Non-homogeneous distribution of solidification phases in Inconel 718 fabricated by powder bed fusion
Date of Award
Master of Science in Engineering (MSE)
Mechanical and Aerospace Engineering
Inconel--Properties., Solidification., Three-dimensional printing., Heat resistant alloys., Nickel alloys.
Inconel 718 (IN718) is a precipitation strengthened, nickel-based superalloy that is used in the Additive Manufacturing (AM) of low volume, complex parts to reduce production time and cost compared to conventional subtractive processes. Critical to the development of cost-effective heat treatments, is the initial characterization of the phases formed during the AM build and their critical temperatures. During solidification, the Niobium (Nb) can segregate into carbide, Laves or delta (δ) phases. Since Nb is also the primary element in the subsequent formation of the strengthening phase (γ”), its formation is hindered if the matrix is depleted during the AM build. Therefore, post-build heat treatments are used to re-solutionize the solidification phases and release the Nb back into the matrix prior to the aging for effective strengthening. This study evaluates the inhomogeneity of these initial phases formed in IN718 produced in the laser powder bed fusion (L-PBF) .
Farris, Laura, "Non-homogeneous distribution of solidification phases in Inconel 718 fabricated by powder bed fusion" (2020). Theses. 336.