Publication Date

10-30-2017

Department

Ames Laboratory

Campus Units

Ames Laboratory

OSTI ID+

1418906

Report Number

IS-J 9562; LLNL-JRNL-736774

DOI

10.1038/NMAT5021

Journal Title

Nature Materials

Volume Number

17

Issue Number

1

First Page

63

Last Page

71

Abstract

Many traditional approaches for strengthening steels typically come at the expense of useful ductility, a dilemma known as strength–ductility trade-off. New metallurgical processing might offer the possibility of overcoming this. Here we report that austenitic 316L stainless steels additively manufactured via a laser powder-bed-fusion technique exhibit a combination of yield strength and tensile ductility that surpasses that of conventional 316L steels. High strength is attributed to solidification-enabled cellular structures, low-angle grain boundaries, and dislocations formed during manufacturing, while high uniform elongation correlates to a steady and progressive work-hardening mechanism regulated by a hierarchically heterogeneous microstructure, with length scales spanning nearly six orders of magnitude. In addition, solute segregation along cellular walls and low-angle grain boundaries can enhance dislocation pinning and promote twinning. This work demonstrates the potential of additive manufacturing to create alloys with unique microstructures and high performance for structural applications.

DOE Contract Number(s)

AC52-07NA27344

Language

en

Department of Energy Subject Categories

36 MATERIALS SCIENCE

Publisher

Iowa State University Digital Repository, Ames IA (United States)

Included in

Metallurgy Commons

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