Direct laser interference patterning of planar and non-planar steels and their microstructural characterization

摘要

The direct laser interference patterning method was used to fabricate periodic structures on flat and cylindrical specimens of austenitic stainless steel (X5CrNi18-10) and martensitic bearing steel (100Cr6). In such laser processing the characterization of materials is a central issue. Therefore, this paper places special emphasis on the chemical, metallurgical and mechanical characterization of the laser processed metals. During the patterning process of 100Cr6, the carbides in the martensitic structure appear as elongated needles and become aligned to the direction of melt flow. The chemical composition analysis before and after laser interference patterning did not reveal any significant changes to either material. However, the surface hardness of 100Cr6 decreased when energy densities above 2.0 J/cm2 were applied. For cylindrical specimens, the grating period changes with position along the circumference. The observed difference, however, is less than ∼6.4% for rotation angles smaller than 20°.