Abstract
Pressure-induced changes in hardness and crack initiation load of three borate glasses of composition xNa2O-10CaO-90-xB2O3 with x = 5, 15, 25 were studied. Each glass series was pre-treated by isostatic compression at 1, 2, 3, 4, 5, and 6 kbar to increase the fraction of tetrahedral boron and to decrease the molar volume and the ionic porosity of the glass network. Hardness H and crack resistance of the compressed glasses were determined from the size of the plastic deformation zone and the number of radial cracks initiated by Vickers indentation at 100 - 1500 mN load, respectively. Brittleness B as a measure of the resistance to permanent deformation and crack propagation was derived from the indent size to crack length ratio (Sehgal & Ito) and the hardness to fracture toughness ratio (Lawn & Marshall) using elastic constants from Brillouin scattering and empirical relationships between stress intensity and the driving force for cracking (Anstis and Niihara factors). The results show pressure history induced changes in H and B as well as a strong compositional dependence in the mechanical response of the three glasses to sharp contact loading with a Vickers diamond.
Originalsprog | Engelsk |
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Publikationsdato | 2012 |
Antal sider | 1 |
Status | Udgivet - 2012 |
Begivenhed | 11th ESG Conference - Maastricht, Holland Varighed: 3 jun. 2012 → 6 jun. 2012 |
Konference
Konference | 11th ESG Conference |
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Land/Område | Holland |
By | Maastricht |
Periode | 03/06/2012 → 06/06/2012 |