AVS 54th International Symposium | |
Advanced Surface Engineering | Monday Sessions |
Session SE-MoM |
Session: | Hard and Nanocomposite Coatings: Synthesis, Structure, and Properties |
Presenter: | A. Flink, Linköping University, Sweden |
Authors: | A. Flink, Linköping University, Sweden J. Sjölen, SECO Tools AB, Sweden T. Larsson, SECO Tools AB, Sweden L. Karlsson, SECO Tools AB, Sweden L. Hultman, Linköping University, Sweden |
Correspondent: | Click to Email |
Ti1-xSixNy (0≤x≤0.22) thin solid films were deposited by arc evaporation onto WC(Co) and c-BN substrates. Elastic recoil detection analysis revealed an N increase with increasing Si content. X-ray diffraction and transmission electron microscopy showed that as-deposited films contain a NaCl-structure phase with a lattice parameter similar to TiN, 4.24 Å. The films exhibited a competitive columnar growth mode where the structure transits to a defect-rich feather-like nanostructure with increasing Si content. As-deposited TiN exhibited random crystallographic orientation, which gradually changed to an exclusive <200> texture for x>0.05. The highest hardness, 42.8±2.1 GPa, was achieved for x=0.14, which was significantly higher than 29.8±1.5 GPa for TiN. The hardness increase is attributed to solid-solution and defect hardening. The hardness was retained for an annealing temperature of 1000°C for 0.05≤x≤0.10, but decreased to below 28 GPa for all other compositions due to recrystallization within the cubic state together with Co and W interdiffusion from the substrate via the grain boundaries. Furthermore, the Si content decrease for the films annealed at 1000°C to x=0.14. Residual stresses were measured with the sin2ψ-method and differential scanning calorimetry was performed in order to investigate phase transformations.