Fabrication and properties of carbon nanotubes reinforced Fe/hydroxyapatite composites by in situ chemical vapor deposition

Carbon nanotubes (CNTs) (Fe)/hydroxyapatite (HA) composite powder with CNTs homogeneously dispersed was successfully prepared by a novel process, which involved producing Fe2O3/HA precursor, calcination in N2 atmosphere and reduction in hydrogen of the Fe2O3/HA precursor to yield Fe/HA catalyst, and in situ synthesis of nanotubes by chemical vapor deposition over Fe/HA catalyst. These excellent CNTs(Fe)/HA composite powder was then employed to produce CNTs(Fe)/HA bulk composites. The CNTs(Fe)/HA bulk nanocomposites produced by pressing and sintering of the CNTs(Fe)/HA composite powder presented that the CNTs distributed homogenously and bonded strongly with the HA matrix. The effective enhancement of mechanical properties of the composites was indicated by a 226% increase in fracture toughness and 49% increase in flexural strength compared to monolithic HA bulk.