Elastic properties of additively manufactured alloys

Abstract

With the advent of metal Additive Manufacturing (AM), or 3D printing, the focus on evaluating and fine-tuning the fabrication process has become crucial. High-resolution volumetric mapping of elastic properties throughout an AM built sample can be done, “biopsy” style, with the highly adaptable Resonant Ultrasound Spectroscopy (RUS) technique. We report results of elastic constants measurements on AM-fabricated Ti64 and CL 80CU bronze (i.e., Cu0.9Sn0.1) alloy with RUS. Despite an easily observable pore distribution, surprisingly sharp spectra and good RUS fits were obtained for both. The average E and G moduli obtained for AM Ti64 at room temperature are ≈104 and ≈39.4 GPa, respectively. The values are only a few percent lower than those of the traditionally manufactured alloy. Moreover, stress-strain measurements on dog-bone samples of Ti64 from the sample batch lead to a value of 101 GPa for E. Heat-treatment of as-manufactured Ti64 samples lead to a slight increase in both moduli. For the investigated bronze, an ≈10% variation of elastic properties within a cross section of a printed sample was observed. The average E and G moduli obtained for AMCL 80CU bronze at room temperature are ≈111 and ≈40.9 GPa, respectively.