Study on Microstructure and Mechanical Properties of（AlCrTiZrNb）N/Al2O3 Nano-multilayer Film

The（AlCrTiZrNb）N/Al2O3 nano-multilayer films with different thicknesses of Al2O3 layer were prepared on single crystal silicon wafer by reactive magnetron sputtering technique using AlCrTiZrNb and Al2O3 as targets alternately. X-ray diffractometer（XRD）, high-resolution transmission electron microscope（HRTEM）, scanning electron microscope（SEM） and nano-indentation tester were used to characterize the microstructures and mechanical properties of the（AlCrTiZrNb）N/Al2O3 nanomultilayer films. The experimental results show that, when the thickness of the Al2O3 layer is less than0.8 nm, the Al2O3 layer transforms from amorphous state to metastable cubic structure under the template effect of（AlCrTiZrNb）N layer and forms coherent interface epitaxial growth structure with（AlCrTiZrNb）N layer. With the increase of the thickness of the Al2O3 layer, the elastic modulus and hardness of the（AlCrTiZrNb）N/Al2O3 nano-multilayer films first increase and then decrease. When the thickness of the Al2O3 layer is 0.8 nm, the elastic modulus and hardness of the（AlCrTiZrNb）N/Al2O3 nano-multilayer film are 317.6 GPa and 29.8 GPa, respectively. At this time, the thin film presents high crystallinity, and clear columnar crystal structure runs through the entire modulation period.