Determination of the anisotropy in mechanical properties of laser powder bed fusion Inconel 718 by ultrasonic testing

Abstract

ABSTRACT This study aims to investigate the effects of build direction on the as-fabricated microstructure and mechanical properties of Inconel 718 specimens manufactured via the Laser Powder Bed Fusion (L-PBF) technique. The microstructures and mechanical properties of the specimens were characterized via SEM, EBSD,ultrasonic wave velocity measurements, hardness and tensile tests. For the as-fabricated condition, the highest tensile strength (1114 MPa) was obtained with the horizontally built specimens while the vertically built ones have the highest 40% elongation. The computational analysis produced results that closely aligned with the measured yield strength values of L-PBFed samples. Additionally, a strong correlation was observed between the hardness values and longitudinal ultrasound velocity of L-PBF Inconel 718 specimens. Consequently, the non-destructive ultrasonic evaluation provided valuable insights into the anisotropy of mechanical properties, complementing information obtained from conventional tensile tests.