Insights and optimization of the structural and mechanical properties of TiWSiN coatings using the Taguchi method

A Taguchi L16(45) orthogonal array design was selected to determine the influence of the deposition parameters on the mechanical properties, wear volume, and corrosion resistance of TiWSiN thin films. The power applied to the silicon-tungsten target, nitrogen to argon flow ratio (N2:Ar), substrate temperature, and bias voltage were set to four levels for depositing the films using co-sputtering equipment. The hardness, wear volume, and corrosion resistance were evaluated via nanoindentation, reciprocating-sliding, and potentiodynamic polarization, respectively. The microstructure, chemical composition, and morphology were also studied, by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The obtained results were transformed into signal-to-noise ratios (S/N), and an analysis of variance (ANOVA) was performed. It was found that the power applied to the silicon target was the factor that makes the greatest difference in the evaluated films' properties. According to the combination of factors, nanocomposite structure and FCC and BCC crystalline structures were detected. Almost all of the films exhibited columnar growth; however, the columns' width was affected as the deposition conditions were modified.