• Synthesis and characterization of mechanical properties of a novel bioceramic composite material for biological applications

      Ladegard, Jillian; Zhang, Jing; Severin, Kenneth P.; Chen, Cheng-fu (2010-08)
      Bioceramics are used in a wide range of human skeletal repair and restoration applications as a synthetic bone substitute. 45S5 Bioglass, a bioactive ceramic, exhibits poor mechanical properties limiting the potential of the material and preventing its use in major load bearing applications. This investigation evaluated the synthesis and mechanical properties of a 45S5 Bioglass composite reinforced with different weight percentages of multi-wall carbon nanotubes. The material was analyzed using an X-Ray Diffractometer and a scanning electron microscope to determine the crystal structure, microstructural homogeneity, and surface texture of the composite material. The material was evaluated during the synthesis process to observe the evolution of the composite. Samples were sintered at 1000°C and 850°C to determine the effect of the sintering temperature on the mechanical properties of the composite. Once synthesized, the material was tested using the Vickers hardness indentation test to determine the mechanical properties of the ceramic, as defined by hardness and fracture toughness values. Hardness of the composite decreased with increasing nanotube concentration for all samples. A maximum fracture toughness value of 47.6 GPa·m¹/² corresponded to the addition of 1 weight percent multi-wall carbon nanotubes in the composite samples sintered at 1000°C. All of the composite samples sintered at 850°C reported lower fracture toughness values than the pure bioglass samples indicating that sintering temperature affects bonding between the composite components. These results prove that a Bioglass-multi-wall carbon nanotube composite has the potential for use as a synthetic material to restore function in load bearing bones