Effect of zirconium addition on the microstructure and mechanical properties of TiSiN films fabricated by reactive magnetron sputtering at room temperature

Transition metal nitrides are widely employed in various industrial applications as hard protective films. The synthesis of such films usually requires elevated temperatures (up to 873 K), leading to increased resource consumption (e.g., for heating elements and cooling water) and higher electricity costs. Here we present a comprehensive investigation of structure and mechanical properties of TiSiZrN films synthesized at room temperature via reactive magnetron sputtering, eliminating the need for elevated substrate temperatures. Despite a broad compositional range, all films exhibit a single-phase cubic (Fm3¯m) structure, with a crystallographic orientation transition from (111) to (200) at higher Zr concentrations. The progressive incorporation of Zr induces an increase in lattice parameter (from 4.245 to 4.628 Å), a reduction in crystallite size (16.5 to 12.6 nm), and a significant enhancement in mechanical properties. Notably, hardness increases by ~40 % (from 24.04 to 36.62 GPa), attributed to synergetic effect of Zr-induced densification of structure and solid solution strengthening. Furthermore, the film with the highest content of Zr demonstrates a plasticity index (H³/E²) of ~0.43, exceeding previously reported values for TiSiZrN films synthesized via magnetron sputtering. These observations demonstrate that high-hardness TiSiZrN films can be synthesized without thermal assistance, offering a more energy-efficient and environmentally favorable alternative for protective film applications.