TiN thin films are widely used as protective and decorative coatings for tools in industry. Previous studies have focused on the deposition of TiN coatings on substrates by reactive magnetron sputtering, whereas the use of TiN targets avoids problems such as ‘nitrogen contamination’ and ‘target poisoning’. TiN coatings were grown on silicon wafers and cemented carbide substrates by varying the parameters of the magnetron sputtering plasma source, operating Ar pressure and deposition temperature. The experimental results show the better mechanical properties of ceramic materials deposited using radio frequency (RF) magnetron sputtering. During RF magnetron sputtering, the hardness of the coating increased significantly to 17 Gpa when the deposition working pressure was reduced from 1.5 Pa to 0.5 Pa. The coefficient of friction tends to decrease as the deposition temperature increases, and at 400 °C the coefficient of friction between the deposited film and the friction pair made of Al₂O₃ material is only 0.36. The nano-scratch experimental tests concluded that the TiN coatings deposited at 300 °C conditions had the best adhesion to the substrate at an Ar pressure of 0.5 Pa under an RF source.

To clarify the instability behavior of the columnar microstructure in RF magnetron sputtered TiN coatings under compressive loading, experimental characterization and finite element simulation were combined to investigate the microstructural features, mechanical properties, and linear and nonlinear buckling responses of the coating. TiN coatings were deposited on cemented carbide and Si substrates by RF magnetron sputtering using a 99.9% purity TiN target. The surface and cross-sectional morphologies were characterized by field-emission scanning electron microscopy, and the nanohardness and Young’s modulus were determined by nanoindentation. Based on the experimentally observed morphology and measured mechanical properties, a finite element model of the columnar structure was established in ABAQUS, and the instability responses predicted by solid, shell, and beam element models were comparatively analyzed. The results showed that the as-deposited TiN coating exhibited a dense and uniform surface and a distinct columnar microstructure in cross-section. Linear buckling analysis indicated that the first-order critical buckling loads predicted by different element models were different, among which the solid element model gave a value of 3.43 × 10⁻⁵ N, showing the closest agreement with the theoretical result. Furthermore, nonlinear buckling analysis was performed by introducing an initial geometric imperfection of 4 × 10⁻³ mm based on the first-order buckling mode of the solid element model. The results showed that the columnar structure became unstable at a load of 0.74 × 10⁻⁶ N, accompanied by irreversible deformation. These findings demonstrate that linking experimentally observed TiN columnar microstructures with microstructure-informed instability analysis provides a useful perspective for understanding the local instability behavior and potential failure tendency of sputtered coatings and offers theoretical support for the structural design and reliability evaluation of protective coatings for cutting tools.