Residual Stress in Additive Manufactured Nickel Alloy 625 Parts

Published

June 29, 2018

Author(s)

Lindsey B. Bass, Justin L Milner, Thomas H. Gnaupel-Herold, Shawn P. Moylan

Abstract

One of the key barriers to widespread adoption of additive manufacturing (AM) for metal parts is the build-up of residual stresses. In the laser-based powder bed fusion process, a laser selectively fuses metal powder layer by layer, generating significant temperature gradients that cause residual stress within the part. This can lead to parts exceeding tolerances and experiencing severe deformations. In order to develop strategies to reduce the adverse effects of these stresses, the stresses first need to be quantified. Cylindrical Nickel Alloy 625 samples were designed with varied outer diameters, inner diameters, and heights. Neutron diffraction was used to characterize the full stress state throughout the parts. The stress state of the parts was generally comprised of tensile exteriors and compressive interiors. Regardless of part height, only the topmost scan height of each part experienced large reductions in axial and hoop stress. Improved understanding of the residual stress trends will aid in model development and validation leading to techniques to reduce negative effects of the residual stress.

Citation

ASME Journal of Manufacturing Science and Engineering

Volume

140

Pub Type

Journals

Download Paper

DOI Link

Keywords

additive manufacturing, 3d printing, residual stress, neutron diffraction, qualification and certification, modeling and simulation

Citation

Bass, L. , Milner, J. , Gnaupel-Herold, T. and Moylan, S. (2018), Residual Stress in Additive Manufactured Nickel Alloy 625 Parts, ASME Journal of Manufacturing Science and Engineering, [online], https://doi.org/10.1115/1.4039063 (Accessed April 29, 2024)