ACOUSTIC EMISSION MONITORING OF DEFECT FORMATION DURING ADDITIVE MANUFACTURING OF METAL PRODUCTS

The paper presents the results of formation of acoustic emission (AE) signatures of processes occurring during direct laser melting. As part of the experimental study, samples of the powder alloy Inconel (EP648) was melting at different conditions with simultaneous registration of acoustic emission signals. Based on analysis of the parameters of registered signals, their characteristic distribution signatures were formed for defect-free and defective samples during direct laser melting. The paper provides a detailed analysis of informative parameters of AE signals with choice of their optimal set with maximum sensitivity to changes in laser radiation power. The relevance of using the AE method for non-destructive testing at the process of defect laser melting for identifying the process of growing blanks of products using additive manufacturing is substantiated. It is established that the AE signature of the recorded signals for samples with transverse hot cracks differs significantly from the signatures of defect-free samples for the entire set of informative parameters of AE signals used.