Microstructure and mechanical properties of TiAlN/SiO 2 nanomultilayers synthesized by reactive magnetron sputtering

Abstract

TiAlN/SiO 2 nanomultilayers with different SiO 2 layer thickness were synthesized by reactive magnetron sputtering. The microstructure and mechanical properties were investigated by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and nano-indentation. The results indicated that, under the template effect of B1-NaCl structural TiAlN layers, amorphous SiO 2 was forced to crystallize and grew epitaxially with TiAlN layers when SiO 2 layer thickness was below 0.6 nm, resulting in the enhancement of hardness and elastic modulus. The maximum hardness and elastic modulus could respectively reach 37 GPa and 393 GPa when SiO 2 layer thickness was 0.6 nm. As SiO 2 layer thickness further increased, SiO 2 transformed back into amorphous state and broken the coherent growth of nanomultilayers, leading to the decrease of hardness and elastic modulus.