Tensile elongation (110%) observed in ultrafine-grained Zn at room temperature

Zhang, X.; Wang, H.; Scattergood, R.O.; Narayan, J.; Koch, Carl C.; Sergueeva, A. V.; Mukherjee, Amiya K.

doi:10.1063/1.1494866

Cited by 73 publications

(31 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…64 This type of plastic mechanism cannot be completely excluded in nc metals as nanovoids could become dislocation nucleation or sink sources. Due to the inadequate experimental data on hcp nc metals, [65][66][67] the general trend of m in this class of materials remains unsolved.…”

Section: (4)mentioning

confidence: 99%

Controlling factors in tensile deformation of nanocrystalline cobalt and nickel

et al. 2012

View full text Add to dashboard Cite

In an effort to understand and enhance the tensile ductility of truly nanocrystalline metals, we have investigated and compared the mechanical behavior, especially the tensile behavior, of hcp nanocrystalline cobalt (~20 nm) and fcc nanocrystalline nickel (~28 nm). Although both materials exhibit obvious plasticity in tension, their uniform tensile ductility, tensile elongationto-failure, and fracture behavior are drastically different. In-situ synchrotron x-ray diffraction and ultra-small angle x-ray scattering reveal distinct deformation disparity in terms of residual strain development, texture evolution, nanovoid formation, and subsequent strain hardening and strain rate hardening behavior. The dependence of tensile property on the strain rate and temperature is examined and discussed. Factors that influence the strength and ductility of nanocrystalline metals are considered and prioritized according to the current findings. A new Hall-petch relationship is proposed for nanocrystalline nickel.

show abstract

Section: (4)mentioning

confidence: 99%

Controlling factors in tensile deformation of nanocrystalline cobalt and nickel

et al. 2012

View full text Add to dashboard Cite

show abstract

“…There are two contributions to the plastic work done on the cylinder: that associated with extending the cylinder and that caused by shrinkage relative to the rest of the fiber [1] where s is the shear flow strength of the fiber. Substituting for ␦v(r) and replacing s with y /2, integration then gives [2] For the case of limited decohesion at interfaces with a length of l d (similar to the case of delamination and necking in experiments), the initial crack opening u 0 has to be replaced by the effective decohesion length (l d ϩ u 0 ). In addition, y increases with strain in the ductile metal cylinder ( y ϭ 0 ( y / o ) n , where n is the work-hardening exponent, o is the yield strain, and 0 is the initial flow stress at yield strain), and the strain in the cylinder can be approximated by (u/u 0 Ϫ 1).…”

Section: Enhanced Tensile Ductilitymentioning

confidence: 99%

“…However, low ductility, and the associated loss of toughness, is a serious deficiency in most of these metals. [1] High ductility in nanostructured materials has been observed in a few cases, but these cases appear to be exceptional, [2,3] often occurring only at high temperatures [4] or with microtensile samples using specialized testing equipment. [5] Inspection of the relevant literature reveals that several approaches have been proposed to enhance the ductility of nanostructured materials.…”

Section: Introductionmentioning

confidence: 99%

Deformation behavior of bimodal nanostructured 5083 Al alloys

Han

Lee

Witkin

et al. 2005

Metall Mater Trans A

242

120

View full text Add to dashboard Cite

Cryomilled 5083 Al alloys blended with volume fractions of 15, 30, and 50 pct unmilled 5083 Al were produced by consolidation of a mixture of cryomilled 5083 Al and unmilled 5083 Al powders. A bimodal grain size was achieved in the as-extruded alloys in which nanostructured regions had a grain size of 200 nm and coarse-grained regions had a grain size of 1 m. Compression loading in the longitudinal direction resulted in elastic-perfectly plastic deformation behavior. An enhanced tensile elongation associated with the occurrence of a Lüders band was observed in the bimodal alloys. As the volume fraction of coarse grains was increased, tensile ductility increased and strength decreased. Enhanced tensile ductility was attributed to the occurrence of crack bridging as well as delamination between nanostructured and coarse-grained regions during plastic deformation.

show abstract

“…In other words, although each partial produces a strain of magnitude a / 6 , the sum of the total strains produced by the three partials is approximately zero if the numbers of three partials are about the same. It is possible to randomly emit the three Shockley partials, b 1 , b 2 and b 3 , on successive (111) slip planes, which will produce a deformation twin with zero net macrostrain. It has been observed that in nc nickel, a majority of twins are formed by the RAP mechanism.…”

Section: Random Activation Of Partials From Gbmentioning

confidence: 99%

“…1 Nanocrystalline and nanostructured (with structural features less than 100 nm) materials have been reported to have superior mechanical properties such as high strength, which could coexist with very good ductility. [2][3][4] These superior mechanical properties are attributed to their unique deformation mechanisms, which are fundamentally different from those in their coarse-grained (CG) counterparts. [5][6][7][8][9] Particularly, deformation twins have been used to increase the ductility of nanostructured metals.…”

Section: Introductionmentioning

confidence: 99%