Elastic properties and atomic bonding character in metallic glasses

Abstract

To cite this version:Tanguy Rouxel, Y. Yokoyama. Elastic properties and atomic bonding character in metallic glasses. Journal of Applied Physics, American Institute of Physics, 2015, 118 (4), pp.44901 -44901. <10.1063/1.4926882>. <hal-01385067>T. Rouxel -Submited to Journal Applied Physics May 2015, revised June 2015 Elastic properties and atomic bonding character in metallic glasses _____________________________________The elastic properties of glasses from different metallic systems were studied in the light of the atomic packing density and bonding character. We found that the electronegativity mismatch (e -) between the host-and the major solute -elements provides a plausible explanation to the large variation observed for Poisson's ratio ( among metallic glasses (MGs) (from 0.28 for Fe-based to 0.43 for Pd-based MGs) notwithstanding a similar atomic packing efficiency (C g ). Besides, it is found that ductile MGs correspond to e -smaller than 0.5 and to a relatively steep atomic potential well. Ductility is thus favored in MGs exhibiting a weak bond directionality in average and opposing a strong resistance to volume change.

Mechanical response of mesoporous amorphous NiTi alloy to external deformations

“…The generated amorphous sample has the density ρ 0 6.17 g/cm 3 that is close to the density of crystalline NiTi, 6.45 g/cm 3 , at the same temperature [44]. Note that the glass transition temperature T g of titanium nickelide estimated by T. Rouxel and Y. Yokoyama is ∼ 750 K [45].…”

The fracture toughness of inorganic glasses

“…Unlike oxide silicate glasses metallic glasses exhibit no straightforward correlation between C g and ν (Figure ). As was shown recently, ν is found to increase as the difference in electronegativity between the host metal and the major solute elements decreases, so that a ductile behavior is expected for Δe − < 0.5 (corresponding to ν > 0.33). This correlation also holds for monoconstituent oxide glasses and hence provides an explanation to the variation of ν observed for seemingly “isostructural” glasses (Figure ).…”

“…Poisson's ratio as a function of the electronegativity mismatch between the host metal and the major secondary solute elements (horizontal error bars show the interval with the two major solutes) (from Ref. )…”

Competing Indentation Deformation Mechanisms in Glass Using Different Strengthening Methods

“…Emerging demand for stronger and lighter car windshields and other novel transparent structural materials further stimulates a need for deeper understanding and improvement of glass strengthening techniques. Studies of contact cracking (Lawn and Wilshaw, 1975;Ostojic and McPherson, 1987;Cook and Pharr, 1990) date back at least one century (Johnson, 1985;Lawn, 1998) and tremendous progress has been achieved to understand the shear flow, densification, and cracking under indentation in brittle solids (Lawn and Swain, 1975;Lawn and Wilshaw, 1975;Marshall and Lawn, 1978;Hagan, 1979;Lawn et al, 1983;Johnson, 1985;Ostojic and McPherson, 1987;Cook and Pharr, 1990;Lawn, 1998Lawn, , 2004Perriot et al, 2006;Gross and Tomozawa, 2008a,b,c;Gross et al, 2009;Kato et al, 2010;Gross, 2012a;Kassir-Bodon et al, 2012;Niu et al, 2012;Tran et al, 2012;Kjeldsen et al, 2013;Smedskjaer et al, 2013;Striepe et al, 2013b;Aakermann et al, 2015;Rouxel and Yokoyama, 2015). It is commonly believed that the surface strengthening against contact cracking comes from the linear superposition of a compressive stress (CS) profile onto the surface of the glass (Marshall and Lawn, 1978;Lawn and Fuller, 1984).…”