Complex thin-walled special-shaped ring based on heterogeneous material cladding and near-net forming method thereof
By wrapping the titanium alloy ring with a dissimilar material, additional stiffness is provided, which solves the problems of insufficient stiffness and precision in the forming process of large-sized titanium alloy thin-walled rings, achieving efficient and low-cost near-net-shape forming and improving material utilization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIHANG UNIV
- Filing Date
- 2026-04-07
- Publication Date
- 2026-06-30
AI Technical Summary
Existing ring rolling technology is difficult to achieve near-net-shape forming of large-sized titanium alloy irregular thin-walled ring parts. It suffers from problems such as insufficient stiffness, easy instability, uneven wall thickness and excessive ellipticity. In addition, it is difficult to invest in equipment and debug the process, and the material utilization rate is low.
A near-net-shape forming method for complex thin-walled irregular ring parts using dissimilar material cladding is proposed. This method provides additional stiffness by cladding the titanium alloy blank with a dissimilar material, and then removes the cladding after rolling to achieve high-precision near-net-shape forming.
Without modifying existing equipment, the forming accuracy and material utilization of titanium alloy rings were improved, processing costs and energy consumption were reduced, and the problem of forming limit thickness constraint caused by insufficient rigidity in traditional processes was solved.
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Figure CN122298900A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of material plastic forming technology, and in particular to a complex thin-walled irregular ring based on a foreign material cladding and its near-net-shape forming method. Background Technology
[0002] Titanium alloys, due to their excellent comprehensive mechanical properties such as high specific strength, high temperature resistance, corrosion resistance, and fatigue resistance, are widely used in high-end equipment manufacturing fields such as aviation, aerospace, marine, weaponry, energy, and machinery. For example, key load-bearing components such as aero-engine and gas turbine casings, wind turbine flanges, rocket propellant tank connecting rings, and high-end bearing rings all rely on ring rolling forming technology. However, existing ring rolling forming technology still faces significant technical bottlenecks.
[0003] While ring rolling, as a localized, progressive plastic forming process, can theoretically achieve near-net-shape forming through precise metal volume transfer, in the actual rolling process of large-sized titanium alloy thin-walled rings, the overall structural stiffness decreases sharply as the ring diameter increases and the wall thickness decreases. This makes the rings highly susceptible to buckling instability or vibration, leading to loss of dimensional accuracy and making it difficult to achieve stable net-size forming. Furthermore, existing ring rolling technologies suffer from excessive subsequent machining workload, uneven wall thickness, and excessive ellipticity during rolling. They also place extremely high demands on the stiffness of the ring rolling equipment and the precision of process parameter control, increasing equipment investment costs and the difficulty of process debugging, thus hindering large-scale application in small to medium batch production.
[0004] The core root cause of the aforementioned problems lies in the inherent lack of stiffness of titanium alloys at ring rolling temperatures. Existing technologies can only delay instability by optimizing equipment structure and process parameters, failing to fundamentally solve the problem of insufficient stiffness during the forming process of titanium alloy rings. CN119426376A discloses a method for analyzing the forming process of large irregularly shaped rings, improving the accuracy of ring rolling process analysis and defect prediction through dynamic material property modeling and multi-physics coupling analysis. CN121402543A proposes a design method for complex irregularly shaped ring rolling preforms with internal and external grooves based on metal flow control. This method effectively promotes metal filling of the cavity and avoids underfill defects, but it is difficult to achieve near-net-shape forming of irregularly shaped rings. CN121289371A introduces a method to achieve near-net-shape forming of casing forgings through optimized irregularly shaped billet preparation and irregularly shaped ring rolling processes, optimizing product allowances and improving raw material utilization. CN121104566A proposes an in-mold forging and rolling composite precision forming method. By controlling metal flow through pre-forming material distribution and final forming resistance grooves, it solves the problem of difficult integral forming of ribbed shell sections, enabling near-net-shape forming of highly ribbed thin-walled structures. However, for large-sized irregularly shaped titanium alloy thin-walled ring parts, due to their complex cross-sections, excessively thin walls, and enormous dimensions, instability and deformation due to insufficient stiffness are inevitable during near-net-shape forming. To achieve precise forming of large-sized ring parts, corresponding process supplements must be designed, i.e., design allowances based on the final cross-section. However, this reduces material utilization and increases costs. Summary of the Invention
[0005] In order to solve the problems existing in the prior art, the present invention provides the following technical solution.
[0006] The first aspect of this invention provides a near-net-shape forming method for complex thin-walled irregularly shaped rings based on dissimilar material cladding, comprising: Determine the required blank material and cross-sectional allowance of the same material for the target ring rolling forming; Based on the aforementioned cross-sectional allowance, a dissimilar material cladding is determined; the stiffness of the dissimilar material is higher than that of the main blank. Production of the main blank and the encapsulation of dissimilar materials; A dissimilar material is wrapped around the outside of the main body blank and then ring rolled to obtain an initial ring. Remove the outer sleeve from the initial ring to obtain the target ring.
[0007] Preferably, the method further includes: Based on the cross-sectional allowance and the main blank, a three-dimensional model of the initial blank is constructed. Finite element simulation was performed on the ring rolling process of the initial three-dimensional billet model to obtain the deformation behavior of the initial three-dimensional billet model; Based on the deformation behavior of the initial three-dimensional model of the billet, the body billet part and the cross-sectional supplementary allowance part are distinguished; Based on the additional allowance of the cross section, the thickness, shape, and position of the sleeve covering the outside of the body blank are determined.
[0008] Preferably, the method further includes: Based on the determined thickness, shape, and position of the sleeve and the body blank, a three-dimensional model of the sleeve blank is constructed; Finite element simulation was performed on the ring rolling process of the three-dimensional model of the cladding billet to obtain the deformation behavior of the three-dimensional model of the cladding billet. Based on the deformation behavior of the three-dimensional model of the encasing blank, the body blank part and the encasing part are distinguished; Based on the sleeve portion, the thickness, shape, and position of the sleeve covering the outside of the body blank are optimized.
[0009] Preferably, the cross-sectional allowance is determined by the following method: based on the net cross-sectional shape of the target ring and the ring rolling process conditions.
[0010] Preferably, the cross-sectional allowance is determined according to the following method: Based on the net cross-sectional shape of the target ring and the net cross-sectional limit size under the ring rolling forming process, the boundary conditions for material flow during the ring rolling forming process are determined. Based on the boundary conditions, calculate the difference between the net cross-sectional forming size and the limit size of the target ring component. The cross-sectional allowance is determined based on the difference; wherein the limiting dimension is determined by the size of the target ring, the shape of the net cross-section, and the plastic forming performance of the material.
[0011] Preferably, the process parameters of the finite element simulation include: roll size, ring size, rolling ratio, roll feed speed, rolling temperature and / or rolling force.
[0012] Preferably, the body blank is made of TC4 titanium alloy.
[0013] Preferably, the dissimilar material is carbon steel and / or stainless steel.
[0014] Preferably, the deformation behavior of the initial three-dimensional model of the billet includes: dynamic material flow, strain distribution and temperature evolution.
[0015] The second aspect of the present invention provides a complex thin-walled irregular ring based on a foreign material cladding, which is prepared by the method described in the first aspect.
[0016] The present invention has the following beneficial effects: (1) To address the limitations on forming limit thickness caused by the decrease in high-temperature yield strength and elastic modulus of titanium alloys in traditional ring rolling processes, and the resulting problems of instability and precision degradation in the rolling of large-size thin-walled rings, this invention proposes a heterogeneous material-titanium composite cladding forming method based on the synergy of dissimilar materials. The core mechanism of this method is: through structural design, the excessive thickness allowance that must be borne by the titanium alloy to maintain stability in the traditional design is replaced by the "auxiliary stiffness" provided by the dissimilar material cladding. After rolling and forming, the cladding is removed, and the thickness of the titanium alloy body can be significantly lower than the process limit thickness when it is rolled alone. Thus, high-precision near-net-shape forming of thin-walled titanium alloy rings can be achieved without modifying existing equipment, effectively overcoming defects such as uneven wall thickness and excessive ellipticity.
[0017] (2) To address the common industry problem of low material utilization and high processing costs caused by the forced use of large-margin titanium alloy billets due to forming limit constraints, this method achieves low-cost material substitution for "functional margin" through cladding design. In traditional processes, the increased processing margin to suppress instability is entirely composed of expensive titanium alloys and is subsequently removed as processing waste. This invention replaces this "functional volume," which only serves as temporary support, with a cladding made of inexpensive dissimilar materials. After rolling, the cladding is removed by machining, and the titanium alloy ring reaches near-net size. This strategy directly reduces the initial amount of titanium alloy feed at the source, concentrating the material on the final load-bearing section of the component, thereby significantly improving the utilization rate of the precious metal titanium alloy. At the same time, it significantly reduces the processing time, energy consumption, and tool wear caused by the removal of large amounts of titanium alloy margin, resulting in significant economic advantages.
[0018] (3) Unlike existing technologies that mainly focus on optimizing the constitutive model of titanium alloys, controlling process parameters, or upgrading equipment, this invention breaks through the limitations of the "single material forming" mindset and proposes a cross-material collaborative forming paradigm based on "structure-process function decoupling." This paradigm decouples the final service performance requirements of the component from the temporary stability requirements of the forming process: the titanium alloy serves as the main structural material to ensure service performance, while the dissimilar material serves as a detachable process medium, providing the necessary rigid support during the forming stage. This concept of temporary composite of dissimilar materials avoids the high-cost material research and development or heavy equipment modification required to overcome the performance bottleneck of a single material. Through a simple and reliable encapsulation structure, it achieves the extension of the forming limit of high-performance titanium alloys with lower technical complexity. This solution is not only scientifically sound and technologically feasible, but also provides an innovative technical path with good engineering transferability for the precision and efficient manufacturing of lightweight complex components in aerospace and other fields. Attached Figure Description
[0019] Figure 1 This is a schematic flowchart of the near-net-shape forming method for complex thin-walled irregular rings based on dissimilar material cladding as described in this invention. Figure 2 This is a schematic flowchart of the near-net-shape forming method for complex thin-walled irregular rings based on dissimilar material cladding, as described in an embodiment of the present invention. Figure 3 This is a schematic diagram of a three-dimensional model of a ring forming simulation system according to an embodiment of the present invention; wherein, the meanings of each symbol are as follows: 1, drive roller; 2, core roller; 3, ring; 4, right guide roller; 5, left guide roller; 6, upper conical roller; 7, lower conical roller; Figure 4 This is a schematic diagram illustrating the simulation principle of the ring-forming of the three-dimensional model of the sheath blank according to an embodiment of the present invention; wherein, the meanings of each symbol are as follows: 8, main blank; 9, sheath of dissimilar materials; Figure 5 This is a schematic diagram of the initial state of the three-dimensional model of the cladding blank during the finite element simulation process described in this embodiment of the invention. Figure 6 This is a schematic diagram of the equivalent stress distribution of the enclosure during the finite element simulation process described in this embodiment of the invention; Figure 7 This is a schematic diagram of the equivalent stress distribution of the bulk blank during the finite element simulation process described in the embodiment of the present invention; Figure 8 This is a schematic diagram of the equivalent strain distribution of the enclosure during the finite element simulation process described in this embodiment of the invention; Figure 9 This is a schematic diagram of the equivalent strain distribution of the bulk blank during the finite element simulation process described in the embodiment of the present invention; Figure 10 This is a schematic diagram of the cross-sectional shape of the main blank and the cladding in the initial state during the finite element simulation process described in this embodiment of the invention; Figure 11 This is a schematic diagram of the cross-sectional shape of the main blank and the sleeve during the forming process in the finite element simulation process described in the embodiment of the present invention. Detailed Implementation
[0020] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.
[0021] The method provided by this invention can be implemented in a terminal environment that may include one or more of the following components: a processor, a memory, and a display screen. The memory stores at least one instruction, which is loaded and executed by the processor to implement the method described in the following embodiments.
[0022] A processor may include one or more processing cores. The processor uses various interfaces and lines to connect various parts of the terminal, and performs various functions and processes data by running or executing instructions, programs, code sets or instruction sets stored in memory, and by calling data stored in memory.
[0023] Memory can include random access memory (RAM) or read-only memory (ROM). Memory can be used to store instructions, programs, code, code sets, or instructions.
[0024] The display screen is used to show the user interface of each application.
[0025] In addition, those skilled in the art will understand that the structure of the terminal described above does not constitute a limitation on the terminal. The terminal may include more or fewer components, or combine certain components, or have different component arrangements. For example, the terminal may also include radio frequency circuits, input units, sensors, audio circuits, power supplies, and other components, which will not be described in detail here.
[0026] Example 1 like Figure 1 As shown, this embodiment of the invention provides a near-net-shape forming method for complex thin-walled irregularly shaped rings based on dissimilar material cladding, comprising the following steps: S101, determine the required body blank and cross-sectional allowance of the same material for the ring rolling forming of the target ring. It is understood that the target ring is the final formed part. Specifically, the target ring can be an irregularly shaped thin-walled ring. Since the initial blank of the target ring undergoes deformation during the ring rolling process, "auxiliary stiffness" can be provided to maintain the stability of the target ring. For example, the thickness of the cross-section can be increased based on the body blank used to form the target ring; this increased portion is the cross-sectional allowance. The cross-sectional allowance can be provided by the same material as the target ring. For example, if the target ring is made of titanium alloy, the cross-sectional allowance is also made of titanium alloy. In this embodiment of the invention, the required shape and size of the body blank, as well as the amount of the cross-sectional allowance, are first determined based on the shape and size of the final formed target ring.
[0027] S102, based on the cross-sectional allowance, determine the dissimilar material cladding; the stiffness of the dissimilar material is higher than that of the main blank.
[0028] In this invention, through structural design, in related technologies, a cross-sectional allowance is required to maintain stability, and this allowance is borne by the same material as the target ring. After the ring is formed, the cross-sectional allowance needs to be removed; therefore, the cross-sectional allowance only serves as a "functional volume" with temporary support. After the target ring is formed, this cross-sectional allowance becomes processing waste and does not appear as part of the final formed ring. Therefore, the cost of the cross-sectional allowance becomes a key part of the manufacturing cost of the target ring. In related technologies, the cross-sectional allowance is made of the same material as the target ring. When the material price of the target ring is high, the cost of the cross-sectional allowance is also high, which significantly increases the manufacturing cost of the target ring. In this invention, a high-stiffness and inexpensive dissimilar material is used to replace the cross-sectional allowance of the same material as the target ring. That is, the "auxiliary stiffness" provided by the dissimilar material is utilized. This can both suppress instability and reduce costs. As an example, the dissimilar material can be ordinary carbon steel or stainless steel.
[0029] This method directly reduces the initial amount of target ring material, such as titanium alloy, at the source, so that the material is concentrated in the final load-bearing section of the component, thereby greatly improving the utilization rate of precious metal titanium alloy. At the same time, it significantly reduces the processing time, energy consumption and tool wear caused by removing a large amount of titanium alloy, and has significant economic advantages.
[0030] Therefore, the method of the present invention can address the common industrial problem of low material utilization and high processing costs caused by the use of large-margin titanium alloy blanks due to forming limit constraints in related technologies.
[0031] In this embodiment of the invention, the sheathing of dissimilar materials can be determined based on the cross-sectional allowance. For example, the thickness of the sheath can be determined.
[0032] S103, Fabricate the main body blank and the dissimilar material casing. Based on the shape and size of the main body blank determined in steps S101 and S102, and the thickness of the dissimilar material casing, the main body blank and the dissimilar material casing are actually fabricated.
[0033] S104, a dissimilar material is wrapped around the outside of the main body blank and then ring rolled to obtain an initial ring. After the dissimilar material is wrapped around the outside of the main body blank, the ring is ring rolled under preset ring rolling process conditions to obtain the initial ring.
[0034] S105, Remove the outer sheath of the initial ring to obtain the target ring. In practice, the sheath of the dissimilar material can be removed by CNC machining to achieve near-net-shape forming of the target ring.
[0035] Unlike conventional technologies that primarily focus on optimizing titanium alloy constitutive models, controlling process parameters, or upgrading equipment, this invention breaks through the limitations of "single-material forming" thinking and proposes a cross-material collaborative forming paradigm based on "structure-process function decoupling." This paradigm decouples the final service performance requirements of the component from the temporary stability requirements of the forming process: the titanium alloy serves as the main structural material to ensure service performance, while the dissimilar material acts as a removable process medium, providing necessary rigid support during the forming stage. This concept of temporary composite of dissimilar materials avoids the high-cost material development or heavy equipment modification required to overcome the performance bottlenecks of a single material. Through a simple and reliable encapsulation structure, it achieves the extension of the forming limits of high-performance titanium alloys with lower technical complexity. This solution is not only scientifically sound and technologically feasible, but also provides an innovative technical path with good engineering transferability for the precision and efficient manufacturing of lightweight complex components in aerospace and other fields.
[0036] The near-net-shape forming method for complex thin-walled irregular ring parts based on dissimilar material cladding provided in one embodiment of the present invention may further include the following steps: Based on the cross-sectional allowance and the billet body, a three-dimensional model of the initial billet is constructed. Finite element simulation was performed on the ring rolling process of the initial three-dimensional billet model to obtain the deformation behavior of the initial three-dimensional billet model; Based on the deformation behavior of the initial three-dimensional model of the billet, the body billet part and the cross-sectional supplementary allowance part are distinguished; Based on the additional allowance of the cross section, the thickness, shape, and position of the sleeve covering the outside of the body blank are determined.
[0037] To better determine the relationship between the cross-sectional allowance and the main blank, this embodiment of the invention uses finite element analysis to simulate the ring rolling process of the initial blank's three-dimensional model. During the simulation, the deformation behavior of the initial blank's three-dimensional model and the forming performance of each part are observed to distinguish between the main blank portion and the cross-sectional allowance portion of the initial blank. This allows for the determination of the quantitative and positional relationships between the main blank portion and the cross-sectional allowance portion.
[0038] In one embodiment of the present invention, the ring rolling process of the initial billet can be simulated using DEFORM software using finite element methods.
[0039] The near-net-shape forming method for complex thin-walled irregular ring parts based on dissimilar material cladding provided by the present invention may further include the following steps: Based on the determined thickness, shape, and position of the sheath and the main body blank, a three-dimensional model of the sheath blank is constructed; a finite element simulation is performed on the ring rolling process of the three-dimensional model of the sheath blank to obtain the deformation behavior of the three-dimensional model of the sheath blank; based on the deformation behavior of the three-dimensional model of the sheath blank, the main body blank part and the sheath part are distinguished; based on the sheath part, the thickness, shape, and position of the sheath covering the outside of the main body blank are optimized.
[0040] The above method allows for the verification and optimization of the relevant parameters of the designed sheath. This enables more efficient and cost-effective ring forming of the target ring component in subsequent practical applications.
[0041] In one embodiment of the present invention, the cross-sectional allowance can be determined as follows: based on the net cross-sectional shape of the target ring and the ring rolling forming process conditions. Specifically, the following steps can be taken: based on the net cross-sectional shape of the target ring and the net cross-sectional limit size under the ring rolling forming process conditions, determine the boundary conditions for material flow during the ring rolling forming process; based on the boundary conditions, calculate the difference between the net cross-sectional forming size and the limit size of the target ring, and determine the cross-sectional allowance based on the difference; wherein, the limit size is determined by the size of the target ring, the shape of the net cross-section, and the plastic forming performance of the material.
[0042] In a specific embodiment of the present invention, the main process parameters for the ring rolling forming of the target ring include: roll size, ring size, rolling ratio, roll feed speed, rolling temperature, and rolling force. Determining these process parameters is a multi-factor, multi-level optimization design problem. Conducting comprehensive experiments on all factors and levels would significantly increase the number of experiments. In this embodiment, orthogonal experimental design is used to select representative points from the comprehensive experiments based on orthogonality, quickly analyzing the influence of each factor on the optimization index and its patterns, thus determining the optimal factor level with a minimal number of experiments. The specific process can be as follows: First, the geometric dimensions and shape accuracy of the part in the ring rolling forming process are used as optimization indicators. Then, based on the actual process conditions of ring rolling forming, the number of levels for each factor is selected. Next, an appropriate orthogonal array is selected to determine the required number of experiments and the experimental plan. Finally, range analysis is performed on the experimental results based on the optimization indicators to determine the optimal process parameters. This step, through scientifically selecting parameter combinations, provides an initial set of optimized parameters for precise control, reducing trial-and-error costs.
[0043] In this embodiment of the invention, the body blank is made of TC4 titanium alloy. The body blank is used to prepare the target ring component, and the target ring component is made of TC4 titanium alloy; therefore, the body blank is made of TC4 titanium alloy. Titanium alloys possess excellent comprehensive mechanical properties such as high specific strength, high temperature resistance, corrosion resistance, and fatigue resistance. The target ring component prepared using TC4 titanium alloy in this invention can be widely used in high-end equipment manufacturing fields such as aviation, aerospace, marine, weaponry, energy, and machinery.
[0044] In one embodiment of the present invention, the dissimilar materials can be carbon steel and / or stainless steel. Specifically, they can be Q235 ordinary carbon steel, Q345 ordinary carbon steel, and 304 stainless steel, etc. Their stiffness is higher than that of titanium alloys, but their price is lower.
[0045] In one embodiment of the present invention, the deformation behavior of the initial three-dimensional model of the billet may include: dynamic material flow, strain distribution and temperature evolution. Specific Implementation like Figure 2 As shown in the figure, a specific embodiment of the present invention provides a near-net-shape forming method for irregularly shaped thin-walled TC4 titanium alloy rings based on dissimilar material cladding, which can be implemented through the following steps: Step one involves determining the target ring's ultimate forming dimension and calculating the minimum process allowance, thus completing the initial billet design. This step aims to provide data for an accurate billet geometry model for subsequent processes. First, based on the final cross-sectional shape of the target complex thin-walled irregular TC4 titanium alloy ring, and considering the ultimate forming dimension determined by material plasticity, cross-sectional complexity, and ring dimensions under the ring rolling process, the boundary conditions of material flow during forming are analyzed. Next, by calculating the minimum material volume required to fill the gap between the target cross-section and the ultimate forming cross-section, the minimum process allowance necessary for forming is determined. Finally, based on this allowance, a three-dimensional model is designed for the shape and dimensions of the initial titanium alloy billet before ring rolling.
[0047] Among them, the ring rolling process and the limiting forming size can be determined in advance through experiments.
[0048] Based on the final cross-sectional shape and ultimate forming size of the ring, the boundary conditions of material flow during forming can be analyzed using the following method: First, extract the contour data of the final cross-section of the target ring and, combined with the structural dimensional parameters of the actual ring rolling equipment (such as the main roll, core roll, and upper and lower tapered rolls), establish an initial ring rolling simulation model. Second, based on the ring rolling simulation results, delineate the regions involved in filling the final cross-section during ring rolling. The minimum material volume required to fill the gap between the target cross-section and the ultimate forming cross-section can be calculated using the following method: First, based on the simulation results under the ultimate forming size, identify the regions in the ultimate forming cross-section that do not participate in forming but only provide support. Calculate the minimum supplementary amount of the ring cross-section under the target size according to stiffness theory. After obtaining the minimum material volume required to fill the gap, the minimum process supplementary allowance necessary for forming can be determined as follows: Considering the thermal expansion effect of TC4 titanium alloy during high-temperature ring rolling and the shrinkage rate after cooling, introduce a thermo-coupling compensation coefficient to correct the theoretical minimum material volume, obtaining the actual required high-temperature supplementary volume. Simultaneously, considering the surface roughness and accuracy requirements of subsequent CNC machining, set a basic machining allowance threshold. The corrected high-temperature supplementary volume is combined with the basic machining allowance and gradient offset is applied along the normal of irregular or thin-walled feature surfaces in the cross-section of the target ring to calculate the minimum process supplementary allowance thickness at each corresponding node.
[0049] The following method can be used to design the shape and size of the initial titanium alloy billet before ring rolling based on the allowance: In the two-dimensional section sketch environment, with the theoretical section of the target ring as the reference, in the irregular or thin-walled areas that require process supplementation, the outline is extended or the nodes are translated according to the allowance thickness calculated in the previous step, and the target section is reconstructed into a smooth "near-net-shape section" that meets the limit forming requirements.
[0050] Step two involves finite element method (FEM) simulation analysis of the billet ring rolling process to evaluate deformation behavior and forming performance. The purpose of this step is to verify the feasibility of the billet design and predict potential defects before process testing. Specifically, DEFORM finite element software can be used to establish a simulation model of the ring rolling system, including the initial billet, drive roll, and mandrel, such as... Figure 3 As shown in the figure, the model comprehensively considers the influence of key process parameters such as roll size, rolling ratio, roll feed speed, rolling temperature, and rolling force, and performs thermo-mechanical coupled numerical simulation. Through simulation, the dynamic material flow, strain distribution, and temperature evolution of the billet during ring rolling are observed, with a focus on evaluating the filling situation, torsion risk, and instability tendency of complex thin-walled regions, providing a quantitative basis for process optimization.
[0051] In this embodiment of the invention, the simulation includes finite element analysis of the initial three-dimensional model of the billet and finite element analysis of the three-dimensional model of the sheathed billet. It can be seen that, compared with the initial three-dimensional model of the billet, under the same compression condition, the thickness of the sheathed billet three-dimensional model is significantly reduced, while the ring maintains a certain degree of overall stiffness. Figure 4 As shown.
[0052] This can be achieved by using finite element analysis on a three-dimensional model of the initial billet to observe material flow, strain distribution, and temperature evolution, thereby determining the bulk billet portion and the cross-sectional supplementary allowance portion within the initial billet. Based on this result, relevant parameters of the sheathing portion can be determined. For example, the thickness of the alternative sheathing portion can be determined based on the thickness of the cross-sectional supplementary allowance portion.
[0053] Finite element analysis of a three-dimensional model of the cladding blank allows for observation of material flow, strain distribution, and temperature evolution. Figures 5-9 As shown, this verifies whether the designed sheath meets the requirements for ring forming, and optimizes the relevant parameters of the designed sheath based on the verification results.
[0054] In the finite element simulation of the three-dimensional model of the cladding blank, the cross-sectional shapes of the main blank and the cladding in the initial state can be as follows: Figure 10 As shown; the cross-sectional shapes of the body blank and the casing during the forming process can be as follows: Figure 11 As shown.
[0055] Step three involves analyzing the finite element simulation results to distinguish between the final net cross-section region and the process-added region. This step, based on simulation data, provides a detailed analysis of the billet's deformation behavior, aiming to identify target regions for material substitution strategies. By analyzing the material flow traces and strain contour maps obtained in Step two, the necessary material regions for forming the final part's net cross-section are clearly identified, along with the additional process-added regions added to ensure forming stability and prevent distortion and cracking in thin-walled areas. This distinction is the core decision-making basis for implementing the subsequent low-cost near-net-shape forming strategy of "replacing titanium with dissimilar materials."
[0056] Step four involves designing and applying a dissimilar material cladding to replace the titanium alloy process supplementary parts. This step aims to solve the problem of insufficient stiffness in thin-walled areas during direct near-net-shape forming of titanium alloys, and to improve material utilization. For the process supplementary areas identified in Step three, a low-cost, high-stiffness dissimilar material is used for local replacement. Through structural design, the dissimilar material is fabricated into a cladding that fits tightly with the corresponding parts of the titanium alloy billet. Before ring rolling begins, the dissimilar material cladding is fitted to the outside or specific parts of the initial titanium alloy billet through welding or mechanical connections such as interference / clearance fits, forming a rigid composite billet. This effectively constrains the deformation of the titanium alloy during rolling, allowing it to exceed its maximum forming thickness.
[0057] Step 5: Perform ring rolling of the encased composite billet. Under the reinforcement and protection of the dissimilar material encasing, the titanium alloy-dissimilar material composite billet undergoes actual ring rolling. The additional stiffness provided by the encasing significantly suppresses instability and torsion of the thin-walled titanium alloy portion during high-temperature rolling, ensuring that complex irregular cross-sections can stably and accurately fill the mold cavity. This step transforms the simulation-designed process scheme into a solid component.
[0058] Step Six: CNC machining removes the foreign material cladding to obtain a near-net-shape titanium alloy ring. After ring rolling, CNC machining is used to precisely remove the external foreign material cladding, which was added only for process assistance. The exposed TC4 titanium alloy ring has the final complex thin-walled irregular cross-section with minimal machining allowance, achieving near-net-shape forming and significantly reducing material loss and subsequent machining costs of the precious titanium alloy.
[0059] Example 2 This invention provides a complex thin-walled irregular ring based on a foreign material cladding, which is prepared using the method described in Example 1.
[0060] For the specific preparation method, please refer to the description in Example 1, which will not be repeated here.
[0061] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if these modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include these modifications and modifications.
Claims
1. A near-net-shape forming method for complex thin-walled irregularly shaped rings based on dissimilar material cladding, characterized in that, include: Determine the required blank material and cross-sectional allowance of the same material for the target ring rolling forming; Based on the aforementioned cross-sectional allowance, a dissimilar material cladding is determined; the stiffness of the dissimilar material is higher than that of the main blank. Production of the main blank and the encapsulation of dissimilar materials; A dissimilar material is wrapped around the outside of the main body blank and then ring rolled to obtain an initial ring. Remove the outer sleeve from the initial ring to obtain the target ring.
2. The near-net-shape forming method for complex thin-walled irregular ring parts based on dissimilar material cladding as described in claim 1, characterized in that, The method further includes: Based on the cross-sectional allowance and the main blank, a three-dimensional model of the initial blank is constructed. Finite element simulation was performed on the ring rolling process of the initial three-dimensional billet model to obtain the deformation behavior of the initial three-dimensional billet model; Based on the deformation behavior of the initial three-dimensional model of the billet, the body billet part and the cross-sectional supplementary allowance part are distinguished; Based on the additional allowance of the cross section, the thickness, shape, and position of the sleeve covering the outside of the body blank are determined.
3. The near-net-shape forming method for complex thin-walled irregular ring parts based on dissimilar material cladding as described in claim 2, characterized in that, The method further includes: Based on the determined thickness, shape, and position of the sleeve and the body blank, a three-dimensional model of the sleeve blank is constructed; Finite element simulation was performed on the ring rolling process of the three-dimensional model of the cladding billet to obtain the deformation behavior of the three-dimensional model of the cladding billet. Based on the deformation behavior of the three-dimensional model of the encasing blank, the body blank part and the encasing part are distinguished; Based on the sleeve portion, the thickness, shape, and position of the sleeve covering the outside of the body blank are optimized.
4. The near-net-shape forming method for complex thin-walled irregular ring parts based on dissimilar material cladding as described in claim 2, characterized in that, The cross-sectional allowance is determined as follows: based on the net cross-sectional shape of the target ring and the ring rolling process conditions.
5. The near-net-shape forming method for complex thin-walled irregular ring parts based on dissimilar material cladding as described in claim 4, characterized in that, The cross-sectional allowance is determined according to the following method: Based on the net cross-sectional shape of the target ring and the net cross-sectional limit size under the ring rolling forming process, the boundary conditions for material flow during the ring rolling forming process are determined. Based on the boundary conditions, calculate the difference between the net cross-sectional forming size and the limit size of the target ring component. The cross-sectional allowance is determined based on the difference; wherein the limiting dimension is determined by the size of the target ring, the shape of the net cross-section, and the plastic forming performance of the material.
6. The near-net-shape forming method for complex thin-walled irregular ring parts based on dissimilar material cladding as described in claim 2 or 3, characterized in that, The process parameters for the finite element simulation include: roll size, ring size, rolling ratio, roll feed speed, rolling temperature and / or rolling force.
7. The near-net-shape forming method for complex thin-walled irregular ring parts based on dissimilar material cladding as described in claim 1, characterized in that, The body blank is made of TC4 titanium alloy.
8. The near-net-shape forming method for complex thin-walled irregular ring parts based on dissimilar material cladding as described in claim 1, characterized in that, The dissimilar material is carbon steel and / or stainless steel.
9. The near-net-shape forming method for complex thin-walled irregular ring parts based on dissimilar material cladding as described in claim 2, characterized in that, The deformation behavior of the initial three-dimensional model of the billet includes: dynamic material flow, strain distribution and temperature evolution.
10. A complex thin-walled irregularly shaped ring component based on a dissimilar material cladding, characterized in that, It is prepared by the method described in any one of claims 1-9.