Precise low-pressure casting process and low-pressure casting ion implanter thereof

Abstract

The invention discloses a precision low-pressure casting process and a low-pressure casting ion implanter thereof. The precision low-pressure casting process comprises the steps that S1, a parting agent is sprayed to a metal mold cavity, and then preheating is conducted; s2, molten metal is smelted in the sealed crucible, dry gas is introduced, and meanwhile the air pressure in the sealed crucible is kept stable; s3, the air pressure in the sealed crucible is increased, so that the molten metal rises along the liquid rising pipe to be filled into the metal mold cavity; s4, after mold filling is completed, the air pressure is increased to be kept till solidification is completed; s5, the air pressure is released, the unsolidified molten metal flows back to the sealed crucible, then the metal mold is opened, and a product is taken out; through the parting agent and preheating of the metal mold, the fluidity and solidification control of molten metal in a cavity are improved, the chilling phenomenon when high-temperature molten metal makes contact with the cavity wall of the low-temperature metal mold is avoided, and therefore the defects of cold shut, cracks and the like are reduced, gas attached to the cavity wall of the metal mold is reduced, and the service life of the metal mold is prolonged. And meanwhile, the volume of the gas is expanded when the gas is heated, so that the gas can be discharged more easily.

Description

Technical Field

[0001] The invention belongs to the technical field of workpiece casting, in particular to a precision low-pressure casting process and an ion implanter for the low-pressure casting. Background Art

[0002] An ion implanter is a device that uses an accelerating electric field to inject charged ions into the surface of solid materials at high speed. By precisely controlling the type, energy, and dosage of ions, it can modify the surface composition and structure of the material to improve its electrical, mechanical, or chemical properties. It is widely used in semiconductor manufacturing, material surface treatment, and microelectronic device processing.

[0003] The ion implanter of the prior art, such as the "A device for measuring the horizontal and vertical angles of an ion beam" disclosed in the patent document "CN111128658B", has a vacuum chamber assembly as the core component of the ion implanter. Currently, the vacuum chamber assembly is mostly produced by die casting. During the die casting process, the molten metal is injected into the mold at high pressure and high speed, which easily brings air and metal surface oxides into the interior of the casting, resulting in an increase in pores and inclusions, affecting the density of the casting.

[0004] Low-pressure casting is a casting process that applies a low positive pressure in a sealed crucible or container, allowing the molten metal to slowly fill the mold cavity along the riser under pressure and solidify into shape under pressure. This method can effectively reduce casting defects such as porosity and shrinkage, and improve the quality of castings. It is suitable for the production of metal parts with complex structures and uniform wall thickness, such as aluminum alloys and magnesium alloys, and is widely used in the automotive, aerospace and other fields.

[0005] Existing low-pressure casting directly pushes high-temperature molten metal into a metal mold cavity and then cools it. However, when the overheated molten metal hits the cooler inner wall of the mold cavity, it will produce sudden chilling, resulting in defects in the molded product. In addition, the air in the mold cavity adheres to the inner wall of the mold cavity and is difficult to be discharged in time, which can cause hole defects in the parts. Summary of the Invention

[0006] The object of the present invention is to provide a precision low-pressure casting process and an ion implanter for low-pressure casting thereof, so as to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A precision low-pressure casting process includes S1, providing a metal mold, spraying a parting agent on the surface of the metal mold cavity, and then

[0009] Preheat to 150°-250°;

[0010] S2, providing a sealed crucible and a gas power mechanism, melting the metal in the sealed crucible to form molten metal, and introducing dry gas through the gas power mechanism while maintaining a stable gas pressure in the sealed crucible;

[0011] S3, using the gas power mechanism to slowly increase the air pressure in the sealed crucible, so that the molten metal rises smoothly along the riser tube and fills the metal mold cavity, maintaining the filling pressure at 0.005MP-0.02MP;

[0012] S4, after the filling is completed, the gas power mechanism is used to immediately increase the gas pressure to 0.03MP-0.08MP and maintain it until solidification is completed;

[0013] S5, after solidification is completed, the gas power mechanism is used to release the air pressure in the sealed crucible, and the unsolidified metal liquid flows back to the sealed crucible, and then the metal mold is opened to take out the molded product.

[0014] A further technical solution, S6, obtains a plurality of defect images, extracts vector data from the defect images, pre-processes the vector data, and forms a reference data set from the vector data;

[0015] S7, obtaining a casting image, extracting vector data from the casting image, preprocessing the vector data, forming a product dataset from the vector data, and forming a collection dataset from the reference dataset and the product dataset;

[0016] S8, splitting the set data set into a training set, a validation set, and a test set according to a preset ratio;

[0017] S9, constructing a product qualification detection model, training the product qualification detection model using a training set, and testing the product qualification detection model after the training is completed, and stopping when the accuracy is higher than a predetermined value;

[0018] S10, using the product qualification detection model to detect the molded product taken out of S5, and determine the product qualification rate.

[0019] A further technical solution is that the metal liquid in S3 rises at a speed of 40 mm / s to 60 mm / s along the raw liquid pipe.

[0020] According to a further technical solution, the increased air pressure in S4 is 1.5 to 2 times the filling pressure in S3.

[0021] According to a further technical solution, the temperature at which the molten metal flows is higher than the liquidus temperature of the metal.

[0022] As a further technical solution, S2.5 is provided before S3 to evacuate the cavity of the metal mold to a vacuum degree of 0.05MP-0.08MP.

[0023] A further technical solution is to provide S2.5 before S3, wherein a second gas is injected into the cavity of the metal mold, and the pressure of the second gas is different from the pressure of the drying gas introduced by the gas power mechanism.

[0024] A low-pressure casting ion implanter is manufactured using the above technical solution.

[0025] Beneficial effects of the present invention:

[0026] The present invention sprays a graphite coating parting agent on the surface of the metal mold cavity and preheats the metal mold to 200°C, effectively improving the fluidity and solidification control of the molten metal in the cavity, avoiding the chilling phenomenon when the high-temperature molten metal contacts the low-temperature metal mold cavity wall, thereby reducing defects such as cold shut and cracks. In addition, by preheating the metal mold, the gas adhering to the metal mold cavity wall is further reduced, which is more conducive to avoiding gas residue. At the same time, the gas expands in volume due to heating, which is more conducive to discharge, further improving air tightness. Compared with the die casting method, the porosity defect is significantly reduced, and the casting density is higher.

[0027] The use of a sealed crucible and a gas-powered mechanism allows for precise control of the temperature and chemical composition of the molten metal, reducing the risks of air inhalation and oxidation. Slow pressurization ensures smooth filling of the molten metal into the mold, preventing splashing and gas entrapment, significantly reducing the occurrence of porosity defects. After filling, the holding pressure is promptly increased to promote uniform solidification of the molten metal under pressure, enhance the shrinkage-feeding effect, effectively reduce shrinkage cavities and porosity defects, and ensure dense castings with excellent mechanical properties.

[0028] The present invention not only improves the overall quality and density of the casting, making it suitable for the manufacture of pressure-bearing parts such as high-performance automobile wheels, but also achieves the advantages of high dimensional accuracy, good surface quality, high material utilization and high production efficiency. At the same time, strict pressure, temperature and air pressure control in the process ensures the stability and controllability of the filling and solidification processes, greatly reducing casting defects caused by quenching and gas retention in traditional low-pressure casting, and improving production reliability and economic benefits.

[0029] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 : Flowchart of embodiment 1 of the present invention.

[0031] Figure 2 : Flowchart of Example 2 of the present invention.

[0032] Figure 3 : Flowchart of Example 3 of the present invention. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0034] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be understood as limiting the scope of protection of the present invention.

[0035] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limitations on the present invention.

[0036] In the description of this invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The terms "first" and "second" are used solely to distinguish technical features and are not to be construed as indicating or implying relative importance, or as implicitly indicating the number or order of the technical features indicated. In the description of this invention, unless otherwise expressly defined, terms such as "set," "install," and "connect" should be interpreted broadly. Persons skilled in the relevant technical field can reasonably determine the specific meaning of these terms within this invention based on the specific content of the technical solution.

[0037] Please refer to Figure 1-3 ;

[0038] In current low-pressure casting processes, hot molten metal is typically injected directly into the mold cavity. Because the molten metal is relatively hot compared to the relatively cool mold cavity, the molten metal cools rapidly upon contact with the cavity walls, causing it to solidify quickly. This rapid cooling can easily lead to internal and surface defects in the casting, such as cold shuts and cracks, which can affect product quality. Furthermore, air trapped in the cavity adheres to the inner walls, making it difficult to expel in time. This traps the air in the molten metal and creates porosity. These pores not only reduce the density of the casting but can also affect its mechanical properties and service life.

[0039] Therefore, the present invention discloses a precision low pressure casting process, referring to Figure 1 ,include:

[0040] S1, provide a metal mold, spray a parting agent on the surface of the metal mold cavity. In this embodiment, the

[0041] Graphite coating is sprayed as a parting agent to facilitate demoulding of the casting and protect the metal mold. The metal mold is then preheated to 150°-250°. In this embodiment, the preheating temperature is 200°. Compared with the preheating temperature of 150°, the flow rate of the molten metal is increased. On the other hand, compared with the preheating temperature of 250°, 200° can increase the solidification rate.

[0042] S2, providing a sealed crucible and a gas power mechanism, melting metal in the sealed crucible to form molten metal. In this embodiment, aluminum alloy molten metal is used. When melting the molten metal, the melting temperature and chemical composition need to be strictly controlled to avoid air absorption and oxidation. The gas power mechanism is used to introduce dry gas while maintaining a stable air pressure in the sealed crucible. The air pressure is usually 0.01MP-0.06MP. In this embodiment, the air pressure is 0.04MP.

[0043] S3, using the gas power mechanism to slowly increase the air pressure in the sealed crucible, so that the molten metal rises smoothly along the riser tube and fills the metal mold cavity, accurately controlling the filling speed to prevent the molten metal from splashing or being entrapped by gas, and maintaining the filling pressure at 0.005MP-0.02MP. In this embodiment, the filling pressure is 0.02MP, and the filling time can be adjusted according to the size of the casting;

[0044] S4, after the filling is completed, the gas power mechanism is used to immediately increase the gas pressure to 0.03MP-0.08MP, so that the molten metal crystallizes and solidifies under pressure, with a significant shrinkage feeding effect, reducing shrinkage cavities and shrinkage defects. In this embodiment, the gas pressure is increased to 0.04MP and maintained until solidification is completed;

[0045] S5, after solidification is completed, the gas power mechanism is used to release the air pressure in the sealed crucible, and the unsolidified metal liquid flows back to the sealed crucible. Then, the metal mold is opened, the molded product is taken out, the residue on the mold surface is cleaned, and preparation is made for the next pouring.

[0046] More specifically, by spraying graphite coating parting agent on the surface of the metal mold cavity and preheating the metal mold to 200°C, the fluidity and solidification control of the molten metal in the cavity are effectively improved, and the chilling phenomenon when the high-temperature molten metal contacts the low-temperature metal mold cavity wall is avoided, thereby reducing defects such as cold shut and cracks. In addition, by preheating the metal mold, the gas attached to the metal mold cavity wall is further reduced, which is more conducive to avoiding gas residue. At the same time, the volume of the gas expands due to heating, which is more conducive to discharge. A sealed crucible and a gas power mechanism are used to accurately control the temperature and chemical composition of the molten metal liquid, reduce the risk of air inhalation and oxidation, and achieve smooth filling of the molten metal by slowly increasing the pressure to prevent splashing and Gas is involved, which significantly reduces the occurrence of porosity defects. After filling is completed, the holding pressure is increased in time to promote the uniform solidification of the molten metal under pressure, enhance the shrinkage feeding effect, effectively reduce shrinkage cavities and shrinkage defects, and ensure that the casting has dense structure and excellent mechanical properties. The present invention not only improves the overall quality and density of the casting, and is suitable for the manufacture of pressure-bearing parts such as high-performance automobile wheels, but also achieves the advantages of high dimensional accuracy, good surface quality, high material utilization rate and high production efficiency. At the same time, strict pressure, temperature and air pressure control in the process ensure the stability and controllability of the filling and solidification processes, greatly reducing the casting defects caused by quenching and gas retention in traditional low-pressure casting, and improving production reliability and economic benefits.

[0047] In this embodiment, the further step S6 is to obtain a plurality of defect images, extract vector data from the defect images, pre-process the vector data, and form a reference data set from the vector data;

[0048] S7, obtaining a casting image, extracting vector data from the casting image, preprocessing the vector data, forming a product dataset from the vector data, and forming a collection dataset from the reference dataset and the product dataset;

[0049] S8, splitting the set data set into a training set, a validation set, and a test set according to a preset ratio;

[0050] S9, constructing a product qualification detection model, training the product qualification detection model using a training set, and testing the product qualification detection model after the training is completed, and stopping when the accuracy is higher than a predetermined value;

[0051] S10, using the product qualification detection model to detect the molded product taken out of S5, and determine the product qualification rate.

[0052] In this embodiment, the rising speed of the molten metal along the riser tube of S3 is 40 mm / s-60 mm / s. In the present invention, the rising speed of the molten metal along the riser tube is 50 mm / s. The speed of 50 mm / s effectively balances the flow stability and defect control while ensuring the filling efficiency, thereby achieving the best process effect of the filling process.

[0053] In this embodiment, the pressure of the increased air pressure in S4 is 1.5 times to 2 times the filling pressure in S3. Specifically, the pressure of the increased air pressure in S4 is 0.04MP, and the filling pressure in S3 is 0.02MP. The pressure of the increased air pressure in S4 is twice the filling pressure in S3 to overcome the influence of the solidification shrinkage of the molten metal on the casting.

[0054] In this embodiment, the temperature of the molten metal flow is higher than the liquidus temperature of the metal. In this embodiment, the aluminum alloy molten metal used is 1050 aluminum alloy molten metal, and the liquidus temperature of 1050 aluminum alloy molten metal is 657°C. Therefore, in this embodiment, the temperature of the aluminum alloy molten metal flow is 700°-750°. Since too high a temperature aggravates oxidation and too low a temperature results in poor fluidity, the temperature of the aluminum alloy molten metal flow is preferably 725°.

[0055] Example 2:

[0056] The process of this embodiment is mostly the same as that of embodiment 1.

[0057] The difference from the process of Example 1 is that

[0058] refer to Figure 2 In this embodiment, S2.5 is provided before S3 to evacuate the cavity of the metal mold with a vacuum degree of 0.05MP-0.08MP. In this embodiment, the vacuum degree is 0.06MP, which further reduces gas entrapment and improves the density of the casting, making it suitable for high-requirement aerospace parts.

[0059] Example 3:

[0060] The process of this embodiment is mostly the same as that of embodiment 1.

[0061] The difference from the process of Example 1 is that

[0062] refer to Figure 3 In this embodiment, S2.5 is provided before S3, wherein gas 2 is injected into the cavity of the metal mold. The gas 2 has a different pressure from the dry gas introduced by the gas power mechanism. By controlling the filling and solidification of the molten metal through the pressure difference, more precise sequential solidification can be achieved, thereby improving the performance of the casting.

[0063] This embodiment also discloses a low-pressure casting ion implanter, which is manufactured by the process of any of the above embodiments.

[0064] In addition, regarding the precision low-pressure casting process and the low-pressure casting ion implanter disclosed in the present invention, it is also possible to monitor parameters such as pressure, temperature, and filling speed in real time through integrated sensors, and combine with PLC or computer control systems to realize automatic adjustment of process parameters and improve production stability. In addition, in order to improve the environmental protection rate, low-energy smelting equipment can be developed, and molten metal and mold coatings can be recycled to reduce waste emissions to meet environmental protection requirements.

[0065] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0066] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A precision low-pressure casting process, characterized in that: include: S1, providing a metal mold, spraying a parting agent on the surface of the metal mold cavity, and then Preheat to 150°-250°; S2, providing a sealed crucible and a gas power mechanism, melting the metal in the sealed crucible to form molten metal, and introducing dry gas through the gas power mechanism while maintaining a stable gas pressure in the sealed crucible; S3, using the gas power mechanism to slowly increase the air pressure in the sealed crucible, so that the molten metal rises smoothly along the riser tube and fills the metal mold cavity, maintaining the filling pressure at 0.005MP-0.02MP; S4, after the filling is completed, the gas power mechanism is used to immediately increase the gas pressure to 0.03MP-0.08MP and maintain it until solidification is completed; S5, after solidification is completed, the gas power mechanism is used to release the air pressure in the sealed crucible, and the unsolidified metal liquid flows back to the sealed crucible, and then the metal mold is opened to take out the molded product.

2. A precision low-pressure casting process according to claim 1, characterized in that: Also includes: S6, acquiring multiple defect images, extracting vector data from the defect images, preprocessing the vector data, and forming a reference data set from the vector data; S7, obtaining a casting image, extracting vector data from the casting image, preprocessing the vector data, forming a product dataset from the vector data, and forming a collection dataset from the reference dataset and the product dataset; S8, splitting the set data set into a training set, a validation set, and a test set according to a preset ratio; S9, constructing a product qualification detection model, training the product qualification detection model using a training set, and testing the product qualification detection model after the training is completed, and stopping when the accuracy is higher than a predetermined value; S10, using the product qualification detection model to detect the molded product taken out of S5, and determine the product qualification rate.

3. A precision low-pressure casting process according to claim 1, characterized in that: The rising speed of the molten metal in S3 along the raw liquid pipe is 40 mm / s-60 mm / s.

4. A precision low-pressure casting process according to claim 1, characterized in that: The pressure of the increased air pressure in S4 is 1.5 to 2 times the filling pressure in S3.

5. A precision low-pressure casting process according to claim 1, characterized in that: The temperature at which the molten metal flows is higher than the liquidus temperature of the metal.

6. A precision low-pressure casting process according to claim 1, characterized in that: S2.5 is also set before S3 to vacuum the cavity of the metal mold with a vacuum degree of 0.05MP-0.08MP.

7. A precision low-pressure casting process according to claim 1, characterized in that: S2.5 is provided before S3, wherein a second gas is injected into the cavity of the metal mold. The gas second has a different pressure from the drying gas introduced by the gas power mechanism.

8. A low pressure casting ion implanter, characterized in that: The method is made by the precision low-pressure casting process as described in any one of claims 1 to 7.

Images