N.G. Mathews; A. Lambai; M. Hans; J.M. Schneider; G. Mohanty; B.N. Jaya
Advanced Engineering Materials 27 (2025) 2500285
Magnetron sputtered titanium nitride (TiN) thin films are widely used as pro-
tective coatings due to their high hardness, but suffer from inherent brittleness
and low fracture toughness, limiting their applicability. The multilayering ofTiN
films with metallic titanium (Ti) interlayers in the form of bilayer and trilayer
architectures has been studied using microcantilever fracture tests. Plastic
dissipation in the Ti layer is shown to lead to an increase in crack growth
resistance. The effect ofthe elastic–plastic mismatch between the two materials
on the crack driving force as well as the size ofthe fully developed plastic zone in
Ti have been quantified in this work for the first time. It is shown that the plastic
zone size of 250 nm in Ti layer improves the overall fracture resistance of the
architecture by nearly ten times compared to the initiation fracture resistance in
TiN, preventing catastrophic fracture of these multilayered films. These results
will aid in physics informed design ofoptimized thickness ofmetallic interlayers
in multilayered thin film architectures.