Structural, mechanical and thermal properties of Ti1-xSixN/CrAlN (x = 0, 0.13 and 0.22) multilayers.

Nanoscaled Ti 1-x Si x N/CrAlN multilayers combining the cutting edges of Ti 1-x Si x N and CrAlN coatings are currently the focus of attention of researchers. Here, the structural, mechanical, and thermal properties of Ti 1-x Si x N/CrAlN multilayers with varied Si content were investigated. The hardness values of Ti 1-x Si x N/CrAlN multilayers are individually enhanced to 30.7 ± 1.0 GPa for x = 0, 36.0 ± 1.3 GPa for x = 0.13, and 35.9 ± 1.5 GPa for x = 0.22 from the 27.4 ± 0.3 GPa for CrAlN due to interfacial strengthening effect. Ti 1-x Si x N insertion layers retard the thermal decomposition process of CrAlN. After annealing at 1200 °C, the hardness of Ti 1-x Si x N/CrAlN (x = 0, 0.13, 0.22) multilayers is individually enhanced by ∼6.9, 12.9 and 13.6 GPa from the 18.7 ± 1.1 GPa for Cr 0.32 Al 0.68 N. However, Ti 1-x Si x N insertion layers lead to a drop in the oxidation resistance of CrAlN coatings due to their inferior oxidation resistance. Noticeable is that increasing Si content of Ti 1-x Si x N/CrAlN multilayers causes a decline in the thickness of oxide scales. • The template effect of multilayer increases the solid solubility of Si into TiN. • Ti 1-x Si x N/CrAlN (x = 0, 0.13 and 0.22) multilayers exhibit coherent interface. • The introduction of Ti 1-x Si x N coatings optimizes the thermal stability of CrAlN. • Increasing of Si content improves the oxidation resistance of Ti 1-x Si x N/CrAlN multilayers. [ABSTRACT FROM AUTHOR]