Prediction of brittle fracture propagation behaviour of hydroxyapatite (HAp) coating in artificial femoral stem component

Purpose: This study addresses the brittle fracture propagation behaviour modelling of hydroxyapatite (HAp) coating in artificial femoral stem component. Design/methodology/approach: A simple two dimensional flat-on-flat contact configuration finite element model consisting contact pad (bone), Ti-6Al-4V substrate and HAp coating is employed in static simulation. The HAp coating is modelled as elastic layer with pre-microcrack which assumed to be initiated due to stress singularity. Findings: The study revealed that reducing coating thickness, pre-microcrack length and artificial femoral stem elastic modulus along with increasing bone elastic modulus will result in significant stress intensity factor (SIF) to promote brittle fracture propagation behaviour. Research limitations/implications: The influence of coating thickness, pre-microcrack length, bone and artificial femoral stem elastic modulus on fracture behaviour is examined under different stress ratio using J-integral analysis approach. Practical implications: The proposed finite element model can be easily accommodating different Hap coating thickness, pre-microcrack length, bone and artificial femoral stem elastic modulus to perform detailed parametric studies with minimal costly experimental works. Originality/value: Limited research focussing on brittle fracture propagation behaviour of HAp coating in artificial femoral stem component. Thus, present study analysed the influence of coating thickness, pre-microcrack length, bone and artificial femoral stem elastic modulus on stress intensity factor (SIF) of HAp coating.