Evaluation of the Mechanical Properties and Microstructure of Hydroxyapatite Reinforced with Carbon Nanotubes

摘要

Synthesized hydroxyapatite was reinforced with functionalized carbon nanotubes, and tensile strength, rupture tension, as well as fracture toughness values were calculated from the indirect method of diametric compression test using the Brazilian disc specimen. Five formulations were evaluated covering the range of 0 to 2 wt.% of nanotubes. Results showed that the addition of carbon nanotubes increases the mechanical properties of the ceramic composite until an optimum value, followed by a decrease. Composites evaluated showed an increase of approximately 58% on their fracture toughness property when 0.1wt.% of nanotubes were mixed to hydroxyapatite. Scanning Electron Microscopy analysis shows that percentages higher than 1 wt.% of reinforce material may cause agglomeration and precipitation of a second phase governed by the reinforcement. This phenomenon instigates a reduction on the mechanical properties of the composite since these agglomerates act as a stress concentrator leading the composite to an early failure.