Mixed modifier effects on structural, mechanical, chemical, and mechanochemical properties of sodium calcium aluminosilicate glass

Glass properties are governed by the interplay between network formers and network modifiers; for a given composition of network formers, the ratio of different cationic modifiers compensating the anionic species in the network has a profound effect, which is often nonlinear, called a mixed modifier effect (MME). We have investigated the MME of sodium (Na) and calcium (Ca) in an aluminosilicate (NCAS) glass series following the formula [Na2O](30-)(x) [CaO](x) [Al2O3](10) [SiO2](60), where x = 0, 7.5, 15, 22.5, and 30. A nonadditive trend was observed in hardness and indentation toughness, with aqueous corrosion resistance exhibiting a shift from incongruent to congruent corrosion, whereas the network structure determined by molecular dynamics simulations revealed no significant trend with composition. Additionally, the NCAS glass containing both [Na2O] and [CaO] within an intermediate range exhibited superior resistance to wear at high humidity, a clear MME phenomenon previously only observed in soda-lime silica.

Automated summary

Glass properties are affected by the interplay between network formers and network modifiers, where the ratio of different cationic modifiers compensating anionic species in the network, known as the mixed modifier effect (MME), has a significant nonlinear impact. The MME of sodium (Na) and calcium (Ca) in an aluminosilicate (NCAS) glass series was investigated. It was found that hardness, indentation toughness, and aqueous corrosion resistance showed a nonadditive trend, while the network structure determined by molecular dynamics simulations did not exhibit a significant trend with composition. Moreover, the NCAS glass with an intermediate range of [Na2O] and [CaO] content showed superior wear resistance at high humidity, demonstrating the MME phenomenon observed in soda-lime silica.