Tribomechanical analysis and machining development for TiSiCN material deposited on industrial steel

In recent years, nanocomposite coatings have become relevant in different metal-mechanical processes related to the increase of the tribomechanical properties. Therefore, this research is focused on improving mechanical behavior and wear resistance of TiSiCN nanocomposite coating with different power applied on the silicon nitride (Si₃N₄) target by means of magnetron sputtering r.f. technique and synthesized on HSS (high-speed steel) and oriented silicon (100) substrates. The response of the nanocomposite coatings to power variation was analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), and instrumented nanoindentation. Ball-on-disc and scratch tests were used for tribological characterization. The XRD study determined an FCC structure with a peak of maximum intensity in the plane (200). XPS analysis showed chemical energies in the bonds and stoichiometry. By means of the AFM technique, the tendency to decrease the roughness and grain size was detected, with the increase of the power for the coatings obtained at 500 W. From the nanoindentation test, it was possible to stablish increases in mechanical properties as the applied power increases; the best performance was obtained for coating with a 500-W power, where the hardness and elastic modulus were 32 GPa and 301 GPa, respectively. The friction coefficient in dry environment decreased with increasing applied power (500 W, 0.31), and the critical load produced by adhesive wear was determined for the TiSiCN nanocomposite coatings for the different applied powers, showing the highest critical load in the coating with 500 W (62.42 N). Finally, the cutting tests with AISI 1020 steel (workpiece) to assess wear as a function of the applied power. A comparison of the tribological properties revealed a decrease of flank wear (approximately 37%) for ASSAB 17 steel burins coated with TiSiCN nanocomposite coatings with 550 W, when compared to uncoated ASSAB 17 steel burins. These results open a great industrial potential in anti-wear applications.