STATIC AND DYNAMIC INDENTATION RESPONSE OF ION-ARMOR™ GLASS

The mechanical properties of Ion-Armor (TM), a chemically strengthened glass, were investigated using static and dynamic micro-Vickers indentation. The strengthened glass was reported to have high surface residual compressive stress approaching 1 GPa.(1) Static indentations were performed using a standard Vickers hardness tester with a loading duration of 15 seconds. Dynamic indentations were generated using a custom-made Dynamic Indentation Hardness Tester (DIHT) with a loading duration of 60 microseconds. It was shown that the strengthened glass exhibited a 22% greater static hardness and a 12% greater dynamic hardness compared to the virgin glass. Furthermore, the strengthened glass showed an increase in Vickers hardness of 23% under dynamic loading compared to static loading as the result of apparent strain rate-sensitivity. Using Meyer's Law, or power law analysis, it was also determined that both the strengthened and virgin glass revealed increased load-dependence (i.e., indentation size effect) under dynamic loading.