21 results about "Neutron diffraction" patented technology

The invention provides a space measurement and analysis method and system for a neutron diffraction rocking curve of a single crystal material, and the method comprises the steps: S1, building a laboratory coordinate system and a sample coordinate system, and setting a test point grid; s2, collecting a two-dimensional diffraction image of each test point to obtain angle information of the test point; s3, integrating the angle information of the test points based on the test point grid, and preprocessing the two-dimensional diffraction image; s4, extracting key structure parameters of each test point based on the preprocessed two-dimensional diffraction image; s5, constructing a stress field according to the key structure parameters; and S6, constructing a distribution map of crystal internal lattice parameters in a three-dimensional space according to the stress field. The method provided by the invention effectively improves the capability of identifying the non-uniformity and local distortion of the crystal structure, can be widely applied to the fields of residual stress evaluation, defect evolution monitoring, material quality control and the like, and has a remarkable engineering application value.

The utility model discloses a positioning adjusting device for a neutron diffraction experiment, and belongs to the technical field of neutron diffraction experiments. The positioning adjusting device for the neutron diffraction experiment comprises a cantilever supporting frame, a rotary driving mechanism, a linear driving mechanism and a connecting frame, wherein one end of the cantilever supporting frame is connected to a rack of neutron diffraction experiment equipment; the rotary driving mechanism is arranged at the other end of the cantilever supporting frame; the linear driving mechanism is connected to the output end of the rotary driving mechanism, and the rotary driving mechanism is used for driving the linear driving mechanism to rotate in an XY plane; the lower portion of the connecting frame is used for installing a fine collimator, the top of the connecting frame is connected with the output end of the linear driving mechanism, and the linear driving mechanism can drive the connecting frame to linearly move in the X direction and / or the Y direction. The positioning adjusting device for the neutron diffraction experiment is relatively high in space utilization rate and relatively high in universality.

The invention relates to a method for measuring dendritic crystal orientation deviation of a single crystal blade through monochromatic neutron diffraction imaging, which accurately captures crystal structure information through neutron diffraction, can clearly obtain diffraction signals of different areas of the single crystal blade, and can accurately measure the orientation deviation of defective crystal grains through the steps of defect position determination, bright spot matching and the like. By utilizing the deep penetrability and volatility of neutrons, the interior of the blade can be detected under the condition that the single crystal blade is not damaged. Meanwhile, the neutron imaging detection range is larger than that of a traditional X-ray method, overall imaging of the single crystal blade can be achieved, operation such as data cutting and splicing is not needed, the result is more visual and accurate, and consumed time is shorter.

This invention belongs to the field of materials science and engineering, and relates to an NS-TNV40 neutron-transparent alloy for high-temperature neutron scattering experiments. The alloy's composition, by weight percentage, is 39.24% Ti, 39.24% Nb, and 21.52% V. Its preparation includes batching, melting, homogenization, and forging. The alloy has a theoretical melting point of 1716℃, exhibits no neutron diffraction peaks after holding at 1000℃ for 100 hours, and demonstrates excellent high-temperature stability. It maintains a single-phase structure without phase transformation after 100 hours of service at 1000℃. It also exhibits good high-temperature oxidation resistance, with oxidation weight gain lower than that of high-purity V and VNi alloys. Mechanically, it combines high strength and high plasticity. This alloy can avoid interference from the scattering signals of the sample container itself, improve the quality of neutron scattering data, meet the requirements of high-temperature in-situ experiments, and promote the development of high-temperature neutron scattering experimental technology.

The invention provides a double-mechanical-arm sample scanning device and method for neutron diffraction stress measurement. The double-mechanical-arm sample scanning device comprises an operation arm, a measurement arm, a control system and a sample disc. The operation arm comprises a first mechanical arm and a clamping jaw, the clamping jaw is used for grabbing a to-be-tested sample from the sample disc, and the first mechanical arm is used for driving the grabbed sample to move in the operation space so as to change the position posture of the sample relative to the neutron beam; the measuring arm comprises a second mechanical arm and a contour measuring sensor, the contour measuring sensor is used for measuring the contour of the sample, and the second mechanical arm is used for adjusting the position posture of the contour measuring sensor; the control system is used for collecting measurement data of the contour measurement sensor, calculating the sample contour and the position posture of the sample relative to the operation arm coordinate system, and controlling the operation arm to drive the sample to perform neutron scanning. Sample movement and rotation positioning in the neutron scanning and measuring process are completed through the mechanical arm, and the flexibility of sample space operation is remarkably improved while the precision is ensured.

This invention discloses a multi-channel collimation device for neutron diffraction, belonging to the technical field of neutron scattering spectrometers. The device includes a base, separating aluminum plates, and a detector. The base has an arc-shaped structure, with two bases arranged opposite each other. Each base has multiple mounting cavities spaced circumferentially on it. Each mounting cavity contains multiple separating aluminum plates spaced vertically, with a channel for the neutron beam to pass between adjacent separating aluminum plates. The detector is configured in a one-to-one correspondence with each channel. This multi-channel collimation device can optimize the neutron signal and reduce stray background signals, thereby ensuring the accuracy of experimental results.

This invention provides an underwater welding stress in-situ measurement device and method based on neutron diffraction. The device includes a wire feeding mechanism, an underwater welding module, a neutron diffraction testing module, a molten pool camera module, and a water supply and drainage system. The underwater welding module includes a welding torch, a robotic arm, and an underwater welding table. The underwater welding table has a welding test chamber. An inclined pressure plate is provided in the welding test chamber. The pressure plate divides the welding test chamber into a water-side chamber and an air-side chamber. The pressure plate is used to press the workpiece. The molten pool camera module is used to acquire welding images. The neutron diffraction testing module includes a neutron incident device and two sets of detectors. The neutron incident device is used to inject a neutron beam into the workpiece test area. The two sets of detectors are respectively set at ±90° positions along the neutron beam diffraction direction. This device can simulate the underwater environment and achieve stable welding, and can acquire stress evolution data of the weld and its surrounding area in real time and continuously during the welding thermal cycle.

The invention discloses a sample positioning method applied to a neutron diffraction spectrometer for measuring residual stress of a material or a workpiece, which is applied to the field of neutron scattering science and technology and comprises the following steps: aligning a to-be-measured point of a to-be-measured sample with cross laser by using an electric displacement table to finish coarse positioning of the to-be-measured sample; measuring equipment is adopted to detect the surface coordinates of the point to be measured, the surface coordinates of the point to be measured are aligned with the beam center coordinates through an electric displacement table, and fine positioning of the sample to be measured is completed; driving the to-be-tested sample to move along the beam direction at a preset step length by using an electric displacement table, recording diffraction intensities of the to-be-tested sample at different positions, and performing deviation compensation through the electric displacement table according to a deviation between a corresponding position of a diffraction intensity peak value and a theoretical position; and repeating the measurement and deviation compensation of the diffracted intensity until the to-be-measured point completely coincides with the beam center and the diffraction centroid. The method effectively improves the positioning accuracy of the to-be-measured sample when the residual stress is measured.

The invention provides a neutron diffraction stress measurement device and method based on space coordinate measurement. The neutron diffraction stress measurement device comprises an autonomous navigation trolley, an attitude adjustment system, a space measurement sensor, a neutron detector, a sample table and a main controller, the attitude adjusting system is fixedly mounted on the autonomous navigation trolley, the neutron detector is detachably mounted on the attitude adjusting system, and the autonomous navigation trolley is used for carrying the neutron detector and the attitude adjusting system to move to a position near a specified position in a measurement space; the space measurement sensor is used for measuring the actual position posture of the neutron detector in a measurement space and sending measurement data to the main controller; the main controller is used for sending a motion instruction, receiving measurement data, executing coordinate transformation operation and kinematics inverse solution operation and outputting a control signal. Through combination of the autonomous navigation trolley, the attitude adjustment system and the space measurement system, accurate positioning of the neutron detector in a neutron measurement space is realized, and a neutron diffraction stress measurement task is completed.

The invention provides a three-dimensional neutron diffraction orientation and strain field reconstruction method, system, medium and equipment, and the method comprises the steps: S1, according to a three-dimensional neutron diffraction technology principle, continuously rotating an Euler ring rotation angle to scan a material sample, and obtaining three-dimensional diffraction data; wherein the coordinates are detector coordinates and Euler ring rotation angles; s2, determining a two-dimensional rocking curve plane based on the three-dimensional diffraction data, discretizing the two-dimensional rocking curve plane to obtain a discretized angle unit, and taking the center of the angle unit as representative orientation; s3, obtaining a diffraction peak curve through in-plane integration for the discretized angle unit, fitting by using a pseudo Volight model to obtain a peak position parameter, calculating the interplanar spacing in the discrete unit based on the peak position parameter, and calculating the lattice strain in the discrete unit based on the interplanar spacing in the discrete unit; and S4, reconstructing a segmented constant orientation field and a strain field by taking all angle units as pixel grids.

The present invention relates to a positive electrode active material for a lithium ion secondary battery, which contains a lithium-nickel composite oxide having a hexagonal layered structure, and which is characterized in that the lithium-nickel composite oxide has a mass ratio of Li: Ni: M = a: b: c (0.90 < = a < 1.00, 0.80 < = b < 1.00, 0.00 < c < = 0.20, and b + c = 1), and in that the mass ratio of Li: Ni: M = a: b: c (0.90 < = a < 1.00, 0.80 < = b < 1.00, 0.00 < c < = 0.20, and b + c = 1); the element M is at least one element selected from the group consisting of Mn, Co, Al, Ti, Zr, W, Fe, Si, Nb, Mg, Ca, B, Na, K, Mo, Cu, V, P, and Ba), the occupancy of nickel present in the lithium site obtained by a powder neutron diffraction pattern is 2.5%-10.0%, and the half-value width of the diffraction peak of the (003) plane in a powder X-ray diffraction pattern is 0.054 DEG or more and less than 0.074 DEG.

This invention relates to the field of neutron scattering experimental materials, proposing a neutron-diffraction-resistant, oxidation-resistant, zero-coherence scattering alloy material with a single-phase BCC structure suitable for high-temperature neutron scattering experiments, and its preparation method. This alloy contains 37.07% Ti, 59.95% Ta, and 2.98% Al, with a theoretical melting point of 1867℃. It exhibits no neutron diffraction peaks and can be used to prepare sample containers and neutron beam windows. The TiTaAl alloy shows no neutron diffraction peaks in X-ray and neutron diffraction patterns, avoiding data interference and improving experimental data quality. Its theoretical melting point is higher than existing TiZr alloys, and it maintains high strength and high ductility at high temperatures, making it suitable for high-temperature experimental environments above 800℃. After oxidation for 80 hours at 1000℃ in an atmospheric environment, the oxidation weight gain is only 43 mg / cm³. 2 It exhibits excellent antioxidant properties, improving the reusability and economy of materials. This invention achieves precise composition control and efficient manufacturing by optimizing steps such as batching, smelting, alloying, homogenization, and forging, solving problems such as inaccurate composition control, low efficiency, and high cost in existing processes, thereby improving product quality and production efficiency.

The application provides a neutron diffraction stress measurement device and method based on spatial coordinate measurement, comprising: an autonomous navigation trolley, a posture adjustment system, a spatial measurement sensor, a neutron detector, a sample table and a main controller; the posture adjustment system is fixedly installed on the autonomous navigation trolley, the neutron detector is detachably installed on the posture adjustment system, the autonomous navigation trolley is used for carrying the neutron detector and the posture adjustment system to move to a position near a specified position in a measurement space; the spatial measurement sensor is used for measuring the actual position and posture of the neutron detector in the measurement space and sending measurement data to the main controller; the main controller is used for sending motion instructions, receiving measurement data, performing coordinate transformation operation and kinematics inverse solution operation and outputting control signals. The application realizes accurate positioning of the neutron detector in the neutron measurement space by combining the autonomous navigation trolley, the posture adjustment system and the spatial measurement system, and completes the neutron diffraction stress measurement task.

The invention provides a neutron diffraction texture measurement method and system based on adaptive angle sampling, and the method achieves the synchronous improvement of the coverage integrity of a pole figure and the measurement efficiency through the adaptive optimization of an Euler ring scanning angle. The method comprises the following steps: dynamically adjusting an angle sampling step length to reduce Debye ring segment overlapping as much as possible on the premise of ensuring non-interval coverage of a pole figure based on the constraint of a detector on the coverage range of a polar angle and the resolution capability of an instrument at different geometric positions, and further adaptively amplifying the angle step lengths corresponding to different polar angle ring bands according to a rule on the basis; therefore, super-resolution oversampling of the central area of the pole figure is avoided.

This invention provides a method and system for simultaneous neutron diffraction detection of texture and stress, comprising: Step 1: obtaining the crystal structure type of each phase and the number of pole figures and crystal planes required for neutron diffraction detection of texture; Step 2: performing neutron diffraction detection to obtain material texture information; Step 3: obtaining the texture component to be tested and the crystal plane to be tested, and calculating the specific position of the crystal plane to be tested of the texture component in the corresponding crystal plane pole figure; Step 4: obtaining the crystal plane pole figure of the detected texture, the pole figure scanning range, and the scanning step size; Step 5: acquiring neutron diffraction data; Step 6: calculating the three-dimensional internal stress field of different texture components of the material; Step 7: projecting the obtained neutron diffraction data onto the crystal plane pole figure, and using the symmetry of the crystal structure and mathematical processes to complete it into a complete crystal plane pole figure. This invention significantly reduces the workload of simultaneous texture-stress detection and improves the efficiency of simultaneous texture-stress detection.

The application provides a three-dimensional neutron diffraction data processing method and system of a single crystal material, comprising the following steps: performing rough scanning on a single crystal sample through a polar diagram mode to determine a rotation center of a single crystal sample signal; performing fine scanning at the rotation center to obtain a three-dimensional neutron diffraction signal; decomposing the three-dimensional neutron diffraction signal to obtain a diffraction peak curve and a rocking curve plane; correcting coordinates of the rocking curve plane; decomposing the corrected rocking curve plane to obtain a rocking curve; and quantitatively analyzing crystal face spacing and orientation distribution information in the three-dimensional diffraction signal according to the diffraction peak curve and the rocking curve. The application can non-destructively characterize the internal microstructure of the single crystal material, provides accurate data support for studying lattice strain distribution and orientation characteristics, and can further synchronously characterize and analyze the lattice spacing and orientation distribution information.

The application provides a three-dimensional neutron diffraction orientation and strain field reconstruction method, system, medium and equipment, including: step S1: according to the principle of three-dimensional neutron diffraction technology, continuously rotating the Euler ring rotation angle to scan the material sample, and obtaining three-dimensional diffraction data; wherein, is the detector coordinate, and is the Euler ring rotation angle; step S2: based on the three-dimensional diffraction data, the two-dimensional rocking curve plane is determined, the two-dimensional rocking curve plane is discretized, the discretized angle unit is obtained, and the center of the angle unit is taken as the representative orientation; step S3: for the discretized angle unit, the diffraction peak curve is obtained by in-plane integration, and the peak position parameter is obtained by using the pseudo Voight model fitting, the crystal plane spacing in the discrete unit is calculated based on the peak position parameter, and the crystal lattice strain in the discrete unit is calculated based on the crystal plane spacing in the discrete unit; step S4: taking all angle units as a pixel grid, reconstructing the segmented constant orientation field and strain field.

The invention belongs to the technical field of neutron diffraction analysis, and provides a neutron diffraction vectorization generation and recognition method. The generation method comprises the following steps: specifying a chemical system, and generating all elementary substances and compounds by means of high-throughput calculation; repeated and unstable structures are removed, and a neutron diffraction spectrum of the stable structure is generated; mixing different concentrations of components of the structure to generate a neutron diffraction spectrum of a mixed phase; generating a one-dimensional vector according to a rule; performing half-peak broadening and noise enhancement processing on the simulation spectrum; extracting the feature of the strongest diffraction peak to form a feature vector; the embedded vector database generates a simulated diffraction vector database. The method has the remarkable beneficial effects that the analysis efficiency is improved through high-throughput calculation and a vector database; the method does not depend on specific chemical system training data, and generalization is enhanced; the accuracy is improved through data processing and correction; the automation degree is high, and manual intervention is reduced; data quality is improved through data preprocessing and feature extraction; and performing similarity query in a vector database to realize rapid prediction.

The invention belongs to the technical field of corrosion tests, and discloses a multichannel seawater / salt spray corrosion test device and method matched with neutron diffraction. The device comprises an environment cavity mechanism, an output shaft connecting mechanism and an environment control mechanism, the environment cavity mechanism comprises a corrosion-resistant environment chamber and a neutron transmission window, and the inner surface of the corrosion-resistant environment chamber is coated with a corrosion-resistant hydrophobic coating; the output shaft connecting mechanism comprises a main output shaft connector, an auxiliary output shaft connector, a main output shaft clamp and an auxiliary output shaft clamp; the environment control mechanism comprises a salt mist concentration sensor interface, a liquid outlet, a liquid level meter interface, a salt mist / seawater inlet and a purging gas inlet; the method comprises the following steps: carrying out a seawater / salt spray corrosion test; residual media and salt crystals in the corrosion-resistant environment chamber are removed through multi-stage treatment, and interference on neutron signals is eliminated. And performing neutron diffraction detection. The invention provides a reliable platform for microstructure change research of the material in the seawater / salt spray corrosion process.

The present application belongs to the technical field of neutron diffraction analysis, and proposes a neutron diffraction vectorization generation and identification method. The generation method comprises the following steps: specifying a chemical system, generating all single elements and compounds by means of high-throughput calculation; removing repeated and unstable structures to generate neutron diffraction spectra of stable structures; mixing different concentrations of components to generate neutron diffraction spectra of mixed phases; generating one-dimensional vectors according to rules; performing half-peak broadening and noise enhancement processing on the simulation spectrum; extracting the features of the strongest diffraction peak to form a feature vector; and embedding the vector database to generate a simulation diffraction vector database. The method has the following beneficial effects: improving analysis efficiency through high-throughput calculation and vector database; enhancing generalization by not relying on specific chemical system training data; improving accuracy through data processing and correction; reducing manual intervention due to high automation; improving data quality through data preprocessing and feature extraction; and realizing rapid prediction through similarity query in the vector database.

The present application relates to the technical field of neutron scattering experiment, in particular to a kind of neutron scattering experiment with no neutron diffraction peak, high-thermal-conductivity VNi alloy plate and its manufacturing method;The plate is composed of vanadium (V) and nickel (Ni), wherein the mass percentage of vanadium is 40% to 60%, and the mass percentage of nickel is 40% to 60%, the alloy plate has no neutron diffraction peak, and the theoretical thermal conductivity at room temperature is not less than 27 W / (m*K);And it has good processing plasticity, meets the requirements of neutron scattering experiment on sample container and neutron beam window, and the demand of efficient high-low temperature in-situ experiment;The VNi plate prepared by the present application has uniform composition, no neutron diffraction peak, meets the demand of neutron scattering experiment, and has excellent thermal conductivity;The VNi plate prepared by the method has uniform composition, no neutron diffraction peak, and good tensile forming plasticity, which meets the further processing and preparation demand of finished product.