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Load dependence of hardness of the doped soda-lime silicate glasses

Suszynska M.

Optica Applicata

2012

Vol. 42, nr 2

399-406

The aim of the work described was to study the load dependence of micro- and nano-hardness for soda-lime silicate glass doped with some univalent cations. The Fourcault-type glass samples were chemically treated by dipping them in melted baths of KNO3, AgNO3 and CuCl. The nano- and micro-hardness were determined by using the Vickers diamond indenters for applied loads ranging between 0.1 and 500 mN (registered loading and unloading mode), and between 0.2 and 30 N (conventional application of the load), respectively. For the behavior of hardness and Young's modulus (registered nano-indentation) the normal indentation size effect has been observed, but in the low load range of conventionally indented specimens the reverse indentation size effect has been found. The detected size effects were discussed in terms of some empirical models proposed in the literature for crystalline materials. It has been shown that: 1) the Meyer's law is only suitable for describing the nano-indentation characteristics measured in a narrow range of indentation load; 2) the classical Meyer's law and the energy balance model are insufficient for describing the reverse indentation size effect; 3) the difficulties in acquiring accurate and precise micro-hardness readings in the range of low loads can result in the inconformity of experimental data with the empirical models.

Microhardness and some fracture related problems in copper doped soda lime silica glass

Suszynska M., Szmida M.

Optica Applicata

2008

Vol. 38, nr 1

245-250

A wide range of practical problems requires the knowledge of the mechanical characteristics of doped oxide glasses. The main purpose of this study was to investigate the effect of ion exchange and a post-exchange thermal treatment upon Vickers microhardness of a multicomponent soda lime silica (SLS) glass in which the mobile sodium ions have been partially substituted by copper. It has been stated that in dependence of the indentation load, the indentation marks have been accompanied by traces of Palmqvist cracks. The deformation and fracture related phenomena are dependent on the temperature and time of the exchange and annealing processes.