Effect of ion energy on microstructure and adhesion of diamond-like carbon on Ti6Al4V by ion beam deposition

Abstract

The microstructure and adhesion of diamond-like carbon (DLC) thin films on Ti6Al4V substrates were investigated using direct ion beam deposition with ion energy varying from 65eV to 90eV. The samples prepared were characterized by Raman spectroscopy, synchrotron near-edge X-ray absorption fine structure spectroscopy, scanning electron microscopy, and X-ray diffraction. Indentation testing by Vickers hardness tester was used for adhesion evaluation. The results show that the adhesion of DLC thin films on Ti6Al4V substrates mainly depends on ion energy used in the deposition process. Higher ion energy results in higher sp3 concentration in DLC thin films, which firstly increases then decreases the adhesion of DLC on Ti6Al4V substrate depending on the sp3 fractions and ion energy of 70eV provides the highest adhesion on both the bare and diamond nanoparticle coated Ti6Al4V.