Thermal and mechanical characterization of borosilicate glass

The dilatometric analysis shows that the thermal expansion variation with temperature is essentially non linear, increasing rapidly up to 200∘C and slowing down beyond. The optimal glass chemical strengthening was obtained for a bath duration of 15 hours. This corresponds to a relatively moderate increase of the mechanical strength (∼70%). The fracture toughness measured by indentation was appreciably improved by the chemical treatment. It seems also to increase with the applied indentation load.