Radiographic methods utilize silver halide film or digital detectors to record differences in transmitted radiation intensity, creating a contrasting black area on the film at the defect location. The smallest identifiable defect size is measured by the sensitivity of the image quality meter. This method is suitable for detecting welding defects (porosity, lack of fusion), and its sensitivity is positively correlated with the material attenuation coefficient and the defect thickness.
Industrial CT reconstructs 3D structures using multi-angle projection data, overcoming the limitations of traditional 2D imaging's superposition effect, achieving a spatial resolution of up to 0.1% density difference. Typical equipment parameters include:
450kV general-purpose type: suitable for inspecting large castings
225kV micro-resolution type: used for microstructural analysis of electronic components.
Small-angle scattering (SAS) analyzes the scattering angle distribution of nanoscale pores to resolve the microstructural characteristics of materials, achieving a detection accuracy down to the micrometer level for microcracks. This method supports both dry and wet sample analysis, and when combined with neutron beam technology, it can be extended to micrometer-level pore analysis.