Enhancement of thermal and mechanical stabilities of silicon doped titanium nitride coating by manipulation of sputtering conditions

This study investigates the influence of substrate (AISI M42 tool steel) bias voltage (from −30 to −80 V), on mechanical properties magnetron sputtered TiSiN coating derived from Ti and Si targets. Thermal stability, microstructure (crystallite size, microstrain, lattice constant), morphology (hardness, Young's modulus, residual stresses) properties, deposited coatings, were investigated with synchrotron powered X-ray diffraction (SR-XRD), photoelectron spectroscopy, field emission scanning electron microscopy, nanoindentation techniques. Rietveld analysis, in-situ SR-XRD, in temperature range 25–800 °C, demonstrated cubic TiN form (Ti,Si)N solid solutions, TiO2 Ti2O3 identified at lower voltages. Density functional theory supplemented experimental results. Increase resulted in: (i) a decrease content, (ii) significant smoothening surface morphology, (iii) change phase composition microstructure, (iv) improved oxidation resistance thermal threshold, (v) hardness modulus coatings increased up 50% 33 GPa 450 GPa, respectively.