Characterization system and method for thermal-mechanical coupling compression molding process of binding material

Abstract

The invention relates to a characterization system and method for the thermal-mechanical coupling compression forming process of a binding material, the characterization system comprises a pressing die assembly, an XRD in-situ test module and a data processing module, the pressing die assembly comprises an upper pressing head, a compression die and a lower pressing head, a through compression cavity is formed in the compression die, a binding sample cavity is formed in the compression cavity, and the upper pressing head is connected with the lower pressing head; the container is used for accommodating a to-be-detected bonding sample; the upper pressing head and the lower pressing head are arranged in the compression cavity and can be close to or far away from the bonding sample cavity; a temperature control module is arranged on the outer wall of the compression mold; the XRD in-situ testing module is used for carrying out XRD testing on the to-be-tested bonding sample in the compression molding process; and the data processing module is electrically connected with the pressing die assembly and the XRD in-situ test module, and is used for controlling the pressing die assembly and the XRD in-situ test module and processing experimental data. By adopting the device and the method, real-time and in-situ monitoring of crystal structure evolution, phase change behavior and texture forming mechanism of the material in the compression deformation process can be realized.

Description

Technical Field

[0001] This invention relates to the field of adhesive material characterization technology, and in particular to a characterization system and method for the thermo-mechanical coupling compression molding process of adhesive materials. Background Technology

[0002] Thermo-mechanical coupling compression molding is an important process widely used in metal processing, powder metallurgy, ceramic densification, and the preparation of functional materials. By applying plastic deformation to materials under the synergistic effect of high temperature and pressure, and under the control of a set temperature gradient and pressure, the grain size can be effectively controlled and specific textures can be induced, thereby optimizing the mechanical, electrical, or magnetic properties of the materials.

[0003] In thermo-mechanical compression molding of bonding materials, compression molding equipment is used. Existing compression molding equipment is typically equipped with basic temperature control and pressure loading systems, enabling uniaxial compression testing under isothermal or gradient heating conditions to obtain macroscopic mechanical parameters such as stress-strain curves and rheological behavior properties of the material. However, existing compression molding equipment lacks the ability to precisely and collaboratively control the temperature gradient, supporting only isothermal compression or simple heating processes. It cannot establish and regulate the temperature gradient field along the axial direction of the bonded sample during compression. The temperature gradient is a key physical field guiding grain orientation and inhibiting the formation of transverse grain boundaries. Its absence prevents the simulation of actual heat flow direction control mechanisms, limiting the ability to actively intervene in grain orientation evolution.

[0004] Furthermore, in existing characterization processes, the material preparation process of compression molding equipment is disconnected from XRD characterization, making it difficult to achieve true in-situ monitoring. Currently, characterization employs an offline mode of "sample preparation-removal-XRD characterization," or only performs XRD scans before and after compression, failing to capture the dynamic evolution of the crystal structure during compression. Summary of the Invention

[0005] The purpose of this invention is to solve the problem that the material preparation process of compression molding equipment is disconnected from XRD characterization in the existing molding process characterization, and the dynamic evolution of crystal structure during compression cannot be captured. This invention provides a characterization system and method for the thermo-mechanical coupling compression molding process of binder materials.

[0006] In a first aspect, the present invention provides a characterization system for a thermo-mechanically coupled compression molding process of an adhesive material, comprising: A compression mold assembly includes an upper pressure head, a compression mold, and a lower pressure head. The compression mold has a through compression cavity, and the compression cavity has a sample bonding cavity for accommodating the sample to be bonded. The upper pressure head is inserted into the compression cavity from top to bottom and can be close to or away from the sample bonding cavity. The lower pressure head is inserted into the compression cavity from bottom to top and can be close to or away from the sample bonding cavity. A temperature control module is provided on the outer wall of the compression mold. The XRD in-situ testing module is used to perform XRD tests on the bonded sample to be tested during the compression molding process and to collect diffraction data. The data processing module is electrically connected to both the molding assembly and the XRD in-situ testing module, and is used to control the molding assembly and the XRD in-situ testing module, and to process the experimental data.

[0007] The present invention proposes an in-situ X-ray diffraction characterization system for compressing bonding materials under thermo-mechanical coupling conditions to prepare oriented crystalline materials and textured materials. The system includes a molding assembly, an in-situ XRD testing module, and a data processing module. The temperature control module provides the required temperature field for the bonded sample, enabling control of the axial temperature of the sample during thermo-mechanical coupling compression to simulate the heat flow conditions in actual thermal processing, promoting oriented grain growth and texture formation. High-precision pressure loading and strain rate control are achieved through the relative movement of the lower and upper indenters, enabling the compression of the bonded sample. Combined with the in-situ XRD testing module, real-time, in-situ monitoring of crystal structure evolution, phase transition behavior, and texture formation mechanisms during compression deformation is achieved. The data processing module enables real-time acquisition and processing of relevant data during the bonding material compression process. This system achieves simultaneous high-precision pressure-strain control and X-ray diffraction acquisition.

[0008] Through the above technical solutions, the characterization system integrates uniaxial compression and motion control, temperature control, X-ray diffraction and detection, and data acquisition and processing, enabling real-time, in-situ monitoring of the evolution of crystal structure, phase transition behavior, and texture formation mechanism of materials during compression deformation.

[0009] As a preferred embodiment of the present invention, the compression mold is a cuboid structure, and the compression mold is made of high-strength steel, which has good rigidity, thermal conductivity and thermal stability. The size of the compression mold is designed according to the actual bonding sample.

[0010] As a preferred embodiment of the present invention, the bonding sample cavity is provided with an entrance window and an exit window along the X-ray testing direction, the cross-section of the entrance window is circular, and the exit window is trumpet-shaped.

[0011] In a preferred embodiment of the present invention, the upper pressure head is connected to the first driving system, the lower pressure head is connected to the second driving system, a first force sensor is connected between the upper pressure head and the first driving system, and a second force sensor is connected between the lower pressure head and the second driving system.

[0012] As a preferred embodiment of the present invention, in the constant temperature test mode, the temperature control module includes a first heating component, the first heating component includes a plurality of resistance heating coils, the resistance heating coils being evenly distributed on the outside of the compression mold; In the temperature gradient experimental mode, the temperature control module includes a second heating component and a semiconductor cooling chip. The second heating component includes several resistance heating coils. The second heating component and the semiconductor cooling chip are distributed at the upper and lower ends of the outer side of the compression mold.

[0013] As a preferred embodiment of the present invention, a plurality of temperature sensors are provided on the inner wall of the compression chamber, and the plurality of temperature sensors are distributed along the length direction of the compression chamber to monitor the temperature at different locations in the compression chamber.

[0014] As a preferred embodiment of the present invention, the XRD in-situ testing module includes an X-ray source, an X-ray collimator, a central beam blocker, and a flat panel detector arranged sequentially. The compression component is located between the X-ray collimator and the central beam blocker. The X-ray source is used to establish an X-ray beam that can pass through the bonded sample cavity, and the X-ray collimator is used to limit the divergence angle of the X-ray beam.

[0015] As a preferred embodiment of the present invention, the X-ray source and the X-ray collimator are located in a shielded X-ray source chamber, the X-ray source is fixed on the side wall of the shielded X-ray source chamber, and the X-ray collimator is located at the outlet of the shielded X-ray source chamber.

[0016] As a preferred embodiment of the present invention, the characterization system further includes a sealed housing, within which both the molding assembly and the XRD in-situ testing module are located. Considering signal divergence and absorption caused by air, the entire experimental setup, including the molding assembly and the XRD in-situ testing module, is housed within the housing, which provides a sealed vacuum environment. Before the experiment begins, the vacuum level within the housing cavity can be reduced to 1 × 10⁻⁶ by activating a vacuum pump. 2 To reduce the interference of air scattering on X-ray diffraction signals, the pressure should be kept below Pa.

[0017] In a second aspect, the present invention provides a characterization method for a thermo-mechanical coupling compression molding process of an adhesive material, using the aforementioned characterization system for a thermo-mechanical coupling compression molding process of an adhesive material, comprising the following steps: S1. The bonding sample to be tested is loaded into the bonding sample cavity of the compression mold, and the bonding sample to be tested is placed in the offset area of ​​the bonding sample cavity. S2. Start the upper pressure head and the lower pressure head to approach the bonding sample cavity and push the bonding sample to be tested to the center region of the X-ray optical path; S3. Start the temperature control module to bring the bonded sample to the temperature test mode. According to the compression loading program, apply pressure to compress the bonded sample by synchronously moving the upper pressure head and the lower pressure head. At the same time as compression, start the XRD in-situ test module to collect diffraction data and transmit it to the data processing module for processing.

[0018] As a preferred embodiment of the present invention, the characterization system further includes a sealed housing, and the molding assembly and the XRD in-situ testing module are both located inside the housing; before step S2, the housing is evacuated to create a vacuum environment inside the housing.

[0019] Compared with the prior art, the beneficial effects of the present invention include: 1. This invention provides a characterization system for the thermo-mechanical coupling compression molding process of adhesive materials, including a compression mold assembly, an XRD in-situ testing module, and a data processing module, to achieve precise control of the axial temperature gradient: the system can establish and maintain a controllable temperature gradient field along the sample axis during compression, effectively simulating the heat flow direction in actual thermal processing, promoting directional grain growth, and realizing the control of the texture structure of the compression-molded material.

[0020] 2. This invention provides a characterization system for the thermo-mechanical coupling compression molding process of bonding materials, realizing the synchronous characterization of mechanical loading and structural evolution: through the coordinated operation of a closed-loop pressure control system and a high-speed X-ray detector, diffraction data can be continuously acquired under constant strain rate or constant load conditions to obtain the dynamic correlation between stress-strain curves and crystal structure parameters (such as lattice strain and phase transition behavior), revealing the microscopic mechanism of crystallization and texture development during the material compression molding process.

[0021] 3. This invention provides a characterization method for the thermo-mechanical coupling compression molding process of bonding materials, which collects complete two-dimensional diffraction information to provide data support for subsequent analysis of texture evolution: The system uses a two-dimensional surface detector, which can quickly collect complete annular diffraction patterns, facilitating subsequent integral analysis, phase identification, grain orientation statistics and texture analysis. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural diagram of the compression mold from one perspective in Embodiment 1 of the present invention; Figure 2 This is a three-dimensional structural diagram of the compression mold from another perspective in Embodiment 1 of the present invention; Figure 3 This is a cross-sectional view of the compression mold in Embodiment 1 of the present invention; Figure 4 This is a cross-sectional view of the compression mold in Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the characterization system for the thermo-mechanical coupling compression molding process of the bonding material in Embodiment 1 of the present invention; Figure 6 This is a cross-sectional view of the characterization system for the thermo-mechanical coupling compression molding process of the bonding material in Embodiment 1 of the present invention; Figure 7 This is the annular diffraction pattern pole figure of the initial state of the bonded sample to be tested in Example 2 of the present invention; Figure 8 This is a pole figure of the annular diffraction pattern during the molding process of the bonded sample in Embodiment 2 of the present invention; Figure 9 This is the annular diffraction pattern pole figure of the bonded sample to be tested in Embodiment 2 of the present invention. Marked in the image: 11-Upper pressure head, 12-Compression mold, 13-Lower pressure head, 14-Temperature control module, 15-Incident window, 16-Outlet window, 21-X-ray source, 22-X-ray collimator, 23-Central beam blocker, 24-Flat panel detector, 3-Tested bonded sample. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0024] Unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of the present invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0025] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," "parallel," and "coaxial" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, parallel, or coaxial. Slight tilt or deviation is permissible, as long as it does not affect the normal function of the relevant component. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," not that the structure must be perfectly horizontal; a slight tilt is acceptable. "Coaxial" means that two components are set as coaxially as possible, allowing them to move coaxially or approximately coaxially when their relative positions change. Alternatively, it can be simplified to mean that the corresponding device / component / element, when set in a "horizontal," "vertical," "suspended," "parallel," or "coaxial" direction, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. For example, the deviation in the "coaxial" direction is controlled within 0.2-1mm, preferably within 0.2-0.5mm. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the solution of the present invention.

[0026] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0027] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as 2, 3, 4, 5, 6, 7, 8, or 9, and can even exceed nine.

[0028] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0029] X-ray diffraction (XRD) is a rapid, non-destructive material structure characterization technique. Its basic principle is that when X-rays with wavelengths comparable to the interatomic spacing are incident on a crystal, they undergo coherent scattering in directions satisfying the Bragg condition (2dsinθ = nλ), forming diffraction patterns with specific spatial distribution and intensity characteristics. XRD tests can precisely determine the position (2θ angle), intensity, and full width at half maximum (FWHM) of diffraction peaks. Combined with crystallographic analysis methods, information such as interplanar spacing (d), lattice constant, phase composition, crystallinity, stress, microstrain, and texture can be deduced.

[0030] Example 1 This embodiment provides a characterization system for the thermo-mechanical coupling compression molding process of adhesive materials, including: a compression mold assembly, including an upper pressure head 11, a compression mold 12, and a lower pressure head 13. The compression mold 12 has a through compression cavity, and the compression cavity has an adhesive sample cavity for accommodating the adhesive sample 3 to be tested. The upper pressure head 11 is inserted into the compression cavity from top to bottom and can be close to or away from the adhesive sample cavity. The lower pressure head 13 is inserted into the compression cavity from bottom to top and can be close to or away from the adhesive sample cavity. A temperature control module 14 is provided on the outer wall of the compression mold 12 for providing the required temperature field for the adhesive sample 3 to be tested. The XRD in-situ testing module is used to perform XRD tests on the bonded sample 3 to be tested during the compression molding process and to collect diffraction data. The data processing module is electrically connected to the molding assembly and the XRD in-situ testing module. It is used to control the molding assembly and the XRD in-situ testing module and to process the experimental data.

[0031] In some embodiments, the compression mold 12 is a cuboid structure, made of high-strength steel, and has good rigidity, thermal conductivity and thermal stability. The dimensions of the compression mold are designed according to the actual bonded sample 3 to be tested.

[0032] In some embodiments, the bonding sample cavity is provided with an incident window 15 and an exit window 16 along the X-ray testing direction of the XRD in-situ testing module. The cross-section of the incident window 15 is circular, and the exit window 16 is trumpet-shaped.

[0033] Specifically, the sample bonding chamber is flat, with dimensions of 1mm × 5mm × 2mm. An entrance window 15 and an exit window 16 for X-ray transmission are respectively opened on the left and right side walls of the sample bonding chamber, as shown below. Figure 3The upper part features a small entrance window 15 with a diameter of 1 mm, while the lower part features a large, horn-shaped exit window 16 with a diameter of 5 mm. Both the entrance window 15 and the exit window 16 are made of high-purity fused silica glass as the X-ray transparent window, which has relatively high strength, high temperature resistance, and a low coefficient of thermal expansion. Furthermore, its XRD characteristics include broad, flat peaks with low intensity and clearly defined peak positions, facilitating subsequent background subtraction. The inner side of the exit window 16 is designed with a horn-shaped flared structure, effectively expanding the X-ray passage angle range and preventing the diffraction beam from being blocked by the edge of the compression mold, ensuring complete acquisition of the diffraction signal.

[0034] In some embodiments, the upper pressure head 11 is connected to the first drive system, the lower pressure head 13 is connected to the second drive system, a first force sensor is connected between the upper pressure head 11 and the first drive system, and a second force sensor is connected between the lower pressure head 13 and the second drive system.

[0035] The upper pressure head 11 and the lower pressure head 13 have similar structures and the same outer diameter, and can move closer to or further away from the bonding sample cavity under the drive of the first drive system and the second drive system. Specifically, the first drive system and the second drive system are servo motors. The upper pressure head 11 and the lower pressure head 13 are respectively connected to the motion shafts of the first drive system and the second drive system. The upper pressure head 11 and the lower pressure head 13 are symmetrically inserted from the upper and lower ends of the compression mold 12, respectively, and are driven by independent servo motors to ensure that the bonding sample is always located in the center of the bonding sample cavity during the pressure loading process, resulting in higher characterization accuracy.

[0036] High-precision first and second force sensors acquire pressure signals applied to the bonded sample 3 in real time. The output signals of the force sensors are read by an independent data acquisition module and transmitted to the data processing module, forming a closed-loop feedback control circuit. The data processing module dynamically adjusts the displacement rate of the servo motor according to the set stress or strain path, thereby achieving precise control of the compressive load, strain rate, and total deformation, meeting the needs of studying the mechanical behavior of the bonded material from elastic deformation to plastic flow during the thermo-mechanical coupling compression molding process.

[0037] In some embodiments, in the constant temperature experimental mode, the temperature control module 14 includes a first heating component, which includes a plurality of resistance heating coils, which are evenly distributed on the outside of the compression mold 12. In the temperature gradient experimental mode, the temperature control module 14 includes a second heating component and a semiconductor cooling chip. The second heating component includes several resistance heating coils. The second heating component and the semiconductor cooling chip are distributed at the upper and lower ends of the outer side of the compression mold 12.

[0038] A temperature control module 14 is integrated on the outer wall of the compression mold 12. The temperature control module 14 is tightly fitted to the outer surface of the compression mold 12 to achieve efficient heat conduction. In the constant temperature test mode, resistance heating coils are configured on the outer side of the compression mold 12. By precisely controlling the power of the heating coils on both sides, the entire compression mold 12 is uniformly heated. In the temperature gradient test mode, the second heating component and the semiconductor cooling chip are distributed on the outer side of the compression mold 12, at the upper and lower ends. This makes one side of the outer side of the compression mold 12 the hot end and the other side the cold end, with the cold end in contact with the mold. The hot end continuously provides heat, while the semiconductor cooling chip actively "draws" heat away from the other side, thereby establishing a controllable temperature gradient field from the hot end to the cold end along the axial direction of the sample to be tested within the compression mold 12.

[0039] In some embodiments, multiple temperature sensors are disposed on the inner wall of the compression chamber, distributed along the length of the compression chamber, for monitoring the temperature at different locations within the compression chamber. Specifically, the temperature sensors are K-type thermocouples, attached side-by-side along the central axis of the bonded sample on the inner wall of the compression chamber, for real-time monitoring of the temperature distribution at different locations. Specifically, two K-type thermocouples are disposed on the inner wall of the bonded sample chamber, and two K-type thermocouples are disposed on the inner walls of the compression chambers corresponding to the upper pressure head 11 and the lower pressure head 13, respectively.

[0040] In detail, the temperature data collected by the temperature sensor is transmitted in real time to the data processing module via a multi-channel data acquisition device. The data processing module then calculates the current temperature field distribution, including the temperature gradient direction and value. This enables the measurement, feedback, and monitoring of the magnitude and spatial distribution of the temperature gradient. Simultaneously, according to a preset experimental program, the data processing module independently adjusts the heating / cooling output power of the temperature control module 14 to actively regulate the temperature field. This establishes an axial temperature gradient in the bonded sample under test, guiding the grains to preferentially grow along the opposite direction of heat flow, thereby achieving controllable induction of grain elongation direction and texture type.

[0041] In some embodiments, the XRD in-situ testing module includes an X-ray source 21, an X-ray collimator 22, a central beam blocker 23, and a flat panel detector 24 arranged sequentially. A compression assembly is disposed between the X-ray collimator 22 and the central beam blocker 23. The X-ray source 21 is used to generate an X-ray beam that can pass through the bonded sample cavity, and the X-ray collimator 22 is used to limit the divergence angle of the X-ray beam.

[0042] The uncollimated X-ray beam generated by the X-ray source passes through a pre-collimated aperture in the X-ray collimator. This aperture, located at the X-ray source exit, has a diameter of 50-200 μm and is used to limit the divergence angle of the incident X-ray beam. The aperture can be changed according to experimental requirements, forming a micro-beam X-ray with a controllable diameter. The typical beam size of this micro-beam X-ray is 100-300 μm, improving spatial resolution and reducing stray light interference. The collimated micro-beam X-ray then passes through the incident window 15 on one side of the compression mold 12, irradiating the central region of the bonded sample. The irradiated sample generates a diffraction signal, and the diffraction cone expands along the Bragg angle direction, passing through the exit window 16 on the other side of the compression mold 12. Finally, it is received by the two-dimensional flat panel detector 24 located on the opposite side, recording the X-ray signal and forming an image or diffraction pattern. Since not all X-ray beams will diffract after entering the sample, most of the beams will be transmitted through the bonded sample. In order to prevent overexposure of the central area of ​​the flat panel detector 24 due to the transmitted beam, a central beam blocker 23 is used to block the central beam, block the direct X-rays, and prevent the detector from saturating.

[0043] Existing XRD characterization methods require avoiding the presence of other components between the sample and the X-ray source. This is because materials located in the X-ray incident or exit path can scatter, absorb, or diffract the X-rays to varying degrees, introducing diffraction peaks or background signals from non-target phases. This results in interfering diffraction patterns in the final results, affecting the XRD characterization outcomes. The aforementioned technical solution utilizes an in-situ XRD testing module to create a low-interference, high-purity X-ray testing environment. The optimized module structure prevents components other than the sample (such as pressure heads, heating elements, and support structures) from entering the main X-ray path, minimizing scattering, absorption, or additional diffraction signals from non-target phases, eliminating interfering diffraction patterns, improving resolution, and enhancing the accuracy and reliability of XRD characterization results.

[0044] Laboratory X-ray sources are typically cone-beam diverging beams. These sources often lack effective optical path collimation systems, leading to excessively large incident beam divergence angles. This results in broadened diffraction peaks, reduced resolution, and severely impacts the accuracy of interplanar spacing and texture analysis. Using an X-ray collimator in the in-situ XRD testing module improves the collimation and spatial resolution of the incident X-ray beam. It transforms the laboratory cone-beam diverging X-rays into a highly collimated, near-parallel beam, reducing the incident divergence angle, suppressing diffraction peak broadening, and significantly improving the accuracy of diffraction angle measurement and the resolution of interplanar spacing calculation, thus meeting the requirements for high-precision texture and residual stress analysis.

[0045] In some embodiments, the X-ray source and the X-ray collimator are located inside a shielded X-ray source chamber, the X-ray source is fixed on the side wall of the shielded X-ray source chamber, and the X-ray collimator is located at the outlet of the shielded X-ray source chamber.

[0046] Because the laboratory X-ray source has a large divergence angle and is accompanied by a strong bremsstrahlung background, a large amount of incoherent scattering and background noise X-ray signals are generated in the space around the sample. These noise signals, once captured by the detector, significantly reduce the signal-to-noise ratio of the diffraction image, especially in the detection of weak diffraction signals (such as high-index crystal planes or trace phases), which are easily masked, thus limiting the ability to identify weak structural information. In the above technical solution, the X-ray source and X-ray collimator are placed in a shielded X-ray source chamber, effectively suppressing background noise and improving the signal-to-noise ratio of the X-ray diffraction signal. By optimizing the optical path shielding design and multi-stage filtering design, and reducing the background noise of bremsstrahlung, the shielded X-ray source chamber made of lead plate can shield the background X-rays from the exit port. Combined with a high-efficiency flat panel detector 24, the detection capability of weak diffraction signals (such as high-index crystal planes and trace precipitates) is enhanced, enabling sensitive identification of weak structural features.

[0047] In some embodiments, the characterization system further includes a sealed housing, within which the molding assembly and the XRD in-situ testing module are located. Considering signal divergence and absorption caused by air, the entire experimental setup, including the molding assembly and the XRD in-situ testing module, is housed within the housing, which provides a sealed vacuum environment. Before the experiment begins, the vacuum level within the housing cavity can be reduced to 1 × 10⁻⁶ by activating a vacuum pump. 2 To reduce the interference of air scattering on X-ray diffraction signals, the pressure should be kept below Pa.

[0048] Example 2 This embodiment provides a characterization method for the thermo-mechanical coupling compression molding process of adhesive materials, using the characterization system for the thermo-mechanical coupling compression molding process of adhesive materials according to Embodiment 1, and includes the following steps: S1. The bonding sample 3 to be tested is loaded into the bonding sample cavity of the compression mold 12, and the bonding sample 3 to be tested is placed in the offset area of ​​the bonding sample cavity. S2. Start the upper pressure head 11 and lower pressure head 13 to approach the bonding sample cavity and push the bonding sample 3 to be tested to the center of the X-ray optical path. S3. Start the temperature control module 14 to bring the bonded sample 3 to the temperature test mode. According to the compression loading program, the upper pressure head 11 and the lower pressure head 13 move synchronously to apply pressure to compress the bonded sample 3. At the same time as compression, start the XRD in-situ test module to collect diffraction data and transmit it to the data processing module for processing.

[0049] In step S1, the sample to be bonded, 3, is a powder sample. The bias region of the bonding sample cavity is such that the powder is placed on one side outside the center of the optical path, not in the exact center of the X-ray optical path. Instead, it is placed in the bias region of the bonding sample cavity, ensuring that the X-ray beam completely avoids the sample in the current state, passing only through the cavity and window. This allows researchers to clearly see in the X-ray image how the powder propagates from the cold end to the hot end, or how the liquid metal fills the cavity.

[0050] When the characterization system also includes a sealed housing, the compression mold assembly and the XRD in-situ testing module are both located inside the housing. Before step S2, the housing is evacuated to create a vacuum environment inside. The compression mold 12 is installed inside the vacuum chamber, the chamber is closed, and the vacuum pump is started to evacuate the experimental environment, maintaining a vacuum level better than 1×10⁻⁶. 2 Pa was used to reduce the interference of air scattering on the X-ray diffraction signal. Simultaneously, an isothermal experimental mode or a temperature gradient experimental mode was set according to the experimental requirements, and the background diffraction pattern was photographed as the environmental background spectrum after the temperature stabilized.

[0051] In step S2, while keeping the vacuum and temperature environment constant, the servo motor is started to drive the upper pressure head 11 and the lower pressure head 13 to advance towards the center of the sample cavity according to a preset low-speed program, so as to smoothly push the biased sample to the center area of ​​the X-ray optical path and make it completely cover the incident and outgoing light spots.

[0052] In step S3, after the sample is in place, an isothermal experimental mode or a temperature gradient experimental mode is set according to experimental requirements, and the target thermal field is established and stabilized in the sample area. After the temperature distribution reaches the set value and remains stable, the compression loading procedure is started. The pressure heads on both sides move synchronously to apply pressure, keeping the sample always in the center of the optical path, and the sample is uniaxially compressed according to the set strain rate or stress path. During compression, the X-ray source and flat panel detector 24 are activated to acquire two-dimensional diffraction images at fixed time intervals or strain steps, and transmit them to the data processing module for data processing. The data processing module uses the background acquired in step S2 to automatically subtract the background through an adaptive algorithm to generate a clean one-dimensional diffraction pattern. The data processing module performs real-time integration of the diffraction rings and extraction of interplanar spacing, and synchronously displays structural parameters such as phase transition characteristics and texture evolution, as well as mechanical and thermal data, forming a dynamic correlation diagram of "process-structure".

[0053] Choose an appropriate time to end the experiment, stop heating, pressurizing and X-ray source, and release the ambient vacuum after the sample returns to room temperature, then open the chamber to recover the sample.

[0054] In this embodiment, the bonded sample to be tested is aluminum (Al). Pole diagrams along the extrusion direction are plotted based on the diffraction patterns of the initial state, during the molding process, and after molding. The color intensity in the diagram represents the relative magnitude of the grain orientation density at the current result. The larger the orientation value, the more grains in that orientation. The ColorBar on the right represents the absolute magnitude of the quantification; the larger the value, the greater the orientation density of the corresponding color. Figure 7 The initial state is powder, without texture, and with a uniform inverse pole figure; Figure 8 During the forming process, texture appears, and the polar pattern concentrates in one corner; Figure 9 The completed polar pattern exhibits a strong texture.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A characterization system for the thermo-mechanical coupling compression molding process of an adhesive material, characterized in that, include: The compression mold assembly includes an upper pressure head (11), a compression mold (12), and a lower pressure head (13). The compression mold (12) has a through compression cavity, and the compression cavity has a bonding sample cavity for accommodating the bonding sample (3) to be tested. The upper pressure head (11) is inserted into the compression cavity from top to bottom and can be close to or away from the bonding sample cavity. The lower pressure head (13) is inserted into the compression cavity from bottom to top and can be close to or away from the bonding sample cavity. A temperature control module (14) is provided on the outer wall of the compression mold (12). The XRD in-situ testing module is used to perform XRD tests on the bonded sample (3) to be tested during the compression molding process and to collect diffraction data. The data processing module is electrically connected to both the molding assembly and the XRD in-situ testing module, and is used to control the molding assembly and the XRD in-situ testing module, and to process the experimental data.

2. The characterization system for the thermo-mechanical coupling compression molding process of the bonding material according to claim 1, characterized in that, The bonding sample cavity is provided with an entrance window (15) and an exit window (16) along the X-ray testing direction. The cross-section of the entrance window (15) is circular, and the exit window (16) is trumpet-shaped.

3. The characterization system for the thermo-mechanical coupling compression molding process of the bonding material according to claim 1, characterized in that, The upper pressure head (11) is connected to the first drive system, the lower pressure head (13) is connected to the second drive system, a first force sensor is connected between the upper pressure head (11) and the first drive system, and a second force sensor is connected between the lower pressure head (13) and the second drive system.

4. The characterization system for the thermo-mechanical coupling compression molding process of the adhesive material according to claim 1, characterized in that, In the constant temperature test mode, the temperature control module (14) includes a first heating component, which includes several resistance heating coils, which are evenly distributed on the outside of the compression mold (12). In the temperature gradient experimental mode, the temperature control module (14) includes a second heating component and a semiconductor cooling chip. The second heating component includes several resistance heating coils. The second heating component and the semiconductor cooling chip are respectively distributed at the upper and lower ends of the outside of the compression mold (12).

5. The characterization system for the thermo-mechanical coupling compression molding process of the adhesive material according to claim 1, characterized in that, Multiple temperature sensors are installed on the inner wall of the compression chamber, and these sensors are distributed along the length of the compression chamber to monitor the temperature at different locations within the chamber.

6. The characterization system for the thermo-mechanical coupling compression molding process of the adhesive material according to claim 1, characterized in that, The XRD in-situ testing module includes an X-ray source (21), an X-ray collimator (22), a central beam blocker (23), and a flat panel detector (24) arranged in sequence. The compression component is located between the X-ray collimator (22) and the central beam blocker (23). The X-ray source (21) is used to establish an X-ray beam that can pass through the bonded sample cavity, and the X-ray collimator (22) is used to limit the divergence angle of the X-ray beam.

7. The characterization system for the thermo-mechanical coupling compression molding process of the bonding material according to claim 6, characterized in that, The X-ray source (21) and X-ray collimator (22) are located in the shielded X-ray source chamber. The X-ray source (21) is fixed on the side wall of the shielded X-ray source chamber, and the X-ray collimator (22) is located at the outlet of the shielded X-ray source chamber.

8. The characterization system for the thermo-mechanical coupling compression molding process of adhesive materials according to any one of claims 1-7, characterized in that, The characterization system also includes a sealed housing, within which the molding assembly and the XRD in-situ testing module are located.

9. A method for characterizing the thermo-mechanical coupling compression molding process of an adhesive material, characterized in that, The characterization process of the thermo-mechanical coupling compression molding process of the adhesive material as described in any one of claims 1-8 is performed, and the characterization method includes the following steps: S1. The bonding sample (3) to be tested is loaded into the bonding sample cavity of the compression mold (12), and the bonding sample (3) to be tested is placed in the offset area of ​​the bonding sample cavity; S2. Start the upper pressure head (11) and the lower pressure head (13) to approach the bonding sample cavity and push the bonding sample (3) to be tested to the center region of the X-ray optical path; S3. Start the temperature control module (14) to bring the bonded sample (3) to the temperature test mode. According to the compression loading program, use the upper pressure head (11) and the lower pressure head (13) to apply pressure to compress the bonded sample (3). At the same time as compression, start the XRD in-situ test module to collect diffraction data and transmit it to the data processing module for processing.

10. The characterization method for the thermo-mechanical coupling compression molding process of the adhesive material according to claim 9, characterized in that, The characterization system also includes a sealed housing, and the molding assembly and the XRD in-situ testing module are both located inside the housing; before step S2, the housing is evacuated to create a vacuum environment inside the housing.

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