Experimental analysis and modeling of the Knoop hardness of lithium disilicate glass-ceramics containing lithium tantalate as a secondary phase

The present study examines the Knoop hardness (HK) via microindentation of lithium disilicate (LD) glassceramics that contain lithium tantalate (LT) as a secondary phase. A 64-sample data set was analyzed to study the relationship between the phase assemblage and the mechanical property. It was found that the HK was dependent on the phase assemblage in a similar manner as previously acquired phase and color data on the same system. The HK data was used to train a linear model to predict the heat treatment needed to acquire a desired HK value. The model allowed us to identify that LT is the best phase to increase the hardness of the sample per XRD count.