A can step-by-step compensation design method based on hot isostatic pressing powder densification process

Abstract

This invention relates to a step-by-step compensation design method for a casing based on the densification process of hot isostatic pressing (HIP), belonging to the field of advanced manufacturing. The method includes the following steps: S1, processing the shape, size, and surface information of the target part using a surface offset method to create a conformal casing with uniform thickness that fits the surface of the target part; S2, simulating the HIP process of the conformal casing and the powder body of the target part using FEM software, and collecting deformation data; S3, processing the deformation data to automatically identify multiple deformation stages in the HIP process; S4, acquiring the deformation characteristics of the multiple deformation stages obtained in step S3, applying different compensation coefficients to each deformation stage, and performing reverse compensation design on the conformal casing and the powder body. This application overcomes the problem of insufficient accuracy in traditional casing design using the above method.

Description

Technical Field

[0001] This invention relates to the field of advanced manufacturing, and in particular to a step-by-step compensation design method for cladding based on the densification process of hot isostatic pressing powder. Background Technology

[0002] Hot isostatic pressing (HIP) technology plays a crucial role in the manufacturing of high-performance, complex structural parts, especially in high-end applications such as aerospace, nuclear industry, and biomedicine. During HIP, the powder undergoes a transformation from loose to dense, accompanied by macroscopic shrinkage deformation. However, current technologies do not compensate for this shrinkage deformation with appropriate encapsulation designs. This results in a significant discrepancy between the actual and predetermined dimensions of the part when it is fully formed within the encapsulation, leading to insufficient encapsulation design precision and low design efficiency. This problem severely hinders the high-precision manufacturing process of parts, causing numerous inconveniences and challenges in related production. Summary of the Invention

[0003] Therefore, it is necessary to provide a step-by-step compensation design method for the cladding based on the densification process of hot isostatic pressing (HIP) powder to address the problem of insufficient cladding design accuracy.

[0004] A step-by-step compensation design method for the cladding based on the densification process of hot isostatic pressing powder, comprising the following steps:

[0005] S1. Obtain the shape, size and surface information of the target part, process the shape, size and surface information of the target part through the surface offset method, create a conformal sleeve that fits the surface of the target part and has a uniform thickness, and establish a finite element model for analyzing the target part and the conformal sleeve in the hot isostatic pressing process.

[0006] S2. Use FEM software to simulate the hot isostatic pressing process of the conformal sleeve and the powder body of the target part, and collect the deformation data of the conformal sleeve and the powder body during the hot isostatic pressing process.

[0007] S3. Process the deformation data to automatically identify multiple deformation stages in the hot isostatic pressing process;

[0008] S4. Obtain the deformation characteristics of the multiple deformation stages of the hot isostatic pressing obtained in step S3, apply different compensation coefficients to the multiple deformation stages respectively, and perform reverse compensation design on the conformal cladding.

[0009] The aforementioned method discloses a step-by-step compensation design method for a casing based on the densification process of hot isostatic pressing (HIP). In the field of traditional casing design, insufficient accuracy and low efficiency have long constrained the development of the manufacturing industry. The step-by-step compensation design method for a casing based on the densification process of HIP disclosed in this application specifically overcomes these problems. First, using surface offset technology, a casing model with a tight fit and uniform thickness is constructed based on the shape, size, and detailed surface information of the target part, and a corresponding finite element model is built. This ensures effective contact between the casing and the powder mesh, guaranteeing sufficient heat and force transfer during HIP and accurately reflecting the compaction deformation of the powder and the coordinated deformation relationship of the casing. Second, advanced FEM software is introduced to simulate the entire HIP process. With the help of simulation, technicians can accurately predict the deformation of the powder and conformal casing in multiple stages of HIP and obtain key deformation data. This data provides a reliable computational basis for subsequent compensation design, ensuring the scientific validity and effectiveness of the compensation strategy. The core highlight of this application is the adoption of a multi-stage compensation strategy, which is highly compatible with the stage characteristics of the hot isostatic pressing (HIP) process. By accurately identifying the deformation characteristics of the conformal sleeve and the powder body of the target part at each stage of HIP, and based on the collected deformation data, different compensation coefficients are applied to optimize the sleeve model in reverse. Simultaneously, by performing reverse compensation on the powder body, the reliability of the method can be verified. In the thermal expansion stage, based on the prediction of the outward expansion trend of the conformal sleeve, the design is reasonably adjusted to prevent abnormal powder flow caused by excessive expansion of the conformal sleeve. In the plastic deformation stage, fine compensation is performed according to the inward deformation requirements of the conformal sleeve to ensure continuous and efficient densification of the powder. In the diffusion creep stage, combined with the further deformation dynamics of the conformal sleeve, the final part is guaranteed to achieve high precision. In the HIP process, the sleeve deformation exhibits obvious stage characteristics, which traditional design methods often fail to fully consider, resulting in limited compensation effects. This method, by automatically identifying multiple deformation stages of hot isostatic pressing, applies different compensation coefficients appropriately based on the unique deformation characteristics of each stage, and inversely optimizes the casing model. This process ensures that the casing provides suitable constraints and support at every critical stage of part forming, minimizing deformation errors, achieving high-precision casing design, and guaranteeing the dimensional accuracy and forming quality of the target part.

[0010] In one embodiment, the plurality of deformation stages include:

[0011] In the thermal expansion stage, which is the initial compaction stage, the conformal sleeve expands due to the increase in temperature. At this time, the pressure has not yet reached the level that causes the conformal sleeve to undergo plastic deformation. Therefore, the conformal sleeve expands outward, the inner cavity volume increases, and the powder flows outward, and the relative density of the powder decreases.

[0012] In the plastic deformation stage, when the external pressure exceeds the thermal expansion effect and the yield strength of the conformal sleeve, the shielding effect of the conformal sleeve weakens, most of the pressure is effectively transmitted to the powder, and the powder softens and undergoes plastic deformation at high temperature, forming closed pores.

[0013] In the diffusion creep stage, as the heat and pressure holding time increases, the initially bonded powder becomes denser through grain boundary diffusion and grain recrystallization, while under continuous pressure, creep deformation occurs and the powder continues to shrink inward.

[0014] In one embodiment, the specific steps of step S1 are as follows:

[0015] S11. Obtain the shape and size of the target part, and construct a three-dimensional model of the powder body and the conformal sleeve based on the shape and size of the target part. The conformal sleeve has a consistent thickness, and the cavity shape and size of the conformal sleeve match the model of the powder body.

[0016] S12. Establish a finite element model, which includes setting the powder material parameters of the target part, the conformal sleeve material parameters, the constitutive model, the mesh model, the contact relationship, and the load curve.

[0017] Based on the shape and size characteristics of the target part, a three-dimensional model of the powder body and the conformal sleeve is constructed. When constructing the conformal sleeve, its thickness is ensured to be uniform and its cavity shape and dimensions match the powder body model of the target part. This ensures effective contact between the sleeve mesh and the powder mesh in the finite element simulation, achieving accurate transfer of thermal-mechanical loads and reasonable simulation of deformation response. The powder material parameters of the target part, the conformal sleeve material parameters, the constitutive model, the mesh model, the contact relationship, and the load curves are set. The temperature, pressure, and material response characteristics in the hot isostatic pressing process are quantified into calculable finite element input data, providing complete and accurate boundary conditions and physical parameters for the finite element simulation. This enables technicians to accurately obtain the deformation and mechanical response of the sleeve and powder at each stage.

[0018] In one embodiment, the powder material parameters in step S12 include:

[0019] General parameters, including density, Poisson's ratio, and initial relative density;

[0020] Thermophysical parameters, including specific heat capacity, thermal conductivity and coefficient of thermal expansion;

[0021] Mechanical parameters that vary with temperature, including Young's modulus and yield stress.

[0022] In one embodiment, the specific steps of step S2 are as follows:

[0023] S21. Based on the finite element model established in step S1, the entire process of hot isostatic pressing of the powder and the conformal cladding is simulated using the implicit thermo-mechanical coupling module of the FEM software.

[0024] S22. Define the required output variables, including the nodal coordinates, displacement, temperature, stress and strain of the powder body and the conformal sleeve, and the relative density of the powder body, and record the deformation data of the powder body and the conformal sleeve throughout the hot isostatic pressing process in the output database Odb file.

[0025] By utilizing the implicit thermo-mechanical coupling module of FEM software, the entire hot isostatic pressing process of the powder body and conformal cladding is simulated, acquiring deformation data under different temperatures and pressures, including nodal coordinates, displacements, and stress-strain information. This data accurately reflects the actual position and trajectory of the powder body and cladding at each stage of hot isostatic pressing, providing a reliable spatial and mechanical basis for subsequent staged compensation design. This step serves to provide a quantitative basis for the reverse compensation of the cladding, enabling the compensation design to closely adapt to actual deformation characteristics, thereby ensuring the stability of the powder densification process and the high precision of part forming. All key data are recorded in the output database (Odb) file, providing complete information for subsequent compensation calculations and finite element verification.

[0026] In one embodiment, the specific steps of step S3 are as follows:

[0027] S31. Use the data processing module to call the Odb file and obtain the node and cell information of the powder body and the conformal envelope from the mesh object of the Odb file;

[0028] S32. Calculate and obtain the coordinate data of the nodes of the powder body and the coordinate data of the nodes of the conformal encapsulation;

[0029] S33. Output the coordinate data of the nodes of the powder body and the coordinate data of the nodes of the conformal sleeve, use the data processing module to track the deformation trajectory of each node of the conformal sleeve and study the curve of the material densification process of the powder body changing with time, and automatically identify multiple deformation stages in the hot isostatic pressing process.

[0030] By calling an Odb file using Python code, node and element information of the powder body and conformal casing is extracted from the finite element mesh object. This data is then processed to calculate the coordinates and displacements of each node throughout the entire hot isostatic pressing (HIP) process. The resulting coordinate data accurately reflects the spatial position and deformation trajectory of the powder body and casing at different time points. Based on this dynamic information, each deformation stage in the HIP process can be automatically identified, and the node displacement data of the conformal casing and powder body at each stage can be obtained. This provides a quantitative basis for subsequent staged anti-deformation compensation design, ensuring that the compensation design closely adapts to the actual deformation characteristics and improves forming accuracy.

[0031] In one embodiment, the specific steps of S4 are as follows:

[0032] S41. Use the data processing module to obtain the coordinates and displacement of the nodes of the conformal sleeve and the nodes of the powder body at each time point, and calculate the displacement of the nodes of the powder body and the nodes of the conformal sleeve in the multiple deformation stages of the hot isostatic pressing.

[0033] S42. Calculate the anti-deformation compensation amount for each node of the powder body and the node of the conformal sleeve in each deformation stage, wherein the anti-deformation compensation amount is equal to the displacement of the deformation stage multiplied by the compensation coefficient corresponding to the deformation stage.

[0034] In one embodiment, the compensation coefficient in step S42 is different in multiple deformation stages, and the method for determining the compensation coefficient in different deformation stages is based on data fitting and multiphysics coupling analysis.

[0035] Data fitting is based on extensive historical experimental and simulation data of hot isostatic pressing (HIP) processes. By extracting working conditions and material properties similar to the current part design, key parameters at each stage are obtained, ensuring that the compensation coefficients accurately reflect actual deformation requirements. Multiphysics coupling analysis comprehensively considers the influence of thermal field, force field, and material deformation on the cladding and powder body, including thermal expansion caused by temperature, plastic deformation under external pressure, and the response of material properties to temperature changes. The compensation coefficients obtained through these methods ensure that the reverse compensation of the conformal cladding closely matches the actual deformation of the powder body during the thermal expansion, plastic deformation, and diffusion creep stages. This achieves high-precision cladding design, guaranteeing the forming accuracy and densification quality of the target part.

[0036] In one embodiment, step S4 is followed by the following step:

[0037] S5. Perform finite element simulation verification on the conformal sleeve after compensation in S4.

[0038] By performing finite element simulation on the conformal sleeve after reverse compensation, the effectiveness of the compensation design and the fitting accuracy between the powder and the sleeve can be quantitatively evaluated. During the simulation, the constraint effect of the compensated sleeve on the powder can be accurately analyzed, and the matching of the two in terms of size and shape can be verified. This step can provide feedback for the design scheme. If deviations are found between the simulation results and expectations, the compensation coefficient or the geometric parameters of the sleeve can be adjusted to ensure that the final part meets the design requirements in terms of forming accuracy and densification quality.

[0039] In one embodiment, the specific steps of S5 are as follows:

[0040] S51. Based on the compensated conformal envelope automatically generated in step S4, repeat the finite element simulation method of S1 and S2.

[0041] S52. By comparing the simulation results with the target part, verify the design accuracy of the compensated conformal sleeve.

[0042] By repeatedly building the model and performing finite element simulations, the actual state of the conformal sleeve and powder body after compensation can be accurately reproduced, and the compensation parameters can be fully incorporated into the model, providing a reliable basis for subsequent analysis. Key data such as temperature, pressure, and deformation obtained during the simulation can be used to evaluate the matching accuracy of the sleeve design and optimize the compensation scheme accordingly, ensuring that the parts achieve high-precision near-net-shape forming requirements in terms of size, shape, and densification. Attached Figure Description

[0043] Figure 1 This is a flowchart illustrating the step-by-step compensation design method for the cladding based on the densification process of hot isostatic pressing powder.

[0044] Figure 2 Flowchart for modeling the target part, constructing the conformal fitting, and building the finite element model;

[0045] Figure 3 This is a flowchart of data acquisition for powder and conformal packaging during hot isostatic pressing.

[0046] Figure 4 A flowchart for identifying multiple deformation stages in hot isostatic pressing;

[0047] Figure 5 Flowchart for the design of conformal encapsulation and multi-stage compensation for powder;

[0048] Figure 6 Flowchart for accuracy verification of conformal sheath design;

[0049] Figure 7 This is a process curve diagram of titanium alloy powder during hot isostatic pressing;

[0050] Figure 8 This is a schematic diagram of the relative density distribution and deformation of the cladding and the part after hot isostatic pressing.

[0051] Figure 9 The graph shows the change in the powder densification process over time.

[0052] Figure 10 Schematic diagram of compensation design for parts and housings;

[0053] Figure 11 A schematic diagram of the finite element simulation of the model after compensation design;

[0054] Figure 12 A schematic diagram comparing the shape of the designed casing after hot isostatic pressing with that of the target part. Detailed Implementation

[0055] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0056] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0057] The following describes, with reference to the accompanying drawings, a step-by-step compensation design method for the cladding based on the densification process of hot isostatic pressing powder, according to some embodiments of the present invention. Example 1

[0058] like Figures 1 to 6 As shown, this embodiment discloses a step-by-step compensation design method for the cladding based on the densification process of hot isostatic pressing powder, including the following steps:

[0059] S1. Obtain the shape, size and surface information of the target part, process the shape, size and surface information of the target part through the surface offset method, create a conformal sleeve that fits the surface of the target part and has a uniform thickness, and establish a finite element model for analyzing the target part and the conformal sleeve in the hot isostatic pressing process.

[0060] S2. Use FEM software to simulate the hot isostatic pressing process of the conformal sleeve and the powder body of the target part, and collect the deformation data of the conformal sleeve and the powder body during the hot isostatic pressing process.

[0061] S3. Process the deformation data and automatically identify multiple deformation stages in the hot isostatic pressing process;

[0062] S4. Obtain the deformation characteristics of multiple deformation stages of hot isostatic pressing obtained in step S3, apply different compensation coefficients to each deformation stage, and perform reverse compensation design for conformal cladding and powder body.

[0063] This application discloses a step-by-step compensation design method for cladding based on the densification process of hot isostatic pressing (HIP), which addresses the problems of insufficient accuracy and low efficiency in traditional cladding design. The method first constructs a three-dimensional model of the powder body and a conformal cladding with uniform thickness, based on the shape, size, and surface information of the target part. This ensures effective mesh contact between the cladding and the powder body, enabling thermo-mechanical coupling transfer and contact deformation analysis. A corresponding finite element model is then established, setting the powder and cladding material parameters, constitutive model, mesh model, contact relationship, and load curves, providing a reliable data foundation for subsequent simulations. Subsequently, the implicit thermo-mechanical coupling module of FEM software is used to simulate the entire HIP process, obtaining key deformation data such as nodal coordinates, displacement, and stress-strain of the conformal cladding and powder body at different stages, providing accurate basis for reverse compensation design. The core innovation lies in the step-by-step compensation strategy: by automatically identifying three deformation stages—thermal expansion, plastic deformation, and diffusion creep—the deformation characteristics of the conformal cladding and powder body at each stage are analyzed. Based on data fitting and multiphysics coupling analysis, compensation coefficients for different stages are determined, and the cladding model is optimized in reverse. During the thermal expansion stage, the encapsulation design is adjusted to control the initial expansion behavior of the powder; during the plastic deformation stage, adaptive compensation is applied to improve the powder densification efficiency; and during the diffusion creep stage, the encapsulation constraints are optimized to ensure the final dimensional and shape accuracy of the part. This method can accurately reflect the mechanical effect of the encapsulation on the powder throughout the entire hot isostatic pressing process, reduce molding deformation errors, achieve high-precision encapsulation design, and ensure the dimensional accuracy and forming quality of the target part.

[0064] like Figures 1 to 6 As shown, in addition to the features of the above embodiments, this embodiment further defines: multiple modification stages include:

[0065] In the thermal expansion stage, which is the initial compaction stage, the conformal sleeve expands due to the increase in temperature. At this time, the pressure has not yet reached the level that causes the conformal sleeve to undergo plastic deformation. Therefore, the conformal sleeve expands outward, the inner cavity volume increases, and the powder flows outward, resulting in a decrease in the relative density of the powder.

[0066] In the plastic deformation stage, when the external pressure exceeds the thermal expansion effect and the yield strength of the conformal cladding, the shielding effect of the conformal cladding weakens, most of the pressure is effectively transferred to the powder, the powder softens at high temperature and undergoes plastic deformation, forming closed pores.

[0067] In the diffusion creep stage, as the heat and pressure holding time increases, the initially bonded powder becomes denser through grain boundary diffusion and grain recrystallization. At the same time, under continuous pressure, creep deformation occurs, causing the powder to continue to shrink inward.

[0068] like Figure 1 and Figure 2 As shown, in addition to the features of the above embodiments, this embodiment further defines the specific steps of step S1 as follows:

[0069] S11. Obtain the shape and size of the target part, and construct a three-dimensional model of the powder body and the conformal sleeve based on the shape and size of the target part. The thickness of the conformal sleeve is consistent, and the cavity shape and size of the conformal sleeve match the model of the powder body.

[0070] S12. Establish a finite element model, which includes setting the powder material parameters of the target part, the conformal packaging material parameters, the constitutive model, the mesh model, the contact relationship, and the load curve.

[0071] Based on the shape and size characteristics of the target part, a 3D model of the powder body and its corresponding conformal sleeve is constructed. When constructing the conformal sleeve, uniform thickness and a cavity shape and size are ensured to strictly match the target part powder body to guarantee effective contact between the sleeve and the powder mesh, enabling thermal-mechanical coupling transfer and contact deformation analysis. Simultaneously, powder material parameters, sleeve material parameters, constitutive model, mesh model, contact relationships, and load curves are set, quantifying the complex hot isostatic pressing process into computationally usable data. This operation allows for the early acquisition of the mechanical response and deformation characteristics of the conformal sleeve and powder body during hot isostatic pressing, providing a reliable data foundation for subsequent staged compensation design, ensuring a scientifically effective compensation strategy, and improving the final part's forming accuracy and structural integrity.

[0072] like Figures 1 to 6 As shown, in addition to the features of the above embodiments, this embodiment further defines the powder material parameters in step S12 as follows:

[0073] Common parameters include density, Poisson's ratio, and initial relative density.

[0074] Thermal properties include specific heat capacity, thermal conductivity, and coefficient of thermal expansion.

[0075] Mechanical parameters that vary with temperature include Young's modulus and yield stress.

[0076] like Figure 1 and Figure 3 As shown, in addition to the features of the above embodiments, this embodiment further defines the specific steps of step S2 as follows:

[0077] S21. Based on the finite element model established in step S1, use the implicit thermo-coupling module of FEM software to simulate the entire process of hot isostatic pressing of powder and conformal cladding.

[0078] S22. Define the required output variables, including the nodal coordinates, displacement, temperature, stress and strain of the powder body and conformal cladding, and the relative density of the powder body, and record the deformation data of the entire hot isostatic pressing process of the powder body and conformal cladding in the output database Odb file.

[0079] Numerical simulations of the entire hot isostatic pressing (HIP) process of powder and conformal cladding were performed using the implicit thermo-mechanical coupling module of FEM software. This allowed for the acquisition of displacement, stress, strain, and nodal coordinates at each stage, accurately reflecting their spatial position and deformation path during HIP. Based on this key data, engineers could identify the deformation characteristics of the powder and cladding, providing a reliable basis for subsequent staged reverse compensation design. During the thermal expansion stage, targeted compensation could be performed by analyzing the outward expansion trend of the cladding to maintain the stability of the initial powder distribution. During the plastic deformation stage, the compensation amount was adjusted according to the deformation behavior of the cladding and powder to optimize pressure transmission and promote pore closure and densification. During the diffusion creep stage, fine compensation was performed in conjunction with overall shrinkage dynamics to ensure that the powder fully completed its microscopic deformation, eliminating residual porosity and ensuring the final forming accuracy of the part. The stress and strain data were further used to optimize the mechanical structure design of the cladding, enabling the cladding and powder to deform collaboratively under high pressure, ensuring the stability and orderliness of the forming process. All simulation results are recorded in the Odb file, providing detailed data support for subsequent compensation design, thereby ensuring that the conformal sleeve design can scientifically and accurately adapt to the deformation characteristics of the entire hot isostatic pressing process.

[0080] like Figure 1 and Figure 4 As shown, in addition to the features of the above embodiments, this embodiment further defines the specific steps of step S3 as follows:

[0081] S31. Use the data processing module to call the Odb file and obtain the node and element information of the powder body and conformal envelope from the mesh object in the Odb file;

[0082] S32. Calculate and obtain the coordinate data of the nodes of the powder body and the coordinate data of the nodes of the conformal wrapping.

[0083] S33. Output the coordinate data of the nodes of the powder body and the coordinate data of the nodes of the conformal sleeve. Use the data processing module to track the deformation trajectory of each node of the conformal sleeve and study the curve of the material densification process of the powder body changing with time. Automatically identify multiple deformation stages in the hot isostatic pressing process.

[0084] By calling Odb files using Python code, node and element information of the powder body and conformal sleeve is obtained from the finite element mesh object. Systematic data processing and calculations are then performed to accurately obtain the coordinates and displacement data of each node throughout the entire hot isostatic pressing (HIP) process. This data digitally presents the actual position and trajectory of the powder body and conformal sleeve at different stages. By analyzing their displacement over time, different deformation stages during HIP can be identified. Based on these staged deformation characteristics, technicians can calculate precise anti-deformation compensation for each node, providing a reliable data foundation for subsequent staged compensation design. This ensures that the conformal sleeve design closely matches the actual deformation, improving the accuracy and consistency of part forming.

[0085] like Figure 1 and Figure 5 As shown, in addition to the features of the above embodiments, this embodiment further defines the specific steps of S4 as follows:

[0086] S41. Use the data processing module to obtain the coordinates and displacement of the nodes of the conformal cladding and the powder body at each time point, and calculate the displacement of the nodes of the powder body and the nodes of the conformal cladding in multiple deformation stages of hot isostatic pressing.

[0087] S42. Calculate the anti-deformation compensation amount of each powder body node and the conformal sleeve node in each deformation stage. The anti-deformation compensation amount is equal to the displacement in the deformation stage multiplied by the compensation coefficient of the corresponding deformation stage.

[0088] This study uses Python code to obtain the coordinates and displacement information of each node of the conformal sleeve and powder body during the entire hot isostatic pressing process, and calculates the displacement at different deformation stages, providing a precise data foundation for process control and compensation design. Using this displacement data, the dynamic changes of the conformal sleeve and powder body at each stage can be clearly reflected, providing a reliable basis for identifying deformation trends and potential anomalies. Based on the displacement and the corresponding compensation coefficients for each stage, the anti-deformation compensation amount for each node is calculated to adjust the actual deformation of the conformal sleeve and powder body, bringing them closer to the design expectation. For the conformal sleeve, anti-deformation compensation can effectively offset excessive expansion or abnormal contraction, ensuring uniform pressure on the powder body, promoting uniform densification, and reducing the risk of local defects. For the powder body, compensation can correct uneven compaction or porosity anomalies caused by early process fluctuations, ensuring that it densifies according to a predetermined trajectory, achieving high precision in internal structure and external dimensions. The purpose of this step is to achieve efficient coordinated deformation of the conformal cladding and the powder body through precise quantification and staged compensation, so as to provide a reliable guarantee for the dimensional accuracy, structural density and overall forming quality of the parts in the subsequent hot isostatic pressing process.

[0089] like Figure 5As shown, in addition to the features of the above embodiments, this embodiment further specifies that: the compensation coefficient of step S42 is different in multiple deformation stages, and the method for determining the compensation coefficient of different deformation stages is based on data fitting and multiphysics coupling analysis.

[0090] The determination of compensation coefficients integrates data fitting and multiphysics coupling analysis. Data fitting integrates data accumulated from extensive past hot isostatic pressing (HIP) processes, extracting deformation patterns under different working conditions and material properties. This yields key parameters highly compatible with current process conditions, ensuring the compensation coefficients reflect actual needs and providing a reliable basis for anti-deformation compensation calculations. Multiphysics coupling analysis considers the interaction of multiple factors, including heat, force, and material deformation, comprehensively evaluating the influence of the temperature field on the thermal expansion of the cladding and powder, the regulatory effect of the pressure field on deformation trends, and the response of material properties to changes in different physical fields. The compensation coefficients obtained through these methods can accurately compensate for conformal cladding at different stages, such as thermal expansion, plastic deformation, and diffusion creep, ensuring a high degree of matching between its deformation and powder behavior. This effectively improves the dimensional accuracy and internal structural density of the parts. The purpose of this step is to provide staged, targeted compensation coefficients through scientific calculation and multi-factor comprehensive analysis, laying a data foundation for high-precision design of conformal cladding and stable forming during the HIP process.

[0091] like Figure 1 As shown, in addition to the features of the above embodiments, this embodiment further specifies that: after step S4, the following steps are also included:

[0092] S5. Perform finite element simulation verification on the conformal envelope after compensation in S4.

[0093] By performing finite element simulation on the conformal sleeve after reverse compensation, the effectiveness of the compensation design and the matching accuracy between the powder and the sleeve can be systematically evaluated. In this step, the deformation and densification of the powder under the constraint of the compensated sleeve, as well as the fit between the sleeve and the powder in terms of size and shape, can be obtained through simulation, thereby determining whether the compensation meets the design objectives. If the simulation results show deviations, the compensation parameters or sleeve design scheme can be adjusted retrospectively based on the analysis results to ensure that the final part meets high standards in terms of dimensional accuracy, shape fit, and internal densification.

[0094] like Figure 1 and Figure 6 As shown, in addition to the features of the above embodiments, this embodiment further defines the specific steps of S5 as follows:

[0095] S51. Based on the compensated conformal envelope automatically generated in step S4, repeat the finite element simulation method of S1 and S2.

[0096] S52. By comparing the simulation results with the target part, verify the design accuracy of the compensated conformal sleeve. Example 2

[0097] like Figures 7 to 12 As shown, this embodiment discloses a step-by-step compensation design method for the cladding based on the densification process of hot isostatic pressing powder, including the following steps:

[0098] S1. Obtain the shape, size and surface information of the target part, process the shape, size and surface information of the target part through the surface offset method, create a conformal sleeve that fits the surface of the target part and has a uniform thickness, and establish a finite element model for analyzing the target part and the conformal sleeve in the hot isostatic pressing process.

[0099] S2. Use FEM software to simulate the hot isostatic pressing process of the conformal sleeve and the powder body of the target part, and collect the deformation data of the conformal sleeve and the powder body during the hot isostatic pressing process.

[0100] S3. Process the deformation data to automatically identify multiple deformation stages in the hot isostatic pressing process;

[0101] S4. Obtain the deformation characteristics of the multiple deformation stages of the hot isostatic pressing obtained in step S3, apply different compensation coefficients to the multiple deformation stages respectively, and perform reverse compensation design on the conformal cladding.

[0102] S5. Perform finite element simulation verification on the compensated conformal cladding model obtained in step S4.

[0103] like Figures 7 to 12 As shown, in addition to the features of the above embodiments, this embodiment further defines the following specific steps in S1:

[0104] S11, according to... Figure 8 Based on the shape and size of the target part shown, construct a 3D model of the conformal sleeve; the conformal sleeve is a conformal structure with uniform thickness, set to 2 mm;

[0105] S12. Establish the finite element model, including setting the powder material parameters, conformal cladding material parameters, constitutive model, mesh model, contact relationship, and load curve;

[0106] S13. The powder material is selected from titanium alloy (Ti-6Al-4V), with general parameters including density of 4.4 g / cm³. 3 It has a Poisson's ratio of 0.3 and an initial relative density of 0.67; its thermal properties include a thermal conductivity of 6.8–11.8 W / (m·K) and a coefficient of thermal expansion of 9.0–10.3 × 10⁻⁶ W / (m·K). -6 / ℃, specific heat 611-712 J / (kg･K); mechanical parameters include Young's modulus 71-103 GPa, yield stress 30-1050 MPa. To ensure mesh quality during reverse deformation, tetrahedral meshes are selected, with linear "temperature-displacement coupling" element type and mesh element size of 3-6 mm. The frictional behavior between the conformal sleeve and the powder body is set to "penalty friction," with a friction coefficient of 0.8-1.0; normal contact is "hard contact"; to reduce computational resource requirements, symmetrical boundary conditions are used on the XY section to simulate 1 / 4 of the part to reflect the overall situation; based on the titanium alloy hot isostatic pressing process, synchronous loading is adopted, and the pressure-temperature curves are as follows. Figure 9 As shown, a pressure load is applied to the outer surface of the conformal cladding, and a temperature load is applied to the nodes on the outer surface of the conformal cladding mesh, with an initial temperature of 25 ℃.

[0107] like Figure 8 As shown, in addition to the features of the above embodiments, this embodiment further defines the specific implementation method of step S2 as including the following steps:

[0108] S21. Based on the finite element model established in step S1, use the implicit thermo-coupling module of FEM software to simulate the entire process of hot isostatic pressing of the powder and the conformal cladding.

[0109] S22. Define the required output variables, including the nodal coordinates, displacement, temperature, stress and strain of the powder body and conformal cladding, and the relative density of the powder body, and record the deformation data of the entire hot isostatic pressing process of the powder body and conformal cladding in the output database Odb file.

[0110] like Figure 9 and Figure 10 As shown, in addition to the features of the above embodiments, this embodiment further defines the specific implementation method of step S3 as including the following steps:

[0111] S31. Use the data processing module to call the Odb file and obtain the node and element information of the powder body and conformal envelope from the mesh object in the Odb file;

[0112] S32. Calculate and obtain the coordinate data of the nodes of the powder body and the coordinate data of the nodes of the conformal wrapping.

[0113] S33. Output the coordinate data of the nodes of the powder body and the coordinate data of the nodes of the conformal sleeve. Use the data processing module to track the deformation trajectory of each node of the conformal sleeve and study the curve of the material densification process of the powder body changing with time. Automatically identify multiple deformation stages in the hot isostatic pressing process.

[0114] like Figure 10As shown, in addition to the features of the above embodiments, this embodiment further defines the specific implementation method of step S4 as including the following steps:

[0115] S41. Use the data processing module to obtain the coordinates and displacement of the nodes of the conformal cladding and the powder body at each time point, and calculate the displacement of the nodes of the powder body and the nodes of the conformal cladding in multiple deformation stages of hot isostatic pressing.

[0116] S42. Calculate the anti-deformation compensation amount of each powder body node and the conformal sleeve node in each deformation stage. The anti-deformation compensation amount is equal to the displacement in the deformation stage multiplied by the compensation coefficient of the corresponding deformation stage.

[0117] S43. The method for determining the compensation coefficients for each stage is mainly through fitting based on empirical data and multi-physics coupling analysis. For this titanium alloy part, the compensation coefficients corresponding to the thermal expansion stage, plastic deformation stage and diffusion creep stage are 1.0, 1.2 and 1.0, respectively.

[0118] S44. After obtaining the compensated mesh node coordinates, the conformal mesh model is reconstructed based on the compensated mesh node coordinates and the original mesh connection information.

[0119] like Figure 11 and Figure 12 As shown, in addition to the features of the above embodiments, this embodiment further defines the specific implementation method of step S5 as including the following steps:

[0120] S51. Based on the compensated conformal envelope automatically generated in step S4, repeat the finite element simulation method of S1 and S2.

[0121] S52. By comparing the simulation results with the target part, verify the design accuracy of the compensated conformal sleeve.

[0122] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0123] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A step-by-step compensation design method for cladding based on the densification process of hot isostatic pressing powder, characterized in that, The described step-by-step compensation design method for the cladding based on the densification process of hot isostatic pressing powder includes the following steps: S1. Obtain the shape, size and surface information of the target part, process the shape, size and surface information of the target part through the surface offset method, create a conformal sleeve that fits the surface of the target part and has a uniform thickness, and establish a finite element model for analyzing the target part and the conformal sleeve in the hot isostatic pressing process. S2. Use FEM software to simulate the hot isostatic pressing process of the conformal sleeve and the powder body of the target part, and collect the deformation data of the conformal sleeve and the powder body during the hot isostatic pressing process. S3. Process the deformation data to automatically identify multiple deformation stages in the hot isostatic pressing process; S4. Obtain the deformation characteristics of the multiple deformation stages of the hot isostatic pressing obtained in step S3, apply different compensation coefficients to the multiple deformation stages respectively, and perform reverse compensation design on the conformal cladding. The multiple deformation stages include: In the thermal expansion stage, which is the initial compaction stage, the conformal sleeve expands due to the increase in temperature. At this time, the pressure has not yet reached the level that causes the conformal sleeve to undergo plastic deformation. Therefore, the conformal sleeve expands outward, the inner cavity volume increases, and the powder flows outward, and the relative density of the powder decreases. In the plastic deformation stage, when the external pressure exceeds the thermal expansion effect and the yield strength of the conformal sleeve, the shielding effect of the conformal sleeve weakens, most of the pressure is effectively transmitted to the powder, and the powder softens and undergoes plastic deformation at high temperature, forming closed pores. In the diffusion creep stage, as the heat and pressure holding time increases, the initially bonded powder becomes denser through grain boundary diffusion and grain recrystallization, while under continuous pressure, creep deformation occurs and the powder continues to shrink inward.

2. The cladding step-by-step compensation design method based on the densification process of hot isostatic pressing powder according to claim 1, characterized in that, The specific steps of step S1 are as follows: S11. Obtain the shape and size of the target part, and construct a three-dimensional model of the powder body and the conformal sleeve based on the shape and size of the target part. The conformal sleeve has a consistent thickness, and the cavity shape and size of the conformal sleeve match the model of the powder body. S12. Establish a finite element model, which includes setting the powder material parameters of the target part, the conformal sleeve material parameters, the constitutive model, the mesh model, the contact relationship, and the load curve.

3. The cladding step-by-step compensation design method based on the densification process of hot isostatic pressing powder according to claim 2, characterized in that, The powder material parameters in step S12 include: General parameters, including density, Poisson's ratio, and initial relative density; Thermophysical parameters, including specific heat capacity, thermal conductivity and coefficient of thermal expansion; Mechanical parameters that vary with temperature, including Young's modulus and yield stress.

4. The cladding step-by-step compensation design method based on the densification process of hot isostatic pressing powder according to claim 1, characterized in that, The specific steps of step S2 are as follows: S21. Based on the finite element model established in step S1, the entire process of hot isostatic pressing of the powder and the conformal cladding is simulated using the implicit thermo-mechanical coupling module of the FEM software. S22. Define the required output variables, including the nodal coordinates, displacement, temperature, stress and strain of the powder body and the conformal sleeve, and the relative density of the powder body, and record the deformation data of the powder body and the conformal sleeve throughout the hot isostatic pressing process in the output database Odb file.

5. The cladding step-by-step compensation design method based on the densification process of hot isostatic pressing powder according to claim 4, characterized in that, The specific steps of step S3 are as follows: S31. Use the data processing module to call the Odb file and obtain the node and cell information of the powder body and the conformal envelope from the mesh object of the Odb file; S32. Calculate and obtain the coordinate data of the nodes of the powder body and the coordinate data of the nodes of the conformal encapsulation; S33. Output the coordinate data of the nodes of the powder body and the coordinate data of the nodes of the conformal sleeve, use the data processing module to track the deformation trajectory of each node of the conformal sleeve and study the curve of the material densification process of the powder body changing with time, and automatically identify multiple deformation stages in the hot isostatic pressing process.

6. The cladding step-by-step compensation design method based on the densification process of hot isostatic pressing powder according to claim 5, characterized in that, The specific steps of S4 are as follows: S41. Use the data processing module to obtain the coordinates and displacement of the nodes of the conformal sleeve and the nodes of the powder body at each time point, and calculate the displacement of the nodes of the powder body and the nodes of the conformal sleeve in the multiple deformation stages of the hot isostatic pressing. S42. Calculate the anti-deformation compensation amount for each node of the powder body and the node of the conformal sleeve in each deformation stage, wherein the anti-deformation compensation amount is equal to the displacement of the deformation stage multiplied by the compensation coefficient corresponding to the deformation stage.

7. The cladding step-by-step compensation design method based on the densification process of hot isostatic pressing powder according to claim 6, characterized in that, The compensation coefficient in step S42 is different in multiple deformation stages, and the method for determining the compensation coefficient in different deformation stages is based on data fitting and multiphysics coupling analysis.

8. The cladding step-by-step compensation design method based on the densification process of hot isostatic pressing powder according to claim 1, characterized in that, The following steps are included after step S4: S5. Perform finite element simulation verification on the conformal sleeve after compensation in S4.

9. The cladding step-by-step compensation design method based on the densification process of hot isostatic pressing powder according to claim 8, characterized in that, The specific steps of S5 are as follows: S51. Based on the compensated conformal envelope automatically generated in step S4, repeat the finite element simulation method of S1 and S2. S52. By comparing the simulation results with the target part, verify the design accuracy of the compensated conformal sleeve.

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