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Showing 1 to 20 of 34 for “"Nanocrystalline materials"”.
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An alloy selection and processing framework for nanocrystalline materials
Nanocrystalline materials have a unique set of properties due to their nanometer-scale grain size. To harness these properties, grain growth in these materials needs to be suppressed, particularly in order to process bulk nanocrystalline components and to use them reliably. Alloying the material …
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Grain size effects on the fatigue response of nanocrystalline materials
… (grain size between 100 nm and 1000 nm) and nanocrystalline metals (grain size less than 100 nm) is relatively unknown. Such lack of understanding is primarily a consequence of the paucity of experimental data on the fatigue response of metals with very fine grains. In this work, the fatigue …
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Advanced Characterization of Nanocrystalline Materials by Synchrotron Radiation X-ray Diffraction
… powerful and versatile tools in the study nanomaterials, supporting a variety of analytical techniques. Among the possible spectroscopies, X-ray Diffraction (XRD) is especially suited to investigate materials at the nanoscale. However, to benefit of the full potential of SR XRD, a complete …
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Modeling the deformation and failure behavior of FCC and HCP nanocrystalline materials
… nowadays are miniaturizing structures in materials to achieve better performance as concerned in technical applications. Reducing grain sizes in polycrystalline materials into the range of less than 100nm, for example, could achieve extraordinary high strength in these so called …
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The synthesis of inorganic semiconductor nanocrystalline materials for the purpose of creating hybrid organic/inorganic light-emitting devices
Colloidal semiconductor nanocrystals (NCs) or quantum dots (QDs) can be synthesized to efficiently emit light from the ultraviolet, across the entire visible spectrum, and into the near infrared. This is now possible due to the continual development of new core and core-shell NC structures to meet …
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Three-dimensional nanostructure determination based on scanning electron nanodiffraction
Nanocrystalline materials in general feature a large density of surfaces, interphase and grain boundaries, and a large surface/volume ratio, which have attracted tremendous interest for their unique mechanical, chemical and electronic properties. For example, nanocrystalline metals and alloys …
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Nanocrystalline alloys : enhanced strengthening mechanisms and mechanically-driven structural evolution
Nanocrystalline materials have experienced a great deal of attention in recent years, largely due to their impressive array of physical properties. In particular, nanocrystalline mechanical behavior has been of interest, as incredible strengths are predicted when grain size is reduced to the …
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Design of stable nanostructure configurations in ternary alloys
The development of stable nanocrystalline binary alloys, which possess a large volume fraction of grain boundaries at elevated temperatures, is a promising route to high yield strength materials. Previous studies have focused on alloying by selecting solute elements that segregate at grain …
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Grain size control and microstructural evolution in nanocrystalline Ni-W alloys
Nanocrystalline materials have been studied extensively over the past two decades because of their useful and interesting physical properties. In most cases, these properties derive from the fine characteristic length scale of nanocrystalline structures and are superior to those realized in …
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Thermal conductivity of fluids containing suspension of nanometer-sized particles
… measurements for several combinations of nanocrystalline materials and base fluids were conducted with the transient hotwire technique. Results show that the thermal conductivity enhancement of nanofluids increases with particle volume concentration, with higher thermal conductivity …
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Selective Laser Melting of Finemet Soft Magnetic Material
Soft magnetic materials have been widely used in electric motors, routers, and detectors. Tremendous studies have been conducted to report microstructural features corresponding to magnetic performance. The laser-based powder bed fusion (L-PBF) additive manufacturing technique was implemented to …
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Síntese e caracterização de ligas nanocristalinas à base de cobre e zircônio com elevada capacidade de formação de estado vítreo
… processes were performed in order to produce nanocrystalline materials. X-ray and scanning electron microscopy results showed that samples produced with arc melting followed by suction casting processes leads to visualization of nanometric phase and have more refined microstructures if …
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Towards personal fabrications : tabletop tools for micron and sub-micron scale functional rapid prototyping
… because they exploit the novel properties of nanocrystalline materials and their interactions with energetic beams. UV contact mask lithography was used to directly pattern metallic nanocrystals on glass and polyimide surfaces without vacuum or etching processes or the use of photoresist …
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Cryomilling of Aluminum-based and Magnesium-based Metal Powders
… yield, has provided a platform for the study of nanocrystalline metals. It has been shown that bulk nanocrystalline materials are attainable and that alloy composition influences mechanical properties.
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Customisable Magnetic Components Using Nanocrystalline Flake Ribbon
… power electronics. In this thesis, a novel nanocrystalline flake ribbon (NFR) is proposed to customise high-performance magnetic components for power electronics in a cost-effective way without high-energy equipment. Conventional nanocrystalline alloys do offer much higher saturation flux …
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Design of a stable nanocrystalline alloy
Nanocrystalline materials are inherently unstable due to their high material fraction of grain boundaries, preventing their improved properties from being used in application. To stabilize the nanoscale grain size against rampant growth, past literature has proposed lowering the grain boundary …
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Experimental determination of the thermoelectric properties of porous silicon nanowires
… is severely degraded due to the disordered yet nanocrystalline structure. We investigate post doping conditions to improve the electrical conductivity by ~3 orders of magnitude. TEM characterization confirmed that porosity and crystalline structure are retained after doping. We characterized the …
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A finite element model of grain boundary sliding for nanostructured metals
Nanocrystalline metals, i.e., polycrystalline metals with grain sizes in the nanometer range, have elicited significant interest recently due to their potential for achieving higher material strength in combination with increased formability at lower temperatures and higher strain rates, among …
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Deformation Behaviour of NiCo Multilayers with Modulated Microstructures
… architecture of modulated coarse-grained and nanocrystalline features stacked in a laminate configuration, represent an ideal structure to study the influence of abrupt heterogeneities on deformation behaviour. While the deformation mechanisms of homogeneous coarse-grained and nanocrystalline …
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