Title: A comparison of adiabatic shear bands in wrought and additively manufactured 316L stainless steel using nanoindentation and electron backscatter diffraction

Abstract

The resistance of stainless steels to shear localization is dependent on processing and microstructure. The amount of research evaluating the shear response of additively manufactured (AM) stainless steels compared to traditionally manufactured ones is limited. To address this gap, experiments were performed on directed energy deposition AM as-built and wrought 316L stainless steel using a forced shear technique with a hat-shaped specimen and a Split-Hopkinson pressure bar. The resulting adiabatic shear bands were characterized with electron backscatter diffraction (EBSD) and nanoindentation to quantify the changes in microstructure and deformation hardening across shear band regions and between the wrought and AM materials. Despite significant differences between the wrought and AM materials including the forced shear response, the postmortem states of work hardening due to the shear band deformation are nearly the same. The maximum nanoindentation stresses occurred in the shear band center with similar magnitudes and only minor differences away from the shear band. Although EBSD data cannot be resolved in the shear band center, misorientation trends, particularly grain reference orientation deviation, were found to closely resemble nanoindentation trends. In conclusion, the combination of EBSD misorientation and nanoindentation, which are linked through changes in dislocation density, is a viable protocol tomore » quantify local changes to macroscopically applied deformation.« less

Authors:

Weaver, Jordan S.  ^[1];

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• Search DOE PAGES for ORCID "0000-0003-4857-5164"
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Livescu, Veronica  ^[2];

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• Search DOE PAGES for ORCID "0000-0003-1623-9270"
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Mara, Nathan A.  ^[3]

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• Search DOE PAGES for ORCID "0000-0002-9135-4693"
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+ Show Author Affiliations

1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Center for Integrated Nanotechnologies, Materials Physics and Applications Div.; National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States). Engineering Lab.
2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States). MST-8: Materials Science in Radiation and Dynamic Extremes
3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Center for Integrated Nanotechnologies, Materials Physics and Applications Div.; Univ. of Minnesota-Twin Cities, Minneapolis, MN (United States). Dept. of Chemical Engineering and Materials Science

Publication Date:

2019-09-11

Research Org.:

Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

U.S. Department of Defense (DOD); USDOE

OSTI Identifier:

1571603

Report Number(s):

LA-UR-19-28732
Journal ID: ISSN 0022-2461; TRN: US2001296

Grant/Contract Number:  

89233218CNA000001

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Materials Science

Additional Journal Information:

Journal Volume: 55; Journal Issue: 4; Journal ID: ISSN 0022-2461

Publisher:

Springer

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; hardness; spherical indentation; directed energy deposition; dynamic deformation; geometrically necessary dislocations; electron microscopy