open access publication

Article, 2023

Effects of initial 3D printed microstructures on subsequent microstructural evolution in 316L stainless steel

In: Acta Materialia, ISSN 1873-2453, 1359-6454, Volume 242, Page 118481, 10.1016/j.actamat.2022.118481

Contributors (3)

Zhang, Chunlei (0000-0002-2783-9397) (Corresponding author) [1] Jensen, Dorte Juul (0000-0001-5096-6602) [1] Yu, Tian Bo (0000-0001-9525-9354) (Corresponding author) [1]

Affiliations

  1. [1] Technical University of Denmark
  2. [NORA names: DTU Technical University of Denmark; University; Denmark; Europe, EU; Nordic; OECD]

Abstract

Plastic deformation of 3D printed components may occur when they are in use. Here we analyze the effects of the initial 3D printed microstructure of 316 L stainless steel on the subsequent deformation behavior, where we apply 10% and 30% thickness reductions by cold rolling. The microstructures are characterized by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). Compared to conventionally manufactured (solution treated) samples, deformation twinning is observed to occur at lower strains in 3D printed samples, and twins are observed to be thinner and intersecting inside some grains. These observations are linked to the pre-existing dislocation structure in the 3D printed samples, where dislocations of various Burgers vectors facilitate deformation twinning. Furthermore, cells with an average size of 125 nm are observed to form inside the initial cellular structure. The strength calculated based on microstructural parameters generally agrees with experimental results, showing a large strengthening contribution from twin–matrix lamellae. The present study provides fundamental ideas for microstructural engineering of 3D printed metals for even better mechanical properties.

Keywords

Burgers vector, average size, backscatter diffraction, behavior, cells, cellular structure, cold rolling, components, contribution, deformation, deformation behavior, deformation twinning, diffraction, dislocation structure, dislocations, effect, electron backscatter diffraction, electron microscopy, engineering, evolution, experimental results, fundamental idea, good mechanical properties, grains, idea, lamellae, low strain, mechanical properties, metals, microscopy, microstructural engineering, microstructural evolution, microstructural parameters, microstructure, observations, parameters, plastic deformation, pre-existing dislocation structures, present study, properties, reduction, results, rolling, samples, size, stainless steel, steel, strains, strength, structure, study, subsequent deformation behavior, subsequent microstructural evolution, thickness reduction, transmission electron microscopy, twin-matrix lamellae, twinning, twins, use, vector

Funders

  • China Scholarship Council
  • Danish Agency for Science and Higher Education
  • European Research Council