MICROSTRUCTURAL CHANGES IN ION-IMPLANTED TITANIUM NITRIDE

The present work considers deriving microstructural data on the effect of ion implantation into TiN as determined using glancing incidence X -ray diffraction. Monolithic TiN coatings, deposited onto cemented car bide by chemical vapor deposition, have been implanted with gas or met al ions at different doses and acceleration energies. The results conf irm that large changes in the residual stress and the strain distribut ions are introduced which extend well beyond the implanted zone (IZ) o f the material. This implantation affected zone (IAZ) extends beyond t he thickness ranges, 0.01-2.6 mu m, studied in the present work. The r esidual stress in the IZ was high and can be tensile or compressive de pending on whether vacancy generation and atom peening effects dominat e. There are also very large, irregular, distributions of strain which correspond to high dislocation densities and-or grain refinement (com minution) and include lattice vacancies detected previously by slow po sitron annihilation. The forward momentum of the ions always introduce s a dense dislocation network and high residual stresses in the IAZ co rresponding to the so-called long range effect. The dislocation densit y increases and the residual stress becomes more compressive with incr easing ion momentum. (C) 1998 Published by Elsevier Science S.A. All r ights reserved.