Titanium - graphite composites for biomedical applications : A study on mechanical properties and biocompatibility

Abstract

This study aims to fully characterize the metallographic, mechanical and cytotoxic properties of the composite and the wear debris generated. Commercial purity titanium was thoroughly mixed with high purity graphite powder, compacted via the blended elemental method and hot isostatically pressed to form metal matrix composites of varying graphite composition. The microstructure of the composites were studied under light microscope as well as scanning electron microscope.The tensile and fatigue properties of the composites were investigated. It was found that these composites have high stiffness but low tensile and fatigue strength.Cytotoxicity tests were next conducted on the raw powder, the sintered compact and wear debris. It was found that the polished titanium composite compact surfaces promoted osteoblast and fibroblast adhesion and are biocompatible.The wear debris, which were smaller in size, proved to be more cytotoxic than the raw powder particles, especially to the rat osteoblasts.