Hardness, elastic modulus, and fracture toughness bulk properties in Corning calcium fluoride

Knoop and Vickers hardness, Young's Modulus, and fracture toughness measurements were performed on Corning's Code 9575 calcium fluoride in various orientations. Other commercially available sources of calcium fluoride were also measured for comparison of properties. Knoop hardness and elastic properties exhibited a dependence on orientation while no such dependence was observed for Vickers hardness and fracture toughness. The results also indicated that these physical properties were not dependent on the source of the material