Mechanical properties of silicate glass-ceramics containing tricalcium phosphate

The flexural strength, elastic moduli, Vickers hardness and fracture toughness for silicate glass-ceramics (anorthite and diopside) containing tricalcium phosphate (TCP) were measured. The microstructures of the silicate glass-ceramics containing TCP were shown to consist of a complex structure of rod-like silicate and TCP crystals. The flexural strengths of glass-ceramics containing 32 wt% TCP for anorthite and 38 wt% TCP for diopside corresponding to a eutectic composition in the phase diagram were 236 and 226 MPa. The Young's modulus and fracture toughness of the eutectic compositions were 89.4 GPa and 2.5 MPa .(1/2) for anorthite and 126 GPa and 2.3 MPa .(1/2) for diopside, respectively. The anorthite glass-ceramic containing TCP has a lower Young's modulus in spite of a high strength as compared to other silicate glass-ceramics containing apatite or TCP.