extraordinary strain hardening by gradient structure pnas

extraordinary strain hardening by gradient structure pnas

(PDF) Carbon Nanotube Yarn Strain Sensors

Repetitive testing of pure dry CNT yarns showing repeatable stressstrain and resistancestrain behaviors up to 1% strain:(a) tensile stressstrain curve, (b) in situ resistance measuring

(PDF) Ductility and strain hardening in gradient and

Nov 05, 2020 · strain hardening and plastic deformation in gradient and lamellar structured materials. Both have typical trans-scale grain hierarch y, leading to (PDF) Dynamically reinforced heterogeneous grain structure Extraordinary back stress hardening in HGS. (A) Tensile true stresstrue strain curves during LUR tests at 298 and 77 K. (B) Hysteresis loops at the maximum uniform strain.

(PDF) Extraordinary strain hardening by gradient structure

Such extraordinary strain hardening, which is inherent to gradient structures and does not exist in homogeneous materials, provides a hitherto unknown strategy to develop strong and ductile (PDF) Stress-gradient plasticity - ResearchGateWu et al. [11,12] found that the interface coupling effect reflected as the intrinsic synergetic strengthening and the extraordinary strain hardening behavior in the gradient structure compared

(PDF) Strong Strain Hardening in Nanocrystalline Nickel

Specific examples include strong strain hardening in a 20 nm grained NC Ni during rolling [39], coarse-grained tensile ductility of a gradient nanostructured Cu [14], a tensile elongation of 22.4% A superior strength-ductility combination in gradient Jul 03, 2020 · Strain hardening rate -true strain curves of CuAlZn samples:(a) SFE-40, (b) SFE-10 and (c) SFE-7 samples. To make it easier to find the optimal combination of the strength and ductility of GS alloys, Fig. 6 depicts the relationship between strength and ductility of

Bio-inspired gradient structure approach for delivering

Jul 12, 2014 · XiaoLei Wu, Ping Jiang, Liu Chen, Fuping Yuan, and Yuntian T. Zhu (2014b) Extraordinary strain hardening by gradient structure, PNAS doi:10.1073/pnas.1324069111 Posted on 12 July 2014 in Materials Permalink Comments (1) Cryogenic temperature toughening and strengthening due Jan 17, 2018 · The hardening exponent n of the CT tensile stress-strain curves after RT pre-torsion (Fig. 2b) and CT pre-torsion (Fig. 2c) are shown in Fig. 3a and Fig. 3b, respectively, where n is obtained from Hollomon's equation:(1) S = K n with S denoting the flow stress and K the strength coefficient.

Ductility and strain hardening in gradient and lamellar

Hence, strain hardening in GS, GS, is a sum of several contri- butions, as described in Eq. (1). The rst term is an additive effect of individual layer by forest hardening in GS. Note that the NS layer in GS only contribute to. . but without strain hardening if loaded alone. The second is extra strain hardening compressive residual stress. Ductility and strain hardening in gradient and lamellar Hence, strain hardening in GS, GS, is a sum of several contri- butions, as described in Eq. (1). The rst term is an additive effect of individual layer by forest hardening in GS. Note that the NS layer in GS only contribute to. . but without strain hardening if loaded alone. The second is extra strain hardening compressive residual stress.

Ductility and strain hardening in gradient and lamellar

Sep 01, 2020 · Large strain gradient helps with obtaining strong HDI hardening for ductility. The strain gradient-oriented design for hetero-structuring is thus suggested. With regard to the trans-scale HS, the larger discrepancy in grain sizes, the larger strain gradient will be at hetero-interfaces due to more drastic plastic incompatibility upon straining. Dynamic creation and evolution of gradient nanostructure Oct 21, 2016 · We demonstrate effective creation of an extreme GNG structure with a single-step, high-velocity-impact process. The high strain rates, pressure, and strain gradients during impact create the GNG structure with a gradient of grain size ~1, where the grain size varies from ~10 to ~500 nm over a distance of ~500 nm.

Dynamically reinforced heterogeneous grain structure

Jul 10, 2018 · In other words, the partially recrystallized starting grain structure facilitates nonhomogeneous plastic deformation and the associated strain gradient hardening. Also importantly, the HGS evolves toward an even more heterogeneous structure during tensile deformation, as more twins, faults, and NGs with high-angle GBs form on the fly due to the Dynamically reinforced heterogeneous grain structure Jul 10, 2018 · In other words, the partially recrystallized starting grain structure facilitates nonhomogeneous plastic deformation and the associated strain gradient hardening. Also importantly, the HGS evolves toward an even more heterogeneous structure during tensile deformation, as more twins, faults, and NGs with high-angle GBs form on the fly due to the

Extra strengthening and work hardening in gradient

INTRODUCTION. Gradient structures ubiquitously exist in natural materials such as bone, shells, and trees. Microstructural gradients are increasingly being introduced into a wide range of engineering materials, providing them with enhanced strength, hardness, work hardening, ductility, and fatigue resistance through deformation mechanisms that are distinct from those operating in gradient-free Extraordinary Bauschinger effect in gradient structured Jun 01, 2018 · The gradient structure can be considered a type of heterogeneous structure , and was also reported to have high back stress . In addition, back stress hardening was found, i.e. the back stress increases with pre-applied tensile strain (pre-strain).

Extraordinary Bauschinger effect in gradient structured

Jun 01, 2018 · The gradient structure can be considered a type of heterogeneous structure , and was also reported to have high back stress . In addition, back stress hardening was found, i.e. the back stress increases with pre-applied tensile strain (pre-strain). Extraordinary strain hardening by gradient structure - The gradient structure shows a surprising extra strain hardening along with an up-turn and subsequent good retention of strain hardening rate. Strain hardening is critical for increasing the material ductility (46). We also show a superior ductilitystrength combination in the gradient structure that is not accessible to conventional

Extraordinary strain hardening by gradient structure

Extraordinary strain hardening by gradient structure Extraordinary strain hardening by gradient structure May 01, 2014 · Here we report that the gradient structure in engineering materials such as metals renders a unique extra strain hardening, which leads to high ductility. The grain-size gradient under uniaxial tension induces a macroscopic strain gradient and converts the applied uniaxial stress to multiaxial stresses due to the evolution of incompatible deformation along the gradient depth.

Extraordinary strain hardening by gradient structure

The gradient structure shows a surprising extra strain hardening along with an up-turn and subsequent good retention of strain hardening rate. Strain hardening is critical for increasing the material ductility (4 6). We also show a superior ductilitystrength combination in the gradient structure that is not accessible to conventional homogeneous microstructures. Extraordinary strain hardening by gradient structureSuch extraordinary strain hardening, which is inherent to gradient structures and does not exist in homogeneous materials, provides a hitherto unknown strategy to develop strong and ductile

Heterogeneous lamella structure unites ultrafine - PNAS

Nov 24, 2015 · Mechanical Properties and Strain Hardening of HL Structure. Fig. 2 A and B shows that HL Ti, e.g., This article is a PNAS Direct Submission. (2014) Extraordinary strain hardening by gradient structure. Proc Natl Acad Sci USA 111 (20): Heterogeneous lamella structure unites ultrafine-grain identified structure produces significant back-stress hardening in addition to conventional dislocation hardening, rendering it higher strain hardening than coarse-grained metals. The high back-stresshardening makes the material as strong as ultrafine-grained

In Situ Analysis of Deformation Mechanics of Constrained

The constrained cutting employs a constraining tool in the cutting process to confine the otherwise free surface and enable direct control of the chip formation deformation. The presented work is a study of the deformation mechanics of plane strain constrained cutting using high-speed imaging and digital image correlation (DIC) methods. Inspired by Nature, Researchers Create Tougher Metal Jul 02, 2014 · The work is described in two recently published papers:Synergetic Strengthening by Gradient Structure, which was published online July 2 in Materials Research Letters, and Extraordinary strain hardening by gradient structure, which is published in Proceedings of the National Academy of Sciences. The work was supported by the U.S

Inspired by nature, researchers create tougher metal materials

Jul 02, 2014 · Such extraordinary strain hardening, which is inherent to gradient structures and does not exist in homogeneous materials, provides a novel strategy to develop strong and ductile materials by Inspired by nature, researchers create tougher metal materialsJul 02, 2014 · Such extraordinary strain hardening, which is inherent to gradient structures and does not exist in homogeneous materials, provides a novel strategy to develop strong and ductile materials by

Making strong nanomaterials ductile with gradients Science

Sep 19, 2014 · Steels can be made stronger, tougher, or more resistant to corrosion either by changing composition (adding in more carbon or other elements) or by modifying their microstructures. An extreme microstructural route for strengthening materials is to reduce the crystallite size from the micrometer scale (coarse-grained) to the nanoscale. Nanograined aluminum or copper (Cu) may become even Metals that mimic Bamboo Gradient structure will make Jul 10, 2014 · PNAS Extraordinary strain hardening by gradient structure. Wu and Zhu collaborated on research that tested the gradient structure concept in a variety of metals, including copper, iron, nickel and stainless steel. The technique improved the metals properties in all of them.

Metals that mimic Bamboo Gradient structure will make

Jul 10, 2014 · PNAS Extraordinary strain hardening by gradient structure. Wu and Zhu collaborated on research that tested the gradient structure concept in a variety of metals, including copper, iron, nickel and stainless steel. The technique improved the metals properties in all of them. Revealing Extraordinary Intrinsic Tensile Plasticity in Mar 25, 2011 · Nano-grained (NG) metals are believed to be strong but intrinsically brittle:Free-standing NG metals usually exhibit a tensile uniform elongation of a few percent. When a NG copper film is confined by a coarse-grained (CG) copper substrate with a gradient grain-size transition, tensile plasticity can be achieved in the NG film where strain localization is suppressed.

Selected Papers:Heterostructured Materials Zhu Research

Selected Papers:Heterostructured Materials . Y.T. Zhu, K. Ameyama, P.M. Anderson, I.J. Beyerlein, H.J. Gao, H.S. Kim, E.J. Lavernia, S.N. Mathaudhu, H. Maghrabi, R.O Selected Papers:Heterostructured Materials Zhu Research Selected Papers:Heterostructured Materials . Y.T. Zhu, K. Ameyama, P.M. Anderson, I.J. Beyerlein, H.J. Gao, H.S. Kim, E.J. Lavernia, S.N. Mathaudhu, H. Maghrabi, R.O

Shear band stability and uniform elongation of gradient

May 01, 2020 · The formation of dispersed shear bands in gradient structure can be primarily attributed to the low strain hardening capability of Jiang P., Chen L., Yuan F.P., Zhu Y.T.Extraordinary strain hardening by gradient structure. Proc. Natl. Acad. Sci. USA, 111 (2014), pp. 7197-7201, 10.1073/pnas.1324069111. CrossRef View Record in Scopus Google Surface severe plastic deformation induced solute and Jan 30, 2019 · 1. Introduction. Surface severe plastic deformation (SSPD) has become one of the prevalent strategies to simultaneously improve the strength and ductility of metallic materials [, , ].Generally, such excellent strength-ductility combination is attributed to the gradient grain architecture, which is of great benefit to strain accommodation during deformation [1,3,4].

Extraordinary strain hardening by gradient structure PNAS

May 20, 2014 · The gradient structure shows a surprising extra strain hardening along with an up-turn and subsequent good retention of strain hardening rate. Strain hardening is critical for increasing the material ductility (4 6). We also show a superior ductilitystrength combination in the gradient structure that is not accessible to conventional homogeneous microstructures.

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