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Title: Gradient twinned 304 stainless steels for high strength and high ductility

Journal Article · · Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing
 [1];  [2];  [2];  [3];  [4]
  1. Univ. of Shanghai for Science and Technology, Shanghai (China)
  2. Zhejiang Univ., Hangzhou (China)
  3. City Univ. of Hong Kong, Hong Kong (China)
  4. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Gradient materials often have attractive mechanical properties that outperform uniform microstructure counterparts. It remains a difficult task to investigate and compare the performance of various gradient microstructures due to the difficulty of fabrication, the wide range of length scales involved, and their respective volume percentage variations. We have investigated four types of gradient microstructures in 304 stainless steels that utilize submicrotwins, nanotwins, nanocrystalline-, ultrafine- and coarse-grains as building blocks. Tensile tests reveal that the gradient microstructure consisting of submicrotwins and nanotwins has a persistent and stable work hardening rate and yields an impressive combination of high strength and high ductility, leading to a toughness that is nearly 50% higher than that of the coarse-grained counterpart. Ex- and in-situ transmission electron microscopy indicates that nanoscale and submicroscale twins help to suppress and limit martensitic phase transformation via the confinement of martensite within the twin lamellar. Twinning and detwinning remain active during tensile deformation and contribute to the work hardening behavior. We discuss the advantageous properties of using submicrotwins as the main load carrier and nanotwins as the strengthening layers over those coarse and nanocrystalline grains. Furthermore, our work uncovers a new gradient design strategy to help metals and alloys achieve high strength and high ductility.

Research Organization:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC52-07NA27344
OSTI ID:
1260478
Report Number(s):
LLNL-JRNL--677428
Journal Information:
Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing, Journal Name: Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing Journal Issue: C Vol. 667; ISSN 0921-5093
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (52)

Eight routes to improve the tensile ductility of bulk nanostructured metals and alloys journal April 2006
Theory of the tensile test journal February 1967
The interaction of twins with existing substructure and twins in cobalt-iron alloys journal September 1974
Repetitive Thermomechanical Processing towards Ultra Fine Grain Structure in 301, 304 and 304L Stainless Steels journal April 2011
Theory of orientation gradients in plastically strained crystals journal January 2002
Formation of nanostructured surface layer on AISI 304 stainless steel by means of surface mechanical attrition treatment journal April 2003
Crystallographic aspects of geometrically-necessary and statistically-stored dislocation density journal March 1999
Three strategies to achieve uniform tensile deformation in a nanostructured metal journal April 2004
Dislocation activity and nano-void formation near crack tips in nanocrystalline Ni journal June 2005
Detwinning mechanisms for growth twins in face-centered cubic metals journal April 2010
The influence of strain rate on the microstructure transition of 304 stainless steel journal May 2011
Detwinning, damage and crack initiation during cyclic loading of Cu samples containing aligned nanotwins journal June 2011
In situ X-ray microdiffraction study of deformation-induced phase transformation in 304 austenitic stainless steel journal February 2014
Microstructural evolution of a 304-type austenitic stainless steel during rolling at temperatures of 773–1273 K journal January 2015
Fatigue behaviors of AISI 316L stainless steel with a gradient nanostructured surface layer journal April 2015
Optimization of strength and ductility in nanotwinned ultra-fine grained Ag: Twin density and grain orientations journal September 2015
Suppression of twinning and phase transformation in an ultrafine grained 2 GPa strong metastable austenitic steel: Experiment and simulation journal September 2015
Fracture in a thin film of nanotwinned copper journal October 2015
The formation mechanisms of growth twins in polycrystalline Al with high stacking fault energy journal December 2015
The effect of cold work on structure and properties of AISI 304 stainless steel journal July 2008
Introducing a hierarchical structure for fabrication of a high performance steel journal October 2011
Tensile and compressive properties of AISI 304L stainless steel subjected to equal channel angular pressing journal February 2008
Formation of ultrafine grained microstructure in the austenitic stainless steel and its impact on tensile properties journal March 2011
Effect of large strain cold rolling and subsequent annealing on microstructure and mechanical properties of an austenitic stainless steel journal May 2012
Gradient nanostructure and residual stresses induced by Ultrasonic Nano-crystal Surface Modification in 304 austenitic stainless steel for high strength and high ductility journal September 2014
Comparison of strength–ductility combinations between nanotwinned austenite and martensite–austenite stainless steels journal October 2015
In situ TEM study on crack propagation in nanoscale Au thin films journal September 2011
Twin stability in highly nanotwinned Cu under compression, torsion and tension journal June 2012
Critique of mechanisms of formation of deformation, annealing and growth twins: Face-centered cubic metals and alloys journal January 2013
Materials science: Nanomaterial advantage journal October 2002
High tensile ductility in a nanostructured metal journal October 2002
Evading the strength–ductility trade-off dilemma in steel through gradient hierarchical nanotwins journal April 2014
In situ nanoindentation study on plasticity and work hardening in aluminium with incoherent twin boundaries journal September 2014
Transition of dislocation nucleation induced by local stress concentration in nanotwinned copper journal July 2015
Retaining ductility journal June 2004
The conflicts between strength and toughness journal October 2011
Defective twin boundaries in nanotwinned metals journal May 2013
Nanodomained Nickel Unite Nanocrystal Strength with Coarse-Grain Ductility journal June 2015
Enhanced tensile ductility and toughness in nanostructured Cu journal April 2002
Nanoscale-twinning-induced strengthening in austenitic stainless steel thin films journal February 2004
Strain hardening and large tensile elongation in ultrahigh-strength nano-twinned copper journal November 2004
Structure and migration of (112) step on (111) twin boundaries in nanocrystalline copper journal December 2008
Plasticity and ultra-low stress induced twin boundary migration in nanotwinned Cu by in situ nanoindentation studies journal June 2014
Stress-gradient plasticity journal September 2011
Extraordinary strain hardening by gradient structure journal May 2014
An Ideal Ultrafine-Grained Structure for High Strength and High Ductility journal October 2014
Controlling factors in tensile deformation of nanocrystalline cobalt and nickel journal January 2012
Ultrahigh Strength and High Electrical Conductivity in Copper journal April 2004
Strengthening Materials by Engineering Coherent Internal Boundaries at the Nanoscale journal April 2009
Revealing Extraordinary Intrinsic Tensile Plasticity in Gradient Nano-Grained Copper journal February 2011
Making strong nanomaterials ductile with gradients journal September 2014
Growth Twins and Deformation Twins in Metals journal July 2014

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Nanotwinned and hierarchical nanotwinned metals: a review of experimental, computational and theoretical efforts journal February 2018
Simultaneous Strength-Ductility Enhancement of a Nano-Lamellar AlCoCrFeNi2.1 Eutectic High Entropy Alloy by Cryo-Rolling and Annealing journal February 2018
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