During the production, processing, transportation, and use of metallic materials and components, various foreign substances may adhere to their surfaces, such as particulate contamination, dust, oil stains, salts, polishing residues, equipment wear debris, plating solution impurities, or embedded inclusions. These foreign substances can affect the quality of subsequent welding, painting, electroplating, bonding, sealing, and assembly. Desktop scanning electron microscopy (SEM) can observe the shape, size, quantity, distribution, adhesion state, and bonding relationship of foreign substances with the substrate. Combined with energy-dispersive X-ray spectroscopy (EDS), their elemental composition can be identified, thereby helping to determine the source of the foreign matter. For contaminants of different natures, such as metal chips, oxides, silicates, salts, and organic residues, morphological and elemental information can corroborate each other, providing a basis for incoming inspection, process control, cleanliness evaluation, and failure analysis.
