MECHANICAL, AND TRIBOLOGICAL PROPERTIES OF TI/TIN BILAYERS: THE DEPENDENCE OF TI INTERLAYER THICKNESS

Ti/TiN bilayers were grown on AISI 316L stainless steel and Dynasil (SiO2) substrates, by using a reactive DC magnetron sputtering system. The Ti interlayer was grown at different thicknesses (0, 50, 100, and 200 nm) in order to study their influence on the morphological, mechanical, and tribological properties of the bilayers. The coatings' morphology was determined using an XP2 profilometer adhesion was measured using micro-scratch test equipment, mechanical properties were obtained by a NANOVEA IBIS-Technology nanoindenter with the Oliver-Parr method. Tribological characterization was carried out with a CSEM tribometer, and wear coefficient was obtained by the Archard law by relating the wear area (Measured by profilometry). Results present a decrease in the roughness as the interlayer was added. A maximum hardness and elastic modulus of 22 and 310 GPa, respectively, were obtained. On the other hand, the system with an interlayer of 100 nm exhibited the highest adhesion with a critical load of 28 N. Moreover, the system with an interlayer of 200 nm showed an improvement in the tribological behavior due to its great load capability, lower substrate deflection, and low wear rate.