Carolina Ortega-Portilla¹, Luis Miguel Ballesteros¹, Guillermo César Mondragón-Rodríguez¹, Abel Hurtado-Macias², Juan Manuel González-Carmona^1
1Secihti-Centro de Ingeniería y Desarrollo Industrial (CIDESI), Querétaro, México
²Centro de Investigación en Materiales Avanzados, S.C., Chihuahua, México
In this investigation, TiAlON and TiAlNbON coatings were deposited on AISI D2 steel using reactive cathodic arc. Structural analysis by X-ray diffraction (XRD) revealed that TiAlON maintains orientations typical of TiAlN, while TiAlNbON exhibits a polycrystalline, multiphase mixture dominated by the separation of Al₂TiO₅ oxides, a result confirmed by transmission electron microscopy. Increasing the in-situ temperature in the XRD analysis revealed the additional formation of crystalline oxides at temperatures above 600 °C, with the appearance of rutile. However, the material remained stable up to 1000 °C, with the systematic appearance of Ti and Al oxides. Additionally, the elemental composition showed the incorporation of 0.16 atm.% Nb and 2.78 atm.% O. The surfaces exhibited macroparticles characteristic of the cathodic arc curing process, increasing the substrate roughness by approximately 50%. The coatings exhibited a nanohardness of 12.85 ± 2.85 GPa, with notable improvements in elastic modulus, resistance to plastic deformation, and adhesion for the Nb-doped coatings, reaching increases of up to 80%. Pin-on-disk tribological tests performed between 25 °C and 900 °C demonstrated that the presence of Nb favors the stability of the oxides formed and limits oxygen diffusion, reducing wear through the transition from abrasive mechanisms to combined abrasion-adhesion at high temperatures.