Metal material coating/plating analysis Coating thickness detection/coating pore detection/coating crack detection

In order to prevent corrosion, wear or fatigue fracture of steel materials during storage, transportation and use, various surface coating treatments have been widely used. Including surface infiltration of Zn, Al, Cr, V, Nb, B, etc. Coating processes include hot dip, electroplating, chemical plating and heat treatment. Coating/plating can not only decorate the appearance of parts and repair surface defects of parts, but also impart special properties to the surface of parts, including improving surface hardness, wear resistance, corrosion resistance, conductivity and high temperature oxidation resistance. The products involved include household appliances, automobiles, doors and windows, metal fasteners and electronic products.

Test items

Coating thickness detection
Coating thickness refers to the vertical distance from the surface to the boundary line of the infiltration layer interface. For the case where only the compound layer is formed and the interface is flat, the determination of the layer depth is very simple. For penetration layers with a diffusion layer, the layer thickness should include the compound layer and the diffusion layer. The measurement methods of coating thickness include coulomb method, metallographic method, eddy current method and X-ray fluorescence method.

Coating porosity detection
During the process of infiltration and leaching, the infiltrated elements diffuse inward, while the iron element diffuses outward, but the diffusion rates of the two are different. Therefore, pores (or looseness) are inevitably generated in the compound layer, especially near the surface. The quantity, size and distribution directly affect the weldability and service performance of steel.

Coating crack detection
During the treatment process, due to phase change stress, cracks may occur in the brittle compound layer, and cracks also directly affect service performance. Therefore, the characteristics of the cracks, that is, the length, number and distribution of cracks, should be examined.
In addition, the metal laboratory can also provide coating composition analysis, surface stain analysis, surface hardness analysis and adhesion strength analysis.