نتایج جستجو برای: ultrafine microstructure

تعداد نتایج: 44214  

2008
O. Srba M. Janeček J. Čížek M. Dopita R. Král

Technical purity Cu (99.95 wt%) polycrystals have been processed at room temperature by equal channel angular pressing. The results of mechanical tests and the microstructure characterization by various experimental techniques are presented. The yield stress as well as the strength were shown to increase with increasing strain and exceed the respective values of a coarse-grained material. The m...

Journal: :Toxicology and applied pharmacology 2001
D M Brown M R Wilson W MacNee V Stone K Donaldson

Studies into the effects of ultrafine particles in the lung have shown adverse effects considered to be due in part to the particle size. Air pollution particles (PM(10)) are associated with exacerbations of respiratory disease and deaths from cardiovascular causes in epidemiological studies and the ultrafine fraction of PM(10) has been hypothesized to play an important role. The aim of the pre...

2015
A. Mohamed M. Yuness M. Abd El-Hady Mona Moustafa

Inhalation of Rn progeny has been recognized as a health risk, primarily as a cause of human lung cancer. Rn progeny in the domestic environment contributes the greatest fraction of the natural radiation exposure to the public. The ultrafine activity of these progeny amounts up to about 10 percent of the total activity (attached and ultrafine), but is considered to yield about 50 percent of the...

Journal: :Journal of toxicology and environmental health. Part A 2002
Günter Oberdörster Zachary Sharp Viorel Atudorei Alison Elder Robert Gelein Alex Lunts Wolfgang Kreyling Christopher Cox

Studies with intravenously injected ultrafine particles have shown that the liver is the major organ of their uptake from the blood circulation. Measuring translocation of inhaled ultrafine particles to extrapulmonary organs via the blood compartment is hampered by methodological difficulties (i.e., label may come off, partial solubilization) and analytical limitations (measurement of very smal...

Journal: :Journal of materials research and technology 2021

A nickel-free high nitrogen duplex stainless steel holding Mn-content was friction stir spot welded under the various rotational speeds. The microstructure/texture evolutions of joints and correlated mechanical properties were investigated in detail. ferrite austenite constituent massive phases refined down to mean grain size 0.9 μm 1.1 μm, respectively. microstructure revealed activation conti...

2012
Lifeng Zhang Haofei Zhou Shaoxing Qu

Recent discovery that nanoscale twin boundaries can be introduced in ultrafine-grained metals to improve strength and ductility has renewed interest in the mechanical behavior and deformation mechanisms of these nanostructured materials. By controlling twin boundary spacing, the effect of twin boundaries on void growth is investigated by using atomistic simulation method. The strength is signif...

2006
Barbee

Large-scale production of high purity (99.999%), nano-twinned, and ultrafine-grained copper foils (22 m thick) was successfully implemented by the use of nanoscale multilayer technology. The process allows the production of up to fourteen 10 cm diameter foils during a single deposition run with high levels of reproducibility. Mechanical tests demonstrate that the strength of the Cu foils (σy ∼ ...

2017
Ningning Liang Yonghao Zhao Jingtao Wang Yuntian Zhu

Nanostructured (NS) and ultrafine-grained (UFG) materials have high strength and relatively low ductility. Their toughness has not been comprehensively investigated. Here we report the Charpy impact behavior and the corresponding microstructural evolutions in UFG Cu with equi-axed and elongated grains which were prepared by equal channel angular pressing (ECAP) for 2 and 16 passes at room tempe...

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