Analysis method for submillimeter-scale defects on the surface of coating materials

Abstract

The invention discloses a method for analyzing submillimeter-scale defects on the surface of a coated material. The method comprises macroscopic observation, section sample preparation, polishing andcomprehensive analysis. The limitation on defect size by section sample preparation in traditional defect analysis is broken through, section samples with submillimeter-scale surfaces are prepared andanalyzed under the condition that surface coated layers are not removed by aid of an FIB / SEM double-beam system or with a chemical method, effective information of samples is reserved, and the problem about section sample preparation in the coated surface submillimeter-scale defect analysis is effectively solved.

Description

technical field [0001] The invention belongs to the technical field of material surface quality analysis, and specifically refers to a method for analyzing submillimeter defects on the surface of coating materials. Background technique [0002] Coating refers to the formation of a covering layer on the surface of the material by physical or chemical methods, thereby improving the appearance of the material, or improving the mechanical or corrosion resistance of the surface. However, due to surface quality problems of raw materials or fluctuations in the manufacturing process, defects are prone to occur on the surface of the coating, which in turn affects the end-use performance of the material. With the improvement of manufacturing technology and the appearance of some precision coated parts, the defects on the surface of coated materials are developing in the direction of miniaturization, gradually developing from centimeter and millimeter levels to sub-millimeter levels. H...

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Problems solved by technology

However, there are great difficulties in the preparation of cross-sectional samples with submillimeter defects. Due to the small size of the defects, the preparation is easy to cause damage to the defects and the patterned coating (over-grinding removes the defects, and grinding causes the destruction of the patterned coating. Introduce external interference, etc.), and this damage is irreversible, which will cause analysis failure, so it is particularly difficult to analyze by traditional preparation methods

The FIB / SEM dual-beam system can use focused ion beams to cut and analyze micron-level defects. However, due to the small effective area of ​​ion beam cutting, it has a better analysis effect on defects with a size of several microns and tens of microns. Analysis of submillimeter defects is limited and the equipment is expensive

[0005] However, when the chemical reagent corrosion method is used to remove the surface coating for analysis, due to the different properties of the surface coating, each coating or coating requires a different corrosion medium. Some coatings have good corrosion resistance, and it is difficult to pass the corrosion method. At the same time, the corrosion method may destroy the effective information in the defect, especially for small-sized defects, the corrosion method is difficult to control the corrosion rate and corrosion degree, and the effective information obtained is less, and the corrosion method may also cause sample surface contamination and environmental pollution

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