Performance-differentiated sand mold preparation method

Abstract

The invention discloses a preparation method of a performance-differentiated sand mold, and belongs to the technical field of additive manufacturing. The method comprises the steps of establishing a first sand mold model; s first yield stresses are distributed on the first sand mold; forming a first yield stress distribution data set of the first sand mold model by the s first yield stresses; dividing the first sand mold into n preset modules according to the first yield stress distribution data set; in the n preset modules, f second yield stresses are distributed on at least one preset module; the number of target modules formed into the target sand mold is obtained according to the number of the preset modules; forming a single target module according to the single preset module; according to the second yield stress between the n preset modules, the single-layer binder target adding amount needed by the n target modules and the number of the mold pieces cut by the n preset modules are obtained; and forming a target sand mold according to the n target modules. According to the sand mold forming method, different performance requirements of the sand mold are met, and the using amount of the binder is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a method for preparing a sand mold with differentiated performance. Background Art

[0002] The emergence of 3D printing technology has certain advantages in additive manufacturing. At present, the application of 3D technology in the field of sand casting has very good application prospects. First of all, modeling and core making are considered to be one of the links with high labor intensity and poor production environment in the foundry industry. The application of 3D technology in the production of sand molds replaces the manual operation link. Due to the particularity of the raw materials of 3D printing sand molds, there will be no dust during the printing process, and the adhesive added for sand mold hardening is also carried out in a relatively closed box, which reduces emissions to the environment and greatly improves the working environment; secondly, the application of 3D printing technology in the field of sand casting omits the link of making molds, which not only saves production costs, but also improves the speed and flexibility of product trial production. Foundry companies no longer need to spend a lot of money to build mold storage workshops and professional mold maintenance personnel; secondly, the application of 3D printing technology in sand casting has greatly improved the dimensional accuracy of products and enhanced the ability to control the size of sand molds, becoming a precisely controlled link. 3D printing makes complex product sand molds simpler. The precise size control system can finely control the product processing volume, ensuring that a small amount of processing allowance can be reserved when designing the product processing surface, thereby improving the efficiency of subsequent product processing; finally, the application of 3D printing technology in the field of sand casting provides sufficient guarantee for the flexibility of product design. Since 3D printed sand molds are not constrained by product size and shape, parameters can be changed at any time during the product production process for partial or overall corrections, thereby improving product research and development verification efficiency.

[0003] At present, the method of 3D printing of casting sand molds is to print the sand molds completely solid. This method of producing casting sand molds for castings generally has the following problems:

[0004] (1) Since there is no compaction method, the strength can only be increased by adding a binder. The large amount of binder added leads to a large amount of gas emission from the sand mold;

[0005] (2) The 3D printed sand mold has poor air permeability and is prone to defects such as pores and inclusions;

[0006] (3) Large sand molds use a large amount of binder and require a long drying time, resulting in high cost of use;

[0007] (4) The performance of 3D printed sand molds is consistent and cannot meet the different requirements of sand mold performance for different structures and positions of castings. Summary of the invention

[0008] In order to solve the problem that the existing sand mold forming method cannot meet the problem that different parts of the sand mold have different properties, and how to reduce the amount of adhesive, the present invention provides a method for preparing a sand mold with differentiated performance, comprising:

[0009] Build the first sand mold model;

[0010] The first sand mold has s first yield stresses distributed therein, and at least one of the s first yield stresses is inconsistent, wherein s is a natural number, and s≥1;

[0011] Using the s first yield stresses to form a first yield stress distribution data set of the first sand mold model;

[0012] Dividing the first sand mold into n preset modules according to the first yield stress distribution data set, each of the n preset modules having at least one first yield stress, wherein n is a natural number, 1≤n≤s;

[0013] Among the n preset modules, at least one preset module is distributed with f second yield stresses, the second yield stress is within the range of the first yield stress, and among the f second yield stresses, at least one second yield stress is inconsistent, where f is a natural number, f≥1;

[0014] Acquire the number of target modules formed into a target sand mold according to the number of the preset modules, wherein the number of the preset modules is consistent with the number of the target modules;

[0015] According to a single preset module, a single target module is formed, and the method for forming the single target module includes:

[0016] Obtaining a target casting sand material according to at least one of the second yield stresses in a single preset module;

[0017] Obtaining the target yield strength of the target module according to the maximum second yield stress among the second yield stresses of the single preset modules and the first yield strength of the target casting sand material;

[0018] According to the second yield stress distribution of the single preset module, the single preset module is cut into m mold pieces, where m is a natural number, m≥1;

[0019] According to the target yield strength, obtain the target amount of single-layer adhesive required to form the m mold pieces into the target module;

[0020] A single target module is obtained by adding the target casting sand material layer by layer and adding the target amount of the single layer binder layer by layer;

[0021] According to whether the second yield stresses among the n preset modules are consistent or inconsistent, obtaining whether the target amounts of single-layer adhesive required by the n target modules are consistent or inconsistent, and obtaining whether the numbers of the dies cut from the n preset modules are consistent or inconsistent;

[0022] The target sand mold is formed according to the n target modules.

[0023] According to an embodiment of the present invention, among the m mold pieces, the thickness of a single mold piece is obtained according to the third yield stress of the single mold piece and the first yield strength of the target casting sand material, and the third yield stress is within the range of the second yield stress.

[0024] According to one embodiment of the present invention, the first yield stress distribution data set includes a first yield stress I, a first yield stress II and a first yield stress III, the first yield stress I≤first yield stress II≤first yield stress III, and the first sand mold is divided into a first preset module, a second preset module and a third preset module according to the first yield stress I, the first yield stress II and the first yield stress III.

[0025] According to one embodiment of the present invention, the first yield stress I is 0-400 MPa, the first yield stress II is 400-800 MPa, and the first yield stress III is 800-1200 MPa.

[0026] According to an embodiment of the present invention, the target yield strength of the target module is obtained according to the maximum second yield stress of the preset module, the first yield strength of the target casting sand material and the standard yield strength of the sand mold.

[0027] According to one embodiment of the present invention, the target yield strength calculation formula of the target module is as follows:

[0028] ;

[0029] Where X is the target yield strength of the target module, σ m is the maximum second yield stress in the preset module, σ Q is the target casting sand material yield strength, Q s It is the standard yield strength of sand mold.

[0030] According to one embodiment of the present invention, the target single-layer binder addition amount required for forming m mold pieces into the target module is obtained based on the target yield strength of the target module, the target casting sand material yield strength and the standard single-layer binder addition amount of the sand mold.

[0031] According to one embodiment of the present invention, the calculation formula for the target amount of single-layer adhesive required for the preset module is as follows:

[0032] ;

[0033] Among them, Y is the target amount of single-layer adhesive required for the preset module, X is the target yield strength of the target module, Q s is the standard yield strength of the sand mold, K is a constant, K=1.32-1.58, P s This is the standard addition amount of a single layer of binder for sand molds.

[0034] According to an embodiment of the present invention, the target amount of single-layer adhesive added is the amount of adhesive added between two adjacent layers of the m dies, and the target amount of single-layer adhesive added required when forming a single target module is the same.

[0035] According to one embodiment of the present invention, based on whether the second yield stress between the n preset modules is consistent or inconsistent, the target amount of single-layer adhesive added required for each of the n target modules is consistent, and the number of mold pieces cut into each of the n preset modules is consistent or inconsistent.

[0036] The present invention has the following beneficial effects:

[0037] 1. In the present invention, during the 3D printing process of the target sand mold, based on the forming stress of the overall structural characteristics of the first sand mold of the model, preset module divisions are performed for different stress distribution areas, and the differentiated yield strengths required for different target modules are designed; according to the specific yield strength requirements of each target module, the amount of binder added per layer required for different target modules is designed; by adding sand layer by layer and spraying the budgeted amount of binder layer by layer, the overall differentiated performance of the 3D printing of the target sand mold is achieved, the requirements of various structural characteristics are met, the quality of the sand mold is improved, and on the basis of meeting the performance requirements of the sand mold, a method of using less single-layer binder is selected to reduce the use of binder, save costs, and be green and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A flow chart of a method for preparing a sand mold with differentiated performance according to the present invention is shown. DETAILED DESCRIPTION

[0039] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present disclosure, rather than implying any limitation on the scope of the present disclosure.

[0040] As used herein, the term "including" and its variations are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "based at least in part on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment". The term "another embodiment" is to be interpreted as "at least one other embodiment". The terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components.

[0041] This embodiment discloses a method for preparing a sand mold with differentiated performance. Figure 1 As shown, the following steps are included:

[0042] Build the first sand mold model;

[0043] The first sand mold has s first yield stresses distributed therein, and at least one of the s first yield stresses is inconsistent, wherein s is a natural number, and s≥1;

[0044] Using the s first yield stresses to form a first yield stress distribution data set of the first sand mold model;

[0045] Dividing the first sand mold into n preset modules according to the first yield stress distribution data set, each of the n preset modules having at least one first yield stress, wherein n is a natural number, 1≤n≤s;

[0046] Among the n preset modules, at least one preset module is distributed with f second yield stresses, the second yield stress is within the range of the first yield stress, and among the f second yield stresses, at least one second yield stress is inconsistent, wherein f is a natural number, f≥1;

[0047] Acquire the number of target modules formed into a target sand mold according to the number of the preset modules, wherein the number of the preset modules is consistent with the number of the target modules;

[0048] According to a single preset module, a single target module is formed, and the method for forming the single target module includes:

[0049] Obtaining a target casting sand material according to at least one of the second yield stresses in a single preset module;

[0050] Obtaining the target yield strength of the target module according to the maximum second yield stress among the second yield stresses of the single preset modules and the first yield strength of the target casting sand material;

[0051] According to the second yield stress distribution of the single preset module, the single preset module is cut into m mold pieces, where m is a natural number, m≥1;

[0052] According to the target yield strength, obtain the target amount of single-layer adhesive required to form the m mold pieces into the target module;

[0053] A single target module is obtained by adding the target casting sand material layer by layer and adding the target amount of the single layer binder layer by layer;

[0054] According to whether the second yield stresses among the n preset modules are consistent or inconsistent, obtaining whether the target amounts of single-layer adhesive required for the n target modules are consistent or inconsistent, and obtaining whether the numbers of the dies cut from the n preset modules are consistent or inconsistent;

[0055] The target sand mold is formed according to the n target modules.

[0056] When performing this embodiment, a first sand mold model is established to obtain a target sand mold through the first sand mold, and the casting forming simulation software Procast is used to simulate and calculate the forming process of the first sand mold to obtain the overall yield stress distribution of the first sand mold, and the yield stress of the overall distribution of the first sand mold is used as the first yield stress. There are s first yield stresses, and there may be the same yield stress among the s first yield stresses, but at least one first yield stress value is different from other first yield stress values, and the first yield stress is formed into a first yield stress distribution data set. The first sand mold is divided into n preset modules through the first yield stress distribution data set, that is, n preset modules constitute the first sand mold, and there is at least one first yield stress in the n preset modules, that is, among the n preset modules, each preset module has at least one first yield stress, that is, a preset module may include only one first yield stress and two or more first yield stresses. In each preset module, a single preset module also has different yield stresses distributed. The yield stress distributed in a single preset module is counted as the second yield stress. A single preset module has f second yield stresses. The second yield stress is within the range of the first yield stress. There may also be a situation where the second yield stress is equal to the first yield stress. There is at least one second yield stress in n preset modules. There may also be a situation where the yield stress is the same in n preset modules, but at least one second yield stress value is different from other second yield stress values. By selecting the number of target modules according to the number of preset modules, the number of preset modules can be selected to be consistent with the number of target modules, and then there are n target modules. Then a single target module is formed according to a single module, so that n target modules can be formed according to n preset modules. The method for forming a single target module includes the following steps:

[0057] By selecting a target casting sand material according to at least one second yield stress in a single preset module, that is, the yield stress of the selected target casting sand material is capable of satisfying the second yield stress;

[0058] Obtaining a target yield strength of a target module according to a maximum first yield stress of a single preset module and a first yield strength of a target casting sand material;

[0059] Slicing the single preset module into m modules according to the second yield stress of the single preset module;

[0060] The target yield strength of the target module is used to obtain the target amount of single-layer adhesive required to form m mold pieces into the target module, that is, the target module is obtained by forming m film pieces of the preset module;

[0061] Through computer discretization and layering processing, the three-dimensional entity of a single target module is sliced, and the target amount of single-layer binder required for the target module is converted into the data of the amount of binder sprayed layer by layer. The required single target module is formed by adding casting sand material layer by layer and spraying the target amount of single-layer binder required for the target module layer by layer using 3DP sand mold printing equipment;

[0062] According to the consistency or inconsistency of the second yield stresses among the n preset modules, obtaining the consistency or inconsistency of the target amount of single-layer adhesive added for the n target modules, and obtaining the consistency or inconsistency of the number of dies cut from the n preset modules;

[0063] The target amount of single-layer binder added for each of the n target modules is carried out according to the above method, so that the n target modules are combined to obtain a target sand mold with diverse properties;

[0064] n target modules constitute the target sand mold.

[0065] In this embodiment, during the 3D printing process of the target sand mold, based on the forming stress of the overall structural characteristics of the first sand mold of the model, preset module divisions are performed in different stress distribution areas, and differentiated yield strengths required for different target modules are designed; according to the specific yield strength requirements of each target module, the amount of binder added per layer required for different target modules is designed; by adding sand layer by layer and spraying the budgeted amount of binder layer by layer, the overall differentiated performance of the 3D printing of the target sand mold is achieved, the requirements of various structural characteristics are met, the quality of the sand mold is improved, the use of binder is reduced, costs are saved, and it is green and environmentally friendly.

[0066] In this embodiment, by obtaining the consistency or inconsistency of the target amount of single-layer binder required for each of the n target modules according to the consistency or inconsistency of the second yield stresses among the n preset modules, the appropriate target amount of single-layer binder required for the target module can be selected while satisfying the performance requirements of the sand mold. And by obtaining the consistency or inconsistency of the number of mold pieces cut from the n preset modules according to the consistency or inconsistency of the second yield stresses among the n preset modules, the number of mold pieces can be controlled to ensure the selection of an appropriate target amount of single-layer binder to satisfy the performance requirements of different parts of the sand mold.

[0067] In some embodiments, the target amount of single-layer adhesive is specifically the amount of adhesive required between two adjacent dies in the m dies. Since at least one target yield strength is inconsistent among the n target modules, based on the method for obtaining the target amount of single-layer adhesive, at least one target amount of single-layer adhesive required among the n target modules may be inconsistent. The target amounts of single-layer adhesive required for the n target modules are calculated separately. If there are n target modules, the target amount of single-layer adhesive required for each target module needs to be obtained n times.

[0068] In some embodiments, a single target casting sand material is selected by the yield stress range corresponding to a single preset module, that is, when the yield stress of the casting sand material belongs to the yield stress range corresponding to the preset module, the casting sand material can be used as a single target casting sand material. It is ensured that after the target casting sand material is formed into a target sand mold, the yield stress of the target sand mold can reach the required yield stress.

[0069] In some embodiments, when the first sand mold model is divided into n preset modules along the horizontal direction, and the n preset modules are stacked to form the first sand mold model, the amount of adhesive used to bond two adjacent preset modules to each other is the target amount of single-layer adhesive used by the preset module with a smaller target amount of single-layer adhesive used in the two adjacent preset modules. Preferably, the target amount of single-layer adhesive used by the preset module with a smaller target amount of single-layer adhesive used is the largest single-layer adhesive added amount among the single-layer adhesive added amounts used by the m diaphragms in the single preset module. This not only ensures the performance of the sand mold after forming, but also reduces the amount of adhesive used.

[0070] According to an embodiment of the present invention, among the m mold pieces, the thickness of a single mold piece is obtained according to the third yield stress of the single mold piece and the first yield strength of the target casting sand material, and the third yield stress is within the range of the second yield stress.

[0071] In this embodiment, the thickness of a single mold piece is obtained according to the third yield stress of the single mold piece and the first yield strength of the target casting sand material, thereby ensuring that the prepared target sand mold meets the required performance requirements.

[0072] In some embodiments, the target amount of sand material added for the single-layer target casting is obtained according to the thickness of a single mold piece, so as to select a suitable amount of sand material added for the single-layer target casting, thereby ensuring the performance of the target sand mold.

[0073] Herein, the first yield stress, the second yield stress and the third yield stress are single point values ​​and / or range values. Preferably, the first yield stress, the second yield stress and the third yield stress are range values.

[0074] According to one embodiment of the present invention, the first yield stress distribution data set includes a first yield stress I, a first yield stress II and a first yield stress III, the first yield stress I≤first yield stress II≤first yield stress III, and the first sand mold is divided into a first preset module, a second preset module and a third preset module according to the first yield stress I, the first yield stress II and the first yield stress III.

[0075] In this embodiment, the yield stress of the first sand mold distribution is divided into three levels, that is, the first sand mold can be divided into three preset modules according to the three levels, and the first preset module is the first yield stress I, the second preset module is the first yield stress II, and the third preset module is the first yield stress III. By setting the yield stress level of the preset module reasonably, the work efficiency can be improved while ensuring that the yield strength of different parts of the target sand mold is met.

[0076] According to one embodiment of the present invention, the first yield stress I is 0-400 MPa, the first yield stress II is 400-800 MPa, and the first yield stress III is 800-1200 MPa.

[0077] In this embodiment, by reasonably setting the yield stress ranges of different levels, the yield strength of different parts of the target sand mold is further met, and the working speed is improved.

[0078] According to an embodiment of the present invention, the target yield strength of the target module is obtained according to the maximum second yield stress of the preset module, the first yield strength of the target casting sand material and the standard yield strength of the sand mold.

[0079] In this embodiment, a method for obtaining a target yield strength of a target module is provided to improve the accuracy of obtaining the target yield strength of the target module.

[0080] According to one embodiment of the present invention, the target yield strength calculation formula of the target module is as follows:

[0081] ;

[0082] Where X is the target yield strength of the target module, σ m is the maximum second yield stress in the preset module, σ Q is the target casting sand material yield strength, Q s It is the standard yield strength of sand mold.

[0083] In this embodiment, the target yield strength of the specific target module is obtained by the above formula, wherein the standard yield strength of the sand mold is the strength of the mold required by the standards of relevant countries, industries, groups or enterprises for different classifications of castings based on the sand mold material, purpose, etc.

[0084] According to one embodiment of the present invention, the target single-layer binder addition amount required for forming m mold pieces into the target module is obtained based on the target yield strength of the target module, the target casting sand material yield strength and the single-layer binder standard addition amount of the sand mold.

[0085] In this embodiment, a method for obtaining a target amount of a single layer of adhesive required for a target module is provided to improve the accuracy of obtaining the target amount of a single layer of adhesive required for a target module.

[0086] According to one embodiment of the present invention, the calculation formula for the target amount of single-layer adhesive required for the preset module is as follows:

[0087] ;

[0088] Among them, Y is the target amount of single-layer adhesive required for the preset module, X is the target yield strength of the target module, Q s is the standard yield strength of the sand mold, K is a constant, K=1.32-1.58, P s This is the standard addition amount of a single layer of binder for sand molds.

[0089] In this embodiment, the target amount of single-layer binder required for a specific target module is obtained by the above formula. Specifically, K is a quantitative constant for the reduction of sand mold strength and the reduction of binder amount. The standard amount of single-layer binder added to the sand mold is the amount of binder added to the mold required by the standards of relevant countries, industries, groups or enterprises for different classifications of castings based on the sand mold material, use, etc.

[0090] According to an embodiment of the present invention, the target amount of single-layer adhesive added is the amount of adhesive added between two adjacent layers of the m dies, and the target amount of single-layer adhesive added required when forming a single target module is the same.

[0091] In this embodiment, a method is provided in which the target amount of single-layer binder required for the target module is the amount of binder added between two adjacent layers of the m mold pieces, and the target amount of single-layer binder is further accurately determined. The target amount of single-layer binder required for forming a single target module is consistent, so that the preparation method is simplified and the working steps are reduced on the basis of ensuring the sand mold performance and reducing the target amount of binder.

[0092] According to one embodiment of the present invention, based on whether the second yield stress between the n preset modules is consistent or inconsistent, the target amount of single-layer adhesive added required for each of the n target modules is consistent, and the number of mold pieces cut into each of the n preset modules is consistent or inconsistent.

[0093] In this embodiment, by setting the target single-layer binder addition amounts required for n target modules to be consistent regardless of whether the second yield stresses between the n preset modules are consistent or inconsistent, and then adjusting the number of mold pieces cut into the preset modules to be consistent or inconsistent, it is ensured that the target single-layer binder addition amounts required for the n target modules are consistent. Therefore, when preparing the same sand mold, compared with the prior art, the method of this embodiment reduces the target single-layer binder addition amount, reduces the demand for the use of the target single-layer binder addition amount, and reduces production costs.

[0094] Preferably, adjusting the number of mold pieces means adjusting the thickness of the mold pieces, that is, when slicing a single preset module, according to the distribution of the second yield stress of the preset module, when slicing a single preset module, some mold pieces have a large thickness and some mold pieces have a small thickness, and the m mold pieces of a single preset module have different thicknesses, thereby reducing the amount of single-layer binder used while ensuring the performance of the sand mold.

[0095] In some embodiments, according to the inconsistency of the second yield stresses among the n preset modules, the target amount of single-layer adhesive added required for the n target modules is obtained to be consistent, and the number of dies cut from the n preset modules is obtained to be consistent or inconsistent. In this embodiment, according to the consistency or inconsistency of the number of dies cut from the n preset modules, the target amount of single-layer adhesive added required for the n target modules is achieved to be consistent, so that the target amount of single-layer adhesive added is minimized.

[0096] In some embodiments, according to whether the second yield stresses of the n preset modules are consistent or inconsistent, the target amount of single-layer binder added for each of the n target modules is consistent, and the number of mold pieces cut from the n preset modules is consistent, so as to ensure that the total target amount of single-layer binder added is minimal when forming the target large sand mold.

[0097] Example 1

[0098] A method for preparing a rolling compacted nearly formed sand mold comprises the following steps:

[0099] (1) The casting forming simulation software Procast is used to simulate and calculate the casting forming solidification process to obtain the overall yield stress distribution. The three yield stress levels are divided into preset modules according to the first yield stress: 0-400Mpa, the second yield stress: 400-800Mpa, and the third yield stress: 800-1200Mpa;

[0100] (2) According to the yield stress of each preset module, combined with the yield strength of the casting sand material within the stress preset module range, use formula 1: Calculate the required yield strength of each part of the sand mold / core, where X is the target yield strength of the target module, σ m is the maximum yield stress in the preset module, σ Q is the target casting sand material yield strength, Q s is the standard yield strength of the sand mold;

[0101] (3) According to the specific yield strength requirements of each part of the sand mold / core, use Formula 2: Calculate the amount of adhesive added per layer for different target modules, where Y is the target amount of adhesive added per layer for the preset module, X is the target yield strength of the target module, and Q s is the standard yield strength of the sand mold, K is a constant, K=1.32-1.58, P s It is the standard addition amount of single layer binder for sand mold;

[0102] (4) Using computer discretization and layering processing, slice the three-dimensional entity of each target module and generate data on the amount of adhesive injected layer by layer;

[0103] (5) Use 3DP sand mold printing equipment to add sand layer by layer and spray the budgeted amount of binder layer by layer to obtain the required sand mold / core.

[0104] The method of the present invention realizes 3D printing of sand molds / cores with overall differentiated performance.

[0105] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present disclosure, and in actual applications, various changes may be made thereto in form and detail without departing from the scope of the present disclosure.

Claims

1. A method for preparing a sand mold with differentiated performance, characterized in that: The steps include: Build the first sand mold model; The first sand mold has s first yield stresses distributed therein, and at least one of the s first yield stresses is inconsistent, wherein s is a natural number, and s≥1; Using the s first yield stresses to form a first yield stress distribution data set of the first sand mold model; Dividing the first sand mold into n preset modules according to the first yield stress distribution data set, each of the n preset modules having at least one first yield stress, wherein n is a natural number, 1≤n≤s; Among the n preset modules, at least one preset module is distributed with f second yield stresses, the second yield stress is within the range of the first yield stress, and among the f second yield stresses, at least one second yield stress is inconsistent, where f is a natural number, f≥1; Acquire the number of target modules formed into a target sand mold according to the number of the preset modules, wherein the number of the preset modules is consistent with the number of the target modules; According to a single preset module, a single target module is formed, and the method for forming the single target module includes: Obtaining a target casting sand material according to at least one of the second yield stresses in a single preset module; Obtaining the target yield strength of the target module according to the maximum second yield stress among the second yield stresses of the single preset modules and the first yield strength of the target casting sand material; According to the second yield stress distribution of the single preset module, the single preset module is cut into m mold pieces, where m is a natural number, m≥1; According to the target yield strength, obtain the target amount of single-layer adhesive required to form the m mold pieces into the target module; A single target module is obtained by adding the target casting sand material layer by layer and adding the target amount of the single layer binder layer by layer; According to whether the second yield stresses among the n preset modules are consistent or inconsistent, obtaining whether the target amounts of single-layer adhesive required for the n target modules are consistent or inconsistent, and obtaining whether the numbers of the dies cut from the n preset modules are consistent or inconsistent; The target sand mold is formed according to the n target modules.

2. A method for preparing a performance-differentiated sand mold according to claim 1, characterized in that: Among the m mold pieces, the thickness of a single mold piece is obtained according to the third yield stress of the single mold piece and the first yield strength of the target casting sand material, and the third yield stress is within the range of the second yield stress.

3. The method for preparing a performance-differentiated sand mold according to claim 1, characterized in that: The first yield stress distribution data set includes a first yield stress I, a first yield stress II and a first yield stress III, where the first yield stress I≤first yield stress II≤first yield stress III, and the first sand mold is divided into a first preset module, a second preset module and a third preset module according to the first yield stress I, the first yield stress II and the first yield stress III.

4. A method for preparing a performance-differentiated sand mold according to claim 3, characterized in that: The first yield stress I is 0-400 MPa, the first yield stress II is 400-800 MPa, and the first yield stress III is 800-1200 MPa.

5. The method for preparing a performance-differentiated sand mold according to claim 1, characterized in that: The target yield strength of the target module is obtained according to the maximum second yield stress of the preset module, the first yield strength of the target casting sand material and the standard yield strength of the sand mold.

6. The method for preparing a performance-differentiated sand mold according to claim 5, characterized in that: The target yield strength calculation formula of the target module is as follows: ； Where X is the target yield strength of the target module, σ m is the maximum second yield stress in the preset module, σ Q is the target casting sand material yield strength, Q s It is the standard yield strength of sand mold.

7. The method for preparing a performance-differentiated sand mold according to claim 1, characterized in that: The target addition amount of the single layer of binder required for forming the m mold pieces into the target module is obtained according to the target yield strength of the target module, the target yield strength of the casting sand material and the standard addition amount of the single layer of binder of the sand mold.

8. The method for preparing a sand mold with differentiated performance according to claim 7, characterized in that: The calculation formula for the target amount of single-layer adhesive required for the preset module is as follows: ； Among them, Y is the target amount of single-layer adhesive required for the preset module, X is the target yield strength of the target module, Q s is the standard yield strength of the sand mold, K is a constant, K=1.32-1.58, P s This is the standard addition amount of a single layer of binder for sand molds.

9. The method for preparing a sand mold with differentiated performance according to claim 1, characterized in that: The target amount of single-layer adhesive added is the amount of adhesive added between two adjacent layers of the m mold pieces, and the target amount of single-layer adhesive added required when forming a single target module is the same.

10. The method for preparing a sand mold with differentiated performance according to claim 1, characterized in that: According to whether the second yield stresses among the n preset modules are consistent or inconsistent, the target amounts of single-layer adhesive added required for the n target modules are consistent, and the numbers of dies cut from the n preset modules are consistent or inconsistent.

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