LIBS as a fast and reliable alternative to µXRF and SEM–EDX for quantitative analysis of aluminium alloy particles in technical cleanliness analysis

• Quantitative characterization of metal particle composition to enable alloy identification comparing results of LIBS to SEM-EDX and uXRF. • Comparability between individual reference particles is shown. • High correspondence of LIBS to established particle characterization methods (SEM-EDX, µXRF). The characterization of metal alloy (particle) characterization is a vital tool in today’s high–tech applications for quality and process control in industry, especially for applications in technical cleanliness analysis (TCA). Here, metal alloy fragments down to sizes of 200 µm need to be quantitatively characterized as accurate as possible. Laser-induced breakdown spectroscopy (LIBS) offers several advantages due to its easy use, short measurements times, and high sensitivity. To enable the application of LIBS in this context, the method must yield adequately accurate results. Therefore, in this study we assess the performance of LIBS by comparison with well–established methods – scanning electron microscopy coupled with energy-dispersive X‑ray spectroscopy (SEM-EDX) and µ‑X‑ray fluorescence (µXRF). We analyse particulate certified reference materials consecutively with non–destructive and destructive methods on the quantitative composition regarding the key elements necessary for distinguishing aluminium alloys: Si, Zn, Mn, Mg, Cu and Fe. Sample inhomogeneity and the effect of sampling location and area is shown via microstructure analysis and combined with an assessment of the analysis volume for each used method. By evaluating the data statistically and by comparing quantitative results achieved with different methods, we can postulate a high agreement between LIBS and the studied reference methods, providing a basis for the use of LIBS in industrial analysis of metal alloy particles.