Laser induced breakdown spectroscopy for in situ multielemental analysis during additive manufacturing process

A feasibility of in situ quantitative multielemental analysis during parts production by additive manufacturing technology (coaxial laser cladding) has been demonstrating for the first time using laser induced breakdown spectroscopy (LIBS). Compact LIBS probe was developed to equip the laser cladding head installed at industrial robot for analysis of key components (carbon and tungsten) during the synthesis of high wear resistant coatings of nickel alloy reinforced with tungsten carbide particles. It was demonstrated that the only acceptable choice for LIBS sampling was the melt pool due to non-uniform distribution of tungsten carbide grains in the upper surface layer. We have not observed any impact of melt pool ablation by LIBS probe on cladding process and clad properties according to clad cross-sections study by optical and scanning electron microscopies. The feasibility of in-situ LIBS quantitative elemental analysis of key components (carbon and tungsten) has been demonstrated during the cladding process. LIBS technique was demonstrated to be a good tool for real-time detection of cladding process failures. For example, failures with powder flows during cladding process resulted in undesirable variation of components concentrations and such problems were identified in real time by LIBS measurements.