Acoustic emission descriptors for the mechanical behavior of selective laser melted samples: An innovative approach

Three different groups of AlSi10Mg specimens are built using Selective Laser Melting (SLM) technique. Each of these groups represents the orientation of the specimens with respect to the building plane. The mechanical characteristics of the specimens are evaluated under uniaxial tensile loading. The Acoustic Emission (AE) technique is used for characterizing the failure modes of the specimens under the uniaxial loading. An innovative parameter, the slope coefficient bAE, is formulated for directly relating the different failure modes in the tested specimens with the acoustic results. The slope coefficient bAE proves to be a powerful tool for understanding the damage characteristics of the specimens. In addition to that, the AE signals are recorded during the tests and are analysed in the Hilbert Spectrum. The signals are first decomposed using Empirical Mode Decomposition (EMD) and then reconstructed after removing the noise. The instantaneous frequencies obtained from the Hilbert Spectrum of the reconstructed signals are used for analysing the damage modes. From the results obtained, it is safe to say that the AE technique is powerful for characterizing the failure modes in materials during their entire loading history.