Microstructure and mechanical properties of AlCrN films deposited by CFUBMS

In this paper, Al1−xCrxN films were synthesized by closed field unbalanced magnetron sputtering (CFUBMS) with vertical magnetron sources for high temperature applications and their chemical composition, crystalline structure, morphology and mechanical properties were characterized by Auger electron spectroscopy (AES), X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), nanoindentation, scratch and wear tests. Also, the thermal stability of the films was evaluated by hardness measurements after annealing treatments at temperatures between 600 and 1000 °C in air for 30 min. Al1−xCrxN films with 0.29 ≤ X ≤ 0.69 formed a ternary solid solution and exhibited the crystalline phases of fcc B1 type structure with strong (111) preferential orientation. Depending on the Cr content (X value), their hardness values were ranging from 31 to 41 GPa and the residual stresses were in the range of − 4.5 to − 5.6 GPa. In comparison to other films, the enhanced mechanical properties and thermal stability were observed from the Al rich Al1−xCrxN film (X = 0.29).