] Feeding and stirring: AZ91D magnesium alloy particles are fed into the feed hopper 42, and the stirring screw 43 is driven by the servo motor 39 to rotate (as shown in FIG. Figure 7 As shown by the arrow R in the middle, the rotation speed of the servo motor 39 is set according to the stirring speed of 100 r / min in the above-mentioned optimal process parameters. The servo motor 39 controls the stirring screw 43 to stir, shear and transport the AZ91D magnesium alloy particles through the coaxiality adjustment device 41. The AZ91D magnesium alloy particles are transported from the tail of the stirring screw 43 to the material pipe 30 when heated and subjected to shear force, and are transported from the tail of the material pipe through the middle of the material pipe to the head of the material pipe. During this process, the AZ91D magnesium alloy particles are transformed from a solid state to a semi-solid melt.

[0179] Preferably, AZ91D magnesium alloy particles are added to the feeding pipe 30 in batches via the feeding funnel 42 to prevent excessive addition at a single time from blocking the stirring screw 43. For example, the feeding amount of AZ91D magnesium alloy particles is set to 300 g each time.

[0180] The rotation time of the stirring screw 43 is set according to the stirring time of 30s in the above-mentioned optimal process parameters. When the stirring time reaches 30s, the semi-solid melt is transported and stored at the front end of the material pipe head under the action of the stirring screw 43 to prepare for the injection operation of the semi-solid melt.

[0181] 3. Injection feeding

[0182] like Figure 8 As shown, injection feeding is performed by the following operations:

[0183] (1) Spray water-based graphite lubricant evenly on the inner wall of the cylinder 19 with a thickness of about 0.1 mm to ensure that the injection head 20 and the injection rod 21 will not rub against the inner wall of the cylinder 19 during the upward and downward movement; spray magnesium oxide release agent evenly on the mold cavity surface inside the fixed mold core 48 and the movable mold core 49 with a thickness of about 0.15 mm to ensure smooth demolding of the casting; pre-introduce argon gas into the cylinder 19 to ensure an argon atmosphere inside the cylinder 19 to prevent oxidation and combustion of the semi-solid melt in the cylinder 19; start the mold opening and closing drive mechanism to control the movable mold frame 9 to descend with a mold closing force of 450 tons until the guide rod on the movable mold frame 9 enters the guide sleeve on the fixed mold frame 18 to complete the mold closing.

[0184] (2) Start the injection cylinder 37, and the piston rod 38 of the injection cylinder 37 pushes the connected motor fixing base 35 forward at a speed of 2.5m / s (such as Figure 8 (As shown by arrow F in the middle, motor guide sleeve 34, fixedly connected to motor mount 35, moves along guide post 29 toward material tube 30, causing servo motor 39 mounted on motor mount 35 to move forward accordingly. Consequently, stirring screw 43, connected to motor shaft 40 of servo motor 39, also moves forward accordingly. As a result, screw head 45 at the front end of stirring screw 43 injects the semi-solid melt stored in the front end of the material tube head at high speed into nozzle cavity 47.1 of nozzle 47 and then into preheated material cylinder 19. High-speed injection of up to 2.5 m / s reduces heat loss during melt transport, ensuring a stable semi-solid melt in material cylinder 19.

[0185] 4. Squeeze Casting

[0186] like Figure 9 and 10 As shown, squeeze casting is performed by the following operations:

[0187] (1) Start the injection drive mechanism to control the injection rod 21 and the injection head 20 to move upward at a speed of 38 mm / s (such as Figure 9 As shown by the middle arrow U21, the semi-solid melt is pushed into the mold cavity through the fixed mold core 48. After the filling is completed, a holding pressure of 40 tons is continuously applied to the injection rod 21 and the injection head 20 to hold the semi-solid melt under pressure for 30 seconds, so that the semi-solid melt is solidified under pressure.

[0188] (2) Start the above-mentioned mold opening and closing drive mechanism to control the movable mold frame 9 to move upward (such as Figure 10 As shown by the arrow U9, the mold is opened, the injection cylinder 37 is started, and the piston rod 38 of the injection cylinder 37 pulls the connected motor fixing seat 35 to move backward (as shown in FIG. Figure 10 As shown by the arrow B in the middle, the stirring screw 43 is pulled back to reset, and the injection drive mechanism is started to control the injection rod 21 and the injection head 20 to reset downward (as shown in FIG. Figure 10 (as indicated by arrow D21).

[0189] (3) Start the ejection drive mechanism to control the push plate 3 to move toward the fixed mold frame 18, and the ejector rod 6 moves downward with the push plate 3 (as shown in the figure). Figure 10 As shown by the arrow D6 in the middle, the molded casting adhered to the mold cavity is ejected. After the ejection is completed, the above-mentioned mold opening and closing drive mechanism is started to control the movable mold frame 9 to move downward to complete the mold closing. The ejector rod 6 is reset under the driving action of the reset rod 7 to obtain an AZ91D magnesium alloy casting.

[0190] By repeating the above steps of adding and stirring, injection feeding, and extrusion casting, batch castings can be continuously extrusion cast.

[0191] 5. Casting cleaning

[0192] The AZ91D magnesium alloy casting was placed on a steel plate and cooled naturally to room temperature. After cooling, the surface of the casting was polished with sandpaper, then cleaned with anhydrous ethanol and dried.

[0193] The macromorphology, microstructure, and mechanical properties of the castings prepared by the light alloy semi-solid melt preparation and injection extrusion casting molding method of the embodiment of the present invention were detected, analyzed, and characterized, and compared with the castings prepared by the conventional extrusion casting molding process of the prior art.

[0194] Figure 11 and Figure 12 The microstructure diagram of the casting prepared by the light alloy semi-solid melt preparation and injection extrusion casting molding method of the present invention is as follows: Figure 13 and Figure 14 The microstructure of the casting prepared by the squeeze casting molding process of the prior art is shown in FIG. 1 . It can be found that the microstructure of the casting prepared by the semi-solid injection + squeeze casting process of the present invention is basically rose-shaped equiaxed crystals, which are typical semi-solid non-dendritic microstructures, and the grains are effectively refined. However, the microstructure of the casting prepared by the squeeze casting molding process of the prior art contains a large number of developed dendrites, and Mg 17 Al 12 The continuous network distribution of the precipitated phase will seriously affect the mechanical properties of the product.

[0195] Figure 15 and Figure 16 The mechanical properties test results of the castings obtained by squeeze casting are shown in FIG. Figure 15 Shows the casting mechanical properties test results, Figure 16 The figure shows the mechanical properties test results of the casting after it was placed in a resistance furnace and subjected to T6 heat treatment at 420℃ / 16h+200℃ / 8h. Figure 15 and Figure 16Curves 1 and 2 represent specimens #1 and #2, respectively, of castings produced using the prior art squeeze casting process, while curves 3 and 4 represent specimens #1 and #2, respectively, of castings produced using the semi-solid injection molding and squeeze casting process of the present invention. As can be seen, the castings produced using the prior art squeeze casting process have an as-cast tensile strength of up to 170 MPa and an elongation of up to 4.1%, while the castings produced using the semi-solid injection molding and squeeze casting process of the present invention have an as-cast tensile strength of up to 200 MPa and an elongation of up to 7.5%. The castings produced using the prior art squeeze casting process have a T6 heat treatment tensile strength of 225-240 MPa and an elongation of 3.2-5.5%, while the castings produced using the semi-solid injection molding and squeeze casting process of the present invention have a T6 heat treatment tensile strength of 275-295 MPa and an elongation of 8.3-10.1%. Therefore, compared to conventional squeeze casting processes of the prior art, the mechanical properties of castings produced using the light alloy semi-solid melt preparation and injection squeeze casting method of the present invention are significantly improved.

[0196] In summary, the light alloy semi-solid melt preparation and injection extrusion casting molding equipment and method of the present invention are developed to address the problems in the prior art such as difficulty in melt transfer, difficulty in temperature control, large deviation between the actual temperature and the predetermined temperature during pouring, and easy occurrence of incomplete filling and inclusions in the casting during semi-solid extrusion casting molding. The semi-solid melt preparation + injection extrusion casting molding is carried out using temperature and speed control mechanical stirring technology, which can realize an integrated process from preparation to molding of the semi-solid melt, eliminate the step of melt transfer, and effectively avoid the oxidation and temperature runaway problems of the melt during transfer while ensuring the simplicity of the process flow. It is of great significance to improving the controllability of the semi-solid melt, the stability of the semi-solid molded casting, and the product quality.

[0197] Compared with the prior art, the light alloy semi-solid melt preparation and injection extrusion casting molding equipment and method of the present invention have at least the following advantages and beneficial effects:

[0198] The present invention uses an intelligent melt microstructure prediction module coupled with a unified phase field model to predict the microstructure morphology changes under different process parameters during the semi-solid melt preparation process. Based on the prediction results, the optimal process parameters such as melt temperature, stirring speed, and stirring time are determined in the semi-solid melt preparation process to prepare a semi-solid melt with stable quality, thereby achieving the purpose of optimizing the melt preparation process and improving casting performance.

[0199] The present invention realizes seamless connection between the melt preparation unit and the extrusion casting molding unit by designing the material cylinder 19 in the fixed mold of the extrusion casting molding unit, adding a sprue sleeve 23 to the material cylinder 19 and assembling it with the nozzle 47 of the melt preparation unit, and adopts the melt injection method to directly inject the prepared semi-solid melt into the material cylinder 19 from the nozzle 47 for extrusion casting molding;

[0200] The present invention adopts electric heating plate, cylinder heating jacket 22 and mold temperature controller 10 to perform oil-electric internal and external coordinated heating on the mold, which can accurately control the temperature of semi-solid melt, improve the stability of semi-solid processing, and enhance the quality of light alloy semi-solid molding castings.

[0201] It should be noted that, in this document, unless otherwise expressly specified or limited, the term "connected" or its synonyms should be interpreted broadly. For example, "connected" can mean fixed or removable, mechanical or electrical, direct or indirect through an intermediary. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances. Furthermore, expressions such as "first" and "second" are used solely to distinguish one entity or operation from another and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, the terms "include," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Furthermore, the terms "front," "rear," "left," "right," "upper," and "lower" herein are used with reference to the placement shown in the accompanying drawings.

[0202] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A light alloy semi-solid melt preparation and injection extrusion casting molding equipment, characterized in that, The invention comprises an intelligent prediction module for melt microstructure, a melt preparation unit and an extrusion casting molding unit. The melt preparation unit is arranged horizontally and comprises an injection cylinder, a piston rod, a cylinder fixing seat, a servo motor, a motor shaft, a motor fixing seat, a motor guide sleeve, a coaxiality adjustment device, a guide column, a feed port guide sleeve, a feed port fixing seat, a feed funnel, a stirring screw, a material pipe, an infrared heater, a material pipe thermocouple, and a nozzle. The extrusion casting molding unit is arranged vertically on a workbench and comprises a fixed mold frame, a fixed mold core, a material cylinder, a sprue sleeve, a sprue sleeve fixing plate, a shot head, a shot rod, a movable mold frame, a movable mold core, a diverter cone, a movable mold electric heating plate, a fixed mold electric heating plate, a material cylinder heating sleeve, a mold temperature controller, and an ejection assembly, wherein: The melt microstructure intelligent prediction module is used to determine the semi-solid melt preparation process parameters by predicting the microstructure based on a unified phase field model. The semi-solid melt preparation process parameters include melt temperature, stirring speed, and stirring time. The evolution equation of the unified phase field model is expressed as: ； ； ； in, ； ； ； ； ； ； ； Where, is the phase field order parameter, For time, is the number of grains, For the The local order parameter of each grain, is the relaxation time, is the characteristic relaxation time, is the minimum liquid phase solute diffusion coefficient, is the thermal diffusivity, is the number of alloy components including matrix components and solute components, for The first alloy component other than the matrix component Solute components, is the equilibrium distribution coefficient, is the dimensionless supersaturation, is the ratio of the thermocapillary length to the chemical capillary length, is the diffusion coefficient of the liquid solute, is the interface energy anisotropy function, is the diffusion interface width, is the characteristic diffusion interface width, is the coupling coefficient, is the dimensionless temperature, is the solid-phase solute diffusion coefficient, is the anisotropic strength, is the orientation angle, which takes a random value between 0 and 2π. To adjust the parameters, is the time iteration scale, and its value is , is the temperature, is the melting point, is the liquidus slope, is the liquid phase solute concentration, is the latent heat of fusion, is the specific heat, is the solute concentration, is the symbol for partial derivative, represents the partial derivative operation with respect to time, represents the gradient operation, is the Laplace operator symbol, and is the intermediate parameter; The process parameters for semi-solid melt preparation are determined by: Determine parameters according to light alloy system 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 ; Melt temperature parameter , stirring speed parameters , stirring time parameters , as input parameters, according to the different input parameters, the unified phase field model is used to obtain the microstructure morphology under different input parameter combinations, and according to the degree of grain spheroidization of the microstructure morphology, the optimal melt temperature, stirring speed, and stirring time are screened as the optimal semi-solid melt preparation process parameters; The servo motor is mounted on the motor fixing seat, the motor shaft is connected to the stirring screw via the coaxiality adjustment device, the cylinder fixing seat is arranged on the outside of the motor fixing seat, the injection cylinder is mounted on the cylinder fixing seat, the guide column is fixed between the workbench and the cylinder fixing seat, the motor guide sleeve is sleeved on the guide column, the motor fixing seat is fixedly connected to the motor guide sleeve, and the piston rod is connected to the motor fixing seat; The feed pipe is divided into three parts: the head of the feed pipe, the middle of the feed pipe and the tail of the feed pipe. The feed port fixing seat is arranged between the coaxiality adjustment device and the tail of the feed pipe. The side of the feed port fixing seat is fixedly connected to the tail of the feed pipe. The upper part of the feed port fixing seat is provided with the feed funnel. The lower part of the feed port fixing seat is fixedly connected with the feed port guide sleeve. The feed port guide sleeve is sleeved on the guide column and fixed to the guide column by fixing bolts. The feed end of the stirring screw passes through the feed port fixing seat, and the stirring screw extends out of the feed port fixing seat. The end of the feed port fixing seat is connected to the motor shaft, the feed funnel arranged on the upper part of the feed port fixing seat is connected to the feed end of the stirring screw, the rest of the stirring screw is installed in the material pipe, the discharge end of the stirring screw is equipped with a support ring for supporting and installing the stirring screw, a screw head for pushing the material, and a check ring for preventing reverse backflow, the nozzle is connected to the material pipe head through a flange and bolts, and the material pipe head, the middle part and the material pipe tail of the material pipe are respectively covered with one of the infrared heaters and are correspondingly configured with one of the material pipe thermocouples; The bottom of the extrusion casting molding unit is provided with a fixed mold heat insulation plate and a fixed mold fixing plate fixed to the workbench through a pressure plate, the fixed mold frame is installed on the fixed mold fixing plate, the material cylinder is installed in the fixed mold frame, the injection head and the injection rod are installed in the material cylinder, the fixed mold core is cooperatively installed on the top of the material cylinder, and the outside of the material cylinder is covered with the material cylinder heating jacket and is correspondingly configured with a material cylinder thermocouple; A gate is provided on the side of the material cylinder facing the nozzle, the gate sleeve is fitted on the gate, the gate sleeve fixing plate is connected between the gate sleeve and the flange, the gate sleeve fixing plate is concentrically mounted with the gate sleeve and internally communicated with the gate sleeve, the nozzle is inserted into the gate sleeve fixing plate and the gate sleeve, and the nozzle cavity of the nozzle is communicated with the gate, and a flange pad is provided on the side of the fixed mold frame facing the nozzle to support and fix the flange; The movable mold frame is mounted on the upper part of the fixed mold frame, and the movable mold frame and the fixed mold frame are positioned and aligned with each other through guide rods and matching guide sleeves, the movable mold core is mounted in the movable mold frame, the diverter cone is connected to the movable mold core, and the movable mold core and the fixed mold core jointly form a mold cavity, the ejector assembly is arranged above the movable mold frame, and comprises a push plate, a push fixing plate, a push rod and a reset rod, the upper part of the movable mold frame is provided with mold feet on both sides of the ejector assembly, the push plate and the push fixing plate are fitted between the mold feet on both sides, the ejector rod and the reset rod are mounted on the lower bottom surface of the push fixing plate, and the free ends of the ejector rod and the reset rod both pass through the movable mold frame and the movable mold core, the ejector rod is arranged to face the mold cavity, the reset rod is arranged to deviate from the mold cavity, and the length of the reset rod is greater than the length of the ejector rod; The outside of the movable mold frame is covered with the movable mold electric heating plate, the outside of the fixed mold frame is covered with the fixed mold electric heating plate, and the movable mold frame and the fixed mold frame are both opened with oil circuits, and the mold temperature controller is connected to the oil circuits of the movable mold frame and the fixed mold frame via a heating oil pipe.

2. The light alloy semi-solid melt preparation and injection extrusion casting molding equipment according to claim 1 is characterized in that: The gate sleeve is covered with a heating device to heat and keep the transported melt warm.

3. The light alloy semi-solid melt preparation and injection extrusion casting molding equipment according to claim 1 is characterized in that: A fixed mold core groove is provided on the lower surface of the fixed mold core, and the fixed mold core is mounted on the top of the material cylinder in a snap-fit ​​manner through the fixed mold core groove.

4. The light alloy semi-solid melt preparation and injection extrusion casting molding equipment according to claim 1 is characterized in that: The gate is processed with a gate groove, and the gate sleeve is installed on one side of the gate and is provided with a gate sleeve convex ring. Through the cooperation of the gate groove and the gate sleeve convex ring, the gate sleeve is installed on the gate.

5. A method for preparing a light alloy semi-solid melt and injection extrusion casting, the method being implemented using the light alloy semi-solid melt preparation and injection extrusion casting equipment according to claim 1, characterized in that: The light alloy semi-solid melt preparation and injection extrusion casting molding method comprises the following steps:

1. Equipment preheating Preheat the movable mold frame and the fixed mold frame respectively, and preheat the material cylinder; Turn on the infrared heaters covering the head, middle and tail of the material pipe to preheat the material pipe; 2. Semi-solid melt preparation Using the melt microstructure intelligent prediction module based on the unified phase field model to predict the microstructure and determine the semi-solid melt preparation process parameters, wherein the semi-solid melt preparation process parameters include melt temperature, stirring speed, and stirring time; The semi-solid melt is prepared according to the determined process parameters, wherein the semi-solid melt is prepared according to the determined process parameters including: Pipe heating: Heat the head, middle and tail of the pipe to corresponding temperatures respectively to ensure that the temperature of the melt reaches the determined melt temperature when it reaches the head of the pipe; Feeding and stirring: Light alloy particles are fed into the feeding funnel. Based on the determined stirring speed and stirring time, the stirring screw is used to transport the light alloy particles into the material pipe and from the tail end of the material pipe to the middle part of the material pipe to the head end of the material pipe; 3. Injection feeding Control the movable mold frame to move downward until the guide rod on the movable mold frame enters the guide sleeve on the fixed mold frame to complete the mold closing; Start the injection cylinder so that the screw head at the front end of the stirring screw will inject the semi-solid melt stored in the front end of the material pipe head into the nozzle cavity of the nozzle at high speed and then into the preheated material cylinder; 4. Squeeze Casting The semi-solid melt in the material cylinder is pushed into the mold cavity through the fixed mold core. After the filling is completed, the semi-solid melt is kept under pressure so that the semi-solid melt is solidified under pressure. Control the movable mold frame to move upward to complete mold opening; The push plate is controlled to move toward the fixed mold frame, and the ejector rod is used to eject the molded casting adhered to the mold cavity.

6. The method for preparing a light alloy semi-solid melt and performing injection extrusion casting according to claim 5, characterized in that: The step of preheating the equipment includes: Turn on the mold temperature controller and the movable mold electric heating plate and the fixed mold electric heating plate to preheat the movable mold frame and the fixed mold frame respectively, and start the cylinder heating jacket to preheat the cylinder. The preheating temperature of the mold temperature controller is set to 295-305°C, and the heating temperatures of the movable mold electric heating plate, the fixed mold electric heating plate and the cylinder heating jacket are all set to 595-605°C, until the temperature inside the cylinder reaches 545-555°C as monitored by the cylinder thermocouple and the temperature inside the mold cavity reaches 295-305°C as monitored by the mold thermocouple; Turn on the infrared heaters covering the head, middle and tail of the material pipe to preheat the material pipe until the temperature inside the material pipe reaches 295~305℃ as monitored by the material pipe thermocouple.

7. The method for preparing a light alloy semi-solid melt and performing injection extrusion casting according to claim 5, characterized in that: The step of preparing a semi-solid melt according to the determined process parameters comprises: Pipe heating: Use corresponding infrared heaters to heat the head, middle and tail of the pipe respectively. The heating temperature of the tail area of ​​the pipe is set to 575~585℃; the heating temperature of the middle area of ​​the pipe is set to 595~605℃; the heating temperature of the head area of ​​the pipe is set to 620℃ to ensure that the temperature of the melt reaches the melt temperature of 620℃ when it reaches the head of the pipe; Feeding and stirring: The light alloy particles are fed into the feeding funnel, and the stirring screw is controlled to rotate at a stirring speed of 100 r / min and a stirring time of 30 s. The stirring screw is used to transport the light alloy particles into the material pipe and from the tail of the material pipe through the middle of the material pipe to the head of the material pipe.

8. The method for preparing a light alloy semi-solid melt and performing injection extrusion casting according to claim 5, characterized in that: The injection feeding step comprises: Spray water-based graphite lubricant evenly on the inner wall of the cylinder, spray magnesium oxide release agent evenly on the mold cavity surface inside the fixed mold core and the movable mold core, introduce argon gas into the cylinder in advance, and control the movable mold frame to move downward until the guide rod on the movable mold frame enters the guide sleeve on the fixed mold frame, completing the mold closing; Start the injection cylinder so that the screw head at the front end of the stirring screw will inject the semi-solid melt stored in the front end of the material pipe head into the nozzle cavity of the nozzle at high speed and then into the preheated material cylinder.

9. The method for preparing a light alloy semi-solid melt and performing injection extrusion casting according to claim 5, characterized in that: The extrusion casting step comprises: Control the injection rod and injection head to move upward, pushing the semi-solid melt in the cylinder into the mold cavity through the fixed mold core. After the filling is completed, continue to apply pressure to the injection rod and injection head to maintain the pressure of the semi-solid melt, so that the semi-solid melt is solidified under pressure; Control the movable mold frame to move upward to complete mold opening; Control the push plate to move toward the fixed mold frame, and use the ejector rod to eject the molded casting adhered to the mold cavity. After the ejection is completed, control the movable mold frame to move downward to complete the mold closing, and reset the ejector rod under the driving action of the reset rod.

10. The method for preparing a light alloy semi-solid melt and performing injection extrusion casting according to claim 5, characterized in that: The casting cleaning step is also included: the casting is placed on a steel plate and naturally cooled to room temperature. After cooling, the casting surface is polished with sandpaper, and then cleaned with anhydrous ethanol and dried.

11. The method for preparing a light alloy semi-solid melt and performing injection extrusion casting according to claim 7, characterized in that: In the feeding and stirring steps, the feeding amount of the light alloy particles is set to 295-305 g each time.

12. The method for preparing a light alloy semi-solid melt and performing injection extrusion casting according to claim 8, characterized in that: In the injection feeding step, the stirring screw is pushed at a speed of 2.4-2.6 m / s.

13. The method for preparing a light alloy semi-solid melt and performing injection extrusion casting according to claim 9, characterized in that: In the squeeze casting step, the injection rod and the injection head are controlled to move upward at a speed of 36 to 40 mm / s. After the filling is completed, a holding pressure of 38 to 42 tons is continuously applied to the injection rod and the injection head to maintain the pressure on the semi-solid melt for 29 to 31 seconds.

14. The method for preparing a light alloy semi-solid melt and performing injection extrusion casting according to claim 9, characterized in that: In the extrusion casting step, after the mold is opened, the injection cylinder is started to pull the stirring screw backward to reset it; and the injection rod and the injection head are controlled to move downward to reset.

15. The method for preparing a light alloy semi-solid melt and performing injection extrusion casting according to claim 5, characterized in that: The light alloy is AZ91D magnesium alloy.

Images