Structure, mechanical properties and thermal stability of CrAlNbN/TiN multilayers

Abstract In this study, TiN coatings with favorable phase stability were introduced to CrAlNbN coatings for stabilizing the structure of CrAlNbN coatings during annealing. The structure, mechanical properties and thermal stability of CrAlNbN/TiN multilayers and the monolithic counterparts were comparatively studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), Thermogravimetric analysis (TGA) and nanoindentation. All coatings exhibit face-centered cubic structure, and CrAlNbN/TiN multilayer with smaller bilayer period reveals superlattice structure. T he coherent growth of CrAlNbN sublayers along with TiN template layers, and the relatively higher binding energy of Ti–N bonds than Cr–N retards the thermal decomposition procedure of CrAlNbN/TiN multilayers, where the initiation temperatures of w-AlN precipitation and N-loss are elevated by 100 and 200 °C, respectively. The architecture of CrAlNbN/TiN multilayers effectively improves the capability of corresponding monolithic layers to maintain hardness upon thermal load, which is beneficial for their high-temperature applications.