DESIGN OPTIMIZATION OF FUNCTIONALLY GRADED HYDROXYAPATITE/ TITANIUM CIRCULAR PLATE USING TWO-DIMENSIONAL FINITE ELEMENT MODELLING

Abstract

Functionally graded Hydroxyapatite/Titanium (HA/Ti) structure shows the combination of two superior properties such as high strength-to-weight ratio of the Ti (metal phase) and good heat resistance of HA (ceramic phase) in a unit structure. The main intention of this combination is to highlight the significance of the extremely low thermal conductivity of HA in enhancing the performance of the advanced material. This paper aims to determine the optimum design parameters of the HA/Ti FGM. The optimization of design parameters which considered the number of layers, grading index and thickness, was achieved through the evaluation of the residual stress distribution along the compositional gradient plane at the circumference surface of the cylindrical FGM plate. Optimization analysis was performed by assuming that the residual stress occurred because of a temperature drop during the sintering process due to a variation in the thermal and elastic properties along the transverse direction of the FGM structure. Since the effective properties vary with the variation in the number of layers, grading index and thickness of the FGM plate, an evaluation of the residual stress distribution was significant when determining the optimal geometrical parameters of the structure. The convergence properties of the present results were examined thoroughly in order to assess the accuracy of the theory applied and to compare them with the established research results