Structural aspects and chemical analyses on cutting process of metallic-ceramic materials

Preliminary results on the behaviour of metallo-ceramic system during the cutting process were presented. The ceramic layer was obtained, after sandblasting of the substrate, through air plasma spraying with thicknesses of 30 μm on a steel substrate. Layers are chemically homogeneous, without cracks, pores or crevices. The thin layer (30 μm) present discontinuities with uncovered surfaces were the substrate is near in contact with the environment. Cutting process was realized on marking fiber laser equipment (Boron), of 30 watts' maximum power and wave length of 1064 nm. There were obtained two different grooves on the test pieces with the following parameters: laser double pass at speed of 500 mm/sec, pulsed laser of 20KHz frequency and the beam power was set at 50% (around 15W) for the first groove) and at 80% (around 24W for the second groove). Structural, morphological and chemical evaluation of the cutting kerf was realized using scanning electron microscopy (SEM, Vega Tescan LMHII, SE detector, 30 kV, 15.5 mm WD) and energy dispersive spectroscopy (EDS, Bruker X-flash) using automatic/element list mode, Point, Mapping and Line features. This analysis highlighted the type of defects along the cut, respectively the phenomena occurring at the ceramic - metal interface.