Preparation method of casting mold with inner cavity structure for aluminum alloy investment precision casting

Abstract

The invention relates to the technical field of aluminum alloy investment precision casting, and discloses a preparation method of an aluminum alloy investment precision casting mold with an inner cavity structure, and the preparation method comprises the steps of module manufacturing, shell manufacturing, module inner cavity and pipeline casting, dewaxing, roasting, pouring, cleaning and checking. Through the designed surface layer and transition layer, the accuracy and stability of the shell are ensured; in a module inner cavity and pipeline casting stage, uniformly mixed casting materials are used, and the materials have good flowability, hardenability and collapsibility when meeting water and can be used for filling fine parts of a shell inner cavity and a pipeline; through reasonable roasting temperature and time control, the thermal conductivity, the easy stripping property and the strength of the shell are comprehensively guaranteed; therefore, the metallurgical quality and the appearance quality of the casting are improved. According to the whole preparation method, the production efficiency and the product quality are greatly improved by optimizing the technological process and the material ratio of each step.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum alloy investment casting, and in particular relates to a method for preparing a casting mold with an inner cavity structure for aluminum alloy investment casting. Background Art

[0002] With the intensification of market competition, the rapid development of metal 3D printing, the reduction of machining costs of die forgings and the stability of internal quality, traditional aluminum alloy structural parts are gradually withdrawing from our precision casting production site. In order to better seize the aluminum alloy precision casting business, some components of aircraft engines, such as lubricating oil pump housings, gear pump housings and other housing castings with complex cavities have become the focus of development in the field of aluminum alloy casting.

[0003] The traditional manufacturing processes for this type of aluminum alloy castings with inner cavities and pipe structures are the following three categories: 3D printing sand mold core casting, investment gypsum mold precision casting, and water-soluble salt core wax pressure precision casting. The problems with using 3D printed sand mold core assembly to cast this type of casting are: the inner cavity and pipe surface of the casting are rough, and there is a risk of local sand sticking. When the whole machine is in working condition, sand particles are easily brought into the airway and oil circuit due to vibration, which reduces the working service time of the whole machine; the problems with using investment wax gypsum mold precision casting this type of casting are: the gypsum mold has poor thermal conductivity and is easy to absorb moisture. The inner cavity and pipe of the casting are prone to looseness and dense holes, and the qualified rate of non-destructive testing is low. Bubbles are prone to appear in the gypsum mold during the manufacturing process, resulting in aluminum beans in the inner cavity and pipe of the casting, which are difficult to remove, reducing the casting yield; the problems with using water-soluble salt core wax pressing precision casting this type of casting are: the water-soluble salt core is easy to absorb moisture, resulting in reactive porosity defects in the inner cavity and pipe of the casting, reducing the working service time of the whole machine. On the other hand, the production cycle of the water-soluble salt core is long, and there is a risk of core breakage during the wax pressing process. X-ray inspection is required for each piece, which extends the production cycle. When the castings produced by the above manufacturing process are subjected to fluorescent penetrant inspection, the quality of the casting inner cavity and the pipeline surface is difficult to meet the relevant standard requirements.

[0004] In recent years, with the deepening of the concept of high quality, high efficiency and low cost, such traditional manufacturing processes have been difficult to meet the market's comprehensive requirements for such products in terms of high quality requirements, production and manufacturing cycle, or cost reduction and efficiency improvement. When using the traditional silica sol ceramic shell precision casting process to produce such products, for aluminum alloy precision castings with more complex cavities and pipelines, unlike stainless steel and high-temperature alloy precision castings, alkali explosion or chemical methods are not used to clean the ceramic materials in the inner cavity and pipeline; on the other hand, due to the low hardness of aluminum alloy materials, physical methods are used to clean the inner cavity and pipeline refractory materials, which can easily cause deformation and damage to the product. Therefore, there is an urgent need to develop a method for preparing a casting mold for aluminum alloy investment casting with an inner cavity structure to meet the current market's comprehensive requirements for such products in many aspects. Summary of the invention

[0005] The object of the present invention is to overcome the above-mentioned problems and provide a method for preparing a mold for aluminum alloy investment casting with an inner cavity structure, so as to improve the overall surface roughness, dimensional accuracy, overall surface quality and overall shell cleaning difficulty of aluminum alloy castings with inner cavity and pipeline, shorten the production cycle and reduce production costs.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: The present invention provides a method for preparing a mold for aluminum alloy investment casting with an inner cavity structure, comprising the following steps: S1, model making and model group tree; S2, module shell production: after the model group tree is completed, the module shell production is carried out, and the module shell production includes a surface layer, a transition layer and a first reinforcement layer; S3, casting the inner cavity and pipeline of the module: draining and casting the evenly mixed casting material into the inner cavity and pipeline of the module shell, wherein the casting material includes α gypsum powder, Shangdian powder and silica sol; S4, subsequent shell making, dewaxing and baking: After the casting is completed, it is dried by itself, and then the subsequent module shell making work is carried out. After the shell making is completed, dewaxing and baking are carried out.

[0007] A further improvement of the present invention is that it also includes pouring, cleaning and inspecting the mold shell. The specific method is: using a modified high-pressure water gun and sandblasting machine to clean the mold shell and the refractory material residues attached to the casting and the inner cavity pipeline, and then using an endoscope to inspect the inner cavity and pipeline of the casting, and performing fluorescent penetration inspection and low-magnification inspection.

[0008] A further improvement of the present invention is that in step S1, the model is made by wax pressing or 3D printing.

[0009] A further improvement of the present invention is that in the step S2, the surface layer of the module shell uses silica sol / zircon powder 320# as slurry and zircon sand 100# as sand; the transition layer of the module shell includes a first transition layer and a second transition layer, the first transition layer uses silica sol / zircon powder 320# as slurry and chromite sand 80# as sand, the second transition layer uses silica sol / Shangdian powder 200# as slurry and Shangdian sand 30~60# as sand; the first reinforcement layer uses silica sol / Shangdian powder 200# as slurry and Shangdian sand 16~30# as sand.

[0010] A further improvement of the present invention is that when the minimum size of the pipe or the inner cavity is 3.5mm<X≤6mm, the module shell production includes a surface layer, a first transition layer and a second transition layer; when the minimum size of the pipe or the inner cavity is X>6mm, the module shell production includes a surface layer, a first transition layer, a second transition layer and a first reinforcement layer.

[0011] A further improvement of the present invention is that the material components for casting the inner cavity of the module and the pipeline in step S3 include: α gypsum powder and Shangdian powder as powders, and silica sol as solvent, wherein the Shangdian powder accounts for 25-35% of the total weight of the powders, and the silica sol accounts for 25-35% of the total weight of the powders.

[0012] A further improvement of the present invention is that in the step S3, reinforcements are pre-embedded before the inner cavity of the module and the pipeline are cast, and the reinforcements are φ2~φ4 stainless steel wires.

[0013] A further improvement of the present invention is that the particle size of the Shangdian flour is 200 meshes.

[0014] A further improvement of the present invention is that in step S4, a steam kettle is used for dewaxing, and then the module is placed in a resistance furnace and heated at a rate of 200-250°C / h, and the temperature is raised to 850±10°C and kept for 2-3h to remove the crystallization water of the module shell and ceramicize the module shell, and then the temperature is lowered along with the furnace.

[0015] A further improvement of the present invention is that the method is suitable for preparing aluminum castings with a minimum inner cavity and pipeline size X>3.5mm.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a method for preparing a mold for aluminum alloy investment casting with an inner cavity structure. The precision and stability of the mold shell are ensured by a carefully designed surface layer and transition layer. In the mold cavity and pipeline pouring stage, a uniformly mixed pouring material is used. These materials have good fluidity, hardening and water disintegration, and can fill the fine parts of the mold shell cavity and pipeline. The thermal conductivity, easy removal and strength of the mold shell are comprehensively guaranteed by reasonable roasting temperature and time control, thereby improving the metallurgical quality and appearance quality of the casting. The entire preparation method greatly improves production efficiency and product quality by optimizing the process flow and material ratio of each step. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings described herein are only for explanation purposes and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the various components in the drawings are only schematic, used to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the various components of the present invention.

[0018] Figure 1 It is a schematic diagram of the process of the preparation method of the present invention; Figure 2 This is a cross-sectional view of an aluminum alloy impeller casting according to Example 1 of the present invention; Figure 3 This is an axonometric view of the aluminum alloy impeller casting of Example 1 of the present invention; Figure 4 A partial cross-sectional view of an aluminum alloy housing casting according to Example 2 of the present invention; Figure 5 This is another partial cross-sectional view of the aluminum alloy shell casting according to Example 2 of the present invention.

[0019] Among them: 1. Impeller; 2. Flow channel; 3. Casing; 4. Pipeline. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0023] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0024] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings: like Figure 1 As shown, the present invention provides a method for preparing a mold for aluminum alloy investment casting with an inner cavity structure, comprising the following steps: Step S1, model making, using wax pressing model or 3D printing rapid prototyping model, and model assembly tree; Step S2, module shell production: After the model group tree is completed, the module shell production is carried out, and the module shell production includes a surface layer, a transition layer and a first reinforcement layer; the selection and proportion of the materials of each layer are carefully designed to ensure the strength and precision of the shell.

[0027] The surface layer uses silica sol / zircon powder 320# as slurry and zircon sand 100# as sanding, which improves the smoothness and precision of the shell. The transition layer includes a first transition layer and a second transition layer. The first transition layer uses silica sol / zircon powder 320# as slurry and chromite sand 80# as sand. The second transition layer uses silica sol / Shangdian powder 200# as slurry and Shangdian sand 30~60# as sand. The first reinforcement layer uses silica sol / Shangdian powder 200# as slurry and Shangdian sand 16~30# as spreading sand.

[0028] The transition layer and the first reinforcement layer are made of different materials and granularity according to the different sizes of the pipe or inner cavity, which not only ensures the strength of the shell, but also avoids the impact of the excessive thickness of the ceramic shell layer on the cleaning of the casting cavity and the pipe in the later stage. Specifically, when the minimum size of the pipe or inner cavity is 3.5mm<X≤6mm, the mold shell production includes the surface layer, the first transition layer and the second transition layer; when the minimum size of the pipe or inner cavity is X>6mm, the mold shell production includes the surface layer, the first transition layer, the second transition layer and the first reinforcement layer.

[0029] Step S3, first weighing the powder alpha gypsum powder and the upper store powder, wherein the upper store powder accounts for 25-35% of the total weight of the powder, and fully stirring and mixing the weighed powders, and then weighing the solvent silica sol, wherein the silica sol accounts for 25-35% of the total weight of the powders, pouring the fully stirred and mixed powders into the solvent and fully stirring for 1-3 minutes, and using a drainage rod or a thin iron wire to drain the casting material into the inner cavity and pipe of the mold shell; As a preferred embodiment, the particle size of Shangdian flour is 200 mesh.

[0030] It should be noted that before the inner cavity of the module and the pipe are cast, reinforcements need to be embedded in advance, and the reinforcements are φ2~φ4 stainless steel wires.

[0031] Step S4, subsequent shell making, dewaxing and roasting: After the casting is completed, it is dried by itself for more than 3 hours, and then the subsequent module shell making work is carried out. After the shell making is completed, dewaxing and roasting are carried out; The steam kettle is used for dewaxing, and then the module is placed in a resistance furnace and heated at a rate of 200-250℃ / h. The temperature is raised to 850±10℃ and kept for 2-3h. The temperature is then lowered with the furnace to the specified shell temperature for pouring and set aside.

[0032] Step S5, pouring, cleaning and inspecting the shell; Specifically, modified high-pressure water guns and sandblasting machines were used to clean the mold shell and refractory material residues attached to the casting and the inner cavity pipeline, which improved the cleaning efficiency and cleanliness; then an endoscope was used to inspect the inner cavity and pipeline of the casting to ensure the integrity and quality of the inner cavity and pipeline of the casting; and fluorescent penetration inspection and low-magnification inspection were carried out.

[0033] It should be noted that the high-pressure water gun and sandblasting machine used in the present invention are improved, and the specific improvements are as follows: By matching the screw thread specifications of the existing hydraulic shell cleaning machine high-pressure water gun nozzle interface and the sandblasting machine nozzle interface, the nozzles of the two post-cleaning equipment are modified; a stainless steel external thread conversion joint that matches the screw thread of the high-pressure water gun nozzle interface and stainless steel pipes of different diameters with a wall thickness greater than 1 mm are selected, and a stainless steel pipe of suitable specifications is selected according to the inner cavity and pipeline structure of the corresponding product and adaptively bent and modified, and it is fastened to the stainless steel external thread conversion joint by welding, and screwed into the hydraulic shell cleaning machine high-pressure water gun nozzle interface to realize the cleaning of the refractory materials of the casting inner cavity and pipeline; considering that the bent sandblasting nozzle rubs against the sand particles at high speed during work and is a vulnerable part, an adaptively bent nozzle data model is designed according to the inner cavity and pipeline structure of the corresponding product, and the outer thread conversion joint part is reserved at the tail for mechanical processing, and the K4169 high-temperature alloy waste is used for casting by the method of 3D printing rapid prototyping mold + investment casting, and then the outer thread of the conversion joint is completed by mechanical processing, and it is screwed to the sandblasting machine nozzle interface to realize the deep cleaning of the casting inner cavity and pipeline.

[0034] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0035] Example 1 This example is to prepare a certain type of aluminum alloy impeller casting, whose outline size is: φ35×17.4mm, the impeller flow channel cross-sectional size is 3.6mm, and the structure is shown in FIG. Figure 2 and Figure 3 As shown, it is difficult to achieve the technical indicators such as surface roughness, dimensional accuracy, and metallurgical quality using traditional casting processes. The preparation steps are as follows: Step 1: Model making, using 3D printing to quickly prototype the model and make a model tree; Step 2: After the model tree is completed, the mold shell is made according to the casting size. Since the flow channel cross-section size of the impeller is 4.7mm, the mold shell production only includes the first three layers, namely the surface layer, the first transition layer and the second transition layer; Step 3: First, weigh 16.5g of α-gypsum powder and 5g of Shangdian powder and stir them thoroughly. Then weigh 6.5g of silica sol (5-10℃), pour the fully stirred powder into the solvent and stir for 1min. Use a thin wire to drain and pour it into the impeller flow channel. Step 4: After the casting is completed and the casting is allowed to dry for 4 hours, the subsequent module shell making work is carried out according to the process requirements; Step 5: Dewaxing and roasting: Dewaxing is done by steam kettle, and then the module is placed in a resistance furnace at room temperature and heated at a rate of 240±10℃ / h, heated to 850±10℃ and kept at this temperature for 2h, and then cooled down with the furnace for standby use; Step 6: Cast the shell according to the process requirements; Step 7: Use a high-pressure water gun with a modified nozzle to clean the mold shell and the inner cavity pipeline gypsum refractory material residue attached to the casting, and use a sandblasting machine with a modified nozzle to perform surface treatment on the casting after cutting; Step 8: Use an endoscope to inspect the inner cavity and pipeline of the casting, and check whether there are defects such as pores and slag inclusions on the surface of the casting; Step 9: Use fluorescent penetrant to check if there are defects such as pores, looseness, slag inclusion, etc. on the casting surface; Step 10: After heat treatment, dissect the casting and use low power to check the cross section for defects such as pores and slag pores.

[0036] This batch of castings has undergone surface inspection, fluorescent inspection and low-power inspection. The surface quality and fluorescent inspection of the castings meet the HB963 Class II casting standards. After heat treatment and low-power inspection, the pinhole degree is better than level 1, which meets the HB963 Class II casting standards.

[0037] Example 2 This example is to prepare a certain type of aluminum alloy shell casting, the outline size of which is: 276×201×197mm. The shell has two large aperture ratio pipelines, the maximum diameter of the pipeline is φ13mm, the length is 130mm, and the structure is shown in FIG. Figure 4 and Figure 5 As shown, it is difficult to achieve the technical indicators such as surface roughness, dimensional accuracy, and metallurgical quality using traditional casting processes. The preparation steps are as follows: Step 1: Model making, using wax pressing model to quickly form the model and make a model tree; Step 2: After the model tree is completed, the mold shell is made according to the casting size. Since the maximum diameter of the shell pipe is 13 mm, the mold shell production includes the first four layers, namely the surface layer, the first transition layer, the second transition layer and the first reinforcement layer; Step 3, first weigh 71g of α-gypsum powder and 21.3g of Shangdian powder and stir them thoroughly, then weigh 27.7g of silica sol solvent (5-10°C), pour the fully stirred powder into the solvent and stir for 1min, and use a drainage rod to drain and pour into the inner cavity and pipeline of the module shell; Step 4: After the casting is completed and the mold is dried for 5 hours, the subsequent module shell making work is carried out according to the process requirements; Step 5, dewaxing and roasting, using a steam kettle for dewaxing, and then placing the module in a resistance furnace at room temperature and heating it at a rate of 240±10℃ / h, heating it to 850±10℃ and keeping it for 2h, and then cooling it down with the furnace for standby use; Step 6, pouring the shell according to the process requirements; Step 7, using a high-pressure water gun with a modified nozzle to clean the mold shell and the inner cavity pipeline gypsum refractory material residue attached to the casting, and after cutting, using a sandblasting machine with a modified nozzle to perform surface treatment on the casting; Step 8, use an endoscope to inspect the inner cavity and pipeline of the casting to check if there are defects such as pores and slag inclusions on the surface of the casting; Step 9, check the casting surface for defects such as pores, looseness, slag inclusion, etc. through fluorescent penetrant inspection; Step 10, after heat treatment, dissect the casting and use low power to check the cross section for defects such as pores and slag pores.

[0038] This batch of castings has undergone surface inspection, fluorescent inspection and low-power inspection. The surface quality and fluorescent inspection of the castings meet the HB963 Class II casting standards. After heat treatment and low-power inspection, the pinhole degree is better than level 1, which meets the HB963 Class II casting standards.

[0039] Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the preceding claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to be a disclaimer of such subject matter, nor should it be considered that the applicants did not consider such subject matter to be part of the disclosed inventive subject matter.

[0040] The above content is a further detailed description of the present invention. It cannot be determined that the specific implementation methods of the present invention are limited to these. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, they can also make several simple deductions or substitutions, which should be regarded as belonging to the protection scope of the present invention determined by the submitted claims.

Claims

1. A method for preparing a mold for aluminum alloy investment casting with an inner cavity structure, characterized in that: The following steps are involved: S1, model making and model group tree; S2, module shell production: after the model group tree is completed, the module shell production is carried out, and the module shell production includes a surface layer, a transition layer and a first reinforcement layer; S3, casting the inner cavity and pipeline of the module: draining and casting the evenly mixed casting material into the inner cavity and pipeline of the module shell, wherein the casting material includes α gypsum powder, Shangdian powder and silica sol; S4, after the casting is completed, it is dried by itself, and then the subsequent module shell making work is carried out. After the shell making is completed, dewaxing and baking are carried out.

2. The method for preparing a mold for aluminum alloy investment casting with an inner cavity structure according to claim 1, characterized in that: It also includes pouring, cleaning and inspection of the mold shell. The specific method is: use a modified high-pressure water gun and sandblasting machine to clean the mold shell and inner cavity pipeline refractory material residues attached to the casting, and then use an endoscope to inspect the inner cavity and pipeline of the casting, and perform fluorescent penetration inspection and low-magnification inspection.

3. The method for preparing a mold for aluminum alloy investment casting with an inner cavity structure according to claim 1, characterized in that: In step S1, the model is made by wax pressing or 3D printing.

4. The method for preparing a mold for aluminum alloy investment casting with an inner cavity structure according to claim 1, characterized in that: In the step S2, the surface layer of the module shell uses silica sol / zircon powder 320# as slurry and zircon sand 100# as sand; the transition layer of the module shell includes a first transition layer and a second transition layer, the first transition layer uses silica sol / zircon powder 320# as slurry and chromite sand 80# as sand, the second transition layer uses silica sol / Shangdian powder 200# as slurry and Shangdian sand 30~60# as sand; the first reinforcement layer uses silica sol / Shangdian powder 200# as slurry and Shangdian sand 16~30# as sand.

5. The method for preparing a mold for aluminum alloy investment casting with an inner cavity structure according to claim 1, characterized in that: When the minimum size of the pipe or inner cavity is 3.5mm<X≤6mm, the module shell production includes a surface layer, a first transition layer and a second transition layer; when the minimum size of the pipe or inner cavity is X>6mm, the module shell production includes a surface layer, a first transition layer, a second transition layer and a first reinforcement layer.

6. The method for preparing a mold for aluminum alloy investment casting with an inner cavity structure according to claim 1, characterized in that: In step S3, the material components for casting the inner cavity of the module and the pipeline include: α gypsum powder and Shangdian powder as powder materials, and silica sol as solvent, wherein the Shangdian powder accounts for 25-35% of the total weight of the powder materials, and the silica sol accounts for 25-35% of the total weight of the powder materials.

7. The method for preparing a mold for aluminum alloy investment casting with an inner cavity structure according to claim 1, characterized in that: In the step S3, reinforcements are embedded in the inner cavity of the module and before the pipes are cast, and the reinforcements are φ2~φ4 stainless steel wires.

8. The method for preparing a mold for aluminum alloy investment casting with an inner cavity structure according to claim 1, characterized in that: The particle size of the Shangdian flour is 200 meshes.

9. The method for preparing a mold for aluminum alloy investment casting with an inner cavity structure according to claim 1, characterized in that: In step S4, a steam kettle is used for dewaxing, and then the module is placed in a resistance furnace and heated at a rate of 200-250°C / h, and the temperature is raised to 850±10°C and kept for 2-3h to remove the crystallization water of the module shell and ceramicize the module shell, and then the temperature is lowered along with the furnace.

10. The method for preparing an aluminum alloy investment casting mold with an inner cavity structure according to any one of claims 1 to 9, characterized in that: The method is suitable for preparing aluminum alloy castings with a minimum inner cavity or pipeline size X>3.5mm.

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