A multi-field coupling self-adaptive vibration method for vacuum diffusion welding of die-casting die

Abstract

The embodiment of the application provides a kind of die-casting die vacuum diffusion welding multi-field coupling adaptive vibration method, it is related to welding technical field, method includes the die workpiece to be welded is assembled in the vibration platform in vacuum diffusion welding equipment, along die contact interface projection area is divided into N vibration control area, each area is provided with vibration drive unit;High temperature strain sensor array is set on the pressing plate or support structure corresponding to each vibration control area, data is collected and interface contact stress gradient matrix is established in heating and initial pressurizing stage;Vacuumizing, heating to welding temperature and applying axial initial pressure;In the holding stage, independently apply vibration to each vibration control area according to the interface contact stress gradient matrix;Reduce amplitude and use low-frequency vibration to release residual stress in the later stage of holding stage;Stop vibration and slow cooling according to the set cooling curve.The application has the effect of improving the interface atomic diffusion efficiency.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular to a multi-field coupled adaptive vibration method for vacuum diffusion welding of die-casting molds. Background Technology

[0002] Diffusion welding is a solid-state bonding technology that achieves interfacial metallurgical bonding through atomic diffusion under high temperature and certain pressure conditions. It is widely used in the welding and manufacturing of high-strength mold steel and large die-casting molds.

[0003] In diffusion welding of large or asymmetric die-casting molds, the following technical problems exist: uneven microscopic contact at the interface; significant differences in local contact stress; difficulty in completely closing interface voids; slow diffusion rate during the heat preservation stage; and large residual stress and excessive deformation after welding. Traditional vacuum diffusion welding typically employs a constant temperature and pressure static heat preservation method. During this stage, the interface is in a thermo-pressure coupling state but lacks a dynamic reconstruction mechanism, making it difficult to actively repair uneven interface contact, resulting in insufficient local diffusion.

[0004] Existing vibration-assisted connection technologies are mostly used in: However, these technologies mainly rely on high-frequency friction or plastic deformation mechanisms, which are not suitable for high-temperature static metallurgical bonding systems in vacuum diffusion welding, and do not perform zoned modulation control for the differences in interface stress distribution in large molds.

[0005] To address the aforementioned issues, there is an urgent need for an adaptive vibration control method to address the uneven stress at the diffusion welding interface of large molds, in order to improve interface diffusion efficiency and reduce deformation without significantly increasing the temperature or extending the holding time. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a multi-field coupled adaptive vibration method for vacuum diffusion welding of die-casting molds.

[0007] This application provides a multi-field coupled adaptive vibration method for vacuum diffusion welding of die-casting molds, which adopts the following technical solution: A multi-field coupled adaptive vibration method for vacuum diffusion welding of die-casting molds includes the following steps: S1. Assembly and partitioning definition: The large die-casting mold workpiece to be welded is assembled on the vibration platform inside the vacuum diffusion welding equipment. The vibration platform is divided into N vibration control zones along the projection area of ​​the mold contact interface. Each vibration control zone is equipped with a vibration drive unit. S2. Interface stress acquisition and modeling: A high-temperature strain sensor array is set on the pressure plate or support structure corresponding to each vibration control zone. Interface contact strain data is acquired during the heating and initial pressurization stages, and an interface contact stress gradient matrix is ​​established. S3. Heating and initial pressurization: Vacuum the equipment, heat it to the welding temperature and apply axial initial pressure; S4. Differentiated vibration modulation in different zones: During the heat preservation stage, vibration is applied independently to each vibration control zone according to the interface contact stress gradient matrix. The modulation principle is to increase the amplitude and frequency in areas with low stress and to reduce the amplitude and introduce phase delay in areas with concentrated stress. S5. Post-stage stress equalization vibration: Reduce the amplitude and use low-frequency vibration to release residual stress in the post-stage of the heat preservation phase. S6. Controlled cooling stage: Stop vibration and slowly cool according to the set cooling curve.

[0008] Optionally, in the N vibration control zones, N ≥ 4.

[0009] Optionally, the high-temperature strain sensor array is a high-temperature foil strain gauge or a fiber optic grating sensor with a sampling frequency of not less than 10Hz, and the interface contact stress gradient matrix is ​​established by converting real-time strain data and using an interpolation method.

[0010] Optionally, the vibration parameters applied to each vibration control zone in step S4 include a frequency of 50~200Hz, an amplitude of 0.02~0.15mm, a phase difference of 0~180°, and a dynamic correction period of 1~5 seconds.

[0011] Optionally, the zone-differentiated vibration modulation in step S4 is performed for 30% to 60% of the total heat preservation time.

[0012] In summary, this application includes at least one of the following beneficial technical effects: Compared with the traditional vacuum diffusion welding method that uses constant temperature and pressure static heat preservation, this invention significantly improves the atomic diffusion efficiency at the interface by establishing a real-time gradient matrix of interfacial contact stress and implementing zoned differentiated vibration modulation. Combined with adaptive control of multi-field coupling of temperature field, stress field, and vibration field, it effectively promotes the closure of micro voids and the increase of the actual contact area. It also achieves dynamic equilibrium release of residual stress and effective suppression of macroscopic warping deformation. Thus, while maintaining high joint strength and high uniformity, it significantly reduces the post-weld deformation of large die-casting molds, improving overall process stability and production efficiency. Attached Figure Description

[0013] Figure 1 This is the overall flowchart of this method. Detailed Implementation

[0014] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to also include expressions such as “one or more,” unless the context clearly indicates otherwise. It should also be understood that in the following embodiments of this application, “at least one” and “one or more” refer to one, two, or more than two. The term “and / or” is used to describe the relationship between related objects, indicating that three relationships may exist; for example, A and / or B can indicate: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character “ / ” generally indicates that the preceding and following related objects are in an “or” relationship.

[0015] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0016] The following is in conjunction with the appendix Figure 1 The present invention will be described in further detail below.

[0017] This application discloses a multi-field coupled adaptive vibration method for vacuum diffusion welding of die-casting molds, referring to... Figure 1 This includes the following steps: S1. Assembly and partitioning definition: The large die-casting mold workpiece to be welded is assembled on the vibration platform inside the vacuum diffusion welding equipment; the vibration platform is divided into N vibration control zones along the projection area of ​​the mold contact interface, N≥4, and each vibration control zone is equipped with a vibration drive unit. S2. Interface stress acquisition and modeling: A high-temperature strain sensor array is installed on the pressure plate or support structure corresponding to each vibration control zone. The high-temperature strain sensor array is a high-temperature foil strain gauge or fiber optic grating sensor with a sampling frequency of not less than 10Hz. Interface contact strain data are acquired during the heating and initial pressurization stages. Real-time contact stress is obtained by converting calibration curves or Hooke's law, and the interface contact stress gradient matrix is ​​established using bilinear interpolation or finite element-assisted mapping methods. ,in , Let the coordinates be those of the interface plane. For time, Reflects the magnitude and gradient of stress in each zone; S3. Increase temperature and initial pressure, then evacuate to ≤5×10⁻⁵. -3 Pa, heat to welding temperature 1050-1200℃, apply initial axial pressure of 5-20MPa, hold pressure for 10-30min to allow the interface to initially adhere; S4. Differentiated vibration modulation by zone: During the first 30% to 60% of the insulation stage, based on the interface contact stress gradient matrix, zoned vibration modulation is performed. Each vibration control zone is independently subjected to vertical / horizontal composite vibration with the following parameters: frequency: 50~200Hz, amplitude: 0.02~0.15mm, phase difference: 0~180°. The modulation principle is: increase amplitude and frequency in areas with low stress; decrease amplitude and introduce phase delay in areas with concentrated stress; the dynamic correction period is 1~5 seconds; the vibration energy is optimized through a multi-field coupling model of temperature, stress, and vibration to ensure that the interface undergoes micro-plastic slippage without causing overall displacement. S5. Rear stress equalization vibration: In the later stage of the heat preservation stage, the amplitude is reduced to 0.01~0.05mm, and low-frequency equalization vibration is used to release residual stress. S6. During the controlled cooling stage, stop the vibration and perform slow cooling according to the set cooling curve; control the cooling rate to ≤5℃ / min to avoid thermal shock deformation.

[0018] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. Any equivalent modifications or variations made by those skilled in the art based on the content disclosed in the present invention should be included within the scope of protection set forth in the claims.

Claims

1. A multi-field coupled adaptive vibration method for vacuum diffusion welding of die-casting molds, characterized in that, Includes the following steps: S1. Assembly and partitioning definition: The large die-casting mold workpiece to be welded is assembled on the vibration platform inside the vacuum diffusion welding equipment. The vibration platform is divided into N vibration control zones along the projection area of ​​the mold contact interface. Each vibration control zone is equipped with a vibration drive unit. S2. Interface stress acquisition and modeling: A high-temperature strain sensor array is set on the pressure plate or support structure corresponding to each vibration control zone. Interface contact strain data is acquired during the heating and initial pressurization stages, and an interface contact stress gradient matrix is ​​established. S3. Heating and initial pressurization: Vacuum the equipment, heat it to the welding temperature and apply axial initial pressure; S4. Differentiated vibration modulation in different zones: During the heat preservation stage, vibration is applied independently to each vibration control zone according to the interface contact stress gradient matrix. The modulation principle is to increase the amplitude and frequency in areas with low stress and to reduce the amplitude and introduce phase delay in areas with concentrated stress. S5. Post-stage stress equalization vibration: Reduce the amplitude and use low-frequency vibration to release residual stress in the post-stage of the heat preservation phase. S6. Controlled cooling stage: Stop vibration and slowly cool according to the set cooling curve.

2. The multi-field coupled adaptive vibration method for vacuum diffusion welding of die-casting molds according to claim 1, characterized in that: Of the N vibration control zones, N ≥ 4.

3. The multi-field coupled adaptive vibration method for vacuum diffusion welding of die-casting molds according to claim 1, characterized in that: The high-temperature strain sensor array is a high-temperature foil strain gauge or fiber optic grating sensor with a sampling frequency of not less than 10Hz. The interface contact stress gradient matrix is ​​established by converting real-time strain data and using an interpolation method.

4. The multi-field coupled adaptive vibration method for vacuum diffusion welding of die-casting molds according to claim 1, characterized in that: In step S4, the vibration parameters applied to each vibration control zone include a frequency of 50~200Hz, an amplitude of 0.02~0.15mm, a phase difference of 0~180°, and a dynamic correction period of 1~5 seconds.

5. The multi-field coupled adaptive vibration method for vacuum diffusion welding of die-casting molds according to claim 1, characterized in that: The zone-differentiated vibration modulation in step S4 is performed for 30% to 60% of the total heat preservation time.

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