In this paper, the airtightness problem caused by welding defects in the manufacturing process of composite mold is analyzed. The mechanism analysis of the weld defects of composite mold is ...conducted. According to the mechanism of weld failure, the welding process monitoring, weld metallographic analysis, weld X-ray inspection, panel airtightness detection, and other methods are used to evaluate the welding quality of different welding forms in the welding process of composite mold panels. The measures to optimize the welding quality of composite mold panels are put forward. Finally, through the actual verification, it is proved that the optimized air-tightness welding method is stable and reliable.
X‐Ray White Beam Interferences on Thin Crystals Heckert, Mirko; Enghardt, Stefan; Bauch, Jürgen
Crystal research and technology (1979),
October 2021, 2021-10-00, Letnik:
56, Številka:
10
Journal Article
Recenzirano
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Results of white beam X‐ray interference measurements on almost perfect semiconductor wafers are presented. A specific measurement geometry allows for the investigation of diffraction effects on thin ...wafers down to at least 375 µm with a simple experimental setup (standard lab CT with microfocus X‐ray tube). Furthermore, the dynamic diffraction effect of double refraction has been studied in detail for thicker samples. This might lead to a new wafer testing method as the observed dynamic effects are very sensible on crystal quality.
Results of white beam X‐ray interference measurements on almost perfect semiconductor wafers are presented. A new measurement geometry allows for the investigation of thin wafers. In this geometry, double refraction inside the sample, a dynamic diffraction effect, can be observed with a simple experimental setup and has been studied in detail. This might lead to a new wafer testing method.
Welding is a key technical means to ensure the safe and stable connection between pipeline systems. The intelligent welding defect assessment based on X-ray inspection helps to improve the efficiency ...and accuracy of pipeline welding fault diagnosis. However, this work is highly challenging and systematic, and includes multiple critical subtasks, such as weld area extraction and defect detection. The existing methods have fallen into the quagmire of various task flow concatenation, resulting in unsatisfactory accuracy and efficiency. To overcome this dilemma, a multiexpert inspection method based on X-ray is proposed to perform welding defect assessment. First, a preprocessing method based on window width and window level adjustment is designed to calibrate original data to ensure high-quality input of the subsequent neural network. Second, a basic network layer with universal representation ability initialization is designed to extract discriminative multitask feature representations. Next, a novel task-specific experts is presented to perform weld area extraction and defect detection in a divide and conquer manner. Finally, a rule-based defect postprocessing is designed to evaluate the level of weld defects. In the experiment, the performance of defect detection expert and weld seam segmentation expert based on hardware testing platform is systematically verified and discussed. In practical defect assessment application cases, we obtained competitive results (recall: 98.5%, precision: 95.2%, accuracy: 97.4%). Hence, the proposed intelligent multiexpert method has shown great potential in actual pipeline weld maintenance and significantly saves operators time and costs.
Owing to the strong penetration ability of X-rays and the imaging visibility, X-ray inspection has been gradually applied to power grids. However, various problems occur in the promotion and ...application of X-ray inspection in ultra high voltage gas-insulated switchgear (UHV GIS) owing to its large size. These problems relate to parameter selection, photography, protection area, random defect recognition, and risk assessment based on the X-ray image. In this paper, an X-ray digital imaging system is set up for UHV GIS inspection. Parameter selection for UHV GIS is discussed, and we demonstrate that UHV GIS can be photographed under a source-to-detector distance (SDD) of 2.8 m, a tube voltage of 300 kV, and an exposure of >240 mA·s. A photographic method for UHV GIS, entailing adjustment of the position of the imaging plate with a fixed position of the X-ray generator, is proposed to reduce the difficulty in image stitching. The influence of the parameters on imaging quality is discussed, and we show that the brightness and contrast increase with increasing exposure or decreasing SDD. The interactions between parameters are qualitatively introduced. Moreover, the sensitivity of X-ray inspection in UHV GIS is studied under selected parameters, and the sensitivity of X-ray inspection to copper particles and aluminum particles in UHV GIS are shown to be <0.7 mm and <1.1 mm, respectively. Radiation protection for operators is also discussed. In addition, a pseudo-color scheme for identifying random tiny defects is proposed to reduce human error. Finally, the risk level of defects with X-ray inspection is defined by size feature.
This study suggests an improved X-ray inspection method to determine the effective atomic number to identify explosives during luggage inspection with high resolution of the effective atomic number ...(Zeff). To obtain high resolution in Zeff, the suggested inspection method uses the ratio of the total and Compton scattering attenuation coefficients between two different energies for decomposing the attenuation coefficients of the Rayleigh scattering and photoelectric absorption that are highly dependent on the atomic number. To acquire the total and Compton scattering coefficient ratio of two different energies, dual-energy X-ray beams and four detectors for the photons transmitted and scattered in three different angles were introduced. MCNP6 simulations were carried out for several materials with X-ray source spectra from a tungsten anode generator to show the effectiveness of the method. The estimated Zeff values with the line beam assumption showed good agreement with the reference values for explosive substances within a relative error of 3% while the additional simulation considering beam width showed increased errors that are acceptable for beam widths less than 1.5 mm.
•An improved method for determining effective atomic numbers of explosives is suggested.•The separation of the photoelectric and Rayleigh components led to improved accuracy.•High accuracy of new method for explosives was shown from Monte Carlo simulations.
Abstract
Pressure pipelines use pressure to transport gas, liquefied gas, and steam in the process of use. If there are defects in the pipeline, it is easy to leak or burst, and even cause secondary ...accidents. To ensure safety, it is necessary to inspect the pressure pipelines in use regularly. However, it is difficult for the pressure pipeline in use to empty the internal medium. Therefore, it is of great significance to inspect the defects of the industrial pressure pipeline under operating conditions. In this paper, X-ray testing experiments are carried out for weld defects of pipelines with the medium. Using the experimental data, multivariate polynomial regression equations of negative blackness and tube voltage, and other variables are established, which provides an effective tool for the formulation of the optimal process route for testing pressure pipelines containing medium.
Defects within chip solder joints are usually inspected visually for defects using X-ray imaging to obtain images. The phenomenon of voids inside solder joints is one of the most likely types of ...defects in the soldering process, and accurate detection of voids becomes difficult due to their irregular shapes, varying sizes, and defocused edges. To address this problem, an X-ray void image segmentation algorithm based on improved PCB-DeepLabV3 is proposed. Firstly, to meet the demand for lightweight and easy deployment in industrial scenarios, mobilenetv2 is used as the feature extraction backbone network of the PCB-DeepLabV3 model; then, Attentional multi-scale two-space pyramid pooling network (AMTPNet) is designed to optimize the shallow feature edges and to improve the ability to capture detailed information; finally, image cropping and cleaning methods are designed to enhance the training dataset, and the improved PCB-DeepLabV3 is applied to the training dataset. The improved PCB-DeepLabV3 model is used to segment the void regions within the solder joints and compared with the classical semantic segmentation models such as Unet, SegNet, PSPNet, and DeeplabV3. The proposed new method enables the solder joint void inspection to get rid of the traditional way of visual inspection, realize intelligent upgrading, and effectively improve the problem of difficult segmentation of the target virtual edges, to obtain the inspection results with higher accuracy.
Abstract
X-ray computed tomography (XCT) is a validated and frequently used tool to verify part geometry and to perform a non-destructive inspection of additive manufacturing parts. However, the ...acquisition of a large number of x-ray projections generates long inspection times. This conflicts with a high throughput of the production process and hinders the integration of XCT as an in-line quality control procedure for low-end parts. In this paper, we propose a method to obtain three-dimensional (3D) information of the internal pores from a limited view or limited angle scan. The method combines a forward projection model of a cone-beam x-ray system and a deep learning neural network to directly classify each individual voxel, based on the x-ray projections in order to avoid the reconstruction and segmentation step. Accompanying reconstruction artifacts for limited view and limited angle XCT scans are thereby reduced, while preserving 3D information of the pores, defects or inclusions inside the material. The method is validated on real x-ray projections of polymer laser sintered industrial parts and shows a significant reduction in the required x-ray projections, hence acquisition time.
Abstract
Strain clamps in the transmission line have a vital role. With X-ray inspection in the transmission line, X-ray images to check defects of the tensioning line clip method have already become ...the mainstream method. In this paper, we concentrate on the strain clamps’ steel anchor end and strand distance defects. We propose a method based on the rotated object detection model RoI Transformer with KFIoU loss to extract the diameter of the steel anchor tube as a reference to determine whether the distance is too long. We first obtain the rotated bounding boxes of the steel anchor and the strand, then calculate the distance between the steel anchor end and the strand and the diameter of the steel anchor by rotated bounding boxes, and finally determine whether there is a defect. Through the study of this essay, the defect detection of strain clamps realizes with high accuracy which has an essential reference for the quality inspection of tension clamp crimping in engineering applications.
In order to clarify the relationship between the efficacy loss of strain clamp joints and the crimping quality, three groups of clamp joints, crimped under unbalanced conditions at both ends, naming ...NY-240/40, NY-400/35 and NY-630/45 were selected and then subjected to tensile tests and X-ray inspection. After a detailed analysis of the experimental results, it can be seen that under the condition of unbalanced crimping quality, the efficacy loss all occurred on the side with better crimping quality, which provides an instructive reference for the crimping technique of strain clamps in actual project construction.
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