FRACTURE-MECHANICS OF TITANIUM BIOACTIVE GLASS-CERAMIC PARTICULATE COMPOSITES

Composite bioactive glass-ceramics reinforced with 30 vol% Ti particles were produced by warm-forging and in situ crystallization. The bend strength of the composite was 87 +/- 7 MPa. A fracture mechanical study in air and Ringer's bioactive solution determined crack velocity vs stress intensity factor and the effect of stressing rate on the bend strength. Time to failure of 10 years is predicted for the composite loaded at 10 MPa in Ringer's solution or 50 MPa in air. A disappointing fatigue performance of the relatively tough metal/ceramic composite illustrates that satisfactory short-time fracture resistance does not guarantee lifetime under fatigue conditions (long-term fracture resistance).