ISSN:
1662-8985
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Although Poisson's ratio (ν) is a macroscopic elastic parameter it depends much on thefine details of the atomic packing. Glasses exhibit a wide range of values for from 0.1 to 0.4which correlate to the glass network polymerisation degree, hence reproducing at the atomic scalewhat is observed in cellular materials at the macroscopic scale[1]. As for pure oxide glasses, wefound in various multi-component glasses built on ionic-, covalent- or Van der Waals bonds that anincrease of Poisson’s ratio corresponds to a decrease of the atomic network crosslink degree[2].Noteworthy, an extension of this analysis to the case of metallic glasses correlate the recentlyproposed cluster-like network structure for these glasses[3,4]. A general feature is that a highlycross-linked atomic network results in a glass with a low atomic packing density (large free volumefraction), as exemplified with the case of amorphous silica. The lower the atomic packing density isand the larger the volume change the glass experiences under high pressure (1 to 25 GPa).Indentation experiments with sharp indenters (such as the Vickers one) give birth to hydrostaticstresses of the same order of magnitude and thus induce glass densification. There is hence a directcorrelation between ν (reflecting the packing density) and the indentation behavior[5]
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/40/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.39-40.137.pdf
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