Effect of bias voltage and nitrogen content on the morphological, structural, mechanical, and corrosion resistance properties of micro-alloyed Ti_1−xAl_0.8xP_0.2XN_y films deposited by high power impulse magnetron sputtering

The applications of multicomponent coatings (such as doped ternary or quaternary coatings) with superior functional properties have been shown to efficiently and sustainably improve the life span of engineering materials. This study reports the synergistic effect of negative substrate bias voltages U_s and reactive gas Q_N2 ratio on the properties of phosphorous (P) microalloyed Ti_1−xAl_0.8xP_0.2xN multicomponent coatings deposited using high power impulse magnetron sputtering. It is found that an increase of U_s enhances the densification of the deposited coatings, with mixed cubic (c)-TiN and cubic (c)-AlN phases, as identified from the XRD pattern analysis. Furthermore, Raman spectroscopy showed that the incorporation of Al and P into the TiN structure increases the gap region between the acoustic and optic bands. An optimized mechanical property of the coatings, with a maximum hardness of 28.6 GPa was measured at U_s = − 40 V and Q_N2 = 7 SCCM, and improved adhesion of coatings with H/E > 0.081, was possible. Improved corrosion resistance was also measured for microalloyed TiAlPN coatings. The microalloying of P with TiAlN has, thus, been shown to affect both the anodic and cathodic reactions and inhibit the corrosion of AISI 5206 steel.