Effect of bias voltage and heating power on the structural and tribo-mechanical properties of chemically complex TiSiBCN nanocomposites

TiSiBCN thin films combine high thermal stability, oxidation resistance, and low friction, making them promising for high-temperature applications. While previous studies focused on the effect of chemical composition on TiSiBCN, it remains unclear how bias voltage and heating power affect the structural and tribo-mechanical properties of TiSiBCN. Therefore, this study investigates the effect of these parameters on the structural and tribo-mechanical behavior of TiSiBCN nanocomposites with different compositions. Thin films were deposited by magnetron sputtering, varying the bias voltage (−100, −150, −200 V) and heating power (2, 5, 8 kW).

The chemical composition remained largely unchanged with heating power, but a slight reduction in Si content was observed at higher bias in B- and Ti-rich films. x-ray diffraction confirmed polycrystalline structures with TiN, TiC, TiB, and TiB₂ phases coexisting in various amorphous phases. Transmission electron microscopy images revealed nanocomposite structures and changes dependent on the initial phase structure and chemical composition, like crystallite refinement with higher bias voltage or growth, as well as further reorganization with higher deposition temperatures. Increasing bias voltage induces residual stresses while the hardness tends to decrease. With higher heating power, internal stresses are released and the hardness increases up to 41 GPa. Tribological evaluation against AW-6060 aluminum alloy showed that C- and N-rich nanocomposites minimized material transfer and friction, while hard crystalline-rich TiSiBCN increased friction and wear due to oxide adhesions. These findings demonstrate how deposition conditions influence the microstructure and performance of TiSiBCN nanocomposites and support their suitability for aluminum forming applications.