Directional solidification in-situ characterization apparatus and directional solidification in-situ characterization device having the same

Abstract

This invention discloses a directional solidification in-situ characterization device and a directional solidification in-situ characterization apparatus having the same. The directional solidification in-situ characterization device includes an in-situ solidification module and an in-situ imaging module. The in-situ solidification module includes a furnace body and a heating element. A channel is formed inside the furnace body, and an inlet and an outlet communicating with the channel are formed on opposite side walls of the furnace body, respectively. The heating element is disposed inside the furnace body. The in-situ imaging module includes an X-ray unit and an infrared unit, both of which are disposed on the channel. In the direction from the inlet to the outlet, the cross-sectional area of ​​the channel first gradually decreases and then gradually increases. According to the directional solidification in-situ characterization device of this invention, microscopic processes such as dendrite arm growth, dendrite spacing changes, and grain competitive growth can be dynamically captured, achieving high-resolution temperature measurement. This enables simultaneous in-situ observation of dendrite growth, crystal orientation, and temperature field, improving X-ray penetration efficiency and infrared temperature measurement accuracy.

Description

Technical Field

[0001] This invention relates to the field of single crystal manufacturing technology, and in particular to a directional solidification in-situ characterization device and a directional solidification in-situ characterization equipment having the same. Background Technology

[0002] The relevant technologies indicate that the microstructure evolution mechanism during the directional solidification process of single-crystal superalloys is still unclear, resulting in a defect rate of up to 65% in single-crystal blades. Existing technologies, such as the "neutron in-situ diagnostic system for the directional solidification process of single-crystal superalloys," can only acquire diffraction patterns and cannot achieve simultaneous observation of dendrite evolution and temperature field; the "vacuum furnace based on synchrotron radiation three-dimensional imaging and diffraction" uses a top-and-bottom heating method, resulting in a low temperature gradient and lacking micron-level infrared thermometry, making it difficult to meet the needs of high-precision in-situ research. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a directional solidification in-situ characterization device, which can dynamically capture microscopic processes such as dendrite arm growth, dendrite spacing changes, and grain competitive growth, to achieve high-resolution temperature measurement and improve X-ray penetration efficiency and infrared temperature measurement accuracy.

[0004] The present invention also proposes a directional solidification in-situ characterization device having the above-mentioned directional solidification in-situ characterization device.

[0005] According to a first aspect of the present invention, a directional solidification in-situ characterization apparatus comprises: an in-situ solidification module, the in-situ solidification module comprising: a furnace body, wherein a channel is formed within the furnace body, at least a portion of the sample is located within the channel, and an inlet and an outlet communicating with the channel are respectively formed on opposite side walls of the furnace body; a heating element disposed within the furnace body; and an in-situ imaging module, the in-situ imaging module being arranged adjacent to the in-situ solidification module, the in-situ imaging module comprising: an X-ray unit and an infrared unit, both the X-ray unit and the infrared unit being disposed on the channel, wherein, in the direction from the inlet to the outlet, the cross-sectional area of ​​the channel first gradually decreases and then gradually increases.

[0006] The directional solidification in-situ characterization device of the present invention, by coupling an X-ray unit and an infrared unit, can dynamically capture microscopic processes such as dendrite arm growth, dendrite spacing changes, and grain competitive growth, and also achieve high-resolution temperature measurement, thereby realizing synchronous in-situ observation of dendrite growth, crystal orientation and temperature field; by forming a channel with a cross-sectional area that gradually decreases and then gradually increases, the X-ray penetration efficiency and infrared temperature measurement accuracy are improved.

[0007] In some feasible embodiments, the size of the inlet is the same as the size of the outlet.

[0008] In some feasible embodiments, the angle between the peripheral wall of the channel and the central axis of the channel is 12°-18°.

[0009] In some feasible embodiments, the X-ray unit includes an X-ray source and an X-ray detector, and the infrared unit includes an infrared source and an infrared detector. The X-ray source and the infrared source are located at the entrance port, and the X-ray detector and the infrared detector are located at the exit port.

[0010] In some feasible embodiments, an injection plate is provided at the injection port, an injection plate is provided at the injection port, and a sealing element is provided between the injection plate and the furnace body and between the injection plate and the furnace body.

[0011] In some feasible embodiments, at least one of the incident plate and the exit plate is formed of sapphire material.

[0012] In some feasible embodiments, the furnace body is movable in a direction perpendicular to the X-rays.

[0013] In some feasible embodiments, a baffle is provided at the end of the channel, the baffle being formed of boron nitride material.

[0014] In some feasible embodiments, the directional solidification in-situ characterization device further includes: a rotary crystal pulling mechanism, the rotary crystal pulling mechanism being movable relative to the furnace body, the rotary crystal pulling mechanism comprising: Crystallization stage, which is used to hold crystals; A cooling element, the cooling element being arranged around the crystallization stage; A first driving unit is used to drive the crystallization stage to move in the vertical direction relative to the furnace body; The second drive unit is used to drive the crystallization stage to rotate relative to the furnace body about its own axis.

[0015] In some feasible embodiments, a heat insulation plate is provided between the cooling component and the furnace body, and the thickness of the heat insulation plate is 10-20mm.

[0016] The directional solidification in-situ characterization apparatus according to a second aspect of the present invention includes a vacuum device and a directional solidification in-situ characterization apparatus according to the first aspect of the present invention described above.

[0017] According to the directional solidification in-situ characterization device of the present invention, by setting the directional solidification in-situ characterization device of the first aspect described above, it has the same technical effect, that is, by coupling the X-ray unit and the infrared unit, it can dynamically capture microscopic processes such as dendrite arm growth, dendrite spacing change, and grain competitive growth, and also realize high-resolution temperature measurement, thereby realizing synchronous in-situ observation of dendrite growth, crystal orientation and temperature field; by forming a channel with a cross-sectional area that gradually decreases and then gradually increases, the X-ray penetration efficiency and infrared temperature measurement accuracy are improved.

[0018] In some feasible embodiments, the furnace body of the directional solidification in-situ characterization device is formed with an exhaust port communicating with the interior of the furnace body, and the vacuum device is connected to the exhaust port to create a vacuum inside the furnace body.

[0019] In some feasible embodiments, the directional solidification in-situ characterization device further includes a control module, which is electrically connected to both the vacuum device and the directional solidification in-situ characterization device.

[0020] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a directional solidification in-situ characterization device according to an embodiment of the present invention; Figure 2 yes Figure 1 A schematic diagram of the directional solidification in-situ characterization device from another angle; Figure 3 yes Figure 1 A schematic diagram of another angle of the directional solidification in-situ characterization device shown; Figure 4 yes Figure 1 A schematic diagram of the vertical cross-section of the directional solidification in-situ characterization device shown; Figure 5 yes Figure 1 The diagram shows a cross-sectional view of the directional solidification in-situ characterization device.

[0022] Figure label: 100. Directional solidification in-situ characterization device; 1. In-situ solidification module; 11. Furnace body; 111. Inlet; 112. Outlet; 12. Heating element; 2. In-situ imaging module; 21. X-ray unit; 211. X-ray source; 212. X-ray detector; 22. Infrared unit; 221. Infrared source; 222. Infrared detector; 3. Rotary crystal pulling mechanism; 31. Crystallization stage; 32. Cooling element; 33. First drive unit; 34. Second drive unit; 4. Channel; 5. Inlet plate; 6. Outlet plate; 7. Insulation layer; 8. Insulation plate; 200. Sample. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0024] The following is for reference. Figures 1-5 A directional solidification in-situ characterization apparatus 100 according to an embodiment of the first aspect of the present invention is described.

[0025] like Figures 1-5 As shown, the directional solidification in-situ characterization device 100 according to a first aspect embodiment of the present invention includes: an in-situ solidification module 1 and an in-situ imaging module 2.

[0026] Specifically, the in-situ solidification module 1 includes a furnace body 11 and a heating element 12. A channel 4 is formed inside the furnace body 11, and at least a portion of the sample 200 is located inside the channel 4. An inlet 111 and an outlet 112 communicating with the channel 4 are formed on the side walls on opposite sides of the furnace body 11, respectively. The heating element 12 is located inside the furnace body 11. The in-situ imaging module 2 is arranged adjacent to the in-situ solidification module 1. The in-situ imaging module 2 includes an X-ray unit 21 and an infrared unit 22. Both the X-ray unit 21 and the infrared unit 22 are located on the channel 4. In the direction from the inlet 111 to the outlet 112, the cross-sectional area of ​​the channel 4 first gradually decreases and then gradually increases.

[0027] Understandably, the furnace body 11 is equipped with a heating element 12, which is used to apply a controllable thermal field to the sample 200 to achieve a directional solidification process from molten state to solid state. The heating element 12 is arranged in the furnace body 11 to ensure the formation of a stable and adjustable temperature gradient along the solidification direction, simulating the actual single crystal blade preparation conditions, providing stable thermodynamic boundary conditions for subsequent in-situ observations, and improving the repeatability of the experiment and the reliability of the data.

[0028] A channel 4 is formed inside the furnace body 11. At least a portion of the sample 200 is located inside the channel 4. The channel 4 penetrates the furnace body 11 and accommodates the sample 200 to be tested. The sample 200 is vertically placed in the channel 4, and the solidification interface is located in the observable area. By arranging the channel 4, an unobstructed transmission path is provided for X-rays and infrared radiation, avoiding the absorption or scattering of signals by the material of the furnace body 11.

[0029] The furnace body 11 has an inlet 111 and an outlet 112 on opposite side walls that are connected to the channel 4. The inlet 111 is used to introduce external X-rays and / or infrared rays, and the outlet is used to receive projected X-rays or diffraction signals. The inlet 111 and the outlet 112 are located at both ends of the axis of the channel 4 to ensure that X-rays penetrate the sample 200 along the solidification direction. This achieves the collinear arrangement of X-ray transmission imaging and diffraction analysis, simplifies the optical path design, and allows for in-situ acquisition of crystal orientation and dendrite morphology through diffraction spots.

[0030] Both the X-ray unit 21 and the infrared unit 22 are located on channel 4. The X-ray unit 21 includes an X-ray source 211, an X-ray detector 212, and related optical components, which are used to acquire two-dimensional / three-dimensional morphological images and crystallographic information of the sample 200 in real time. In this way, the X-ray unit 21 can dynamically capture microscopic processes such as dendrite arm growth, dendrite spacing changes, and grain competitive growth. The infrared unit 22 can be an infrared thermal imager with micron-level spatial resolution or a focused infrared temperature probe, which is used for non-contact measurement of the temperature distribution on or near the surface of the sample 200.

[0031] The cross-sectional area of ​​channel 4 gradually decreases and then gradually increases in the direction from the inlet 111 to the outlet 112. That is, channel 4 has an hourglass or double cone structure. The narrowest part in the middle corresponds to the solidification front observation area of ​​sample 200, which optimizes the focusing effect of X-ray beam and reduces the interference of furnace body 11 thermal radiation on infrared temperature measurement. Furthermore, narrowing the middle area can reduce the path length of X-rays through the furnace body 11 material, reduce background noise, limit the volume of high temperature area, enhance the local temperature gradient, and make it more conducive to the formation of stable plane front or regular dendrites. The expansion section also helps to alleviate thermal stress concentration, prevent the furnace body 11 from deforming due to thermal expansion, improve the long-term operating stability of the device, and improve the accuracy of temperature measurement.

[0032] According to the embodiment of the present invention, the directional solidification in-situ characterization device 100, by coupling the X-ray unit 21 and the infrared unit 22, can dynamically capture microscopic processes such as dendrite arm growth, dendrite spacing changes, and grain competitive growth, and also realize high-resolution temperature measurement, thereby achieving synchronous in-situ observation of dendrite growth, crystal orientation and temperature field; by forming a channel 4 with a cross-sectional area that gradually decreases and then gradually increases, the X-ray penetration efficiency and infrared temperature measurement accuracy are improved.

[0033] In some embodiments of the present invention, the size of the entrance port 111 is the same as the size of the exit port 112. This eliminates X-ray flux asymmetry caused by window size differences, avoids overexposure on one side of the image, ensures the wavefront integrity of the transmitted X-ray beam, and also ensures the optical path symmetry of the X-ray beam before and after penetrating the sample 200. This avoids beam truncation, enhanced scattering, or uneven intensity attenuation caused by window size differences. Simultaneously, it maintains the axially symmetrical distribution of heat flow and airflow within channel 4, suppressing the lateral temperature gradient caused by structural asymmetry, thereby reducing the risk of heterogeneous crystal nucleation.

[0034] Furthermore, if the exit port 112 is smaller than the entrance port 111, some diffraction signals or high-angle scattered photons will be blocked. If the exit port 112 is larger than the entrance port 111, it will increase heat leakage and background noise in the furnace body 11. Consistent dimensions ensure unobstructed passage of the entire effective X-ray cone beam, improving crystal orientation resolution accuracy and reducing diffraction spot distortion or loss caused by beam truncation. Moreover, if the entrance port 111 and exit port 112 have different dimensions, it will lead to local thermal conductivity differences, causing inert gas flow to deviate towards the larger aperture side, resulting in a skewed radial temperature distribution. It will also cause the X-ray field of view center to shift from the infrared observation area. Therefore, setting the entrance port 111 and exit port 112 to have the same size can effectively suppress competing grain growth induced by lateral temperature gradients, reduce the impurity defect rate, and improve the authenticity and reliability of experimental data.

[0035] For example, if the inlet 111 is circular, then the outlet 112 is also circular and has the same diameter as the inlet 111.

[0036] For example, if the inlet 111 is rectangular, then the outlet 112 is also rectangular, and has the same width and height as the inlet 111.

[0037] In some embodiments of the present invention, the angle between the peripheral wall of the channel 4 and the central axis of the channel 4 is 12°-18°. In other words, the channel 4 is in the shape of a perfect circular cone, and the angle between the central axis and the generatrix of the cone surface is 12°-18°. Therefore, the angle between the radially opposite generatrixes of the cone surface is 24°-36°.

[0038] For example, the included angle can be 12°, 13°, 14°, 15°, 16°, 17°, 18°, etc.

[0039] Preferably, the included angle is 12°, that is, the included angle between the radially opposite generatrices of the cones is 24°.

[0040] In some embodiments of the present invention, the X-ray unit 21 includes an X-ray source 211 and an X-ray detector 212, and the infrared unit 22 includes an infrared source 221 and an infrared detector 222. The X-ray source 211 and the infrared source 221 are located at the entrance port 111, and the X-ray detector 212 and the infrared detector 222 are located at the exit port 112. It is understood that the X-ray source 211 emits high-energy X-rays that penetrate the high-temperature alloy sample 200 located within the channel 4, and the X-ray detector 212 is located at the exit port to receive transmitted X-rays, achieving non-destructive, real-time, and high-resolution observation of the internal microstructure. The infrared source 221 is used to irradiate the surface of the sample 200, and the infrared detector 222 is used to receive mixed signals of reflected / transmitted / thermal radiation. Combined with quality modulation and demodulation technology, high-precision temperature measurement is achieved, overcoming the difficulty of temperature measurement on low-emissivity metal surfaces, and is particularly suitable for unoxidized clean alloys.

[0041] Because in existing technologies, leakage of the furnace atmosphere at high temperatures leads to oxidation or contamination of the sample 200, and the window material is directly subjected to thermal expansion of the furnace body 11, it is prone to cracking and failure. Replacing the window or performing maintenance requires disassembling the entire furnace body 11, which is inefficient. Therefore, in some embodiments of the present invention, such as... Figure 4 As shown, an incident plate 5 is provided at the inlet 111, and an exit plate 6 is provided at the outlet 112. Sealing elements are provided between the incident plate 5 and the furnace body 11, and between the exit plate 6 and the furnace body 11. This achieves long-term high sealing of the furnace atmosphere, ensuring the solidification of single-crystal alloys in an oxygen-free environment. It also supports the rapid replacement of different functional windows (such as X-ray windows, infrared windows, and composite windows), improving the flexibility of the directional solidification in-situ characterization device 100.

[0042] In some embodiments of the present invention, at least one of the incident plate 5 and the exit plate 6 is formed of sapphire material. It is understood that the incident plate 5 can be formed of sapphire material, the exit plate 6 can be formed of sapphire material, or both the incident plate 5 and the exit plate 6 can be formed of sapphire material. Since sapphire material has good X-ray transmittance and high transmittance for infrared light, and sapphire material has good high-temperature stability and good mechanical inertness, setting the incident plate 5 and the exit plate 6 as sapphire material can prevent the window itself from contaminating the sample 200, avoid deformation or qualitative changes in the incident plate 5 and the exit plate 6 due to excessive temperature, maintain optical axis stability, and further avoid affecting signal attenuation and aberrations of X-rays and infrared rays.

[0043] In some embodiments of the present invention, the furnace body 11 is movable in a direction perpendicular to X-rays. This allows for switching of the observation area without disassembling the sample 200, improving experimental efficiency, reducing experimental result errors, ensuring continuous and stable thermal field and atmosphere within the furnace, and avoiding disturbances introduced by reloading the sample.

[0044] In some embodiments of the present invention, a baffle is provided at the end of channel 4, and the baffle is formed of boron nitride material. It is understood that setting a baffle made of boron nitride material can slow down the rapid heat dissipation, prevent the solidification front from becoming too cold, form a thermal buffer layer, and make the temperature gradient distribution smoother; in addition, boron nitride is non-wetting to most molten metals (including Ni, Co, and Fe-based superalloys), with a contact angle >90°, and does not react with active elements such as Al, Ti, Ta, Re, and W (in contrast, alumina (Al2O3) reacts with Al / Ti, and graphite will increase carbon), avoiding the induction of heterogeneous nucleation, maintaining the original composition of the alloy, and ensuring the authenticity of experimental data; the boron nitride material has good transmittance and will not block X-ray imaging and diffraction signals. Even if the baffle is located within the field of view, no artifacts are produced, allowing infrared thermometry to penetrate the baffle and obtain the true interface temperature.

[0045] In some embodiments of the present invention, the directional solidification in-situ characterization device 100 further includes: a rotary crystal pulling mechanism 3, which is movable relative to the furnace body 11. The rotary crystal pulling mechanism 3 includes: a crystallization stage 31, a cooling element 32, a first driving unit 33, and a second driving unit 34. The crystallization stage 31 is used to support the crystal, the cooling element 32 is arranged around the crystallization stage 31, the first driving unit 33 is used to drive the crystallization stage 31 to move vertically relative to the furnace body 11, and the second driving unit 34 is used to drive the crystallization stage 31 to rotate relative to the furnace body 11 around its own axis. Figures 1-4 As shown, the rotating crystal pulling mechanism 3 can be understood to achieve rapid start-up and precise positioning, ensuring that the solidification interface is always within the channel 4 for easy observation of the solidification process. The crystallization stage 31 directly contacts the bottom of the primary solid phase and can serve as a seed crystal substrate or initial solidification interface for single crystal epitaxial growth. The cooling element 32 surrounds the outer periphery of the crystallization stage 31, which can quickly dissipate the latent heat of solidification and maintain the planar leading edge or regular dendritic shape. The first driving unit 33 drives the crystallization stage 31 to move in the vertical direction to move the single crystal in the vertical direction, thereby precisely controlling the solidification rate. The second driving unit 34 drives the crystallization stage 31 to rotate around its own axis, uniformly distributing the radial temperature and eliminating the lateral temperature difference caused by heating asymmetry. Thus, the rotation makes the radial temperature and concentration field more uniform, improves the single crystal orientation consistency, reduces the impurity rate, and truly reproduces the single crystal growth process.

[0046] In some embodiments of the present invention, a heat insulation plate 8 is provided between the cooling element 32 and the furnace body 11, and the thickness of the heat insulation plate 8 is 10-20 mm. It is understood that the cooling element 32 (such as a water-cooled copper sleeve or liquid nitrogen cooling finger) is used to rapidly dissipate the latent heat of solidification to form a high temperature gradient, while the furnace body 11 needs to maintain a high-temperature molten zone (typically >1500°C). If the two are in direct contact or too close, heat loss will occur, resulting in unstable molten pool temperature, drift of the solidification front position, a surge in heating power demand of the furnace body 11, high energy consumption, and a tendency to overheat. Therefore, the heat insulation plate 8 can suppress parasitic heat conduction from the furnace body 11 to the cooling element 32, ensure that heat is controllable along the axial direction of the sample 200, reduce the heating power of the furnace body 11, improve energy efficiency, extend the life of the heating element, and prevent condensation or thermal stress cracking on the surface of the cooling element 32, thereby improving the long-term reliability of the directional solidification in-situ characterization device 100.

[0047] The directional solidification in-situ characterization apparatus according to a second aspect of the present invention includes a vacuum device and a directional solidification in-situ characterization apparatus 100 according to the first aspect of the present invention described above.

[0048] The directional solidification in-situ characterization device according to the embodiments of the present invention, by setting the directional solidification in-situ characterization device 100 of the first aspect embodiment, has the same technical effect, that is, by coupling the X-ray unit 21 and the infrared unit 22, it can dynamically capture microscopic processes such as dendrite arm growth, dendrite spacing change, and grain competitive growth, and also realize high-resolution temperature measurement, thereby realizing synchronous in-situ observation of dendrite growth, crystal orientation and temperature field; by forming a channel 4 with a cross-sectional area that gradually decreases and then gradually increases, the X-ray penetration efficiency and infrared temperature measurement accuracy are improved.

[0049] In some embodiments of the present invention, the furnace body 11 of the directional solidification in-situ characterization device 100 is provided with an exhaust port communicating with the interior of the furnace body 11, and a vacuum device is connected to the exhaust port to create a vacuum inside the furnace body 11. Thus, by setting up the vacuum device, a vacuum state can be achieved inside the furnace body 11, completely isolating oxygen and moisture, preventing oxidation of high-temperature alloying elements, ensuring compositional purity, suppressing high vapor pressure elements, avoiding dendritic composition distortion and furnace contamination, eliminating gas convection thermal disturbances, forming a more stable pure conductive heat field, improving the stability of the solidification front, and also reducing X-ray absorption and scattering in air, thereby improving the imaging signal-to-noise ratio and the clarity of diffraction spots.

[0050] In some embodiments of the present invention, the directional solidification in-situ characterization device further includes a control module, which is electrically connected to both the vacuum device and the directional solidification in-situ characterization device 100. For example, the control module is electrically connected to the heating element 12 and can adjust the power to maintain the molten pool temperature; the control module is also electrically connected to the rotating crystal pulling mechanism 3 and can control the first drive unit 33 (pulling speed) and the second drive unit 34 (rotation speed). This improves the level of experimental automation and supports unattended long-term operation (such as 24-hour directional solidification).

[0051] The following will refer to Figures 1-5 A directional solidification in-situ characterization apparatus is described according to a specific embodiment of the present invention.

[0052] Reference Figures 1-5 As shown, it includes a vacuum device, a control module, and a directional solidification in-situ characterization device 100. The directional solidification in-situ characterization device 100 includes: an in-situ solidification module 1, an in-situ imaging module 2, and a rotating crystal pulling mechanism 3. The in-situ solidification module 1 includes a furnace body 11 and a heating element 12. The in-situ imaging module 2 includes an X-ray unit 21 and an infrared unit 22. The rotating crystal pulling mechanism 3 includes a crystallization stage 31, a cooling element 32, a first driving unit 33, and a second driving unit 34.

[0053] Specifically, such as Figures 1-5 As shown, the furnace body 11 is configured to a vacuum state through a vacuum device, and the heating element 12 is a resistance heating method to melt the sample 200 material and maintain it in the high temperature zone for a certain period of time to ensure uniform melt temperature. The sample is moved at a certain speed by pulling down, and under the influence of the cooling element 32 and the crystallization stage 31, the solid-liquid interface is gradually advanced. The directional solidification in-situ characterization device 100 can remotely monitor and adjust parameters such as temperature field and crystal pulling rate in real time through a control module (e.g., a host computer) to achieve dynamic control of the solidification process. During this process, X-rays are coupled to observe the solid-liquid interface in real time and non-destructively through diffraction or imaging techniques, thereby studying key issues such as solid-liquid interface morphology, dendrite growth kinetics, solute distribution, and defect formation.

[0054] For example, the upper heating is set, with a maximum operating temperature of 1750℃ and a stable temperature of 1550℃; the temperature accuracy is ±3℃; the temperature gradient is ≥120K / cm; the sample size is 30mm wide × 70mm long × 0.5mm thick; the distance between the heating element 12 and the cooling element 32 is 10-50mm; the ultimate vacuum is 1×10-3Pa; the working vacuum is 5×10-3Pa; the sample 200 can rotate within the furnace body 11, with a rotation angle of ±15°; the crystal pulling speed is 1μm / s-1000μm / s; and the crystal pulling stroke is set to 70mm.

[0055] The vacuum furnace body 11 provides a sealed environment for the directional solidification process. It has a vertical square cavity design and is mounted on a four-axis guide bracket. Both the upper and lower flanges can be moved and opened. The furnace body 11 and the upper and lower flange covers are made of double-layer stainless steel with water cooling in the interlayer. The side walls on opposite sides of the furnace body 11 have an inlet 111 and an outlet 112, respectively. The dimensions of the inlet 111 and the outlet 112 are approximately 80mm*65mm. The inlet plate 5 and the outlet plate 6 are both made of sapphire glass. There are seals between the inlet plate 5 and the furnace body 11, and between the outlet plate 6 and the furnace body 11.

[0056] The incident plate 5 and the exit plate 6 are both made of sapphire glass (usually single-crystal α-Al2O3). Specifically, (1) excellent X-ray transmittance: Sapphire glass is mainly composed of low atomic number elements aluminum (Z=13) and oxygen (Z=8). Low atomic number means a small absorption cross section for X-rays (especially hard X-rays) and weak scattering. In the hard X-ray energy range commonly used in synchrotron radiation (usually from 5 keV to tens of keV), sapphire glass has very high transmittance (usually >80% or higher, depending on thickness and energy). This minimizes the attenuation of X-ray signals and background noise, ensuring the quality of experimental data and signal-to-noise ratio. Single-crystal sapphire glass also has low coherent scattering intensity and incoherent neutron scattering cross section, which can effectively avoid strong Bragg diffraction peaks appearing on the detector of small-angle scattering spectrometers. In contrast, polycrystalline materials (such as polycrystalline alumina) produce continuous Debye ring scattering in all directions, forming a high background that is difficult to remove. Monocrystalline sapphire glass significantly reduces this coherent scattering background by avoiding polycrystalline structures.

[0057] (2) Extremely high temperature stability: Sapphire glass has a melting point of approximately 2050°C, far exceeding the temperature range required for most heat treatment experiments. At high temperatures, sapphire glass maintains excellent mechanical strength and structural stability, and is not prone to softening, creeping, or deformation, ensuring that the incident plate 5 and / or the exit plate 6 maintain their shape and sealing performance under prolonged high temperatures. Sapphire glass is chemically very stable at high temperatures and is not prone to reacting with the furnace atmosphere (such as inert gases, reducing gases, or even some weak oxidizing gases) or sample 200, thus avoiding transmittance reduction or failure caused by contamination or corrosion of the incident plate 5 and / or the exit plate 6.

[0058] (3) Excellent vacuum sealing: The sapphire glass incident plate 5 and exit plate 6 can achieve a reliable and highly airtight vacuum seal with metal flanges (such as stainless steel, Kova alloy, etc.) through metallization (such as titanium plating, molybdenum manganese plating, etc.) and brazing processes. This is crucial for maintaining a vacuum or specific atmosphere environment in the heat treatment furnace cavity.

[0059] (4) Excellent thermal shock performance: Although the thermal expansion coefficient of sapphire glass is not the lowest, its high thermal conductivity helps to distribute heat quickly and evenly, enabling it to withstand the unavoidable rapid heating and cooling process (thermal shock) in experiments, reducing the risk of cracking due to thermal stress.

[0060] Table 1. Comparison of several typical X-ray transmission window materials

[0061] Furthermore, the cross-sectional area of ​​channel 4 gradually decreases and then gradually increases, and the size of the inlet 111 is the same as the size of the outlet 112. That is, the detection part of sample 200 falls into the minimum cross-sectional area of ​​channel 4, and channel 4 is symmetrically arranged about the minimum cross-sectional area. The angle between the generatrix of the peripheral wall of channel 4 and the central axis of channel 4 is calculated based on the maximum angle that synchrotron X-rays can pass through. The energy range of the synchrotron radiation beamline used is 50keV-100keV.

[0062] From Bragg's formula:

[0063] It can be seen that when θ is at its maximum, the wavelength λ of the X-rays is required to be at its maximum, and the interplanar spacing d is required to be at its minimum.

[0064] From Planck's formula:

[0065] It can be concluded that when the energy E is 50keV, the maximum wavelength λ = 0.248Å. Referring to the list of interplanar spacings for nickel metal, the interplanar spacing d = 0.7188Å of the 9th diffraction peak (422) is selected as the minimum interplanar spacing. Using the Bragg formula, θ≈10° is obtained. It is confirmed that the window can be appropriately increased to θ≈12°. The Bragg angle of the window is actually a cone, so the final window opening angle is determined to be θ'≈24°. That is, the angle between the radially opposite generatrices of the cones is 24°.

[0066] Heating element 12 is an isostatically pressed graphite component. Compared to heating elements made of molybdenum or tungsten, graphite is more resistant to high temperatures and has a faster heating rate. The surface temperature distribution of heating element 12 is highly uniform, making it suitable for applications with strict temperature gradient requirements. Its low coefficient of thermal expansion also prevents deformation or cracking during use. The maximum design temperature inside the furnace body 11 is 1750℃. The furnace body 11 has an inner diameter of approximately φ60mm and a height of 80mm. Compared to traditional insulation materials such as ceramic fiber and aluminum silicate, or metal insulation layers such as tantalum and tungsten, graphite hard felt can work stably for a long time in an inert atmosphere or vacuum up to 2500℃ without melting or softening, exhibiting extremely strong structural stability. Its insulation efficiency under high temperature and vacuum far exceeds that of other materials. However, graphite hard felt has certain electrical conductivity, so a layer of boron nitride is added as an insulation layer between the heating element 12 and the insulation layer 7 in the design of the furnace body 11.

[0067] To achieve a larger temperature gradient, a 10-20mm thick insulation plate 8 is installed between the bottom of the furnace body 11 and the cooling component 32. The thickness of the insulation plate 8 can be replaced during use to achieve an even higher temperature gradient. Temperature measurement inside the furnace body 11 is achieved by directly inserting thermocouples into the furnace body 11, combined with a high-precision temperature controller for PID control of the heating temperature. Four thermocouple interfaces (including temperature control) are reserved to facilitate multi-point temperature monitoring during the experiment.

[0068] The rotating crystal pulling mechanism 3 enables rapid start-up and precise positioning, ensuring the solidification interface remains within the channel 4 for easy observation of the solidification process. The crystallization stage 31 directly contacts the bottom of the nascent solid phase, serving as a seed crystal substrate or initial solidification interface for single-crystal epitaxial growth. The cooling element 32 surrounds the outer periphery of the crystallization stage 31, rapidly dissipating latent heat of solidification and maintaining the planar leading edge or regular dendritic shape. The first driving unit 33 drives the crystallization stage 31 to move vertically, thereby precisely controlling the solidification rate. The second driving unit 34 drives the crystallization stage 31 to rotate around its own axis, uniformly distributing radial temperature and eliminating lateral temperature differences caused by heating asymmetry. Thus, rotation makes the radial temperature and concentration field more uniform, improving the single-crystal orientation consistency, reducing the impurity rate, and realistically reproducing the single-crystal growth process.

[0069] The drive unit uses a high-precision servo motor and planetary reducer, along with linear guide rails and ball screws, to realize the movement and rotation of sample 200. Sample 200 can rotate within furnace body 11 with a rotation angle of ±15°; crystal pulling speed: 1μm / s-1000μm / s; rotation speed: 1r / min-10r / min; crystal pulling stroke is set to 70mm.

[0070] Furthermore, considering that the directional solidification in-situ characterization equipment of this embodiment needs to be disassembled and transported periodically, the directional solidification in-situ characterization equipment is modularly designed. The vacuum device adopts an integrated molecular pump unit, which is connected to the furnace body 11 of the directional solidification in-situ characterization device 100 through a vacuum bellows. Disassembly is quick and simple, and at the same time, the influence of the vibration of the integrated molecular pump unit on the directional solidification process is eliminated. The vacuum device includes a molecular pump, a backing pump, a vacuum gauge, a vacuum gauge, and vacuum valves. The vacuum level is directly displayed on the unit. The unit and the control system establish communication, and the vacuum level can also be displayed on the host computer control interface. The unit frame is designed with casters for easy movement.

[0071] Heating element 12 is a graphite component with a resistance of 0.3-0.4Ω, requiring a low-voltage power supply. A thyristor voltage regulator is selected as the heating power source, allowing for precise adjustment of AC voltage or power output. The thyristor voltage regulator offers sensitive voltage regulation, no contact loss, and high efficiency. The control module consists of an electrical control cabinet and a host computer. The electrical control cabinet is a fully enclosed cabinet equipped with exhaust ventilation and heat dissipation devices. The control module needs to be placed outside the light source room and connected to the equipment inside the light source room via wires and connectors to establish communication. A laptop computer is used for easy transport with the equipment. The control module uses a programmable logic controller (PLC) for control, realizing data acquisition and control of the melting process, crystal pulling process, and vacuum pressure. The equipment's operating status and faults are displayed intuitively on the laptop screen, allowing operators to monitor the equipment status in real time while operating outside the light source room. Necessary logic protection is implemented, ensuring that the equipment can only start and perform corresponding operations when certain conditions are met, improving the system's automation level and preventing equipment damage caused by improper operation.

[0072] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0073] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0074] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0075] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0076] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A directional solidification in-situ characterization device (100), characterized in that, include: In-situ solidification module (1), the in-situ solidification module (1) includes: A furnace body (11) has a channel (4) formed inside it, at least a portion of the sample (200) is located inside the channel (4), and an inlet (111) and an outlet (112) communicating with the channel (4) are formed on the side walls of opposite sides of the furnace body (11). A heating element (12) is disposed inside the furnace body (11); An in-situ imaging module (2) is arranged adjacent to the in-situ solidification module (1). The in-situ imaging module (2) includes an X-ray unit (21) and an infrared unit (22), both of which are located on the channel (4). In the direction from the inlet (111) toward the outlet (112), the cross-sectional area of ​​the channel (4) first gradually decreases and then gradually increases.

2. The directional solidification in-situ characterization device (100) according to claim 1, characterized in that, The size of the inlet (111) is the same as the size of the outlet (112).

3. The directional solidification in-situ characterization device (100) according to claim 1, characterized in that, The angle between the peripheral wall of the channel (4) and the central axis of the channel (4) is 12°-18°.

4. The directional solidification in-situ characterization device (100) according to claim 2, characterized in that, The X-ray unit (21) includes an X-ray source (211) and an X-ray detector (212), and the infrared unit (22) includes an infrared source (221) and an infrared detector (222). The X-ray source (211) and the infrared source (221) are located at the entrance (111), and the X-ray detector (212) and the infrared detector (222) are located at the exit (112).

5. The directional solidification in-situ characterization device (100) according to claim 4, characterized in that, An injection plate (5) is provided at the injection port (111), and an injection plate (6) is provided at the injection port (112). Sealing elements are provided between the injection plate (5) and the furnace body (11) and between the injection plate (6) and the furnace body (11).

6. The directional solidification in-situ characterization device (100) according to claim 5, characterized in that, At least one of the incident plate (5) and the exit plate (6) is formed of sapphire material.

7. The directional solidification in-situ characterization device (100) according to claim 6, characterized in that, The furnace body (11) is movable in a direction perpendicular to the X-rays.

8. The directional solidification in-situ characterization device (100) according to any one of claims 1-7, characterized in that, A baffle is provided at the end of the channel (4), and the baffle is formed of boron nitride material.

9. The directional solidification in-situ characterization device (100) according to any one of claims 1-7, characterized in that, Also includes: A rotating crystal pulling mechanism (3) is movable relative to the furnace body (11), and the rotating crystal pulling mechanism (3) includes: A crystallization stage (31) is used to hold a crystal; A cooling element (32) is arranged around the crystallization stage (31); The first driving unit (33) is used to drive the crystallization stage (31) to move in the vertical direction relative to the furnace body (11); The second drive unit (34) is used to drive the crystallization stage (31) to rotate about its own axis relative to the furnace body (11).

10. The directional solidification in-situ characterization device (100) according to claim 9, characterized in that, A heat insulation plate (8) is provided between the cooling component (32) and the furnace body (11), and the thickness of the heat insulation plate (8) is 10-20mm.

11. A directional solidification in-situ characterization device, characterized in that, include: Vacuum apparatus and directional solidification in-situ characterization apparatus (100) according to any one of claims 1-10.

12. The directional solidification in-situ characterization device according to claim 11, characterized in that, The furnace body (11) of the directional solidification in-situ characterization device (100) has an exhaust port that communicates with the interior of the furnace body (11), and the vacuum device is connected to the exhaust port to create a vacuum inside the furnace body (11).

13. The directional solidification in-situ characterization device according to claim 12, characterized in that, Also includes: The control module is electrically connected to both the vacuum device and the directional solidification in-situ characterization device (100).

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