The long range effect in high dose ion implanted titanium nitride

Dense coatings of titanium nitride can be deposited at high temperatures without substrate bias. Post-treatment by ion implantation causes a dislocation network to develop (work-hardening) which extends well beyond the implanted zone to increase the depth of increased wear resistance further. The dislocation density and residual stress developed have been studied as a function of ion species, acceleration voltage and dose using glancing incidence XRD methods. The `long range effect´ is confirmed; ion bombardment leads to the formation of a dislocation network but there is a threshold level of ion energy density before any compressive residual stress is developed. The stress is proportional to the ion momentum reaching values as high as 3-4 GPa compressive. Further, in the present samples which comprise a 7 μm coating on a cemented carbide substrate there is a significant change in the stress in the carbide also. This stress change can be tensile or compressive and is very sensitive to the ion species implanted