The purpose of this paper is to describe finite element modelling for fracture and fatigue behaviour of zirconia toughened alumina microstructures.
A two‐dimensional finite element model is developed with an actual Al2O3‐10 vol% ZrO2 microstructure. A bilinear, time‐independent cohesive zone law is implemented for describing fracture behaviour of grain boundaries. Simulation conditions are similar to those found at contact between a head and a cup of hip prosthesis. Residual stresses arisen from the mismatch of thermal coefficient between grains are determined. Then, effects of a micro‐void and contact stress magnitude are investigated with models containing residual stresses. For the purpose of simulating fatigue behaviour, cyclic loadings are applied to the models.
Results show that crack density is gradually increased with increasing magnitude of contact stress or number of fatigue cycles. It is also identified that a micro‐void brings about the increase of crack density rate.
This paper is the first step for predicting the lifetime of ceramic implants. The social implications would appear in the next few years about health issues.
This proposed finite element method allows describing fracture and fatigue behaviours of alumina‐zirconia microstructures for hip prosthesis, provided that a microstructure image is available.
