Tensile and nanoindentation tests analysis of Ti6Al4V alloy manufactured by laser powder bed fusion

Abstract

Additive manufacturing (AM) technologies are widely used in the fabrication of topologically complex components with thin-walled features, such as lattice structures. In this context, Laser Powder Bed Fusion (L-PBF) is one of the most commonly used AM technologies for producing such components. In order to further expand and justify the application of these components in operation and to model their mechanical behavior, it is necessary to know the mechanical properties of the matrix material from which they are formed. Therefore, there is currently a high interest in studying the behavior of these materials when subjected to monotonic or cyclic loading. However, determining the mechanical properties of the matrix material of thin-walled structures using tensile tests is challenging on the required subsize specimens. As a micro- or even nano-scale technology, nanoindentation can be used to probe a small volume of specimen, thus allowing the mechanical properties such as Young modulus, of thin-walled structures to be determined. In this work, Young's modulus of L-PBF Ti6Al4V alloy produced using different laser power and scanning speed combinations, has been determined on nano and macro scale. By comparing obtained results at both scales, it is evident that Young's modulus values determined at nano scale are higher and more scattered when compared to results determined at macro scale. Furthermore, this study implies that a wider range or a higher number of L-PBF process parameters should be considered to model it's influence on Young's modulus with higher accuracy.