Abstract
Hydroxyapatite (HA) has been introduced as a bone grafting material due to its similar composition to that of natural bone, along with its lack of toxicity and high chemical stability, which prevent inflammatory or antigenic reactions. However, the high porosity of HA leads to increased osteoconductive capacity to the implant, while reducing its mechanical resistance and hence limiting its clinical use. Research on the mechanical properties of HA such as superplasticity has been necessary to solve these disadvantages. In this study, boron nitride (BN; 0, 2, 4 wt %) was added as the second phase reinforcement to increase the bone strength and improve the mechanical combination. The BN was added using the appropriate sintering method in order to control the grain size and reduce the chances of HA being dissociated into tricalcium phosphate (TCP) due to the shorter exposure at high temperature. The microstructures of the samples with various percentages of BN-reinforced HA demonstrated some variation. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses were conducted to determine the elemental composition of the materials and observe the microstructural transformation. As a result, the various percentages of BN-reinforced HA combined with hot press (HP) and spark plasma sintering (SPS) methods demonstrated the improved consolidation of the HA composites with BN, which is a promising result for the development of bioactive load bearing ceramic bone substitution with improved mechanical properties.
