Authors: I. Singh and P. Allan
Affilation: Brunel University, United Kingdom
Pages: 145 - 148
Keywords: nanoparticles, nano coatings, nano-indentation
Hydroxyapatite (HAP) is an important material for biomedical implants, as its chemical composition is similar to that of bone tissue. Synthetic HAP is a biocompatible prosthetic material, bonding strongly to the bone and promoting the formation of bone tissue on its surface. Compared with human cortical bone, however, HAP has poor mechanical properties and lower fracture toughness. Therefore, it would be desirable to develop bioactive composite materials with improved mechanical properties. In the present study, high quality multi wall carbon nanotube (CNT) reinforced nano particle hydroxyapatite composite coatings have been successfully deposited on the surface of Ti alloy substrate using electrophoretic deposition. The resulting nano-composite materials showed good dispersion and homogeneous distribution of carbon nanotubes in HAP nanoparticles coating. Nano-mechanical properties (e.g., hardness and elastic modulus), the scratch resistance, adhesion, the deformation and damage behaviours of this potential implant material were evaluated using nano-indentation and nano-scratch techniques. The linearly increasing load mode of nano-scratch test was studied to determine the most effective and informative testing conditions and to determine critical load (Lc) for coating failure. The mode of failure was examined by high resolution SEM and AFM.