Laser-induced breakdown spectroscopy for three-dimensional elemental mapping of composite materials synthesized by additive technologies.

Three-dimensional multi-elemental mapping of composite wear-resistant coatings by laser-induced breakdown spectroscopy has been demonstrated for the first time, to the best of our knowledge. Individual clads of 1560 nickel alloy reinforced with tungsten carbide were synthesized by a co-axial laser cladding technique. Electron energy dispersive x-ray spectroscopy revealed elemental maps for major elements (W, Ni, Co, Cr, Fe) but failed to measure silicon and carbon. Laser-induced breakdown spectroscopy was utilized for elemental mapping of carbon and all other elements of interest. It was demonstrated that three-dimensional elemental profiling for a few tens of micrometers requires substantial laser spot overlapping during the scanning procedure in order to achieve good accuracy of depth measurements. Elemental maps for nickel, iron, chromium, silicon, tungsten, and carbon were quantified for 900  μm×900  μm×45  μm volume with 30 μm lateral and 4 μm depth resolution in the case of tungsten carbide particles in nickel alloy.