Abstract

Disk-shaped 316L stainless steel parts with various diameters and heights were additively manufactured using a direct metal laser sintering (DMLS) technique. Neutron diffraction was used to profile the residual stresses in the samples before and after removal of the build plate and support structures. Moreover, distortion level of the parts before and after the removal was quantified using a coordinate measuring machine (CMM). Large tensile in-plane stresses (up to ≈ 400 MPa) were measured near the as-built disk top surfaces, where the stress magnitude decreased from the disk center to the edges. The stress gradient was steeper for the disks with smaller diameters and heights. Following the removal of the build plate and support structures, the magnitude of the in-plane residual stresses decreased dramatically (up to 330 MPa) whereas the axial stress magnitude did not change significantly. The stress relaxation caused the disks to distort, where the distortion metric was higher for the disks with smaller diameters and heights. The distribution of the residual stresses revealed a marked breakdown of self-similarity in their distribution even comparing disk-shaped samples that were fabricated under identical printing parameters; the stress field profiles were not linearly scaled as a function of height and diameter.

Department(s)

Mechanical and Aerospace Engineering

Comments

Air Force Research Laboratory, Grant FA8650-12-2–7230

Keywords and Phrases

Additive manufacturing; Distortion; Neutron diffraction; Residual stress; Stainless steel

International Standard Serial Number (ISSN)

0921-5093

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2023 Elsevier, All rights reserved.

Publication Date

07 Nov 2017

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