Fatigue Behaviour Evaluation of Additively and Conventionally Produced Materials by Acoustic Emission Method

Abstract

Additive manufacturing of metals is today one of the most growing fields in materials research. Selective laser melting (SLM) allows to produce metal parts with complicated shapes, but the quality of produced material is relatively low (in compare with conventionally produced materials). The main aims of latest studies is to improve materials properties and reach the same or better quality.Presented paper shows the comparison of fatigue behaviour of SLM and conventional material using copper (Cu7.2Ni1.8Si1Cr) and aluminium (AlCu2Mg1.5Ni and AlSi10Mg) alloys. SLM and standard material samples were subjected to bending fatigue tests which were supplemented by acoustic emission (AE) measurement and fractography analysis. The results from AE measurement allows to analyse fatigue process, determine different fatigue stages and compare the results from SLM and standard material in more detail.The results show that the main difference between fatigue behaviour of SLM and standard material is not only in total fatigue life (the SLM material has significantly worse fatigue resistance), but mainly in the length of fatigue stages and in mechanism of crack development. As we expected, the fatigue resistance of SLM is strongly affected by amount of production defects.