Análise numérica e experimental de propagação de trinca aplicada a biocimentos de fosfato de cálcio

Abstract

The fracture toughness is an intrinsic property of the material, defined as the mechanical energy required to initiate and propagate a crack in the material until rupture occurs. In this property ceramics and bioceramics, in general, has very low values that can be explained by the existence of very small defects present in the material, which act as stress concentration factors. Calcium phosphate biocements are being intensely studied due to their potential use in biomedical applications as well as for their biocompability and ability of hardening on site. The main objective of the present work was to develop nanometric calcium phosphate biocements based on the system composed by beta-tricalcium phosphate/calcium sulfate, to determine the value of fracture toughness. Samples of the material produced also were characterized by x-ray diffraction (XRD) for determination of cristalline phases, and diametral compression tests. X-ray difracton analysis of the biocements revealed the presence of di-calcium phosphate dihydrate (CaHPO4.2H2O or DCPD) as the major phase and β-TCP as the minor phase. Results from diametral-compression tests of the biocement compared well with the values for trabecular or spongy bone. The process described in this work is a simple, based on a comparative study of crack propagation between numeral modes based on finite element method and experimental.