Toughening mechanisms in V-Si-N coatings

Microstructural evolution and deformation mechanisms of magnetron sputtered V-Si-N coatings with various Si contents are investigated by transmission electron microscopy, X-ray absorption spectroscopy, ab initio calculations. A small amount atoms was dissolved into the cubic VN lattice, locally reducing neighboring V-N p-d hybridization near site. The content found to impact architecture coating significantly. With increasing content, microstructure evolved through three different architectures: (i) highly textured columnar grains, (ii) refined (iii) nanocomposite structures where elongated grains were bounded vein-like boundaries. Enhanced damage tolerance observed in structure, multiple toughening become active. Ab calculations revealed that incorporation monolayer (1 1 1)-oriented resulted formation weaker Si-N bonds compared bonds, which allowed a selective response strain shear deformations assisting activation slip systems.