Nanostructuring and coherency strain in multicomponent hard coatings

Abstract

Lattice resolved and quantitative compositional characterizations of the microstructure in TiCrAlN wear resistant coatings emerging at elevated temperatures are performed to address the spinodal decomposition into nanometer-sized coherent cubic TiCr- and Al-rich domains. The domains coarsen during annealing and at 1100 °C, the Al-rich domains include a metastable cubic Al(Cr)N phase containing 9 at. % Cr and a stable hexagonal AlN phase containing less than 1 at. % Cr. The cubic and the hexagonal phases form strained semi-coherent interfaces with each other.