Evaluation of properties of the laser modified surface layer

This research concerns a surface layer formed on 21H12NMFA steel with a continuous wave 6 kW CO2 laser. The purpose of the study was the determination of the physical properties of the layer with chosen methods of identification. Electromagnetic method with a point probe has been used to determine the homogeneity in numerous points of the layer. Optic and electron (TEM) microscopy enabled the identification of the microstructure of the layer, whereas using Hanemann's meter the microhardness on the surface of the sample, and also its distribution in the layer, could be evaluated. The complex characteristic of the laser formed surface layer based on the results of the above methods of investigation is presented. The study has shown that the electromagnetically determined homogeneity of the surface layer (i.e, concerning its permeability and permittivity) can be also related to thickness, structure, and microhardness of the layer.