Journal ArticleDOI
Ultrahigh strength and high electrical conductivity in copper
TLDR
Pure copper samples with a high density of nanoscale growth twins are synthesized and show a tensile strength about 10 times higher than that of conventional coarse-grained copper, while retaining an electrical conductivity comparable to that of pure copper.Abstract:
Methods used to strengthen metals generally also cause a pronounced decrease in electrical conductivity, so that a tradeoff must be made between conductivity and mechanical strength. We synthesized pure copper samples with a high density of nanoscale growth twins. They showed a tensile strength about 10 times higher than that of conventional coarse-grained copper, while retaining an electrical conductivity comparable to that of pure copper. The ultrahigh strength originates from the effective blockage of dislocation motion by numerous coherent twin boundaries that possess an extremely low electrical resistivity, which is not the case for other types of grain boundaries.read more
Citations
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Mechanical properties of nanocrystalline materials
TL;DR: The mechanical properties of nanocrystalline materials are reviewed in this paper, with emphasis on their constitutive response and on the fundamental physical mechanisms, including the deviation from the Hall-Petch slope and possible negative slope, the effect of porosity, the difference between tensile and compressive strength, the limited ductility, the tendency for shear localization, fatigue and creep responses.
Journal ArticleDOI
Strengthening Materials by Engineering Coherent Internal Boundaries at the Nanoscale
TL;DR: An approach to optimize strength and ductility is outlined by identifying three essential structural characteristics for boundaries: coherency with surrounding matrix, thermal and mechanical stability, and smallest feature size finer than 100 nanometers.
Journal ArticleDOI
Revealing the Maximum Strength in Nanotwinned Copper
TL;DR: The maximum strength of nanotwinned copper samples with different twin thicknesses is investigated, finding that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced strain hardening and tensile ductility.
Journal ArticleDOI
Extreme grain refinement by severe plastic deformation: A wealth of challenging science
Yuri Estrin,Alexei Vinogradov +1 more
TL;DR: A brief overview of the available SPD technologies is given in this paper, along with a summary of unusual mechanical, physical and other properties achievable by SPD processing, as well as the challenges this research is facing, some of them generic and some specific to the nanoSPD area.
Journal ArticleDOI
Heterogeneous lamella structure unites ultrafine-grain strength with coarse-grain ductility.
TL;DR: A heterogeneous lamella structure in Ti produced by asymmetric rolling and partial recrystallization that can produce an unprecedented property combination: as strong as ultrafine-grained metal and at the same time as ductile as conventional coarse- grained metal.
References
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Journal ArticleDOI
High tensile ductility in a nanostructured metal.
TL;DR: A thermomechanical treatment of Cu is described that results in a bimodal grain size distribution, with micrometre-sized grains embedded inside a matrix of nanocrystalline and ultrafine (<300 nm) grains, which impart high strength, as expected from an extrapolation of the Hall–Petch relationship.
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Elastic and tensile behavior of nanocrystalline copper and palladium
TL;DR: The elastic and tensile behavior of high-density, high-purity nanocrystalline Cu and Pd was determined in this paper, showing that porosity increases with decreasing porosity, and may be significantly affected by a few large processing flaws.
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Tensile Strength of Whiskers
TL;DR: In this article, tensile tests have been performed on whiskers of iron, copper, and silver 1.2 to 15 μ in diameter, and the strongest whiskers which were less than 4 µ in diameter exhibited resolved elastic shear strengths of from two to six percent of their shear moduli.
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Nanocrystalline nickel and nickel-copper alloys: Synthesis, characterization, and thermal stability
TL;DR: In this article, the influence of the physical and chemical deposition parameters on the nanostructure of the deposits and demonstrate that the grain size can be tuned to values between 13 and 93 nm, with rather narrow grain size distribution.
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The effect of grain boundaries on the electrical resistivity of polycrystalline copper and aluminium
TL;DR: In this paper, the contribution of electrical resistivity caused by grain boundaries has been measured in polycrystalline specimens of high purity copper and high purity aluminium and the specific grain boundary resistivity appeared to be independent of the impurity content, depended to a small extent on the temperature in the range 4·2 to 77°K.